Document rB5K3DoJOeJ64wJMbwr4GjJJr

Modern m ining methods are used to sta rt lead on its way to industry. I EAD In Modern Industry MANUFACTURE, APPLICATIONS AND PROPERTIES OF LEAD, LEAD ALLOYS, AND LEAD COMPOUNDS ! ...... i!1 ........ Pu b l is h e d b y LEAD INDUSTRIES ASSOCIATION 420 Le x in g t o n Av e n u e Ne w Yo r k 17, N. Y. i-ni--.jjn^wnHniiiiimiiT--~iin--iiiiini[ iiBnmillimiiiaaaaBteimgaitiiiB^gBBife. COPYRIGHT 1952 BY Le a d In d u s t r ie s As s o c ia t io n Ne w Yo r k , N. Y. PRINTED IN THE UNITED STATES OF AMERICA LORD BALTIMORE PRESS Table of Contents J1. Th e His t o r y o f Le a d ..................................................... 2. Fr o m Min e t o Fin is h e d Me t a l .................................. Concentrating the Ore........................................ Smelting the Concentrates................................ Refining Processes ........................................... Secondary Lead................................................. Lead Consumption ............................................ 3. Le a d in Mo d er n Liv in g ................................................., 4. Fo r ms a n d Fa b r ic a t in g Pr o c e s s es ........................... Extruded Products............................................ Rolled Products................................................. Castings ............................................................. 5. Le a d St o r ag e Ba t t e r ies .............................................. How the Battery Operates................................ Where Batteries Are Used.............................. 6. Le a d Co v er ed Ca b l e....................................................... Manufacture of Lead Covered Cable............... Telephone and Television Cable........................ Power Cable....................................................... 7. Le a d in Mo d e r n Ch e mic a l Co n s t r u c t io n ............. Composition ...................................................... ......... Methods of Joining........................................... Methods of Construction.................................... Lead Pipe in Chemical Equipment................... 8. Co r r o s io n Re s is t a n c e o f Le a d a n d Le a d Al l o y s Corrosion Rate Interpretation........................... Fatigue and Stress Corrosion........................... Galvanic Corrosion.................................. . Atmospheric and Sea Water Exposure----------Soil Corrosion ..........'........................................ Soil, Waste and Vent Exposure......................... Chemical Corrosion Resistance......................... 9. Co mp o s it io n o f Co mme r c ia l Pig Le a d .................. 10. Th e So l d e r in g a n d We l d in g o f Le a d ..................... Soldering......................................................... ,. Welding............................................................... 11. Le a d in Mo d er n Pl u mb in g ........................................ Lead Water Service Pipe.................................. ; Calking Lead.................................................... Lead in the Plumbing System........................... 12. Le a d in Mo d er n Ar c h it ec t u r e.................................. Vibration Isolation............................................ Ornamental Lead .............................................. 1 4 5 8 9 11 11 14 18 19 22 25 27 29 32 36 38 39 41 43 43 44 44 48 51 51 52 54 54 57 57 58 70 71 71 72 75 75 79 81 87 92 94 13. Ra d ia t io n Pr o t ec t io n ................................................................................ 97 X-Ray Protection.................................................................................. 103 Lead Shielding Construction............................................................... 105 14. Le ad a n d Le ad Al l o y Co a t in g s ...................................... 109 Teme Plate................................................. 109 Hot Dip Lead Alloy Coatings............................................................. 110 \l Electroplating........................................................................................ Ill Sprayed Coatings.................................................................................. 113 15. So f t So l d er s ................................................................................................... 115 16. Be a r in g Me t a l s .......................................................... 118 Lead-Base Bearing Alloys................................................................... 119 17. Ammu n it io n ................................................................................................... 122 18. Ot h e r Me t a l l ic Le a d Pr o d u c t s a n d Al l o y s .................... 127 Type Metal.............................................................................................. 127 Powdered Lead........................................................................... 128 Lead Wool ................................... .......................................................... 129 Molds and Dies........................................................................................ 130 Packaging .............................................................................................. 131 Lead Foil ................................................................................................ 132 Low Melting Alloys................................................................................ 132 Lead Heat Treating Baths...................... 133 Miscellaneous Alloys............................................. 136 Lead Weights ........................................................................................ 137 19. Wh it e Le a d ................ 138 Basic Lead Sulphate.............................................................................. 139 White Lead-Varnish Cement............................................................... 140 20. Le ad Ox id es ................................................................................................... 141 Litharge ........ 141 Litharge-Glycerin Cement.................. 142 Red Lead.................................................................*............................... 143 Other Oxides.......................................................................................... 144 21. Te t r a e t h y l Le a d .................................................................. 145 22. Ot h er In d u s t r ia l Le a d Co mp o u n d s ......................................... 147 Lead Chromates ...................... 147 Blue Lead, Lead Azide, Lead Arsenate............................................. 148 Lead Silicates, Basic Silicate White Lead, Basic Lead Silicate, Lead Stabilizers ...................................................................................149 Miscellaneous Lead Chemicals........................................................... 150 23. Wh it e Le a d Pa in t s .......................................................... 151 Primers ..................................................................................................... 155 House Paints.......................................................................................... 157 24. Me t al Pr o t e c t iv e Le ad Pa in t s .................................................................. 160 Red Lead Paints...................................................................................... 160 Atmospheric Exposure ........................................................................ 163 Marine Atmosphere and Intermittent Sea Water Immersion... 165 Continuous Sea Water Immersion.............................. 167 Continuous Fresh Water Immersion.................... 169 Blue Lead Paints........................................................... 171 Atmospheric Exposure ........................................................................ 172 Fresh Water Immersion........................................................ 172 Intermittent Sea Water Immersion................................................... 173 iv 25. Th e Sa f e Ha n d l in g o f Lead a n d It s Pr o d u c t s ................................ 174 26. Sp e c if ic a t io n s f o r Le a d , Le a d Al l o y s a n d Le a d Pr o d u c t s ........... 177 27. Pr o per t ies o f Lead a n d Lead Al l o y s ............................................... 183 General Properties................................... 183 Weight and Density........................................................ 184 Thermal Properties .......................... 184 Low Temperature Properties......................................................... 190 Mechanical Properties .............................................................. 190 Electrical Properties.................................................................... 194 Miscellaneous Properties.............................................................. 196 Comparative Data ........................................................................ 196 28. Ph y s ic a l Co n s t a n t s o p Le a d Co mp o u n d s ........................ 203 Inorganic Lead Compounds........................ 204 Organic Lead Compounds............................... 217 In d e x ......... 225 Foreword iio me t a l , perhaps, has as wide a variety of uses as lead nor contributes more broadly to our modern way of life. Lead is vital to all our modem means of rapid transportation-- airplane, automobile, railroad and ship; it is essential to modern methods of communication and electrical power transmission, and to the use of X-rays and radium; it plays a vital role in the development and utilization of atomic energy; it is a part of the finest plumbing, one of the greatest contributions to the comfort and sanitation of modern homes; it makes possible the economical production of many of the most useful chemicals and their derivatives of this chemical age. The list could be extended almost indefinitely. ................. . The interesting thing is that these varying uses depend not upon a single property or characteristic of lead but upon many different properties. It is employed in some instances primarily for its weight, in others because of its resistance to corrosion, or its softness and malleability, or its atomic weight, or its ability to alloy readily with certain other metals to change or modify its properties. Lead is particularly unusual among the metals in that about a third of all the lead used is the result of properties of its chemical compounds, many of which, like white lead, red lead, litharge and tetraethyl lead, are of immense industrial importance. Old as the use of lead is, its age has merely enabled us to learn more about it and thus adapt the metal to our needs. Many of its most important applications are developments of very recent years. Tetraethyl lead, lead azide and lead soaps for greases, lead in steel, lead alloys for stamping aluminum, lead molds and lead compound stabilizers for plastics, lead counter weights in aircraft are just a few of these recent applications that are leaving a decided impression on modern living. Modern research, too, has broadened the application of old and established uses of lead. The field of lead-base bearing alloys has been substantially widened, lead and lead-alloy coatings for other metals have stepped into the limelight and new formulations for metal primer paints have increased the importance of red lead, to name only a few. This book has been prepared to gather in one place a large amount of technical and general data regarding lead and its compounds so that metallurgists, chemists, engineers, executives and others may determine more readily whether lead has proper ties that can help them in these rapidly changing times. No claim is made that the data are complete or that new developments may not make some of it obsolete from time to time. Therefore, the Lead Industries Association stands ready to help further if this book does not answer all questions. In peace and in war, lead has been and will continue to be one of mankind's most useful metals. Despite its antiquity, we have only begun to learn what lead can do for us in modern living. Lead has many personalities. Understanding them enables us to put lead to use for the greatest good of the greatest number of people. V1U The History of Lead Lead is one of the oldest metals known to man and many of its modern uses have persisted through centuries. It was utilized in many ancient lands and for strangely varied pur poses. The earliest known specimen of lead, dating from 3000 B.C., is a figure found at the Dardanelles on the site of an ancient city called Abydos. The heavy gray metal was evidently well known in Biblical times for it is mentioned in Exodus and sev eral other places in the Old Testament. In the days of the Pharaohs lead was used to glaze pottery, to make solder and orna mental objects; Old lead pipes have also been found in Egypt. In ancient India red lead was used as a cosmetic by women, while the metal itself was employed for weights of various kinds, for purifying silver, as a charm, and as an early monetary medium. The Assyrians had many uses for lead, and the hanging gardens of Babylon were floored with sheets of lead soldered together to retain the moisture which the vegetation demanded. Babylonians also used lead for calking purposes and to fasten iron bolts in the masonry of bridges, dams, and other stone structures, much as it is used to-day. The ancient Chaldeans of Persia were well acquainted with lead; in fact, they were the first to associate metals with gods, the sun, moon and planets. This custom was handed down to the alchemists, predecessors of modern chemists. The alchemists used planetary signs in their writings to represent the metals. Thus their sign for Saturn, was used to designate lead. Authorities differ as to the reason for connecting lead with Saturn, some saying because the alchemists considered lead to be the oldest of the metals and Saturn, the father of the gods; others 1 2 LEAD IN MODERN INDUSTRY that the dull, heavy metal reminded them of Saturn, the most distant and slowest moving planet. In 2000 B.c. the Chinese made their first money of lead, and later, when silver coins came into use, the government forbade working the lead mines to stop counterfeiting. Imagine the crippling effect on industry were such a step taken in modern times! In ancient Greece and Rome bronze coinage contained from 3 to 30 percent lead. Counterfeiters and impoverished gov ernments have often made lead coins coated with the precious metals. One of the most important historical applications of lead was its general use for water pipes by the Roman people. The pipe was made in fifteen standard sizes and regular ten-foot lengths. Many of these pipes, in almost perfect states of preservation, have been dug up in recent years in the ruins of Pompeii and Rome, and in England, where the Romans penetrated during invasions. Roman public baths were often completely lined with sheets of lead. A room in a house in Pompeii has been uncovered in which the walls were completely moisture proofed with lead. The Romans used the word "plumbum," lead, to denote spouts, or water conductors, and the same word finds its modern coun terpart in our word plumber. Romans also understood the art of lead burning and soldering. ' Lead has always had an important place as an article of war fare. Our modern bullets and shot were preceded by leaden pro jectiles hurled from slings, and molten lead or great chunks of the solid metal were often thrown down from the battlements of a besieged town upon its invaders. Roman gladiator pugilists wore leaden knuckles to give their blows more authority. Many famous warriors, among them the Black Prince and Richard II, as well as men prominent in more peaceful walks of life, lie buried in leaden caskets, beautifully decorated and in scribed. Richard Coeur de Lion's heart was for many years kept in a lead casket at Rouen. Another lead casket in the Santo Domingo Cathedral is said to be the resting place of Columbus. Still another, recently found in England, is believed to be that of THE HISTORY OF LEAD on teacher of Ptolemy Philadelphus, was so thin that he wore lead soled shoes to keep from being blown over. Greek gamblers used lead-loaded dice. In medieval times lead was widely used as a material of con struction. Many magnificent buildings built in the 15th and 16th centuries still stand under their original lead roofs. Leaden ornaments, statues, leader-heads and cisterns were widely used and lent distinction to the arts of the period. Although many of these old uses were based on some supposed property of lead that did not exist, by far the majority depended on the easy work ing qualities, the permanence and beauty of lead. CHAPTER TWO From Mine to Finished Metal A d u l l colored pig of lead gives no inkling of the romantic story connected with its production. It fails to reveal, for one thing, the risk someone must have taken to discover the lead ore from which the metal was made, or the effort required in mining, the skill necessary to concentrate the ore, and the tech nique involved in subsequent smelting and refining. Without some appreciation of these items an uninformed reader is apt to imagine that lead mining, in common, perhaps, with other metal mining, is a simple and immensely profitable business with few of the worries plaguing other occupations. The following para graphs are intended, therefore, to tell briefly those who are inter ested where lead is mined and how it becomes a raw material of commerce. Although today reliable figures on lead production and con sumption from some countries are not available, it can be esti mated that the world produces and uses close to 2,000,000 tons of lead in a single year. Although the United States is the prin cipal lead producing country it only mines about 20 percent of world consumption and practically all this is used within its borders. In addition, it produces almost an equal amount from scrap and imports enough additional lead from Mexieo, Canada, Peru, Australia, Europe and elsewhere, to bring United States consumption up to about half of the world's total. Mexico normally ranks second in world lead mine production, followed by Australia and Canada. Peru, Yugoslavia, Germany, French Morocco, Italy, Southwest Africa, Spain and many other countries are also important producers. In the United States, Missouri mines the most lead, with Idaho, Utah, Arizona, Colorado, Montana and others adding to the sup ply in the order named. The lead mining districts of the Union 4 { FROM MINE TO FINISHED METAL 5 have contributed immeasurably to the welfare and prosperity of their respective States. Lead occurs in nature usually associated with other metals, notably silver and zinc. Its association with silver is especially noteworthy, and there was a time, not so many years ago when lead was considered mainly a by-product of silver mining to be sold for extremely low prices. Although many minerals contain ing lead are known, the most important by far is galena (lead sulphide), an easily recognized, brightly metallic mineral. Of the other lead minerals the carbonate, cemtsite, and the sulphate, anglesite, are of commercial importance, but are not so frequently found as galena. It is very pleasing to the miner to find and mine ore rich enough in lead to be shipped directly to a smelter without intermediate processing; but he is ordinarily not so lucky. He is indeed fortu nate to find any ore even after extensive and costly prospect ing with churn drill, diamond drill, shafts, drifts, crosscuts and other development work. Sometimes an ore is phenomenally rich in lead but contains so much zinc and copper that special treatment is required. More often the miner will struggle with a low grade of lead ore, perhaps as low as 3 percent lead, and at tempt to mine it at a profit. One large mining company has to mine about 3,000,000 tons of ore to recover 100,000 tons of lead. Obviously, with low grade ore, large amounts of waste rock, or gangue, must be removed before shipment to a smelter in order to reduce transportation and smelting charges. Moreover, it is necessary to remove nearly all zinc-bearing minerals in the ore so that the miner will not be penalized by the lead smelter for the zinc content, which is classed as an "impurity," because it interferes with the lead smelting operation. CONCENTRATING THE ORE To concentrate the lead ore it is crushed extremely fine, some times to particles less than 1 mm. in diameter, and treated by one of the modern processes of mineral concentration. The remark able flotation process may be used, a method simple enough to describe but complicated in execution, and such an important and marvelous metallurgical development of the twentieth cen- I 6 FROM MINE TO FINISHED METAL 7 PRIMARY LEAD PRODUCTION AREAS IN THE UNITED STATES STATE ARIZONA NO. DISTRICT O HARSHAW O WARREN (BISBEE) PIMA OLD HAT BIG BUG COWTY OR COUNTIES SANTA CRUZ COCHISE PIMA PINAL YAVAPAI CALIFORNIA O RESTING SPRINGS COSO INYO INYO COLORAOO CREEDE ANIMAS PIONEER (RICO) UPPER SAN MIGUEL SNEFFELS TOM!CHI LEADVILLE RED CLIFF MINERAL SAN JUAN DOLORES SAN MIGUEL OURAY GUNNISON LAKE EAGLE IDAHO WARM SPRINGS BAY HORSE COEUR D'ALENE BLAINE CUSTER SHOSHONE ILLINOIS UPPER MISSISSIPPI VALLEY KENTUCKY AND SOUTHERN ILLINOIS NORTHERN PART OF STATE HARDEN KANSAS TRI-STATE AREA CHEROKEE KENTUCKY KENTUCKY AND SOUTHERN ILLINOIS CRITTENDEN MISSOURI TRI-STATE AREA SOUTHEASTERN MISSOURI AREA 12 COUNTIES IN SOUTH WESTERN PART OF STATE SOUTHEASTERN MISSOURI MONTANA BUTTE HEDDLESTON EAGLE SILVER BOW . LEWIS & CLARK SANDERS NEVADA BATTLE MOUNTAIN PIOCHE LANDER .................... LINCOLN NEW MEXICO c e n t r a l GRANT MAGDALENA SOCORRO . NEW YORK /m ST. LAWRENCE OKLAHOMA TRI-STATE AREA OTTAWA UTAH OPHIR RUSH VALLEY BINGHAM ' PARK CITY TINTIC TOOELE TOOELE SALT LAKE SUBMIT. WASATCH JUAB. UTAH VIRGINIA AUSTINVILLE WYTHE WASHINGTON BOSSBURG METALINE STEVENS PEND OREILLE WISCONSIN UPPER MISSISSIPPI VALLEY LAFAYETTE. IOWA. GRANT 8 LEAD IN MODERN INDUSTRY tury that it has left a deep impression upon the lead and practi cally all other metal mining industries. Flotation is applicable principally to the sulphide type of ore, fortunately the common est variety, or to an oxide ore which has received a preliminary sulphiding. Briefly, the flotation process generally constitutes taking finely crushed ore diluted with, say, four times as much water, and agitating the mass violently with air in a tank to which a fraction of one percent of pine oil, with or without small amounts of other suitable chemicals, has been added. As a result of the agitation a froth containing most of the metallic constitu ents of the ore is formed on top of the tank while the valueless gangue matter remains unaffected at the bottom of the tank. The froth flows from the tank and is easily dried. Flotation practice has reached such a stage of perfection that extraordinarily efficient work is being done, not only in extract ing a single mineral from an ore, but also in separating the sev eral minerals in so-called complex ores, for example, an ore con sisting of an intimate mixture of lead, copper and zinc minerals. For years the treatment of many complex ores baffled metallur gists, but with selective flotation as a tool, many mineral deposits considered practically worthless a few years ago have developed into important lead mines. Furthermore, many straight lead ores formerly believed too low grade for economical treatment have suddenly become profitable possibilities, adding greatly to the world's available lead reserves. Flotation has, to a considerable extent, supplanted earlier methods of concentration using gravitational methods of milling, that is, pulsating jigs, vibrating tables, and many other ma chines, but the older mechanical methods are used alone or with flotation in treating many ores for which they are particularly suited. SMELTING THE CONCENTRATES Lead concentrates when they leave the mill contain 40 percent and upwards of lead. The richer the lead content the better, for it reduces transportation and smelting costs. Smelting is a con tinuous operation generally conducted in blast furnaces but, before the concentrates can be charged into the furnace, they Almost perfectly preserved lead pipe used by the Romans for conducting water more than 1900 years ago. i Lead covered domes of world famed St. Sophia in Istanbul. The lead roofs date from the middle of the Seventeenth Centurv. Surface plant of a typical western lead mine and ore concentrating mill. The lead-rich component of the ore is collected as a froth in flotation cells. FROM MINE TO FINISHED METAL 9 must be roasted to remove most of the sulphur contained in the concentrates and to agglomerate the very fine flotation product which is not a physically desirable blast furnace material. The roasted concentrate, or sinter, now in the form of lumps, is charged into the top of the heated blast furnace with limestone and other suitable fluxes and coke for fuel. A blast of air is admitted to the lower part of the furnace to aid combustion and to complete the formation of metallic oxides which are reduced to metal by the coke and carbon monoxide present. The nonmetallic waste forms a slag with the fluxing materials.' The blast furnace is then tapped so that the lead flows off into kettles or molds. In this form the lead is a semi-finished product known as base bullion, containing silver and impurities. Specifi cally, base bullion contains small amounts of gold, silver, copper, zinc, antimony, arsenic, bismuth and other impurities which must be removed in whole or in part by refining to produce a commercial lead. REFINING PROCESSES ........... The most widely used refining process is the Parkes process. By this treatment the lead is first melted and allowed to cool below the freezing point of copper, which crystallizes and is re moved by skimming. It then passes to a reverberatory or soften ing furnace where the temperature is raised and the molten lead stirred. A blast of air oxidizes any antimony or arsenic present, both of which impurities harden lead (hence the term "soften ing" furnace), and these oxides are skimmed off. A continuous softening process for the elimination of antimony and arsenic from lead bullion has been perfected which repre sents more than just a conversion from batch to continuous pro cedure. In this process, oxidation rates many times in excess of those obtainable by usual batch softening methods are realized by the continuous maintenance of the antimony content of the fur nace metal within a determined optimum range of Q.01-0.05 per cent antimony. The accelerated oxidation rate obtainable in con tinuous operations permits a marked reduction not only in the operational costs of batch methods, but also in space and equip ment requirements. 10 LEAD IN MODERN INDUSTRY ....... After softening- the lead goes to the desilverizing kettles where small quantities of zinc are added. Gold and silver are more soluble in zinc than in lead, and, consequently, any of these metals present in the lead immediately leaves it in favor of the zinc. As zinc is lighter than lead, the zinc rises to the surface and, when the temperature is lowered, solidifies, and is skimmed. This leaves only a little zinc remaining as an impurity which is oxi dized and skimmed in a reverberatory furnace. A more recent development removes the zinc as a vapor by creating a vacuum over the surface of the molten lead. The zinc vapor is condensed as metal on the cool dome of the vacuum vessel and re-used. Re fined lead becomes one of the purest of the commercial metals through this treatment, and is cast into pigs. The Pattinson process, now rarely used, depends upon the fact that when lead is cooled slowly part of it will solidify and can be skimmed off while the silver will remain in the molten lead left behind. The Betts process, employed in several plants includ ing one in the United States, is an electrolytic method advantage ously used with bullion high in bismuth. The bismuth is removed and recovered, which is not the case with the Parkes process. The Harris process of softening and dezincing by the use of molten caustic salts is used in some plants in England, Europe and Japan. The process is designed to remove impurities from molten desilverized lead by pumping it through a mixture of molten salts contained in a tank above the lead kettle. The metal lic impurities react with the chemicals and are collected in the form of their oxides or oxysalts. The Harris process while sound in theory has not been universally adopted since in practice it cannot always compete economically with the Parkes or Betts process. Some ores, such as those of southeastern Missouri, contain too little silver for profitable desilverizing. Therefore the finished pigs, while free from other impurities, are noted for their com paratively high silver and copper content and are given the desig nation "chemical" lead because of wide use in the chemical indus tries in the form of sheet and pipe. This is but one of the commercial grades of pig lead available to the consumer. These grades are described on page 70. FROM MINE TO FINISHED METAL 11 SECONDARY LEAD The importance of secondary lead, which is derived from lead or lead alloy scrap cannot be underestimated. It is a significant factor in the lead market because lead is easily melted and re fined and does not become contaminated by impurities during service. In 1950 in the United States, approximately 421,000 tons of lead were produced from secondary sources. This com pares to a mine production figure of 430,000 tons. Over the past twenty-five years secondary lead accounted for slightly over 37 percent of the total amount of lead consumed in this country. The chief source of secondary lead is from automobile storage batteries that have been scrapped, generally after about 2 years' service. It has been estimated that over a period of years, 80 percent of the lead used in the manufacture of storage batteries re-enters the market as secondary lead. Additional sources of secondary metal include cable sheathing, pipe and sheet, solder and lead drosses. Secondary lead is reclaimed by fire refining methods in refin eries usually devoted exclusively to the handling of secondary lead and lead alloys. A comparatively small percentage is also refined at primary refineries. Much of the secondary lead produced is sold as lead alloy, par ticularly lead from reclaimed batteries and cable sheathing which contain small percentages of antimony and other metals. The bulk of the secondary lead recovered containing antimony is re sold to battery manufacturers. Secondary lead containing tin is most often re-used in the manufacture of solder, bearing metals and other lead-tin alloys. By applying proper refining techniques soft lead can be pro duced from secondary sources to meet primary lead specifications. LEAD CONSUMPTION The largest amount of lead used in the United States goes into the manufacture of storage batteries. Among the other top con sumers of lead are cable covering, paint, construction (includ ing chemical construction), and gasoline. The following tables show the uses of lead percentagewise from 1938 through 1950 and the amount of lead used for various purposes in 1950. )3 >3 >3^ 3 USES OF LEAD IN THE UNITED STATES BY PERCENTAGE * Purpose White lend ................ Red lead and litharge..,. Storage batteries ...., Cable covering.......... . Building ...................... Tetraethyl .................... Automobiles .............. . Ammunition ................ Foil ............................. Bearing metal ............ Solder .......................... Typemetal .................... Calking ...................... . Other uses................ :. 1038 7.87 1030 11.24 8.68 20.60 11.16 7.60 4.60 1.83 0.84 8.27 1.02 3.00 2.10 2.40 6.98 1040 8.88 7.60 28.16 18.78 8.81 6.81 1.41 7.10 3.00 1.70 8.07 2.16 2.40 6.48 Total tons............ 607,000 782,000 * American Bureau of Metal Statistics. 1041 8.10 8.48 28.34 10.48 0.05 4.74 1.14 6.81 4.20 2.88 8.48 1.90 2.06 6.01 1,040,000 1042 7.60 6.80 21.66 16.60 11.00 4.88 0.30 8.30 0.77 2.00 8.80 2.00 4.00 10.69 1,000,000 1048 4.65 7.18 23.86 12.82 6.64 5.48 0.00 10.18 1.18 8.18 8.46 1.66 2.78 12.61 1044 6.60 7.84 28.17 12.02 0.42 7.82 0.09 6.78 1.47 8.70 8.70 2.11 2.93 12.83 1,100,000 1,090,000 1045 4.10 6.82 20.60 10.70 0.80 7.60 0.10 4.80 1.66 4.20 4.70 2.60 8.62 18.61 1,000,000 1946 6.19 0.69 28.11 12.00 8.43 6.10 0.11 8.24 0.43 4.43 6.78 8.67 4.22 12.70 1947 4.00 6.60 82.42 18.64 6.60 6.68 0.09 8.41 0.81 8.42 6.03 2.18 4.26 12.71 926,000 1,172,000 1948 8.04 5.22 88.06 16.82 6.80 7.42 0.09 8.70 0.27 8.68 6.08 6.24 3.60 0.07 1,129,000 1940 2.87 6.60 82.88 14.99 6.66 11.72 ,_. 2.07 0.81 8.07 0.72 2.88 8.80 8.60 868,000 Pouring lead bullion into a kettle for fire refining. m* ts.. a Tl 3 1 Casting fully refined lead into pigs. FROM MINE TO FINISHED METAL 13 CONSUMPTION OF LEAD* Use Storage batteries ................................................................... Cable covering........................................ Building (including chemical construction).......................... Tetraethyl lead ....................................................................... Red lead and litharge (other than for storage batteries) ... Solder...................................... White lead.............................................................. Calking ........................................................................... Bearing metal......... .............................................................. Ammunition.................... Typemetal........................................... Foil.......................................................................................... Other uses ............................................................................. Tons 406,800 136,800 61,500 111,100 75,900 88,100 34,000 61,100 33,100 32,800 30,900 3,300 136,600 Total ........................................................................................ 1,212,000 * American Bureau of Metal Statistics. CHAPTER THREE Lead in Modem Living X o u n d e r s t a n d the possibilities of lead, some knowl edge of its existing uses and why it is used for these purposes is helpful. Its applications are so broad throughout industry that no review of them can hope to be complete or nearly complete. Yet this discussion will give some idea of how its properties are being put to work and what a factor it has become in our modern way of life. We would still be cranking our automobiles and using gas lights on them were it not for the peculiar electrochemical proper ties of lead and its oxides utilized in storage batteries. This same kind of battery propels submarines under water, lights and air-conditions railway cars, is used in telephone communication, provides emergency power in utility plants, powers industrial trucks and mine locomotives, lights miners' lamps, and now even provides the power for pocket flashlights and hearing aids. The corrosion resistance of lead, together with its flexibility, accounts for its broad use as sheathing for power and telephone cable, underground, under water and strung on poles, on land and on ships at sea. In this case, a seamless lead sheath is ex truded around the insulated conductors which form the core. Sulphuric acid and other corrosive chemicals are essential in the production of thousands of modern necessities and conveniences, from high explosives to rayon garments, from synthetic rubber and gasoline to fertilizers for the farm and garden. Equipment and pipe lines made of or lined with lead, which resists the fiery attack of these corrosives, make possible the economical produc tion of many of these modem chemical wonders. Lead's density supplies the necessary ballistic properties to small arms ammunition. Extruded as rod, the lead is cut and swaged in a single operation to the approximate size and shape 14 LEAD IN MODERN LIVING 15 of bullet cores. For shot to be used in shot grin shells, it is poured through sieves from considerable height, forms by surface ten sion into round drops, and falls into vats of water. Large shot is cast. Lead azide, a chemical compound, has become a standard detonator explosive because it is less sensitive to shock, flashes at a higher temperature, is more stable than those previously used, and can be stored at elevated temperatures for indefinite periods without deterioration. It makes possible safer, surer ammunition. Lead takes wings in the latest high-powered aircraft in the form of counterweights in ailerons and rudders which eliminate flutter and provide ease of control through perfect balance. It is also used to balance propellers. Lead alloys often form the dies for stamping aluminum parts of these same planes. Lead as an alloying element is found in bronzes and babbitts and, as the principal ingredient of lead-base bearing alloys, has reduced costs and removed our dependence on imported tin. These alloys are found in all kinds of vehicles on land, sea and in the air, and wherever machinery is used. Even more universal in use are the soft solders, which are alloys of lead and tin usually, but may be alloys of lead and other metals. Low melting alloys of lead are used as matrices to hold punches in intricate dies and for bending tubing. Hardening in liquid nitrogen enables certain lead alloys to be used as the die material itself for shortrun sheet metal stamping. The X-ray and gamma ray are both vitally important to medicine and are rapidly assuming equal industrial importance as a means of non-destructive testing for hidden flaws in products. The high density and atomic weight of lead make it the most efficient material economically to confine these rays to the places where they are useful and protect operators against their harm ful effects. In the wartime development of the atom bomb and subsequent utilization of atomic energy, lead continues to play an indispensable role in protecting operating personnel by con fining dangerous radiation. Red lead paint is a standard protection for modern steel struc tures of all kinds, including buildings and ships, and white lead is one of the basic paint pigments used in the protection and beautification of our homes. 16 LEAD IN MODERN INDUSTRY Tetraethyl lead in high octane gasoline has been a major factor in making possible the tremendous power of our airplane and automobile engines, while litharge is used to remove corrosive sulphur from motor fuel, thereby helping to prolong the life of these engines. Litharge, too, is an ingredient in the manufacture of both natural and synthetic rubber and in certain lubricating greases. Broad use of lead and lead alloy coatings to prolong the life of iron and steel is a recent development. They are being used on a variety of steel products from telephone pole-line hardware to sheets for duct work. Coated steel is ideal for products that must be formed because the lead acts as a lubricant in the dies. For instance, it has been used widely in drawing steel shell cases. Lead added as an ingredient in steel is another modern develop ment that has improved the machining properties of steel greatly, speeding production and increasing the life of tools astonishingly. Lead is also added to brass for the same reason. In all sorts of building construction, lead has its part in the plumbing and water distribution systems. Modern piumbing and electrical installations, to both of which lead contributes so much, probably are the biggest advances in building construction of recent years, for it is not so long ago that such facilities were virtually unknown. Sheet lead is used, too, for roofing, flashing and other waterproofing on many structures, including refriger ator room linings on ships. Lead headed nails have a big field for fastening sheet steel. Lead is sometimes used for its non sparking properties alone or combined with some of its other properties. Floors in plants where explosive substances are manufactured offer a good example. It is also used as lead mats to insulate against vibration both under building and machinery foundations, and on pipe line hangers, particularly on ships. Lead anchors are commonly used for fastening objects to con crete, stone or brick facings. The plastics industry makes extensive use of lead. Metallic lead molds for plastics are made by several processes, including die casting and dipping steel patterns into molten lead, the lead solidifying on the steel. Molds are stripped from the pattern, used once and remelted. Certain lead compounds are excellently suited and extensively used as heat and light stabilizers for LEAD IN MODERN LIVING 17 familiar household vinyl plastics. They prevent hardening' and embrittlement and aging and discoloration on exposure to light. Powdered metallic lead is added to grease for heavy duty ma chinery where it provides lubrication at heavy loads and prevents corrosion and frictional wear. Powdered lead is also used in the manufacture of bearings, heavy duty clutch facings and even as a pigment in paint. The foregoing, as stated, is in no sense complete, but may give some idea of lead's wide range of usefulness and how many of our modern conveniences and necessities would be lacking without lead. Some of the most important applications and alloys are discussed on the following pages. CHAPTER FOUR Forms and Fabricating Processes JLh o s e who wish to use lead not only have a choice among several grades of pure lead (see page 70) but of a variety of alloys as well. In addition, it can be obtained as pigs or ingots or special shapes, as semi-fabricated products in a variety of forms, and as completely finished items. Pigs of lead and antimonial lead usually weigh about 100 lb. each, while ingots of lead or its alloys may have almost any desired weight and shape from the small 3- to 5-lb. cakes to be melted in portable gasoline furnaces to 100-lb. cylindrical billets to fit extrusion presses. In semi-fabricated and fabricated form, a variety of lead and lead alloy products are available. Examples are: Extruded........................ pipe, rod, wire, ribbon, traps, bends, wedge lead, special shapes Rolled..............................sheet, foil, strip, blanks for drawing, stamping and spinning, blanks of various shapes Cast ................................sand or die-cast (gravity or pres sure) Chemical Compounds... .oxides, carbonates, sulphates, chro mates, organic compounds, silicates, acetate, etc. Other.............................. metallic powder, wool, shot Lead and its alloys can be fabricated by almost all commercial processes. It can, for instance* be extruded, drawn, roll' d, cast, stamped, spun, and can be applied as a coating to other metals either by hot-dipping, electroplating or spraying. Thick layers of lead can be bonded to steel or other metals for greater strength. Joints may be made by soft soldering or welding. The properties of lead and most of its alloys are quite different 18 FORMS AND FABRICATING PROCESSES 19 from those of other metals, but this very difference makes lead peculiarly suitable for many applications where other metals would not be practical. On the other hand, it is often possible to gain some useful property of lead in cases where lead may not at first seem suitable, if these differences are clearly recog nized. For instance, slight design changes or changes in manu facturing technique may make it possible to use lead with greater satisfaction in place of a metal with quite different characteristics. In general, lead and its alloys have high resistance to corrosion, high specific gravity, are comparatively soft, have a low melting point and are easily fabricated. They have low electrical conduc tivity and tensile strength and a relatively high coefficient of thermal expansion. However, the properties can be varied within quite a wide range by judicious use of alloying elements. For instance, strength and hardness of ordinary lead can be multiplied many times or melting point greatly reduced by alloying. Tools used in working lead are usually of somewhat different design form those employed with other metals. For instance, hard wood is preferred in spinning lead. Tools should not be so sharp and should be of such a design that they will not bite too strongly into the soft metal. Thus relatively dull tools have been found preferable for broaching, threading and other operations. EXTRUDED PRODUCTS Lead and most of its alloys may readily be fabricated by the extrusion process. This process is used to make seamless lead pipe which can thus be produced in continuous pieces of considerable length. Hydraulic presses exerting pressures up to 45,000 lb. per sq. in. are employed for this purpose, the pressure depending upon the cross-section of the product extruded and the metal or alloy used. At the top of the typical lead pipe press is a nozzle with a round hole in its center. Below this is a cylinder containing lead which has been drawn from the melting pot and allowed to solidify. As hydraulic pressure is applied, lead is forced out of the press through a die in the bottom of the nozzle. However, this would make a solid rod of lead, so means must be used to make the hole in the center of the pipe. This is accomplished by fastening a 20 LEAD IN MODERN INDUSTRY steel rod the size of the hole in the pipe to the bottom of the lead chamber in the press and allowing it to extend up into the center of the hole in the nozzle. Thus the lead is forced out through the ring between the steel rod, or mandrel, and the walls of the hole in the nozzle, forming a seamless, continuous lead pipe. For small sizes of tubing the slender mandrel is fastened by arms to the die itself, as it would not be rigid enough if it extended to the bottom of the chamber. Although the lead is separated as it flows past these arms, it is forced together again above them and forms the solid wall of the pipe. Lead pipe, because of its corrosion resistance and flexibility, finds countless uses, the principal ones being in the chemical industries and plumbing and water distribution. Its flexibility makes fabrication of coils of various shapes for heating and cooling particularly easy. Joints may be made by welding (lead "burning"), soldering or mechanically, the choice depending upon the use to which the pipe is put. Sizes may range from fine tubing tV-in. inside diameter and even less to 12-in. or larger pipe, with almost any desired wall thickness. Either pure lead or alloys may be used. Special extrusion presses make it possible to extrude lead sheaths around cable or other cores, and still other presses to -Lead pipe S-Trap 1 Cylinder Ram Core rod N Hydraulic ram Hydraulic press for extrud ing lead pipe. Hydraulic press with double ram for extruding lead traps and bends. Sheet lead rolling mill and cutting table. a Hydraulic presses for extruding lead pipe. Large, thin wall pipes are extruded in straight lengths; smaller sizes are coiled. Diagram on page 20. , , 0*>, 1 *5 0^^ Double ram lead trap and bend press. Controls in the foreground in dependently regulate hydi*aulic pressure on two horizontal lead cylinders. Diagram on page 20. FORMS AND FABRICATING PROCESSES 21 Channels for cooling water Downward pressure Collapsible tube Cylinder block Lead sheath Core tube Hydraulic press for extruding a lead sheath on electric cable. Method of producing a collapsible tube by im pact extrusion. extrude specially shaped products such as traps and bends. Solder is extruded with or without a core of flux. Cable presses usually have the die at the side of the cylinder instead of at the top as in a pipe press. The unsheathed cable is fed into one side of the cylinder emerging through the die on the other side. The cable itself acts as the core and the lead extrudes around it through the die to form the sheath. Similar presses are used to extrude a lead sheath around rubber hose, this sheath forming a mold during the curing process and later being stripped from the finished hose. Such presses played one of the most dramatic production roles of the last War. On them were produced great lengths of lead pipe, with the core of electrical conductors omitted. This pipe was then wrapped with steel wire, tape and jute just like a sub marine cable and welded together into continuous armored lead pipes as much as 40 miles long which were laid under the English Channel from England to continental Europe. Through these lines was pumped a large part of the gasoline needed to keep the Allied armies on the continent moving on the land and in the air. Trap and bend presses have two horizontal cylinders to contain the lead instead of one vertical cylinder. These cylinders are opposed to each other and feed the metal to a die at the top 22 LEAD IN MODERN INDUSTRY between them. When equal pressure is applied to the two cylin ders, the lead extrudes through the die as a straight pipe. However, if lead is fed from one cylinder at a slower rate than from the other, the pipe bends in the direction of the slow cylinder. The bend can be reversed by reversing the pressure on the cylinders. Many other forms of lead and its alloys are extruded. As examples may be cited bullet core rod, welding rod, lead wire, cames, wedge lead, lead ribbon and lead anodes. Small counter weights of uniform cross-section are often extruded as rod or pipe and cut to length, while counterweights for airplanes and gliders are frequently extruded as strip which is cut to the exact size and weight needed. Lead may also be extruded by the impact method, this pro cedure being employed for the production of collapsible tubes for tooth-paste, shaving cream, glue and many other plastic products. Discs or blanks are cut from rolled sheet lead or lead alloy and may have a coating of tin on one or both sides. In special ma chines, the discs are formed into tubes by a combination of extrusion and impact forces. The method has also been applied, for instance, in making condenser tubes, so that tubes of cross section other than round, that is, oval or rectangular, are pro duced satisfactorily. Special synthetic linings have been developed for lead collaps ible tubes, the selection being dependent upon the material to be packaged. By the regular extrusion method, lead or lead alloy pipe or tubing can also be produced having a completely uniform ex truded tin lining, both pipe and lining extruded in a single operation. ROLLED PRODUCTS Among the most generally useful lead and lead alloy products are those produced by cold rolling. These may range in thick ness from foil only 0.00035 in. thick to sheets 2 in. thick or more, and may be rolled to any desired thickness. Sheet lead weighs approximately 1 lb. per sq. ft. for each ^ in. of thickness. Thus 4-lb. sheet lead, as it is termed commercially, is in. thick, 8-lb. sheet lead is l in. thick. Above 16-lb. sheet, this FORMS AND FABRICATING PROCESSES 23 relationship does not hold exactly, and -in. sheet lead weighs 30 lb. per sq. ft. while 1-in. weighs 60 lb. per sq. ft The thickness of foil, that is, weights less than about 1 lb. per sq. ft, is usually designated in thousandths or ten-thousandths of an inch. The machinery and equipment in general use for the rolling of sheet lead consists essentially of a kettle, slab casting pan, rolling mill and roller tables, and cutting table. The slab casting pan is a heavy open top steel casting, the sides of which are tapered sufficiently to facilitate removal of the frozen slab. Slabs are normally cast 4 to 6 inches thick, the length being determined Pounds per sq. ft. ?4 1 Vh 2 2Vt 3 S]A 4 5 6 SHEET LEAD WEIGHT AND THICKNESS Approx, thickness mV mm Decimal .0117 .0156 .0234 .0312 .0391 .0468 .0547 .0625 .0781 .0937 Fraction a* %28 %2 &2S %4 %28 %e %4 %2 Pounds per sq. ft. 8 10 12 14 16 20 24 30 40 60 Approx, thickness mV .. rDecimal Fraction .1250 % .1563 96a .1875 9ie .2188 %2 .2500 Vi .3333 a .4000 % .5000 a .6667 % 1.0000 l by the width of the mill. Large slabs sometimes weighing as much as 8 tons are usually cast in a horizontal position. Alloy lead is generally cast on end in a vertical mold often oil- or water-cooled to prevent segregation. Rolling mills used for the production of sheet lead are of the reversible type having either a single-roll or double-roll drive. The rolls are mounted one above the other; the lower roll has a fixed , elevation while the upper can be raised or lowered several inches to accommodate the thickness of full slabs. Larger mills have rolls SO in. in diameter by 12 ft. in effective length. These rolls have a slight crown to compensate for deflection when wide sheets are rolled. The slab of lead is passed back and forth between the rolls reducing the clearance after each pass until the proper thickness is reached. It is possible to roll the sheet to obtain different thicknesses at different points in the length. Roller tables extend about 45 ft. on either side of the main 24 LEAD IN MODERN INDUSTRY mill rolls and are at the same elevation as the top of the lower roll. The sections adjacent to the large rolls consist of closely spaced, power driven, live rollers to move the heavy lead sheet. The remainder of the roller table consists of idle rollers. On the cutting table the lead is mechanically trimmed and cut to size. Sheets may be produced in widths up to 10 or 11 ft. and lengths up to 40 ft. depending upon thickness, but 8 ft. wide and 20 ft. long is usually considered standard. Likewise, they are available as strips of various widths such as 12, 18 or 24 in., as for flashings. Foil usually comes in rolls with widths anything up to 24 in. The metal used for rolled products may be lead, an alloy, or laminated. In the latter case, for instance, lead foil is produced with a thin layer of tin firmly bonded to it on one or both sides. Although sheet lead has a multitude of applications, the most important are in the construction of corrosion resistant equip ment for the chemical industries (see page 44) and for roof flashings, roofing, and other waterproofing (see page' 87). Durability and flexibility are the big advantages lead has for these purposes, although appearance and non-staining are also important in the case of roofing and flashing. Joints may be made by welding (this is a must for chemical installations to avoid corrosion of the joints), by soldering, or by loose-locking (this is a must for roofing and flashing instal lations to provide for expansion and contraction). The principal use of foil is in packaging articles or products that must be protected from moisture or light or must have their moisture content preserved. It also has a number of important industrial uses as in condensers, electrotypers' foil, solder foil, and metallic packing. In X-ray work, lead foil protects the packaged film and lead sheets averaging 0.003 to 0.005 in. in thickness are used extensively as intensifying screens. Methods have been developed for making absolutely airtight joints in foil by special and extremely simple soldering techniques. Rolled products have a number of miscellaneous uses such as blanks for making collapsible tubes, for making etched name and instruction plates for machinery and equipment, blanks for spinning, drawing or further fabrication, and for gaskets and washers. FORMS AND FABRICATING PROCESSES 25 CASTINGS Lead and certain of its alloys are excellent metals for making a variety of castings providing high strength is not a requisite and the castings are not used at high temperatures. The casting qualities are excellent, the melting temperatures low, and cor rosion resistance superb under most conditions. Certain kinds of castings have long been made of lead or its alloys, ranging from anchors for masonry, cast lead joints in cast-iron bell and spigot pipe (see page 79) and counterweights, sinkers and sound ing leads to intricate printers' type (see page 127), pumps, valves and 17-ton vessels for handling corrosives and tiny scale ship, plane and tank models and practice bombs for military training purposes. More recently it has been found advantageous to use lead for certain kinds of castings for which it had not previously been considered. This should not be taken to indicate that lead can be used indiscriminately in lieu of other metals, for the proper ties are often quite different. Yet advantage may frequently be taken of some of lead's desirable characteristics, such as cor rosion resistance, to produce superior products if its properties, advantages and limitations are clearly recognized. The strength of the lead alloys, while usually much higher than lead itself, is low compared with most other metals. For instance, lead base castings may run as high as one-third the strength of common zinc-base die-casting alloys. The lead alloys also lose strength quite rapidly at elevated temperatures. On the other hand, casting qualities and corrosion resistance, as men tioned, are excellent and the castings take electroplate, paint, enamel or lacquer finishes well where desired for decoration. Such finishes are not ordinarily required for protection. Further more, the lead alloy castings are not subject to dimensional changes with the passage of time. Lead and its alloys may be cast in almost any kind of mold, either by gravity or under pressure. Articles that require no great strength are easily cast of lead or its alloys. Many others, where strength is a factor, can be cast of lead alloy as well as stronger metal through proper design to provide reinforcement where needed. Sometimes reinforcing 26 LEAD IN MODERN INDUSTRY elements made of stronger metals are cast into the lead to give greater strength. In general, the lead alloys will produce castings with tensile strengths ranging from 3,000 to 11,000 lb. per sq. in., Brinell hardness from 7 to 22, and with points of complete liquefaction from about 475 to 600 deg. F. While lead and its alloys have been used for years, a few examples of products recently converted to lead alloy will illus trate its adaptability. Trap screws or clean-out plugs for plumb ing traps, and a number of other threaded closures used under no great pressure are now made of lead alloy. Practice bombs were converted from stronger metal to lead alloy without redesigning because no great strength was required. Machinery and equip ment name and instruction plates have been made of cast lead alloy as well as etched alloy sheet lead mentioned elsewhere. Water closet floor flanges are being made of lead even though considerable strength is necessary. This conversion was accom plished by increasing the thickness of the flange about 50 per cent and providing reinforcing ribs on the back. Die-cast lead alloy working parts and nozzles for fire extinguishers are ex amples of lead castings used for reasons of corrosion resistance, as are valves and pumps used in chemical installations. Battery connectors with steel inserts are examples of lead castings with internal reinforcement. The best casting temperature for typical lead base die castings is about 600 deg. F. Minimum wall thickness for large die cast ings is about 0.05 in. and for small die castings about 0.035 in. The variation from drawing dimensions is 0.001 in. and the maximum number of threads is 32 threads per in. Draft for both cores and sidewalls is 0.001 in. per side per in. while minimum diameter of holes is 0.05 in. depending on depth. Tables listing properties of some of the lead base casting alloys will be found on pages 198 and 202. CHAPTER FIVE Lead Storage Batteries .... JL HE lead storage battery is so much a part of our everyday lives that seldom are we aware of our dependence upon it. Everyone knows battery power starts the motor of an automo bile, but most of us do not know about the hundreds of ways battery power is used by electric utilities, transportation and communication companies and almost every type of industry. This wide use of lead storage batteries is not accidental, but a natural result of the important assistance which lead storage batteries gave the pioneers of the electrical industry in develop ing machinery and equipment for the generation, distribution and use of electricity. Storage batteries became such an integral part of all of the many electrified services now so essential to modern living that storage battery power serves us every day in many unsuspected ways. Lead storage batteries constitute the most dependable appara tus by which energy can be conveniently stored for future use. They can be charged with enough energy to lift their own weight well over 32,000 ft., or more than six miles, and they possess the unique ability of being able to deliver large amounts of energy quickly in a short period of time, or small amounts of energy over long periods of time. A good example of this highly important operating characteristic is the battery used to energize the elec trical system of an automobile. Press the starter button and the battery instantly supplies large amounts of starting energy for the few seconds this high power is required, or turn on the park ing light switch and the battery supplies the insignificant amount of energy required for as long as necessary. It is this simple operating characteristic inherent in lead storage batteries which enables them to provide a reliable and economical solution to an extremely wide variety of electrical problems. 27 28 LEAD IN MODERN INDUSTRY Flexibility of operation is another useful characteristic of stor age batteries. Cells of these batteries can be combined to meet the specific voltage requirements of any electrical system whether it is a few volts or a thousand volts. Such batteries can be de signed to deliver high current at low voltage or low current at high voltage. They range in capacity from a few amperes to the many thousands of amperes needed to propel a giant submarine underwater. Lead storage batteries, or "accumulators" as they were once called, occupy an interesting place in the development and growth of the electrical industry. From the time Volta discovered the galvanic battery, or pile, in 1800, scientists experimented with many types of batteries made from different kinds of metals. These early storage batteries were crude. None of them were commercially successful, but they were useful in the laboratories and helped in the discovery of many working principles of the great mystery--electricity. It was not until 1859 that Gaston Plante began a series of ex periments which proved that battery electrodes, or plates, made from two different forms of lead were superior to electrodes made with other metals. Batteries made with lead plates had many more satisfactory electrical and operating characteristics than any other type of energy accumulator and they lasted longer. The Plante battery was the first lead-acid type of storage battery. The first commercial use of storage batteries was for teleg raphy in 1879. However, none of the early types of storage bat teries were of much practical use outside laboratories until the commercial development of the dynamo put the possible useful ness of lead storage batteries on an entirely new and different basis. It created an urgent need for a reliable means of storing energy which would enable managers of the early lighting plants to overcome many of the operating difficulties which plagued them. . At the same time the dynamo became commercially useful, a method of pasting perforated plates with lead oxides was in vented. This new battery discovery increased the storage capac ity of lead batteries. Since they could be formed in a few days with relatively cheap power from a dynamo, this type of battery seemed to be an answer to the pioneer electrician's prayers. The Electric Storage Battery Co. An automatic grid casting machine for making automotive battery plates. The Electric Storage Battery Co. Left. Submarine battery plates assembled as elements for cells. Right. Partially pasted section of a lead-acid storage battery grid. The Electric Storage Battery Co. Typical applications of storage batteries. Heavy duty batteries provide power for industrial trucks. Standby batteries are ready to supply cur rent for emergency lighting or communications. Practically all forms of transportation--automobiles, trains, planes and buses--depend on storage batteries to supply their electrical needs such as starting, ignition, lighting, air conditioning. LEAD STORAGE BATTERIES 29 This new battery development occurred in 1881, the year before Thomas Edison opened the world's first electric lighting central station on Pearl Street in New York City. In 1882, the Pennsyl vania Railroad experimented with the new kind of lead battery as a substitute for kerosene in the lighting of passenger cars. These batteries also were used in 1882, to light a few incandescent lamps on the trans-Atlantic steamship "Labrador." It was not until 1885 that storage batteries were first used for central station operations. At this stage in the development of the electric industry mechanical failures were frequent, due to sudden fluctuations of the load on generating machines. It was at this point that the ability of lead storage batteries to quickly deliver large amounts of energy for short periods of time was first suggested as a remedy for these troubles. A few years later, storage batteries used for this purpose enabled many pioneer electric light and power companies to put their service on a con tinuous 24-hour-a-day basis. In.the early 1890's, many additional uses were found for stor age battery power. These were trolley car operation, 1890; rail road signaling and propulsion power for electric carriages, 1891; the operation- of telephone exchanges, police and fire alarm sig nal systems, electro-plating,. welding, elevators, 1892; Edison's Kinetoscope (forerunner of moving pictures), 1893; electric loco motives, surgical knives, mine locomotives, 1894; wireless (Pro fessor Preece), 1896; Holland's submarine, 1897; automobile lighting and ignition, and the cranking of stationary Otto engines, 1900 and Marconi wireless, 1901. The first distress signal sent by wireless in 1909 was battery-powered; battery-started auto mobiles first appeared in 1911 and, in 1912, batteries started air plane motors. HOW THE BATTERY OPERATES The simplest form of a storage battery is two plates of different (dissimilar) metals immersed in an electrolyte. When connected to an electric circuit, pressure (voltage) is created by the plates. The electric pressure of each lead battery cell is approximately 2 volts. Incidentally, the addition of plates to a cell only increases its capacity (amperes or ampere hours), the pressure, 2 volts, remains the same. 30 LEAD IN MODERN INDUSTRY The plates of lead acid storage batteries are prepared from perforated grids cast from an alloy of lead containing between 7 and 12 percent antimony, about 0.25 percent tin, and small amounts of arsenic and copper. The presence of antimony gives additional hardness and corrosion resisting characteristics. The presence of tin gives better casting qualities. The interstices in the negative grid are pasted with litharge, or a mixture of litharge and finely divided metallic lead made into a paste with water and sulphuric acid. The positive plate usually contains litharge and finely divided metallic lead and in some cases up to 25 percent red lead. The mixture of litharge and metallic lead is sometimes referred to as "black oxide." After the plates have been pasted, dried, and the cell assembled, sulphuric acid is added. The plates are then "formed" by passing an electrical current through them to convert the positive plate into lead peroxide and the negative plate into finely divided sponge lead. Formation usually requires from 24 to 48 hours. What takes place is shown by changes in chemical composition indicated in the table below. The material of the positive plate is oxidized from lead oxide to lead peroxide. The material of the negative plate is reduced from lead oxide to metallic lead. Negative plate . J. Final Initial formed composition,, composition percent percent PbO....................90 3 PbSO, ................ 10 2-5 Pb ......................-- 95-92 Positive plate ,---------------- *----------------, Pinal Initial formed composition, composition, percent percent Pb02 ................. 20 86-78 PbO................... 55 7 PbSO,................ 25 7-15 For maximum capacity on discharge it is essential that both plates be quite porous to permit an extended reaction between the sulphuric acid and the active material of the plates. This porosity is determined by the original characteristics of the raw materials, such as the fineness of the oxide employed, and by the densities of the paste mixtures utilized in preparing the plates. On discharge, both the finely divided sponge lead constituting the negative plate and the lead peroxide constituting the positive plate react with the sulphuric acid electrolyte and are converted to lead sulphate. During such discharge an oxidation-reduction takes place opposite to that occurring during charge and current inter-cell connector Cover Positive strap LEAD STORAGE BATTERIES Vent plug SI Post Negative strap IX Partition Positive plate Separator Container Negative plate Construction of a typical lead-acid battery cell. flows in the opposite direction. The sulphuric acid concentration is depleted during charge and the state of charge can be mea sured by the specific gravity of the sulphuric acid. Batteries of the lead-acid type can be discharged at very high rates. The only limit is the ability of motors and wires in the electrical circuit to handle the current. It is this operating char acteristic that makes storage batteries an ideal source of power for many heavy-duty services, such as providing power to crank the engines of giant diesel-electric locomotives or supplying mo tive power for the operation of electric industrial trucks, mine locomotives or submarines. Whether a lead battery is discharged quickly at high rates or intermittently at high (peak) or low rates, makes no difference in its life. Charging the battery is just the reverse. The lead sulphate is converted to lead peroxide and sponge lead and sulphuric acid is regenerated, increasing the concentration of the electrolyte. During the early part of a charge, large amounts of direct cur 32 LEAD IN MODERN INDUSTRY rent can be utilized. This is why it is permissible, with proper control equipment, for a local serviceman to give an automobile battery a so-called "fast charge," which, however, is never a full charge. Battery capacity is rated according to the current (amperes) it can deliver for a certain length of time or the product of amperes and hours. For example, an automobile battery may deliver 4 amperes for 20 hours--thus, it is an 80 ampere hour battery on the 20-hour basis. About 60 to 70 percent of the total weight of most storage batteries is lead and about 52 percent of this is antimonial lead, lead oxides comprising the balance. They consume more lead than any other use of this remarkably versatile metal. WHERE BATTERIES ARE USED The largest numerical use of lead storage batteries is to fur nish power for starting, lighting, ignition, radio and accessory equipment on automobiles, trucks, buses and motor coaches. On farm tractors and heavy construction equipment, they are used for starting, lighting and ignition. On airplanes they provide power for engine starting, cabin, landing and navigation lights, radio, radar and other navigation instruments. Aviation batteries are of a special design which will not spill their acid even when the plane is flying upside down. Typical automobile batteries are three cell 6 volt types, al though six cell 12 volt batteries are also used for motor coaches. Automobile batteries are rated as to capacity at the 20-hour rate at 80 degrees Fahrenheit and 300 ampere rate at zero degree Fahrenheit, due to the dual service they must perform of provid ing small currents for a long time for lighting and larger cur rents for a short time for starting. Capacities commonly used in passenger cars range from 80 to 150 ampere hours at the 20hour rate. The containers of automobile batteries are either made of hard rubber or a bituminous composition material. Wood is cus tomarily used for separators, although porous rubber is often substituted, or glass fiber mats are used in conjunction with the wood. LEAD STORAGE BATTERIES 33 Electric utility companies are large users of storage batteries for the operation of switchgear to supply emergency lighting in central and substations. Formerly, in the D. C. districts of large cities, immense storage batteries were used to take over the en tire load of business areas during emergencies. It has been esti mated that the emergency discharge rate of one of these standby batteries for six minutes was 2,125,000 amperes at 125 volts. However, batteries of this type are gradually being eliminated as utilities change their systems from D. C. to A. C. Today there are a number of conditions that disrupt service (storms, fires and accidents) over which utility companies have no control. In places such as hospital operating rooms, crowded theatres, school auditoriums, large stores or other places of public assembly where interruptions of electric lighting might be dan gerous to life or property, storage batteries are used to provide emergency lighting. In numerous and varied industrial activities, batteries provide emergency power to assure the uninterrupted operation of important processes or process control equipment. In the field of electrical communications, storage batteries are used to assure the continuous operation of telephone, telegraph, telephoto, teletype, radio, radio-telephone, television and munici pal fire and police alarm equipment. Motion picture companies use batteries to assure the highest quality of sound recording. In central telephone stations, storage batteries are essential to the operation of the transmitting, signaling and relay circuits. In an emergency, they carry the entire load. They are generally eleven-cell batteries with a second similar battery used with the first for toll or long distance calls. These batteries have capaci ties up to 13,000 ampere hours, which are doubled when the two are used in parallel. Similar batteries of 120 volts are used for telegraph operation. All forms of transportation use storage batteries. The rail roads use them to crank the engines of diesel-electric locomotives and to operate their control circuits. Storage batteries provide power for passenger car lighting and air conditioning. They are relied upon to safeguard the operations of vitally important rail road signals, switches and communication systems. Aboard fishing vessels, work boats, river boats, freighters, ocean liners and yachts, storage batteries provide power for light 34 LEAD IN MODERN INDUSTRY ing, ship-to-shore telephones, radar, sounding equipment, inter ship communication systems, fire alarm systems and the opera tion of numerous other auxiliary apparatus. On submarines they supply all these services in addition to providing for propulsion when noiseless operation and a non-oxygen consuming power source is paramount. In the mechanization of metal and coal mines, lead storage batteries provide the motive power for shuttle cars and electric locomotives. They are also used to power tramming locomotives used in tunneling operations. In this connection, storage bat teries have been used in building the Holland, Cascade and New York-to-Brooldyn tunnels, New York City subways, and the water supply systems of Los Angeles, Detroit, Baltimore and New York. Storage battery haulage locomotives have also helped in build ing such well-known projects as Boulder Dam, the Golden Gate Bridge, and the George Washington Bridge over the Hudson River. Supplying motive power for the operation of electric materials handling trucks is probably the most outstanding way storage batteries are used by almost every kind of industry. These battery-powered trucks are highly efficient tools which enable one man to handle more material in less time and with greater safety than could be handled manually by a gang of men. The first electric industrial truck was used by the Pennsylvania Railroad in 1906. Today more than 60,000 are in operation in this country. It is estimated that 90 percent of those installed in the past twenty years are still operating. The lead storage batteries which power them have a life ranging from five to ten years, depending upon the type of work and the kind of care given them. With two sets of batteries, one charging while the other is in use, an electric truck can operate 24 hours a day. Battery-electric industrial trucks are rarely out of service for unscheduled repairs. Thus, their utility value is high and their operating and maintenance costs are low. Today these battery-powered materials handling trucks are providing indus try with its most effective way of cutting production costs. Another industrial use of storage batteries for motive power work is the operation of storage battery diesel locomotives for switching and intra-plant haulage in large mills. The locomotive LEAD STORAGE BATTERIES 35 can run for several hours on batteries alone and, by using both batteries and diesel engine, can exert greater power for starting heavy loads than any other kind of locomotive having a selfcontained power unit. Farmers and others not served by power companies have greatly benefited from the development of isolated electric cur rent generating plants. These plants consist primarily of a small gasoline engine, a generator and storage batteries. The battery stores up energy generated intermittently by engine and genera tor, and in turn supplies current on the farm, when needed, in a steady even flow. As these batteries are usually discharged inter mittently over several days, they are given a 72-hour capacity rating as well as the customary 8-hour rating. The 8-hour rating is about 70 percent of the 72-hour rating. Lead storage batteries have recently been developed for spot welding which supplies current as high as 38,000 amperes. Another recent development is a tiny lead-acid storage battery no bigger than a pack of cigarettes. It is so small that it is filled with a hypodermic needle, yet has as many as 18 cells. U. S. Government services use large quantities of storage bat teries in a great many military, as well as peacetime, activities. Among the latest important uses of lead storage battery power is in the field of atomic research, and they continue to be widely used in scientific, college and industrial laboratories for conduct ing experiments which will produce the new electrical services and products for tomorrow. CHAPTER SIX Lead Covered Cable Lik e storage batteries, lead covered cable exemplifies the importance of lead to modern living. Both uses are electrical in this electrical age, and both require huge tonnages of lead to place them among the largest consumers of the metal. As much as 200,000 tons of lead have been used in a year to cover cable, and the cable thus covered has been estimated at some 30,000 miles annually. Lead is used in the construction of two general types of elec trical cables, i.e., cable for communication over telephone and telegraph lines and cable for the transmission and distribution of electric power from public utility generating stations. A char acteristic feature of both the telephone business and industries selling electric power is the fact that the nature of their busi ness requires engineering planning to provide for future devel opments many years ahead. In the formulation of such plans, consideration is given not only to the continued expansion of de mand as shown by past records, but also to the effects of the slow steady increase in the number of families and business concerns in the country and of the continuing improvement in the stand ard of living upon telephone usage and electrical output and its distribution. Lead covered cables are used both in overhead and under ground line construction, but the modern trend is, in spite of higher first cost, to place electrical cables underground where they will be undisturbed and out of the way. This is particularly true in congested cities where overhead construction is unsightly and inadequate to meet the service requirements. All types of underground and overhead power and communi cation cables having hygroscopic material such as paper for in sulation must be protected from moisture to insure the successful 36 A lead cable sheathing press, ca ble reel and melting kettle. Diagram on page 21. n>.s(er Electric Co. Western Electric Co. Left. A fanned out view of typical lead sheathed 2121-pair telephone cable, about 2b in. in diameter. Right. Similar view of lead sheathed six coaxial cable used in the nation-wide television and communications net work, about 2 in. in diameter. tm i Top. A cable train burying lead sheathed coaxial cable for cross-coun try communication. Left. Inside a manhole, showing the variety of lead sheathed power cable carried in conduits beneath city streets. Right. Overhead 23,000-volt lead sheathed power cable and terminating pot head. Genera! Cable Co. (A) (B) (C) (A) Low voltage, lead sheathed, varnished cambric insulated cable. (B) Arsenical lead alloy sheathed, paper insulated, oil-filled 138,000- volt cable. (C) Lead sheathed, paper insulated, nitrogen gas-filled 27,000-volt cable. LEAD COVERED CABLE 37 operation of the cable. Lead was recognized early as having de sirable properties for use as a protective cable sheath and has*been used successfully many years for that purpose. It is impervious to moisture and provides good protection from mechanical injury to the insulation. It protects effectively against all kinds of weather and oxidation. Its low melting point permits it to be applied in a semi-liquid condition without damage to the insula tion and its pliability allows it to be used without destroying the flexibility of the cable as required for reeling, unreeling and ease of installation. Also its comparative chemical inertness results in high resistance to corrosion and long life when exposed to the acids and salts encountered in soil water. Ideas which seem grotesque to us now permeated the minds of the first lead covered cable makers. For example, one cable was constructed of twenty bare wires, each drawn into small glass tubes and then pulled through a lead sheath and a mixture of oil and rosin added under pressure. When the lead pipe was bent, the glass broke but the wires were said to have been kept apart by the resulting glass compound. Pure lead was used to make the first cable sheathing and is still principally employed for power cables. Early telephone cable was manufactured with a relatively soft or loose core and in order to maintain the circular cross-section of the surrounding lead sheath, about 3 percent of tin was alloyed with the lead to stiffen it and prevent its distortion under pressure of successive windings when coiled upon the reel at the factory or when bent during installation. In 1907, experimental research was under taken to discover an alloy which would satisfactorily replace ex pensive tin. After much experimentation with lead alloys con taining antimony, tin, copper, nickel and bismuth, an alloy was developed about five years later containing 1 percent antimony which has been used extensively for telephone cable ever since. Power cable, having a more compact core, does not require the additional stiffness imparted by antimony except where the cable is used in overhead construction or subjected to vibration, where the characteristics of a lead alloy of tin or antimony are desirable. Lead-calcium alloy containing 0.03 to 0.04 percent calcium has been used to some limited extent for cable sheathing with satisfactory results. In England, alloys of 98.25 percent lead, 1.50 38 LEAD IN MODERN INDUSTRY percent tin and 0.25 percent cadmium, or 99.25 lead, 0.50 anti mony and 0.25 cadmium have been developed for the same pur pose. ' A newer arsenical lead cable sheathing1 alloy containing small percentages of bismuth, arsenic and tin has been perfected. Its chief advantages are increased tensile and bursting strengths and a higher annealing temperature. The latter improvement is particularly significant because wiped joints may be made on this sheath without unduly softening or lessening its tensile or burst ing strengths adjacent to the joints. The alloy is composed of 0.1 to 0.2 percent arsenic, 0.07 to 0.2 percent bismuth, 0.05 to 0.25 percent tin and the balance lead. Where lead covered cables are used for submarine purposes or for direct earth burial a metallic armor is normally applied over the sheath for protection against mechanical injury. For sub marine cable this armor usually consists of an asphalt impreg nated jute bedding directly over the lead followed by a serving of galvanized steel wire armor with a layer of asphalt impreg nated jute yarn over the armor. Where cable is for direct earth burial, flat steel tapes and 0.010 in. lead tapes are used in place of steel wire for the metallic armor. Other types of protective cov erings or modifications of the above are sometimes used for spe cial service conditions. MANUFACTURE OF LEAD COVERED CABLE In the early days the core of wires was pulled into a lead sheath which had already been made, but it was soon found pos sible to extrude the sheath directly around the core. The prin ciple is the same as that used in the manufacture of lead pipe, except that the fixed mandrel or core which makes the hole in the pipe is replaced by a hollow mandrel through which the cable core passes, moving with the lead. Molten lead is placed in the chamber of a hydraulic press and cooled under pressure to the proper temperature for extrusion. "When pressure is applied, the lead is extruded through the die and carries the cable along with it. A drawing of a cable press is shown on page 22. As the filling of the lead chamber and cooling requires considerable time, the tendency has been toward presses with larger lead LEAD COVERED CABLE 39 containers, which has increased the speed of the operation. The pressure on the lead is about 54,000 lb. per sq. in. Constant study of temperatures, speed of extrusion and contour of the extrusion chamber has led to marked refinements in the quality of the product. One of the problems in telephone cable production has been to carry as many messages as possible in as small a space as pos sible. Present telephone cable consists of a maximum 2,121 pairs of 26 A.W. gauge wire enclosed in a 2% in. inside and 2% in. out side diameter sheath. This is the size of sheath which has been found desirable in duct work and the problem has been to in crease the number of wires that the sheath may hold. The prog ress that has been made is shown by the fact that the number of pairs of wires has increased from 50 in 1888 to 2,121 in 1939. As these wires are first covered with paper insulation either in the form of a wrapping of paper or of paper pulp applied directly to the wire, improvement in both paper and pulp and in the in sulating machines to apply these has made it possible to use less insulation, thus economizing on space. The insulated wires are twisted into pairs which are stranded into groups of suitable sizes and then stranded into a compact core. Development of coaxial cable, which has a solid conductor at the center surrounded by a copper tube separated from the con ductor by insulating discs at about 1-in. intervals, permits trans mission of the same number of messages as formerly but on a much smaller and less expensive cable. A lead sheath of course protects coaxial cable just like other cables. This is a compara tively recent development, an experimental installation between New York and Philadelphia having been installed in 1936, and the first commercial installation between Minneapolis and Stevens Point, Wis., completed in 1940. Now something on the order of 6,000 miles of this cable are in service, including the transcontinental line from the eastern seaboard to Los Angeles. TELEPHONE AND TELEVISION CABLE The first long distance lead sheathed toll cables in the United States were placed in service in 1906 between New York and 40 LEAD IN MODERN INDUSTRY Philadelphia and between Chicago and Milwaukee. Each was about 93 miles long. In 1913, an underground toll cable was com pleted between Boston, New York, Philadelphia and Washington, a distahce of 453 miles. In 1925, the New York-Chicago line was completed and a year later extended to St. Louis. Since that time, toll cable lines have been extended to span the continent and con versations between all principal cities in the United States are carried over toll cable lines. One of the newer developments is gas filled telephone cable. In 1928, about 50 miles of aerial toll cable between Philadelphia and Reading, Pennsylvania, had been filled with nitrogen gas under pressure and the cable divided into sections by means of gas-tight dams. The purpose of this was to provide a means of monitoring the physical condition of the cable sheath. Should the cable sheath be injured, the gas pressure drops in that par ticular section, sounding an alarm which locates the trouble ap proximately and allows "trouble shooters" to make repairs before any serious damage occurs. This was one of several pioneer in stallations of gas pressure maintenance systems in a program which developed to the point where the greater portion of the toll cable plant is now under pressure. To protect this warning system, it is common practice to test wiped joints in cable sleeves with soap solution to insure that there will be no pressure leak in gas filled areas due to porosity of the wiping solder. A unique sealing method which assures the tightness of such joints has been developed by Bell Telephone Laboratories, Inc. The method consists of applying a supplemen tary layer of a lower melting solder over the surface of the wiped joint. By taking advantage of the residual heat in the joint im mediately after wiping, the sealing solder is melted and the joint permanently sealed without requiring extra heat. The special solder used for sealing by this method is the lowest melting (eu tectic) alloy of lead, bismuth and tin, which contains 32 percent lead, 52^4 percent bismuth and 15*4 percent tin. The alloy melts completely at 95 C. In operation the sealing solder in the form of a thin stick is touched to the wiped joint as soon as the latter has solidified. The sealing alloy melts readily and is wiped around the joint with a finishing cloth. The same technique can LEAD COVERED CABLE 41 be used to seal old joints providing the joint is well cleaned and then heated from 150 to 170 C. The contrast between the capacity of the familiar telephone pole containing several crossarms and the modern toll cable line is particularly striking. A typical open wire line carrying four fully equipped ten-pin crossarms, or 20 pairs, has provided what is known as 20 physical telephone circuits and 10 phantom cir cuits, a total of 30 voice frequency talking circuits. The introduc tion of carrier frequencies on open wire lines has increased the number of available talking circuits to 262 for the same wire and crossarm installation. A further increase in the number of talking circuits has been provided by the use of coaxial cable. With eight coaxial tubes in a single cable as many as 3,600 one way telephone channels or a lesser number of telephone and tele vision channels are possible. POWER CABLE Cables used for the transmission and distribution of electric power are furnished in many types and sizes. Unlike telephone cable using a large number of small wires with thin insulation, power cables usually have only one, two or three conductors, with heavier insulating walls. The conductor sizes normally range from 14 A.W. gauge to 750,000 circ. mil in multi-conductor cables and up to 4,000,000 circ. mil in single conductor cables. The thick ness of insulation on the individual conductors depends on the voltage rating of the cable, with the heavier walls used at the higher voltages. The thickness of the lead sheath increases with the cable diameter and covers a normal thickness range of from in. to H in. The three general types of insulation used in the manufacture of power cable are paper, varnished cambric and rubber or syn thetic material. Varnished cambric and rubber are used only for the low and intermediate voltages, while paper is used over the full voltage range up to 220,000 v. The first 220,000-v. cable was placed in operation in France in 1936. This was a single conductor, paper-insulated, oil-filled, lead-covered type. Many of the principal cities in the United States have cables operating in the high voltage range from 66,000 to 138,000 v. 42 LEAD IN MODERN INDUSTRY Because of the extrusion method used for applying the lead sheath along with other manufacturing facilities such as strand ing, insulating and cabling, it is possible to manufacture cable in long lengths as often required for submarine installations. Where cable is to be pulled in underground ducts, it is usually supplied in specified lengths corresponding to the distance be tween manholes. The individual lengths are spliced together to form the complete circuit. In splicing lead covered cable a lead sleeve, used to seal the splice, is wiped with solder to the cable sheath at each side of the splice forming the well-known plumber's joint. In some places where severe corrosive conditions are encoun tered or where scoring of the sheath is inevitable, neoprene or polyethylene jacketed cables are being used. These are regular lead sheathed cables to which a jacket of neoprene or polyethylene about 44 in. thick is applied by extrusion. One of the most dramatic developments of World War II was the installation of a series of 3-in. inside diameter lead pipe lines under the English Channel from the British Isles to the Euro pean mainland. Through these lines were pumped the huge quan tities of gasoline and oil needed to keep the Allied armies moving. These pipe lines were constructed exactly like submarine cable except that the conductor and insulation core were omitted. Thousands of tons of lead have also been used for sheaths on Signal Corps cable and for communication and power cables on shipboard. CHAPTER SEVEN Lead in Modern Chemical Construction Lead and some of its alloys are extensively employed in the construction of equipment for the production, transporta tion, storage and use of many corrosive chemicals. Details regard ing many of the chemicals with which lead is used and some corrosion rates are given on pages 51 to 69. COMPOSITION It is important in selecting lead for corrosion resistant equip ment to decide upon the correct grade or alloy for the purpose. If unalloyed lead is used, it is generally one of the A.S.T.M. grades known as chemical lead, acid lead, or copper lead. Although these grades are somewhat stronger than others, there are installations where still greater strength or fatigue resistance are needed. In such cases an alloy may be used. The alloys also may have better corrosion resistance under some operating conditions. One of the most common lead alloys thus employed is antimonial lead containing up to 12 percent--usually about 4 to 6 percent--antimony, but since this alloy loses strength rapidly at elevated temperatures, its principal use is with temperatures only up to 250 deg. F. Tellurium-lead, an alloy of lead with about 0.05 percent tellurium, has found recognition in the last few years because of higher resistance to fatigue failure. This alloy workhardens and in corrosion resistance is comparable to chemical lead. A proprietary lead alloy has been developed especially for use in contact with chromium plating baths. Like the lead sul phate film which forms on contact with sulphuric acid, the pur pose of this alloy is to promote the formation of ap adherent protective film of chromates which will inhibit corrosion by chromic acid. An alloy of lead with about 7 percent tin has also 43 44 LEAD IN MODERN INDUSTRY been used successfully in chromium plating- operations, and a 1 percent silver alloy is used for insoluble anodes in electrolytic zinc refining and plating. METHODS OF JOINING Joints in lead used for corrosion resistant equipment are made by fusion welding, a method of joining that is commonly known by the somewhat misleading term of lead "burning" (see page 72). This method is used so that no metal other than lead will be exposed to corrosive attack. Likewise, it is necessary to see that the lead exposed to attack is uniform in composition in order that all exposed metal may resist attack uniformly. Therefore, if metal has to be added through the use of a filler or welding rod in making joints, the rod should have the same composition as the lead being joined. Thus, chemical lead should be joined by the use of a chemical lead welding rod, 6 percent antimonial lead by the use of a 6 percent antimonial lead welding rod, and so on. Oxygen and hydrogen are the most generally preferred gases for lead welding, but others, such as oxygen and acetylene, and oxygen and city gas, are also used. METHODS OF CONSTRUCTION Because of its low strength, lead is usually supported by some other stronger material, such as steel, wood or concrete. Occa sionally chemical equipment is made of cast lead alloy, but then the walls are unusually thick to gain the necessary strength; valves, pumps and fittings are also frequently made of cast lead alloy. Sometimes the supporting structure may be merely a framework of steel, but more often the entire outer shell is made of strong material with a lead lining applied to it in various ways. Small tanks may simply have the sheet lead lining hung in them by turning the lead over the upper edge. Thickness of sheet lead linings depends largely on the degree of corrosive attack. Rarely is sheet lead lighter than 8-lb. ( in. thick) used in chemical equipment. Frequently different thick nesses are used for different parts of equipment, tank bottoms often being lined with heavier lead than sides because of greater wear. For example, the upper part of a vertical tank might be Cup welding the sections of a sheet lead gas conduit on a Mills-Packard sulphuric acid chamber. Note strap hanger method of supporting conduit. Sheet lead cage construction. Note unlined steel framework at upper right, helical lead pipe cooling coils and lead lined steel pipe and valves at lower left. Interior of a completely bonded lead lined steel reaction vessel. LEAD IN MODERN CHEMICAL CONSTRUCTION 45 at)? 4-in. lead, the lower part f-in., and the bottom -in. lead. Abrasion may also be a factor in determining the correct thickness. For better support, the lining is often held by 2-in. half-oval, steel flats fastened at frequent intervals inside the lead and through it to the outer steel shell. These straps are covered with strips of lead welded to the lead lining on either side. Vertical straps are usually about 18 in. apart and no more than 24 in. Horizontal strapping in lieu of vertical strapping is seldom used, particularly when under-hand welding is involved. Occasionally in tanks more than 10 feet deep one or two horizontal straps are used in conjunction with the usual vertical strapping to help support the weight of lead. Automatic stud welding eliminates drilling of the steel shell 0% and positioning of the lead sheet, generally resulting in time and cost savings on the installation of strapped linings. A threaded stud can be butt-welded by means of a special gun directly to the inside of the shell, either through precut holes in the lead or between two lead sheets where they butt together. Half-oval steel strapping is slipped over the threaded stud and bolted down on top of the lead. Steel Sheet lead lining Burned joint Bolt Sheet lead covered steel strap Threaded stud butt welded to steel Sheet lead cover strip Burned Half-oval joint steel strap . recessed for stud * nut / 4 Sc*t.eel Sheet lead lining Bolted strap. Welded stud fastened strap. 4G LEAD IX MODERN INDUSTRY Out side of tank -Steel frame work hoop Cage construction. Occasionally it is advantageous to use a large steel cut washer and a roundhead bolt to fasten sheet lead to a steel or wooden shell. The bolt and washer are covered with a lead cap which is burned to the lining. This tends to distribute the load over a large area and aids considerably in minimizing fatigue. The bolts used in this manner are evenly spaced over the entire lining at about 18-in. centers. Combine the corrosion resistance of lead with the strength of steel and, in effect, you have what has been achieved with bonded lead lining. Bonded lead is simply a thick layer of lead bonded to a steel plate so as to form a homogeneous metallic structure. The thickness of the layer, depending upon the ulti mate use, ranges from % in. to | in. Bonded lead lined vessels are especially recommended for use where heat transfer is im portant, where rapid temperature fluctuations, high tempera tures (up to 450 F.), vibration or repeated shock are encoun tered or when the vessel operates under vacuum. LEAD IN MODERN CHEMICAL CONSTRUCTION 47 Brick and lead linings--a steel shell lined first -with lead and then a layer or two of acid-proof brick set in suitable cement-- provide another approach to corrosion problems in chemical construction. Brick and lead lined vessels are recommended where high temperature (above 450 F.), vacuum, pressure, abrasion or erosion must be contended with. Brick linings alone are always considered permeable, due to the porosity of the brick and the inability of the bricklayer to secure a continuous cement film between and in back of the brick. The lead lining acts as an impervious barrier between the shell and the brick so that any corrosive seepage is retained by the lead thus pre venting damage to the steel shell. Asbestos sheet lining (~ in. or less) Weld line ^ in. bed joint in. no greater than | in. Sheet or bonded lead lining Acid proof cement Acid proof brick Steel KCjX--A------ Special corner standard / /s>^_ brick dished head Lap lead here, side sheet covering bottom sheet about 4 in. Brick lining with impervious lead interliner. 48 LEAD IN MODERN INDUSTRY LEAD PIPE IN CHEMICAL EQUIPMENT Horizontal runs of lead or lead alloy pipe are generally continuously supported in steel or wooden troughs, or in specially constructed sheet metal shells. Vertical runs are supported at frequent intervals, say every 18 in. Long runs are provided with expansion bends if they operate at high or fluctuating tempera tures. When greatest strength is essential, lead-lined steel pipe may be used. The inside of the steel pipe is coated with a bonding agent such as solder and extruded lead pipe inserted. The lead is expanded under steam pressure against the heated' steel and is thus "sweated" to the steel pipe. Lead or lead alloy pipe may be joined by welding or by welded flanges and bolts. Lead flanges are usually backed by loose steel flanges. Flanged joints are generally used for lead-lined steel pipe. Heating or cooling coils made of lead pipe are important items in many pieces of chemical apparatus. Usually they are helical in shape but may take other forms. Lead spacers are welded at intervals, generally not more than 18 in. apart, around the coil between the turns for support. Where greater strength is needed, the coils may be made of copper tube completely covered with lead. Also flat coils for the ends and bottoms of tanks are used. ................. .. Thickness of lead pipe depends on several factors including corrosive attack, abrasion and the pressure to be handled. For instance, if wall thickness is calculated in the usual manner to accommodate a given pressure, additional wall thickness is al lowed to compensate for loss through corrosion or abrasion. Pipe 1| in. in diameter with -in. walls is commonly used with steam pressures up to 45 lb. per sq. in. The formula generally used to calculate wall thickness is given on page 192. To the wall thickness thus calculated must be added allowances for corrosion and abrasion. The velocity at which a corrosive solution flows across the surface of lead is also a factor in rate of corrosion, but no definite relationship has been established between the two. If the pipe is not used under pressure, then corrosion or abrasion is the principal factor, and the lightest weight of pipe generally selected under such conditions is the class known as "B" or "M" weight in sizes up to 2 in., and |-in. : ..... LEAD IN MODERN CHEMICAL CONSTRUCTION 49 wall in larger sizes. Standard weights of lead pipe are designated by the actual inside diameter and by a letter showing the wall thickness or weight per running foot (see page 76). He a t in g Co il Fo r mu l a For Calculating Length of Lead Pipe Needed for Heating Solutions--Time 1 Hour Mean temperature difference deg. F.= (T---Ti) -- (T--Ta) 2n.3olwg 10(<Tt--"TTs*>) where T = Temperature of steam or heating medium in deg. F. Ta=Initial temperature of solution in deg. F. T2=Final temperature of solution in deg. F. Length of pipe required = Y * Tl H X M X D X 3.1416 where V=Volume of solution in gallons Wss Weight of solution in lbs. per gal. Ts=Temperature to which solution is to be heated in deg. F. Ti=Initial temperature of solution in deg. F. Sp=Specific heat of solution H=Heat transfer in B.t.u./sq. ft./deg. F./hr.=150 M=Mean temperature difference deg. F. D=Outside diameter of lead pipe in inches. No t e.--H varies with the thermal conductivity of the solution, the den sity of tine solution and the amount of stirring. As a general figure H=150 when convection currents function well or there is mild stirring. For a more thorough consideration of heat transfer problems, engineering books on the subject should be consulted. The graph which follows may be used to estimate the safe work ing pressures of chemical lead or 6 percent antimonial lead pipe at various temperatures and equivalent steam gauge pressures. On page 192 is a table of values upon which this graph is based along with formulas for calculating the proper pipe sizes under specific conditions of temperature and pressure. The curve of safe working pressure limits for tellurium lead can be assumed to follow that of chemical lead. 50 LEAD IN MODERN INDUSTRY 20 60 100 140 160 220 260 300 TEMPERATURE, C. Safe working pressures for lead pipe. The following table is an approximate guide to the length of lead pipe needed in heating coils to heat solutions in open tanks under certain conditions: ' APPROXIMATE FEET OF LEAD PIPE TO HEAT 100 GAL. IN 2 HR. Temperature of solution, deg. F. 100 110 120 130 140 150 160 170 180 190 200 Steam pressure _ _-_____ >- _ - 10 lb. per sq. in. SO lb. per sq. in. | in. I. D. Feet 3 4 5 6 7.75 9.5 11.75 14.5 17.5 21.25 23.25 1 in. I. D. Feet 2.5 3.25 4 5 6 7.75 9.25 11.75 14 17 20.25 'S in. I.D. Feet 2.5 3 4 5 5.75 7 8.25 10 11.75 14 16.5 . 1 in. I. D. Feet 2 2.5 3.25 4.25 4.75 5.5 6.5 8 9.25 11.25 13 CHAPTER EIGHT Corrosion Resistance of Lead and Lead Alloys Be h in d many of the most important uses of lead lies its remarkable resistance to corrosion by a wide variety of chemi cals. It is used for protection against weather and soil, for con veying water and protection against moisture, and for handling corrosive chemicals, including what is probably the most impor tant of all industrial chemicals, sulphuric acid. Lead usually relies for its high resistance to corrosion upon a thin protective coating that forms on its surface. For instance, when the coating which forms on lead in contact with corrosives is one of the highly insoluble lead salts such as the sulphate, car bonate or phosphate, resistance to corrosion is high. On the other hand, if the soluble nitrate forms, little protection is afforded the lead, and it may corrode further. Likewise, if insoluble protective coatings are removed mechanically, as by abrasion or erosion, corrosion resistance is reduced. Lead generally has good resistance to neutral solutions where lead carbonate and possibly oxide are corrosion products, and fair resistance to alkaline solutions in which these are soluble. Ex perience has shown that lead is commercially resistant to chromic, sulphuric, sulphurous and phosphoric acids; that it is subject to corrosion at somewhat higher rates by hydrochloric and hydro fluoric acids; and that it is susceptible to being strongly corroded by acetic, formic and nitric acids. Also, nitrate salt solutions are moderately corrosive whereas carbonate solutions are not. CORROSION RATE INTERPRETATION It is important in discussing corrosion that a uniform system of designation be used, such as mils or inches penetration per month or year, or milligrams, per square decimeter per day. But either of these systems can be somewhat misleading insofar as 51 52 LEAD IN MODERN INDUSTRY the common tendency is to judge best performance on the basis of the lowest corrosion rate. This is especially true in the case of lead in chemical equipment which for mechanical reasons is used in thicknesses generally of in. or greater. Such thicknesses are of a distinct advantage from a corrosion viewpoint. Other corro sion resistant materials are normally used in much lesser thick nesses. Thus for equal uniform corrosion rates, lead would far outlast such other materials because of this difference in thickness. Designating corrosion rate according to weight loss as milli grams per square decimeter per day instead of volume loss as inches penetration per year is also misleading in the case of lead since lead has the highest density of any commonly used corrosion resistant material. This means that what might appear to be an excessive corrosion rate expressed in weight loss of lead could actually be a very nominal rate of corrosion in terms of volume loss. When comparisons are being made between various corrosion resistant materials an appreciation of the above will lend much to the proper interpretation of corrosion rate data. CORROSION RATE CONVERSION DATA ipy=Mdd X 0.00144 -7- density where: ipy=inches penetration per year Mdd=milligTanis per square decimeter per day density=grams per cubic centimeter of metal in question. Metal Density (gm/cm3) Lead .......................................................................... 11.35 4% Antimonial lead.......................................................... 11.03 6% " " ..................................................................................... 10.88 8% * " 10% " " 12% " " Mils penetration per year = 10.74 10.59 10-52 FATIGUE AND STRESS CORROSION Since lead has a relatively high linear coefficient of thermal ex pansion (29 x 10'6 per deg. C, 17 to 100 deg. C, or approximately three times that of steel) it undergoes considerable movement Mills-Packard chambers for making sulphuric acid. They are con structed entirely of sheet lead supported in a steel frame and cooled ex ternally by water flowing down the sloping sides. Lead lined vacuum filter, piping and valves for handling sodium sulphate and viscose rayon spinning bath slurries. Lead heat exchanger coils for hot dimethylaniline sulphate. Inset. Cross section of coil. Area of space between the pipes equals inside area of the finned pipe. .S t nithfis-WfiHs < Left. Seventeen-ton evaporator made entirely of cast 8 percent antimonial lead and used for concentrating titanium sulphate solution. Rifflit. Lead and brick lined sulphuric acid sludge concentrator and sheet lead electro static acid mist precipitator. CORROSION RESISTANCE OF LEAD AND LEAD ALLOYS 53 when subjected to severe cyclic temperature changes. It is this differential in expansion rates which largely accounts for the oc casional cracking of lead due to buckling. Adequate and proper strapping serves practically to eliminate or minimize this effect. Other factors which occasionally contribute to fatigue conditions include vibration such as that transmitted by nearby machinery, stirring equipment, etc. and strain induced as a rule by inadequate support of hanging sheet lead. Fracturing caused by repeated bending is hastened by simul taneous exposure to corrosive conditions, thus resulting in a form of stress corrosion. The normal fatigue fracture of lead is inter crystalline and in a corrosive environment fresh crystal surfaces of metallic lead are being constantly exposed until the full depth of the metal is penetrated. Thus, indication of stress corrosion in lead is evidenced by more or less severe intercrystalline etching, sometimes to the point of fracture if the stress conditions are not removed or modified. Cracks from fatigue failures in lead pipe are often transverse and usually at the outside of a bend. There are two approaches toward the elimination of difficulties brought about by the above conditions: 1. Remove the source of stress. a. This may be done by insulating the equipment from vibration or, b. Spreading out the heating-cooling cycle or, c. Lowering the peak temperature if possible. 2. If the source cannot be removed, counteract the effect by, a. Providing adequate strapping to relieve stress caused by hanging or, b. Use a homogeneously-bonded lead lining to counteract severe cyclic temperature changes or, c. Protect the lead mechanically and thermally with a brick lining or, d. Use thicker lead to reduce fibre stress. Fatigue characteristics may vary with different alloys of lead. Chemical lead alloyed with 0.04 to 0.05 percent tellurium is ame nable to work-hardening, an effect which normally takes place during the sheet rolling operation. The property of work-harden ing coupled with the fact that the presence of tellurium in chemi 54 LEAD IN MODERN INDUSTRY cal lead acts as a grain growth inhibitor, raises the fatigue re sistance of tellurium lead above that of unalloyed chemical lead. GALVANIC CORROSION Corrosion associated with the current of a galvanic cell made up of dissimilar electrodes is defined as galvanic corrosion. This is also known as "couple action." Galvanic corrosion is gener ally understood to consist of the sum total corrosion, which com prises the normal corrosion that would occur on a metal exposed alone plus the additional amount due to contact with the more noble metal. Since all metals are electrically conductive, the possi bility of galvanic corrosion taking place when two or more dissimi lar metals come in contact in the same electrolytic medium is almost always present. However, in most chemical installations using lead in a corrosive electrolyte, galvanic corrosion usually is of little consequence and is ordinarily ignored. The film which forms on lead as a result of ordinary chemical reaction, in most instances, acts as an electrical insulator. This is especially true in sulfuric acid exposure, lead sulfate being practically nonconductive. ATMOSPHERIC AND SEA WATER EXPOSURE This table is reproduced from a paper of the Institute of Metals, London, by J. Newton Friend, head of the Department of Chemis try, The Technical College, Birmingham, England, entitled, "The Relative Corrodibilities of Ferrous and Non-Ferrous Metals and Alloys." It summarizes the results of his study. The specimens used were cylindrical bars 2 ft. long and 1-J in. in diameter. They were exposed to the city air of Birmingham, an industrial center, for seven years on the roof of the Birmingham Technical College. Similar tests were also carried on at Weston-super-mare, where the samples were exposed to sea water. The relative percentage losses shown in the last two columns of figures reveal that antimonial lead and soft lead stand first and third respectively in the atmospheric corrosion tests and fourth and fifth in the sea-water tests, being exceeded only by tin and nickel, much more expensive metals. > .'I > ) > 1 3 3- 3 SUMMARY OF RESULTS OF EXAMINATION OF THE IIARS EXPOSED TO CITY AIR BIRMINGHAM FOR SEVEN YEARS, 1922-1929 N. Metid Copper, "arsenic free" i " ordinary ......... 21 IIi>I "<1 arsIeI nical ......... II II n Nickel-copper ................ r j! Nergandln brass............ Naval brass .................. it Muntz metal ................ 7 Screw metal .................. 8 Aluminum ....................... Com position,* percent As 0.01 As 0.10 As 0.25 As 0.43 As 0.45 Nll.75 -- -- Pit 1.37 SI 0.25 Fc 0.32 Saifare eomlilion pilot- to exposure Polis<1hed II II II II II II II - II II Original weight, grin. 3520.4 3530.9 3535.0 3481.2 3502.0 3508.0 3373.5 3305.5 3314.1 3311.2 1057.7 has!! in Weight, grm. S.l 0.5 5.0 7.7 0.3 0.0 13.3 11.4 12.4 11.7 1.2 boss as percent of original weight 0.230 0.184 0.107 0.221 0.180 0.188 0.301 0.345 0.374 0.353 0.113 9 Lend, soft....................... Ph 09.00 Id " nntiinonlnl ......... SI) 1.0 It Nickel ............................. -- li II ll 4304.3 4375.7 3552.5 3.8 0.5 10.8 0.080 0.011 0i473 12 Tin, English common Sn 90.2 Ingot i:i " high-grade, pure. . Sit 00.75 ii Zinc ............................... Zn 09.82 ir Wrought iron (mean of -- 11-12 bars) Id Mild steel (mean of 7 ---- bars) |K Stainless steel (mean Or 12 13 of 3 bnrs) As east II Polished As rolled, with scale As rolled, with scale Polished 2703.3 2855.5 2819.4 c. 3000 c. 3000 c. 3000 2.8 2.0 15.2 207.2 308.5 3.0 0.100 0.070 0.539 0.71 10.28 0.10 For full analyses, see J. Inst. Metals, 1028. 30, 115. Table I. 1 Taklnpr nersanmn brass as Btiuidnrd since It lost the same |percentage ninium! In the tests lit Weston. t Calculated from data In Table III., .7. Inst. Metals, 1028, 80 122. Itelallvc percent Itehlllvc losses la per sea tests mit ngc nt losses! West oat 58 .---. 47 42 73 -- - 50 -- 40 08 48 01 inn ino 88 112 1)5 57 Oil 20 20 80 22 3 120 25 18 137 1703 2000 25 13 10 !) 1 2 01 inn 112 40 weight as the wr Rema Green stain .coat; tenaciou Metal surface condition Closely adhere } underneath b Metal surface condition White deposit coating; ten herent PerIfIect Greenish unde lnyer. Incipie \ciosely adhere j posit under b Small pinhole Surfaces rou slightly pHted Excellent. cond 56 LEAD IN MODERN INDUSTRY CORROSION IN SALT WATER SOLUTION (200 days at 8.5 deg. C.) Loss in wgt., percent 0.00 0.25 0.50 0.75 NaCl con centration, percent 0.0334 0.2331 0.2626 0.4003 Loss in wgt., percent 1.0 1.5 3.0 6.0 XaCl con centration, percent 0.6982 0.567 0.243 0.127 Corrosion rate increases up to about 1 percent solution concentration, and then decreases. Sea water has a salt concentration of 2.7 percent resulting in a corrosion rate of about 0.25 percent. ATMOSPHERIC CORROSION Location Exposure, years Altoona, Pa.................. New York, N. Y........ ........ 9.38 Sandy Hook, N. J----- ........ 9.45 Key West, Fla............. ........ 9.32 La Jolla, Cal............... ........ 9.14 State College, Pa----- ........ 9.27 Phoenix, Ariz................ ........ 9.10 Average penetration, inches Chemical lead 0.000267 0.000167 0.000200* 0.000216 0.000162 0.000188 0.000094 29c Antimonial lead 0.000214 0.000113 0.000190* 0.000205 0.000236 0.000129 0.000109 * Samples lost--values estimated. The above data is based on the 1944 report of A.S.T.M. Committee B-S. 24 0 20 X u -INDUSTRIALALTOONA PA. SEMI INDUSTRIAL N Y. N Y. t<t Ui 5 12 CL c02n 1 oo 8 6 oli ' 'i =>ui "" TIN LU 2 <Or ID tc ijj CL CL 2 oo b- METALS AND LOCATION Atmospheric corrosion tests. Ten-year period. ASTM-Proc. 1944. Antimonial lead 1%. COEROSION RESISTANCE OF LEAD AND LEAD ALLOYS 57 From the foregoing, it is obvious that the losses are of such small magnitude over even a ten-year period as to be negligible and of no practical importance. Therefore, the chief value of the A.S.T.M. exposure studies with respect to lead is to indicate that the use of lead exposed to atmospheric corrosion is practical under all conditions of exposure and that atmospheric corrosion has little or no effect on lead. SOIL CORROSION Soil Tears buried Muck .............................................. 2.11 Sand .............. 2.07 Clay...................................................2.10 oz. per sq. ft. per yr. 0.51 0.36 0.16 No t e.--Above figures approximate as rate varies in different localities and with different conditions. Rate of corrosion in soils decreases in the following order: (1) muck, (2) cinders, (3) sand, (4) day SOIL, WASTE AND VENT EXPOSURE................... In a recent test of various materials used in plumbing soil, waste and vent lines conducted under accelerated conditions in Fort Worth, Texas, lead pipe proved to be outstanding. It was shown to have a relative life expectancy of more than six times that of any of the other materials tested.* After exposure for one year in a moist atmosphere containing hydrogen sulphide from sewage disposal sludge, the lead pipe showed a uniform penetration of only 0.000259 in. All of the ma terials tested were either customarily used or suggested for use in soil, waste and vent lines. In addition, lead was the only material not effected by pitting whereas all of the others were pitted in varying degrees. In one case, the pits penetrated completely through the pipe wall. Results of this test prove that the use of lead as a soil, waste or vent material is definitely to be recommended for safety and long life in a plumbing installation. * The results of the test were described in a paper presented at the 1949 Annual Convention of the American Society of Sanitary Engineering and published in the 1949 Yearbook. 58 LEAD IN MODERN INDUSTRY CHEMICAL CORROSION RESISTANCE The data given here are indicative of the performance of lead in contact with various corrosive chemicals. Since operating con ditions vary widely, it is usually wise to use actual exposure tests under operating conditions whenever possible to forecast per formance. However, the performance of lead is so well known when exposed to many chemicals, such as sulphuric acid, with which it has been employed so extensively for a long time, that such tests are not always necessary. Among the many variables determining the suitability of lead, or any other material for that matter, may be temperature, con centration, grade of lead or type of alloy, rate of flow, presence of oxygen, degree of abrasion and presence of impurities. Metal Lead Hard lead Lead Lead CORROSION DATA Solution aiifl concentration. percent 2.4 H,SO< 5 50 Rate of cor . Tempera rosion. in. ' ture. penetration fie". (\ per mo. 25 0.000165 25 0.000024 20 0.00001 100 0.0002 1 H,SO, 10 50 95 20 0.00002 100 0.00006 20 0.00006 100 0.00003 20 0.00001 100 0.0002 20 0.0001 100 0.0041 20 Hj-SO, 18 15 10 5 2. 0 HC1 2 5 10 15 18 25 0.0001 25 0.0032 25 0.0179 25 0.0489 25 0.0856 25 0.1326 42 pure phosphoric acid 76 pure 42 impure 10 pure 25 pure 50 pure 15 0.00165 15 0.00469 15 < 0.00001 80 0.00035-0.00748 80 0.00417-0.01480 80 0.00602-0.01197 COEROSION RESISTANCE OF LEAD AND LEAD ALLOYS 59 Metal Lead Lead Hard lead Lead Lead CORROSION DATA--Continued Solution and concentration, percent dilute crude phosphoric acid concentrated crude Tempera ture, deg. C. 80 80 Hate of corrosion. in. penetration per mo. 0.00001-0.00008 0.00002 8.3 H,SO, 1.7 NaCl 20 0.0016 100 0.0234 16.7 3.3 20 0.0002 100 0.0265 31 17 20 0.0081 00o.0r> 100 0.0369................. 6.7 20 0.0007 100 0.0148 50 10 20 0.0010 100 0.0034 1 HC1 5 10 20 25 0.001 100 0.003 25 0.0015 100 0.0045 25 0.001 100 0.013 25 0.007 100 0.120 1 HC1 5 10 35 20 0.0001 100 0.0001 20 0.0001 100 0.0006 20 0.0002 100 0.0006 20 0.0010 100 0.0024 5 NaOH 25 35 20 100 20 40 60 80 100 20 100 0.0011 0.0035 0.0004 0.0002 0.0005 0.0007 0.0014 0.0003 0.0005 Alum 38 Be 100 0.00174 100 antimony trichloride 100 0.0049 20 comm. (95) sodium hydrosulphite 25 0.00007 60 LEAD IN MODERN INDUSTRY Metal Lead Lead CORROSION DATA--Continued Solution and concentration, percent 4 acetic acid 3 2 1 0.5 5 10 20 40 60 Glacial 98 Teiuperaturo. dec. C. Room 25 50 Rato of cor rosion. in. penetration per mo. 0.00177 0.00175 0.00183 0.00162 0.00162 0.0024 0.0015 0.0023 0.0018 0.0023 0.007 0.020 5 sodium suphide 10 15 20 25 25 100 25 100 25 100 25 100 25 100 0.002 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 The foregoing data on chemical corrosion rates of lead are largely from "Laboratory Corrosion Tests" by Calcott and Whetzel, and "Corrosion Resistance of Metals and Alloys" by MacKay and Worthington. Corrosion of lead by mixed acids and by phosphoric acid. CORROSION RESISTANCE OF LEAD AND LEAD ALLOYS 61 Corrosion of lead by sulphuric acid as a function of temperature. Concen trations below 50% are not shown because resistance of lead is very good even at temperatures including boiling. 2nd. & Eng. Chem., Sept., 1951. 40*\ TEM?RA?i;?r 0s SOLUTION. c. Effect of temperature on lead in sulphuric acid. 62 LEAD IN MODERN INDUSTRY "Results show a rapid increase in the rate of attack when the stress ex ceeds 100. Measurements made under other conditions suggest that the curves obtained will be of similar shape, but of course, possessing different ordinates, according to the severity of the corrosive conditions. The effect of the applied stress upon the coating of lead sulphate is to allow the acid to penetrate through the cracks to the metal below." "Some Observations on Corrosion of Lead," Metal Industry, June 16, 1933. . 0040 1 i ,i jj i I 1/ 3a 0035 i 1 i IsUKKUblUN Ur l_CttU j i/ */ 2 EFFECT OF'VELOCITY OFSULPHURIC ACID j t O5 .0050 i ACROSS FACE OF THE METAL 1 . /i \i 1 j 7 i j| I / .0025 // !______ 2 o .0020 A S s' < <r .0015 X 'N ^ 20% *<2S04 et 25* C fe JO010 s' < CL .0005 *--i*'*! . 'i j s' .0000 O 40 80 120 160 200 240 280 320 360 400 440 VELOCITY-OF SOLUTION ACROSS SURFACE - FEET/MINUTE Increased velocity of liquid in contact with lead increases the rate of cor rosion because: 1. Protective coating of PbSO cut off and exposes fresh metal surface to acid; 2. Protective coating of hydrogen stripped from sur face, de-polarizing the metal; 3. Mechanical erosion of metal by cutting action of impurities or scale in the acid solution. Effect of 350 ft. per min. is equivalent to the rate of corrosion of 95% H.SCh at 50 C. Calcott, AIChE Trans. Vol. XV. CORROSION RESISTANCE OF LEAD AND LEAD ALLOYS f>n Some common chemicals and the behavior of lead toward them are discussed here. ACETIC ACID Moderately corrosive to lead but corrosion is greatly accelerated by high velocities and temperatures. Acetic anhydride and glacial acetic acid are handled in lead. ACETONE Lead may be used satisfactorily. ac et o pheno ne Lead equipment used in manufacture. ACETYLENE Has little effect on lead. ADIPIC ACID Lead lined digester used in manufacture. ALCOHOL, ETHYL Does not affect lead. ALCOHOL, METHYL Does not affect lead. ALUMINUM CHLORIDE Lead is used to some extent in condensers. ALUMINUM SULPHATE OR ALUM Lead used satisfactorily in manufacture and handling of liquid alum. AMMONIA Lead is unaffected by the dry gas, and by the liquid. AMMONIUM AZIDE Does not affect lead. AMMONIUM BIFLUORIDE Lead used satisfactorily. AMMONIUM CHLORIDE Lead may be used at ordinary temperatures with concentrations up to 10 percent. AMMONIUM FLUORIDE Solutions at room temperature and free of ammonia satisfactorily han dled in lead. AMMONIUM FLUOSILICATE............. Lead is used occasionally for valves and fittings. AMMONIUM HYDROXIDE Lead satisfactory with liquid or gas at practically all temperatures and concentrations. AMMONIUM PHOSPHATE Lead may be used satisfactorily. AMMONIUM SULPHATE Lead may be used freely. ANTIMONY CHLORIDE Lead is somewhat corroded, but is used with comparative economy for . chlorinating the trichloride to the pentachloride. ARSENIC ACID Lead salt forms on contact but lead pipe known to last 10 to 15 years if salts cleaned out periodically. 64 LEAD IN MODERN INDUSTRY BARIUM SULPHIDE Lead tanks are used in handling solutions prior to precipitation of barium sulphide. BENZOL Has little or no effect on lead if pure. BENZYL CHLORIDE Lead may be used satisfactorily. BENZYLPHENOL Manufactured in lead lined vessels at temperatures up to 40 C. BORIC ACID Lead is used satisfactorily. BRINE (See Sodium Chloride) BROMINE Lead may be used when cold and add free. CADMIUM SULPHATE ................ Lead is widely used for lining plating tanks. CALCIUM ACID PHOSPHATE Lead can be used in a wide range of concentrations and temperatures. CALCIUM BISULPHITE Lead can be used in a wide range of concentrations and temperatures. CALCIUM CARBONATE Found in natural waters and forms a good protective coating on lead. Added to water to reduce plumbo-solvency. CALCIUM HYDROXIDE Presence in "green" cement corrodes lead in presence of moisture and oxygen. However, added to soft waters reduces plumbo-solvency. CARBONATES, SOLUBLE Act as a protection to lead by formation of lead carbonate coating. CARBON DIOXIDE Acts as a protection to lead in natural waters unless present in excess, when it increases solubility. Lead is used in acid-carbonate systems of generating COa. CARBON TETRACHLORIDE Lead is used at ordinary temperatures. CASTOR OIL IN ACID Lead is used for piping and valves. CHLORINATED HYDROCARBONS Action on lead varies from slight to severe depending upon breakdown to HC1 and presence of organic acids. CHLORINATED POLYVINYL CHLORIDE Lead used throughout manufacture. CHLORINATION PROCESSES Lead is slowly corroded at temperatures usually used, but has satisfac tory life compared with other common metals, and greater economy. CHLORINE Dry does not affect lead and lead may be used with moist chlorine up to about 110 deg. C. with slight corrosion. Amounts of chlorine used in water treatment do not affect lead. CORROSION RESISTANCE OF LEAD AND LEAD ALLOYS 65 CHLOROBROMOMETHANE When dry (less than 0.02 percent H20) practically non-corrosive to lead. CHROMIC ACID Since chromates form a good protective coating on lead, lead may be used with fairly high concentrations of this acid. High lead alloys are widely used in chromium plating. CINDERS Lead embedded in cinders should be protected. COAL TAR Lead used in refining and recovery of many by-products. CONCRETE, CEMENT OR MORTAR ...... When "green," free lime present attacks lead. Aging to carbonate lime or applying asphalt coating on lead recommended to prevent such corrosion. COPPER SULPHATE Lead is used for anodes and tank linings in electroplating. . DIBUTYL THIODIGLYCOLATE.... ............................ Part of manufacturing process conducted in lead lined vessels. DIHYDROXYDIPHENYL SULPHONE.. .......... ........ Lead cooling coils and bonded lead lined pressure vessel used in manu facture. ELECTROGALVANIZING Lead equipment finds good usage. ETHER Little or no effect on lead. Used in its manufacture. FATTY ACIDS Lead may be used but it will react slowly in presence of oxygen. FERRIC CHLORIDE Lead not recommended. FERRIC SULPHATE Lead stands up well over a wide range of concentrations and tem peratures. FERRIC AMMONIUM SULPHATE Lead stands up well over a wide range of concentrations and tem peratures. FERROUS CHLORIDE Lead is recommended. FERROUS SULPHATE Lead used for tank linings and coils in production and use. FLUOROLUBES ............................ Addition polymers of trifluorovinyl chloride used as lubricants. Shipped in lead lined pails to prevent contamination and discoloration. FORMALDEHYDE (Formic Acid) Action on lead similar to that of acetic acid. HEXACHLORBUTADIENE .............................. Highly corrosive to all metals except lead. Lead used throughout manu facture at temperatures up to 205 C. HEXACHLORETHANE Lead lined equipment used for chlorination vessel and crystallizing basins up to 60 percent concentration and 1366 C. 66 LEAD IN MODERN INDUSTRY HYDROCHLORIC ACID Use of lead is not generally recommended but it has been used with some corrosion in concentrations up to 30 percent at normal tempera tures and 20 percent at 100 deg. C. Antimonial lead shows better resis tance than ordinary lead. HYDROCYANIC ACID Lead used in manufacture. HYDROFLUORIC ACID Lead is commonly used and has fair resistance to cold acid up to 60 per cent concentration. HYDROGEN CHLORIDE (Anhydrous Hydrochloric Acid) Little effect on lead. HYDROGEN PEROXIDE Not likely alone to affect lead, but accelerates acid corrosion. Lead is an active decomposition catalyst causing peroxide to decompose into water. KOCH ACID REDUCTION MASS Lead may be used safely. MAGNESIUM CHLORIDE Corrodes lead as it does other metals, though lead pumps are used with it. MAGNESIUM SULPHATE Lead stands up well over a wide range of concentrations and tem peratures. MALACHITE GREEN MOTHER LIQUOR No appreciable effect on lead at 80 deg. C. MERCURIC SULPHATE Highly oxidizing, but lead in general has good resistance to most acid sulphate conditions. MIXED ACIDS Mixtures of sulphuric and nitric acids can be used with lead at ordi nary temperatures if water present is less than 30 percent. NAPHTHALENE Lead may be used. NICKEL SULPHATE AND NICKEL PLATING SOLUTIONS Plating tanks are commonly lined with lead. Lead heating coils com monly used. , NITRATION MIXTURE OF H-ACID Lead is used with rather high corrosion. NITRIC ACID Lead is not generally recommended with this acid, but is used with little corrosion when concentrations are in the range of 52 to 70 per cent by weight at normal temperature. NITRO-BENZOL AND NITROCHLOR-BENZOL Corrosive to lead. NITROCELLULOSE Lead widely used, as in all rayon manufacturing processes. NITROGLYCERIN Lead used to handle spent acid. NITROSYL-SULPHURIC ACID Action on lead is least at specific gravity of about 1.5 to 1.6. Close con trol thus minimizes corrosion. CORROSION RESISTANCE OF LEAD AND LEAD ALLOYS G7 ORGANIC ACIDS In general, accelerate the corrosion of lead, but their presence in solu tions does not always preclude the use of lead. OXALIC-SULPHURIC ACIDS Lead satisfactory with oxalic acid containing 1 percent free HSO in all concentrations from 5 to 50 percent and all temperatures from cold to boiling. OXYGEN Dry gas merely tarnishes lead. In presence of water, initial attack is usually followed by formation of protective coating formed by salts such as carbonates, sulphates and silicates in the water. In absence of these salts, deaeration may be employed to remove oxygen .because of its action on all metals. OXY-L ACID Lead is corroded to some extent but is about the only economical metal that can be used with satisfaction. ' PENTACHLORETHANE Lead used in manufacture and storage at temperatures up to 80 C. PHENOL Lead can be used satisfactorily. PHOSPHATES Generally form protective films on lead. PHOSPHORIC ACID Lead may be used with concentrations up to 80 percent below 200 deg. F. Impure acid has even less effect on lead and can be used up to 85 percent .concentration. PHOSPHORUS OXYCHLORIDE Storage tanks constructed of lead or bonded lead. Lead piping, coils and receivers also used. Shipped in lead carboys, lead lined drums or lead lined tank trucks. . PHOTOGRAPHIC SOLUTIONS Lead is satisfactory generally. POTASSIUM METABISULPHITE Preferred material of construction is lead and lead lined steel. Evapo rated in lead lined tanks at 160 F. POTASSIUM PERMANGANATE Attacks lead. ` PYRIDINE Does not affect lead. SILICATES Form protecting coatings on lead and thus can be recommended for treating natural waters if necessary. SODIUM BIFLUORIDE Successfully handled in lead. SODIUM BISULPHATE Can be handled in lead even when highly concentrated. SODIUM BISULPHITE ` Lead may be used with a wide range of concentrations and tem peratures. 68 LEAD IN MODERN INDUSTRY SODIUM CARBONATE Dilute solutions do not affect lead; in natural waters forms protective coating on lead. SODIUM CHLORIDE Lead satisfactory for dilute solutions at ordinary temperatures. Sea water or brine are commonly handled in lead or antimonial lead. SODIUM CHLORITE Lead may be used with low concentrations at room temperature. SODIUM HYDROSULPHITE Lead can be used satisfactorily. SODIUM HYDROXIDE Lead can be used with concentrations up to 80 percent and temperatures to 25 deg. C. With concentrations up to 10 percent temperatures may reach 90 deg. C. SODIUM HYPOSULPHITE Lead can be used satisfactorily. SODIUM HYPOCHLORITE Attacks lead. SODIUM SULPHATE Lead can be used satisfactorily with solutions up to 10 percent con centration boiling. SODIUM SULPHIDE Lead can be used satisfactorily with these solutions at temperatures up to 100 deg. C. SODIUM SULPHITE Lead can be used with solutions up to 20 percent concentration at 25 deg. C. SULPHATES AND SULPHITES Generally form protective coatings on lead. SULPHUR CHLORIDE Has little effect on lead. SULPHUR DIOXIDE Has little effect on lead when dry and can be used moist up to about 200 deg. C. . SULPHUR TRIOXIDE Can be used satisfactorily with lead. SULPHURIC ACID Lead is the standard material for handling this acid. It can be used with concentrations up to 96 percent at room temperature and 85 per cent up to 220 deg. C. It is sometimes used satisfactorily even up to 250 deg. C. SULPHUROUS ACID Lead is satisfactory up to about 220 deg. C. TANNIC ACID Somewhat similar to acetic acid. TARTARIC ACID Lead covered copper tubes and cast hard lead used in evaporators. TETRACHLORETHANE Bonded lead reaction tower and other lead lined equipment used in manufacture. CORROSION RESISTANCE OF LEAD AND LEAD ALLOYS 69 THIONYL CHLORIDE Lead is used satisfactorily up to 220 deg. C. and sometimes higher. TITANIUM SULPHATE These solutions can be handled satisfactorily in lead. TITANIUM TETRACHLORIDE ................. Lead gaskets used in pipe flanges. UREA Lead lined autoclave and stills used in manufacture at temperatures up to 190 C. VICTORIA GREEN MOTHER LIQUOR Lead may be used satisfactorily up to 80 deg. C. WATER, DISTILLED No effect in the absence of dissolved COa or Oa. WATER, NATURAL .......... Usually no effect on lead because of protective coating formed from dissolved salts. Very soft waters or those of peaty origin may react with lead slightly, as they do other metals, but such action can be .. prevented by treatment of the waters with lime or sodium silicate. WOOD Most wood has little or no corrosive effect on lead. A few instances of corrosion by wood containing organic acids, such as green oak, have been reported. Wood to be lined with lead should be inspected for presence of borers. ZINC CHLORIDE Lead can be used satisfactorily. ZINC HYDROSULPHITE................ Manufactured in lead lined tanks using lead cooling coils. ZINC SULPHATE ................................... Lead preferred when solution is acid. CHAPTER NINE Composition of Commercial Pig Lead Th e following1 are the chemical requirements for the various grades of commercial pig lead included in the American Society for Testing Materials Specification, Serial Designation B29: t sS *5 K o~ Z? Silver, max., percent___ 0.0015 w 0.020 s. 0.002 w 0.020 2=*3C: VZ 0.002 0.002 4m> * Z xcn cc 0.002 Silver, min., percent----- -- 0.002 -- -- -- -- -- Copper, max., percent... 0.0015 0.080 0.080 0.080 0.0025 0.0025 0.04 Copper, min., percent... -- 0.040 0.040 0.040 -- -- -- Silver and copper together, max., percent........... 0.0025 -- -- -- -- -- -- Arsenic, max., percent... 0.0015 --- _ -- -- -- -- Antimony and tin to- gether, max., percent. 0.0095 -- -- -- -- -- -- Arsenic, antimony and tin together, max., per cent ............................. 0.002 0.002 0.015 0.015 0.015 0.015 Zinc, max., percent........... 0.0015 0.001 0.001 0.002 0.002 0.002 0.002 Iron, max., percent........... 0.002 0.002 0.002 0.002 0.002 0.002 0.002 Bismuth, max., percent.. 0.05 0.005 0.025 0.10 0.15 0.25 0.005 Lead (by difference), min., percent....................... 99.94 99.90 99.90 99.85 99.85 99.73 99.93 Corroding lead is a designation that has been used for many years in the trade to describe lead which has been refined to a high degree of purity. Chemical lead has been used for many years in the trade to describe the undesilverized lead produced from Southeastern Missouri ores. Acid lead is made by adding copper to fully refined lead. Copper lead is made by adding copper to fully refined lead. Common desilverized leads A and B are designations that are used to de scribe fully refined desilverized lead. Soft undesilverized lead is used in the trade to describe the type of lead produced from ores of the Joplin, Mo., district. 70 0*i CHAPTER TEN The Soldering and Welding of Lead So l d e r in g and welding are the two most common ^ methods of joining lead. Both are effectively applied to this metal and when done properly result in joints stronger than the metal itself. SOLDERING ^ Only mild, non-corrosive fluxes are needed in soldering lead, a distinct advantage. After the metal at the joint has been me chanically cleaned by scraping, wire brushing or use of a scratch cloth, salt-free mutton tallow or rosin is applied as flux. Rosin ^ may be dissolved in alcohol for use as a liquid. Lead does not have to be pre-tinned before soldering except in particularly diffi cult soldering operations. Preparation of the lead by thorough cleaning and close fitting is essential to successful results. The lead surfaces in contact should be cleaned and fluxed as well as ^ the lead on the outside so that the solder will sweat between the layers of lead. Soldering coppers or "irons" should be cleaned and well tinned. Coppers weighing about 2 lb. each (4 lb. per pair) are satisfac* * tory for most lead work except the heaviest lead for which heavier coppers are used. Because of the low melting point of lead, coppers should not be too hot. For general soldering of lead using a soldering copper, 50-50 solder is most popular. For wiping, however, solder containing ^ about 37 to 40 percent tin, balance lead, with or without a small percentage of antimony, is employed. Tin content as low as 32.5 percent has been used for this purpose where the joints will not be under pressure but such low tin content is not recommended as a rule. The high melting point solders, such as lead-silver solder, cannot be used successfully with lead as the melting point is too close to that of lead itself. 71 72 LEAD IN MODERN INDUSTRY On page 40 a special sealing solder for use on wiped solder joints is described. This wTas developed especially for effecting gas-tight seals on lead sheathed cable splices. WELDING Lead welding, often called lead ``burning," truly fuses the parts together without addition of any different metal, although additional lead is frequently added in building up the joint. A torch is used to fuse the metal. Since little heat is required to fuse lead, only the smallest tips should be used on the torch. The smallest sizes of tips are suitable for ordinary weights of lead, say up to 10-lb. sheet lead, and the next larger two or three sizes for heavier lead. Smaller tips are used for vertical and overhead work than for flat work. Butt joint for sheet lead I in. thick or less. Butt joint for sheet lead over in. thick. Two gases are usually employed to produce the flame. Oxygen and hydrogen are most popular, with oxygen and acetylene or other hydrocarbon gases also being used. Oxygen and city gas is sometimes employed for shop work such as storage battery welding. For light weights of lead when joints are made on the flat, flames using a single gas, such as propane, are satisfactory. Flames should be neutral for welding lead. An oxidizing flame can be easily recognized by formation of a brown oxide on the surface of the molten metal. Lap joint in sheet lead. Butt joint for pipe with 1 in. wall thickness or less. THE SOLDERING AND WELDING OF LEAD 73 v -4 Butt joint for pipe over 1 in. wall thickness. Technique for welding pipe in the horizontal fixed position. For welding-, lead is prepared much the same as for soldering, being scrupulously clean, but no flux is employed. lap joints are preferred except in very heavy lead. Lead welding rod used as a filler in the joints should have the same composition as the lead being joined and should be from Ys to % in. in diameter, depend ing upon the thickness of lead. Welding rod is not ordinarily used for vertical lap joints. On butt joints, a rough rule of thumb for rod consumption for a single pass is 1 ft. of rod to 1 ft. of joint where i-in. rod and 8-lb. lead are employed. There is slightly over 4 ft. per pound of i-in. rod. WELD Cup joint for pipe in vertical fixed position. All of the lead welding drawings shown in this chapter appear in Chapter 36 of the Welding Hand book, 3rd Ed., Amer. Welding Soc. Manipulation of the torch and the kind of flame used depend on the type of joint being welded and the position of welding. In general, a semi-circular or V-shaped motion is used. The molten lead is controlled and flowed with the flame, thus accounting for the circular or herringbone appearance of the joint. Each semi 74 LEAD IN MODERN INDUSTRY circle or Vee is made in one continuous operation, the flame being flicked away from the work at its completion. The speed ojf welding butt joints in the flat position is not much different from the speed of gas welding steel. Speeds of 30 ft. per hr. are common with 6-lb. sheet lead. Granj on's formula for determining welding speed is: T7_ 1.92 to 3.85 T *, T=lead thickness, in. V=welding speed, ft./hr. ` The principal precaution to take in lead welding is to avoid burning through or reducing the thickness of the lead. CHAPTER ELEVEN Lead in Modem Plumbing LEAD WATER SERVICE PIPE.......... Lead has probably a longer record of satisfactory per formance than any other water service pipe material. As a conse quence, it is used extensively for that purpose today, and many of America's greatest cities use it exclusively. The flexibility of lead pipe allows adjustment to ground settle ment without damage and minimizes the number of necessary joints. The well known resistance of lead to corrosion and the thick walls of the pipe result in exceptionally long life. Water flowing through lead pipe does not become discolored and the pipe does not clog with corrosion product. The first essential is to select pipe of proper quality and weight for the pressure to be handled. Pipe should meet one of the recog nized national standards which have been adopted to control the quality of lead pipe for plumbing and water distribution and of lead traps and bends. Federal Specification WW-P-325 covers pipe, bends and traps, while Commercial Standards CS95-41 and CS96-41 promulgated by the National Bureau of Standards cover lead pipe and lead traps and bends respectively. The Lead Industries Association also has standards on these products and licenses manufacturers to use its Seal of Approval on products meeting these standards as a protection to the purchaser against inferior quality. All of the standards mentioned here are sub stantially the same in their requirements, the principal differences being in the form of the standards and the degree of detail into which they enter. The following dimensions and weights of lead pipe for plumb ing and water distribution are from Federal Specification WW-P-325: . 76 76 LEAD IN MODERN INDUSTRY Class Commercial designation ------------- '------------ . East West 100 AAA XXS (Maximum working pres sure 100 lb. per sq. in.) 75 AA XS (Maximum working pres sure 75 lb. per sq. in.) 50 A S (Maximum working pres sure 50 lb. per sq. in.) BBM (Soil and waste pipe) C CL (Soil and waste pipe) D D XL (Soil and waste pipe) Size (nominal inside Wall thick diameter) ness (inches) (inches) 1 0.256 i .256 t .256 4a .293 1 .298 15 .320 li .386 2 .504 i 0.175 l .188 .228 I .231 1 .246 li .258 11 .288 2 >376 H 0.143 i .149 I .197 a4 .203 1 .214 15 .210 11 .242 2 .252 15 11 2 2i 3 4 5 6 0.171 .191 .205 .250 .250 .250 .250 .250 15 0.139 11 .165 2 .177 15 0.118 11 .138 2 .142 21 .125 3 .125 4 .125 5 .125 6 .125 Outside diameter (inches) 0.888 1.012 1.137 1.336 1.596 1.889 2.272 3.008 Minimum outside oircum! <Tence (inches' 21 3* 3* 4* 41 6 7 9* Nominal weight ?>er toot (inches) 2.50 3.00 3.50 4.75 6.00 7.75 11.25 19.50 0.725 .876 1.082 1.212 1.492 1.765 2.076 2.751 21 1.50 21 2.00 31 3.00 Bii 3*d 0 4* 4.75 51 6.00 61 8.00 81 13.75 0.661 .798 1.019 1.156 1.428 1.670 1.984 2.503 2* 21 3* Bi ' 4& 51 6* 71 1.25 1.50 2.50 3.00 4.00 4.75 6.50 8.75 1.592 1.882 2.410 3.00 3.50 4.50 5.50 6.50 41 5i 7* 9* 101 14 171 201 3.75 5.00 7.00 10.62 12.50 16.38 20.25 24.12 1.528 4 3.00 1.830 51 4.25 2.354 71 6.00 1.486 1.776 2.284 2.75 3.25 4.25 5.25 6.25 41 5* 7* 81 10* 13* 161 191 2.">0 3.d 0 4*75 5.00 6.00 8.00 10.00 11.75 0^1 0% Left. Extension of a lead service pipe to a new and larger water main. 0 > *) Note "gooseneck" at the connection to the main. Right. Wiping a "tee" branch in a lead water service line in the field. 0*,. Wiping a curb stop to a long lead water service line in the shop. p * 0^ . : 0^ . . : , LEAD IN MODERN PLUMBING 77 All service pipes should be laid with goosenecks to allow for settlement. These are simple to provide in lead pipe because they can be bent integrally into the pipe without making an extra joint. In long services, say 100 ft. or more, a second small goose neck may be provided where they enter the foundation wall. Gooseneck sizes should vary with the diameter and wall thickness of the pipe. The following table gives approximate gooseneck sizes: LENGTH OF GOOSENECK AND LENGTH OF 100 LBS. OF PIPE Cl a s s 50 (A or S Weight) For Pressures up to 50 Pounds Per Square Inch Inside diameter (inches) 34 1 14 11 '2 Length of pipe in gooseneck (feet) 2 2 21 S 4 Width across gooseneck (feet) 14 14 11 11 21 Number of feet in 100 pounds 33.3 25.0 21.0 15.5 11.8 Cl a s s 75 (AA or XS Weight) For Pressures up to 75 Pounds Per Square Inch ; *> 4 2 14 28.5 l 2 14 21.0 14 21 11 16.6 11 3 11 12.5 2 4 21 7.2 Cl a s s 100 (AAA or XS Weight) For Pressures up to 100 Pounds Per Square Inch 34 2 . 12 14 . 21 11 3 2 "" ' 4 14 14 11 li 21 21.0 16.6 12.9 8.8 5.1 The reason for using larger goosenecks with larger and thicker- walled pipe is to prevent thinning the pipe wall on the outside of the bend and distortion of the pipe's cross-section. ..... It helps to insure a proper gooseneck if the corporation cock has a tail-piece bent at a 45-degree angle. Then the pipe has to start off in that direction and be bent around to its ultimate 78 LEAD IN MODERN INDUSTRY direction, at least forming part of the gooseneck. The gooseneck should, however, have a reverse bend to form a question mark. The gooseneck should preferably lie in a horizontal position to the right when facing the main. Sometimes tappings are taken off the top of the main. This should be avoided, if possible, but when it is done, the gooseneck should be formed in the same way. Blocking, however, should be placed between the top of the main and section of gooseneck above it just beyond the joint. In case of settlement, this will relieve strain on the joint and tapping and will allow it to be taken up in the gooseneck. On long services or those in particularly bad ground, the pipe may be left slightly wavy to take up settle ment all along the line. Both these waves and regular goosenecks should lie almost horizontally to prevent trapping of water in the pipe if drained. SAFE WORKING PRESSURE OF LEAD SERVICE PIPE Class of lead pipe 100 75 50 Application Maximum working pressure, pounds per square inch Nominal inside diameter (inches) Service and supply 100 i to 2, inclusive Service and supply 75 i to 2, inclusive Service and supply 50 1 to 2, inclusive Commercial designation A East West AAA xxs AA xs As If the bottom of the trench contains rocks or stones that might damage the lead, fine soil or sand should be filled in the trench bottom before laying the pipe. Similarly it is wise to backfill for at least 6 in. with soil or sand free from rocks so that the pipe is protected all around. Where electrolysis is known to exist or where the soil contains much free lime or where the pipe passes through cinder fill, the pipe should be wrapped or laid in a trough filled with pitch. Protection should also be afforded lead pipe where it is bedded in "green" cement. A cast-iron sleeve should be provided where lead passes through the foundation wall, the joint being made water-tight by calking with lead wool. In the installation of lead service pipe, joints have been suc cessfully made by wiping, welding, cupping and soldering, and by means of compression-type couplings. It is usually possible to make up the wiped, welded or soldered joints on the bench in the LEAD IN MODERN PLUMBING 79 shop. This is a great time and money saver and insures the best kind of joint because working conditions are ideal. CALKING LEAD Lead is used for calking joints in cast-iron water mains, sewer and soil pipe. It has the great advantages of durability and flexi bility, the latter permitting the pipe line to adjust itself to ground or building movement without damage to the joint and without putting strain on the pipe itself. Repairs to lead joints can .usually be made by simple calking without shutting off the water. Procedure is much the same for making joints in both pressure and soil pipe except that in pressure pipe the oakum comes to about 2 in. from the end of the hub, leaving a space at least 2 in. deep for the lead, while in soil pipe, the lead space is only 1 in. deep. The following table gives the amounts of lead and oakum required for various sizes of water and gas pipe: CALKING LEAD AND OAKUM REQUIREMENTS FOR CAST IRON PIPE Spizipeeof 3 4 6 8 10 12 14 16 18 20 24 30 36 42 48 54 60 72 Approximate pounds of lead per joint 2 in. thick ,---------------- ---------------- , Water Gas 6.00 -- 7.50 8.14 10.25 11.31 13.25 14.56 16.00 17.67 19.00 22.00 20.85 -- 30.00 33.80 27.20 -- 37.00 41.28 44.00 49.07 54.25 60.06 64.75 71.57 75.25 83.13 8d .50 97.60 102.63 --- 108.30 746.00 -- -- Approximate pounds of hemp per joint ,>- Water Gas' .18 .21 .23 .31 .34 .44 .49 .53 .59 .61 .67 .81 _ .94 1.00 1.03 -- 1.25 1.39 1.50 1.67 2.06 2.28 3.00 3.32 3.62 4.00 4.37 6.25 8.25 5.20 -- -- 12.50 -- 84 170.00 -- 15.00 4 From Cast Iron Pipe Research Association Handbook. Clamping rings are usually used in connection with lead joints in gas mains. 80 LEAD IN MODERN INDUSTRY For soil pipe it is usually estimated that 12 oz. of lead per joint are required for each inch of pipe diameter. Thus a joint in 4-in. soil pipe requires about 3 lb. of lead. Pipes should be carefully aligned and braced after the first two or three turns of oakum have been calked. Final calking of the oakum should be done with a wide yarning tool to leave an even foundation for the lead. Asbestos joint runners with the clamp at the top are used around the bell opening for pouring joints in horizontal pipe. The clamp forms a gate for pouring. The com plete joint should be made with one pouring. The hub should be dry and clean before pouring the lead. Joints should not be calked until cool. Then both inside and outside calking irons should be used all around the joint on soil pipe, keeping the inside iron always against the spigot and the outside iron always against the inside of the bell. For joints in water mains, a series of calking irons shoud be used because the lead space is larger than in soil pipe. Enough irons should be used so that when the joint is completed the entire surface of the lead will have been calked. Large pipe thus requires use of more calking irons than small pipe. Pneumatic hammers may be used advantageously for calking. While particularly suitable for large pipe, they have also been used successfully for water mains as small as 3 or 4 in. in di ameter. Maximum air pressure at the compressor varies with the size of pipe. For example 65 lb. per sq. in. has been found suitable for 12-in. pipe and 50 lb. per sq. in. for 4-in. pipe, using a light portable hammer and not more than 150 ft. of hose. If moisture should get into a joint before pouring, some kero sene poured in will prevent the molten lead from "exploding" when it hits the moisture. It pays to use calking lead of high quality as it results in lower dross losses, easier calking, and fewer imperfect or "missed" joints. Use of lead meeting the requirements established by the American Water Works Association's Standard Specifications for Laying Cast Iron Pipe, Commercial Standard CS94-41 of the Na tional Bureau of Standards,, or the Standard of the Lead Indus tries Association assures proper quality. All of these standards are essentially the same in substance and are as follows: LEAD IN MODERN PLUMBING 81 ......... COMPOSITION OF CALKING LEAD Lead for calking purposes shall contain not less than 99.73 percent of lead. Maximum allowable impurities: Percent Arsenic, antimony, and tin together.................................. 0.015 **5 Copper ...............................................................................................08 Zinc.................. 002 Iron...................... 002 Bismuth ...................................................................................... 25 Silver ................................................................................................. 02 ^ ................. Calking lead of such quality is readily identified by the Lead Industries' Seal of Approval stamped or cast on it along with the manufacturer's name or identification mark which also must ap pear on it. Lead wool may be used instead of poured lead and should be of the same quality. It has the advantage, of requiring no melting and may thus be used where fire is a hazard. Since the joint is made cold, lead wool may also be used under water or in damp locations. Yarning is the same as for a poured joint but the lead wool is calked in one or two turns at a time. If more than one length of lead wool is needed for a joint, the ends of the two lengths should be thinned down and loosely rolled together to prevent forming ^ .... a lump or projection in the joint. LEAD IN THE PLUMBING SYSTEM Lead serves a multitude of purposes in the plumbing drainage O .. and venting system. It is extremely durable when exposed to the polluted water and air in those systems, being little affected by the hydrogen sulfide, ammonia and other corrosive substances found in them. It is flexible, permitting movement and settlement with out damage to pipes, joints or fixtures. It requires no multitude v 0 fittings to assemble it, and joints are wiped or welded, bonding the pipe together into integral continuous lengths without danger of leaky joints and offering a smooth inner bore at the joints which does not obstruct flow or tend to clog. In fact ^ the smooth inner bore of lead pipe and fittings offer minimum resistance to flow and corrosion product does not form to reduce the diameter and clog. Because lead pipe is flexible, easy sweep 82 LEAD IN MODERN INDUSTRY bends, promoting good flow of water and air, may be used. It consumes little space and reduces the necessity of cutting and weakening joists, beams and studs. The drawing on the next page shows the purposes for -which lead is most widely used in plumbing and emphasizes some of the methods to follow in its installation to get best results. As in all things, proper quality and weight of material must be used. Lead pipe should not be lighter in weight than the class known as D or XL, as shown in such recognized standards as Federal Specifica tion WW-P-325, Commercial Standard CS95-41 of the National Bureau of Standards, or the Lead Industries Association Stand ards (see page 76). Traps and bends should have walls 0.125 in. thick in accordance with Federal Specification WW-P-325, CS96-41 and the Lead Industries Association Standards. Such material, if of proper weight and quality, may be easily identified by the Lead Industries' Seal of Approval stamped on it. Proper support and easy sweep bends are shown in the drawing. Where pipes change direction to run alongside a structural mem ber, sufficient space should be left between the pipe and structural member to allow the pipe to expand without jamming up against the structure. Branches should be made at a 45 deg. angle in the direction of flow. This promotes both better flow and allows ex pansion to be taken up in the bend. Where pipe or fittings pass through concrete floors, they should be protected by sheet metal sleeves, and lead imbedded in or in contact with cement should be coated in the usual way with asphaltum or wrapped with tar paper to protect it from possible attack by the seepage water of "green" concrete. In addition to the lead pipe, traps, bends and calking lead so commonly used in the plumbing system, lead has a number of other plumbing applications. Lead vent pipe flashings have sev eral advantages. Extremely durable, lead flashings have a pleas ing color and do not cause discoloration and staining of adjacent materials. They should weigh at least 3 lb. per sq. ft. Cast hard lead floor flanges make an excellent means of setting water closets and connecting to lead bends or stubs. They do not require tinning before soldering or welding to the lead bend or stub, but, since they have a somewhat lower melting point than soft lead, care must be exercised in soldering or welding not to overheat. LEAD IN MODERN PLUMBING 83 Permits settlement Lead shower pan Should be coated both sides with asphaltum Flexible, permitting settlement Vertical lead pipes, supported about every 3% ft. 4; 5*or 6-lb. lead shower pan seepage to ruin ceilings or rot beams Flexible, few joints, easy bends, permits > settlement \ Ift-- V ' * 4 Gooseneck, permits settlement Lead water service Lead joints are flexible, allowing for settlement or other movement j * * . L. - >n . ; . -.j /' ?. # v Castiron with lead joints prevents roots dogging pipe Typical residence lead and soil plumbing installation. j *' 1 0* ^\ 1 .\<i i Nominal Inside diameter (Inches) W eight pc running 1 (pounds) Inlet (Inches) O u tle t (inches) 84 n li 2 LEAD IN MODERN INDUSTRY LEAD TRAP AND BEND STANDARDS Ha l f S o r P Tr a p s Short traps Lon? traps " .......... > > A,. Dimes Total Dimen - Total sions 1 weight " sions f weight SO E DcC Cw sc SC Cw ow K 5 S&cC Cn 2g 41 7 4 0 41 14 59 3i 41 7 4 15 41 14 6 12 41 41 8 72 41 14 93 Dr u m Tr a p s i'rnp sizes (inches) rhickness of cap and flange (Inches) [length of thread and ring (inches) 4x 8"I 4x 9l 4.x 10J 3x 81 3x9} 3x10 & Screw cap and ring thread 3-inch straight pipe thread, 8 threads per inch, ft free-fit (nominal pitch diameter, 3.388 inch). 2-inch straight pipe thread, 11 threads per inch, ft free-fit (nominal pitch diameter, 2.296 inch). l-inch nominal inside diameter .................. A . Total weight ,------------ S'" 4x 7 4x12 4x15 4x18 4x20 2 12 41 4 13 5 10 62 Be n d s 3-inch nominal inside diameter -- iin i ^ % Total weight . OS DO O SEf 51x10 51x12 51x15 51x18 51x20 fcsot* soss o 73 83 9 12 11 4 12 4 4-inch nominal inside diameter Total weight DO 5 51x10 51x12 51x15 51x18 51x20 Cs9Oh Oes 95 10 10 12 10 14 10 16 0 7x 7 3 8 10 x 10 9 8 10 x 10 12 5 7x12 4 13 10 x 12 10 8 10 x 12 13 10 7x15 5 10 10 x 15 12 0 10 x 15 15 10 7x18 6 6 10 x 18 13 8 10 x 18 17 10 7x20 6 15 10 x 20 14 8 10 x 20 18 15 Reducing bends shall be considered as meeting this standard provided (1) the reduc tion in diameter occurs exclusively on the top and sides, leaving the bottom of the bend, when in the installed position, smooth and straight so that it cannot form a trap for substances passing through the bend, and (2) they meet the requirements of this standard in all other respects except total weight. Lett. Lead reducing bend 4 x S-in. used to connect water closet to 3 in. stack. Riffht. Two properly vented wall-hung water closet connections in stalled on opposite sides of access space using lead bends and lead vent connections. Left. Lead drum trap for bath fixture using lead waste and vent connections. Right. Two lead P-traps for urinals with lead waste and vent connections. T Vent pipe flash ings made from 4lb. sheet lead on roof of apartment house. 0S 0* Cut-away sheet lead shower pan, lead P-trap and vent, showing the proper method of first coating the sheet lead with asphaltum and then cover ing with tar paper. LEAD IN MODERN PLUMBING 85 Hangers for rigid pipes are often lined with about 8-lb. sheet lead. This prevents transmission of vibration from the pipe line to the structure and also permits adjustment to the movement of the structure without damage to the rigid pipe. The method is often used, for instance, on pump lines and on pipe lines on ships. Shower pans and other waterproofing are additional important uses of lead. Shower pans should be made of at least 4-lb. sheet lead and should turn around the edges to finish 1 or 2 in. above the finished floor level. Corners are made as shown in the draw ing. Tops of upstands should be dressed tight against masonry walls or set back about i in. into notches in wood studs. Con crete under pans should be smooth and the lead coated on both r ................. 86 LEAD IN MODERN INDUSTRY sides with asphaltum. If the pans are set on wood floors, the boards should be firm and even, nail heads set, and covered with asphalt impregnated building paper, while the inside of the pans should be coated with asphaltum. A cement and sand mixture should be used on the pans as a foundation for the tile. Pans should be graded to the drain to which they should be soldered, clamped or calked. The trap flange should be countersunk and weep holes provided just above the lead. The trap should be plugged and tested with water before tiling. Pans which are left open for some time before tiling should be protected by heavy building paper until tiled over. Lead shower pans properly installed will give long, troublefree protection against leakage. They are easy to fit to irregular spaces and dress down tight against floor and walls. f . 0S 0% 1^ CHAPTER TWELVE Lead in Modern Architecture Lead roofing and flashing has a successful background of hundreds of years under all sorts of climatic conditions. In addition to being used on many European buildings erected cen turies ago and on early American structures, it is widely used on modern buildings, large and small, here and abroad. Lead's appeal to architects, engineers and builders for these purposes largely arises from its great durability, ease of instal lation and the fact that it does not cause unsightly stains or dis coloration on adjacent materials. Its pleasing grey color blends well with any color scheme. Lead's long life makes its ultimate cost extremely low.......... Modern alloys have made possible reduction of thickness, and consequently, costs comparable with other roofing materials, with out sacrifice of any of lead's advantages. Modern practice is to use antimonial sheet lead, usually composed of lead with about 6 or 7 percent of antimony, which has about twice the strength of soft lead and greater stiffness. Certain patented lead alloys are also available as well as the long familiar soft sheet lead. This section gives some general considerations to be followed in the installation of antimonial sheet lead roofing and flashing. The patented alloys should be installed in accordance with the rec ommendations of their manufacturers. Soft sheet lead may be used in much the same way as antimonial sheet lead, but the weights of sheets should generally be increased 1 to 2 lb. per sq. ft., and often smaller sheets and more support are desirable. All metals expand and contract with temperature changes, and roofing and flashing are exposed to wide temperature variations. Therefore, provision must be made for expansion and contraction in metal roofing. The coefficient of linear expansion of antimonial lead is about 0.000015 in. per in. per deg. F. That means that 88 LEAD IN MODERN INDUSTRY for every 100 deg. temperature change, antimonial lead will ex pand or contract about in. for each foot in length of the sheet, or that a 4-ft. sheet will expand or contract slightly less than TV in. for 100 deg. temperature change. EXPANSION IN INCHES The expansion of soft lead is slightly greater than antimonial or "hard" lead under the same conditions of temperature change, and sheet length. A similar expansion graph for soft lead appears on page 187. One step in providing for these dimensional changes is to limit the size of sheets in order to minimize expansion and contraction in any one sheet. This is useless, however, if the sheets, when in stalled, are soldered or joined together in any way that will make two or more sheets expand and contract together as a unit. Obvi ously such a procedure would be virtually equivalent to installing one large sheet the size of all the smaller sheets combined. There fore, joints between sheets should always be unsoldered looselocked or overlapped joints, the use of lock or overlap depending upon conditions which will be described later. In making loose-locks, a space should be left between the edge of one sheet and the bend of the other to provide for contraction. The size of this space will depend upon the size of the sheets and the temperature conditions. Normally about in. should be suffi cient, but if the temperature is unusually high when laying, or if LEAD IN MODERN ARCHITECTURE 89 unusually great temperature drops may be expected in the local ity, or if the sheets are larger than usual (which should be avoided so far as possible), this space should be increased. If the foregoing precautions are not taken, expansion and con traction may be cumulative over an entire roof area or run of flashing and may amount to several inches. In that event, buck ling and tearing of the sheets would occur. This can be avoided by minimizing and properly providing for expansion and contrac tion as suggested. This is nothing new, for all metals expand and contract. Sections through a sheet lead roof batten (left) and horizontal seam (right). Specifically, antimonial lead roof sheets, which may be installed by either the batten or standing seam method, should not usually exceed 2 ft. by 4 ft. in size, the greater dimension being installed parallel to battens or standing seams. Forming of sheet metal so that part of the sheet is at right angles to the plane of the rest of the sheet naturally reinforces the metal, and the narrower the part of the sheet between such breaks, the greater the reinforce ment. Flashing should be installed so that flat widths, as a rule, are not more than 6 or 8 in. wide without forming. Therefore, flashing sheets may be longer than roof sheets, but should not exceed 6 or 8 ft. in length. Judgment should be used in determin ing the length of flashing sheets, based on the amount of forming and the width of unformed flat surfaces. When more than 4 or 5 in. of a flashing that is built into a wall is exposed, a loose-lock should be provided where it emerges from the wall and a separate sheet used for the exposed part. Likewise, 90 LEAD IN MODERN INDUSTRY when flashing must be calked into a reglet. a separate locking strip should be installed in the reglet and the flashing loose-locked to it. Proper thickness of antimonial lead sheets is also an important factor. For general roofing and flashing purposes, cornice cover ings, gutter linings and other architectural sheet lead, 3-lb. anti monial lead is the proper weight. For certain purposes, such as small pieces of flashing interwoven with shingle or slate courses, 2|--lb. antimonial lead may be employed, and in special cases where it is impossible to avoid unusual strain or wear on sheet lead, 4-lb. antimonial lead is the weight preferred. In order to avoid tearing or buckling resulting from expansion and contraction, cleats should always be used for fastening lead roofing and flashing. Nails should never be driven through lead sheets unless the sheets are less than 18 or 20 in. long and the nails covered. Even in this case, the sheets may be nailed at one end only. Cleats, if concealed, may be 16-oz. soft copper, but if exposed, they should be 3-lb. antimonial lead. One end of the cleat should be folded into the loose-locks between lead sheets or into a hem on the edge of the sheet if it is an overlap or if no joint occurs at that point and the other end should be turned back over the heads of the nails holding it to prevent the nail heads damaging the lead. Continuous cleats, when necessary, should be in not greater than 8 ft. independent lengths, so the cleats will not buckle when they expand, which would in turn cause the lead sheets to buckle. Frequently flashing must come in contact with cement, con crete, or mortar, as, for instance, in the case of through wall flash ing. Free lime -which occurs in "green" cement, concrete or mor tar, may corrode lead in the presence of moisture and oxygen. As the cement, concrete or mortar cures, the free lime carbonates and no longer has an effect on the lead. Therefore, it may be ad visable to protect lead against this form of possible corrosion, particularly in locations where the cement, concrete or mortar may not become thoroughly cured for some time. This can be readily accomplished by coating the lead wherever it comes in contact wflth new cement,- concrete or mortar with a layer of black asphaltum. Surfaces over which lead is to be laid should be carefully pre- LEAD IN MODERN ARCHITECTURE 91 Batten Roof Parapet wail flashing Open valley Methods of installation of some typical architectural sheet lead applica tions. Antimonial lead (6 percent antimony) of S-lb. weight is commonlv used in these applications. * 92 LEAD IN MODERN INDUSTRY pared. Nail heads should be set and screws countersunk. Concrete and similar materials should be screeded to a smooth surface and the lead should be laid over a layer of roofing felt weighing at least 15 lb. to the square. Sharp edges under the lead should be rounded off so they will not cut into it. As previously mentioned, joints between lead sheets should either be loose locks or overlaps. For general roofing, base flash ings, cornice coverings and other purposes where -water or snow are likely to stand or where the length of the joint might make overlaps liable to open up, loose locks should always be employed. On the other hand, in valleys with a pitch of more than 6 in. per ft., on batten caps, ridges and hips, and on cap flashings or through flashings built into the walls, overlaps may be used. In general, loose locks should have a turn back of in. and should be filled with a non-hardening compound. Overlaps should be 3 or 4 in. in the direction of pitch, or where horizontal, as on ridg ing, should be made away from prevailing weather, and the over laps should be bedded in non-hardening compound. When lead sheets are formed in a brake on the ground, flat stages should be provided for hoisting to the roof so they will not get out of shape. The brake should be adjusted to the extra thickness of the lead so the metal will not be cut and bends will have an easy sweep. Because of the ease with which lead is formed, this work is often done on the roof. In such cases, tongs are handy for bend ing the lead. Much lead work can be accomplished simply with the hands and a wooden mallet. Tools should always be used that will not cut into lead's soft surface or damage it. Lead anchors are commonly used for fastening objects to con crete, stone or brick facings. This application utilizes the calking characteristics of lead; i.e., softness and lack of elasticity, by anchoring or cinching a steel bolt or similar object within a masonry hole. The lead may be either cast in or inserted as a pre-cast ring or rings and cinched mechanically. VIBRATION ISOLATION . Lead has been used in a number of ways to prevent the trans mission of vibration. Most materials employed for this purpose Yale I'niversitv Left. An ornamental cast lead fountain dating from 1769. Right. Leaded windows, sheet lead spandrels and lead roofed bay are attractive examples of other ornamental architectural applications of lead. Through-wall and parapet sheet lead flashing on the coping of a public building, the Federal Court House in New York City. Lead covered dome 400 feet in circumfer ence on the New Jersey Reformatory, Rahwav, N. J. Close-up of loose-locked bat ten type roof used on the above dome. The loose-locked sheets are held by copper cleats nailed to the battens. One lead batten cap is seen loose-locked in place. A modern private dwelling with a lead gravel stop and fascia piece, lead chimney caps and flashing and lead skylight flashing. LEAD IN MODERN ARCHITECTURE 90 are non-metallic and some are more efficient than lead, yet lead has certain properties that make its use either desirable or essen tial under certain conditions. Among these properties are the strength of lead, which is sufficient in comparison with other materials used so that heavy loads can be carried without distributing them over a large area. Also being highly corrosion resistant, lead is little affected by moisture, oils and other substances and consequently does not deteriorate either in strength or vibration-isolating ability when exposed to them. i Solder Construction and method of installation of lead vibration pad between steel columns and footings. The widest used of lead in isolating vibration is in the founda tions of buildings adjacent to railroad tracks or other sources of vibration. In such cases the use of a combination lead-asbestos pad has become virtually standard practice in railroad terminal construction and they have been employed under many other structures, such as most of the large buildings along the Park Avenue undergound tracks leading to Grand Central Terminal in New York. The pads are composed of a bottom layer of sheet lead $ in. thick, a layer of %-in. asbestos board, a sheet of 20-gage steel, another layer of %-in. asbestos board and a top sheet of i/8-in. 94 LEAD IN MODERN INDUSTRY lead, making a total thickness of about 1 in. The bottom lead sheet is sufficiently larger than the rest to be turned up onto the top sheet and soldered or welded to it. This makes a moistureproof lead envelope to protect the inner layers. These pads are placed on top of the foundations and under the grillages or column footings, preventing transmission of vibra tion from the ground, through the foundations and into the building itself through the columns. Similar pads are also frequently used under machinery founda tions in buildings to prevent the vibration of ipachines from being transmitted to the building. Solid blocks of lead are often employed under delicate laboratory instruments so they will not be affected by vibration. Pipe lines, particularly from pumps, are insulated from their hangers by pieces of 6 or 8-lb. sheet lead, sometimes folded over once. This method of vibration isola tion is commonly used on shipboard piping. In the manufacture of nitroglycerin, a powerful liquid explo sive highly sensitive to percussive shock, lead plays an important triple role. It is used to line various reaction tanks, floors, table tops, etc., because it effectively resists the attack of the corrosive acids used in the manufacturing process and also because of its excellent non-sparking characteristic. But in addition, lead is capable of absorbing shock waves much as it blankets vibration. Therefore, to prevent accidental detonation of the nitroglycerin it is stored and transported in leaden vessels which if dropped or jammed would not transmit the shock to the explosive. The containers also would deform instead of breaking, thereby pre venting the nitroglycerin from spilling. ORNAMENTAL LEAD Lead occupies an honored place in the list of mediums of artistic and decorative expression. Through the past centuries, the decorative uses of lead have ranged from primitive amulets, coins, vases and statuettes to monumental sculpture and archi tectural decoration. The easy working qualities of lead have al ways been attractive to artists. Probably the best known decorative uses of lead are archi tectural. Ornate lead gutters, leader heads and downspouts are LEAD IN MODERN ARCHITECTURE 0" excellent examples. Other architectural uses are spandrels, roof ing features such as cupolas and spires, cames. grilles and light ing fixtures. Closely allied to architectural details are garden ornaments and sculpture, sundials and fountains. The great fountain of Apollo at Versailles is an outstanding example of this use. The pleasing surface color of weathered lead, called patina, is due to an exceedingly thin oxide film which develops upon pro longed exposure to the elements. This patina, sought after by architects and lead sculptors may be artificially produced or altered with the aid of chemicals. By wiping clean lead with linseed oil, the surface acquires a natural, evenly distributed patina as the oil wears off. A tried and effective method for preparing lead and leadbase alloys for subsequent plating is as follows: (a) degrease, (b) clean cathodically in a mixture of 1 oz. soda ash, 1 oz. trisodium phosphate, for a few seconds only (do not overclean), (c) rinse, (d) if necessary, scrub with pumice to remove any film, (e) rinse, (f) pickle in 10 percent fluoboric acid for about 15 sec., (g) rinse, and (h) plate. For producing a green imitation bronze finish cleaned lead may be dipped in or painted with a solution made according to the following formula: Copper nitrate..........................................................8 ounces Ammonium chloride............................................... 4 ounces Acetic acid................................................................4 ounces Chromic acid............................................................1 ounce Water .................................................................... 1 gallon The following solution has also been used successfully for obtaining a green patina on lead. Nickel chloride............................... 150 parts by weight Copper sulphate........................... 150 parts by weight Potassium chlorate ..................... 100 parts by weight Water ..............................................1 quart Swab on this solution. The lead first turns brown and then becomes green producing an antique effect. A perhaps less artistic but nevertheless decorative use of lead is in souvenir badges and insignia, novelties and bric-a-brac. These are usually made of a lead alloy rather than pure lead and 96 LEAD IN MODERN INDUSTRY they can be found in shops wherever tourists travel as well as in the cheaper stores. Lead is adaptable to all of the common metal working proce dures. Its natural color is pleasing and it weathers well. It will take plating or paint and can be finished smooth or textured. It is adaptable to high speed production such as die casting or it can be hand wrought by the artist into individual artistic creations. For these reasons it is one of the most versatile of metallic mediums for artistic expression available. While lead is relatively low in cost, it has great durability. Therefore, its decorative uses can well range from the most inexpensive novel ties to elaborate enduring monuments. CHAPTER THIRTEEN Radiation Protection X h e harnessing of atomic energy has brought with it the problem of controlling the powerful rays emitted during atomic disintegration. Basically the problem of protection from these rays is the same as from X-rays and radium. Technicians have for many years known the hazards involved and they have worked out several methods of protection. But while today's radiation problems are similar, they are far more significant both because of the wider use of radioactive materials and the po tentially greater intensities to be worked with. The various types of rays--alpha, beta, gamma, neutron-- differ chiefly in their ability to penetrate and ionize matter. It is the latter characteristic which injures living tissue and which must be guarded against. The alpha particle is a positively charged helium nucleus which is completely stopped by 3 or 4 inches of air or a piece of paper. Beta particles are high-speed electrons of varying energies. In general, they produce less ionization in matter than alpha particles but are more penetrat ing. Most common substances such as 1 in. of wood will com pletely absorb beta rays. Gamma radiation on the other hand has great powers of penetration. High energy gamma will not be wholly absorbed by even a foot of lead while lower energy gamma may be safely absorbed by fV in. or less of lead. Gamma rays produce large scale ionization by a secondary process, that is, the gamma ray first produces a high-speed electron and this, in turn, produces the ionization. Neutrons emitted by the cyclotron and the atomic pile are uncharged particles which will also ionize certain material indirectly. Neutrons are classified according to their energy levels as very fast, fast, slow and thermal, the last having the lowest energy level. 97 98 LEAD IX MODERN INDUSTRY The dangers of exposure to radiation are classified into two separate categories: internal and external. The former is pri marily a hygiene and medical problem and because it does not involve shielding as such it will not be discussed here. External radiation comes from a source outside the human body such as an X-ray tube, cyclotron, radium or radioactive samples. Protec tion against external radiation is a question of shielding the body from the rays, keeping a safe distance away from the rays, and limiting the time of exposure to the rays. In shielding against neutrons metallic cadmium or a hydrog enous material such as water or paraffin is generally used. How ever, because gamma rays are emitted when the neutrons are absorbed, it is still necessary to provide a protective shield of lead. The use of protective shielding is identical in all cases, regardless of the type of ray, the thickness of the shielding de pending upon the penetrating power of the rays. The first consideration in preventing penetration of rays is density. Lead enjoys the advantage of being the densest of any commonly available material. Where space is at a premium and utmost radiation protection is paramount lead is always pre scribed. Another advantage, particularly in shielding neutrons and gamma rays, is that lead does not become contaminated. It may be used continuously without fear of itself becoming radioactive and emitting its own harmful rays. For this reason it is important that lead specified for shielding purposes be free of alloying elements, particularly those which may become radio active upon exposure to high energy radiation. Being a metal, lead has an advantage over various aggregate materials such as concrete in that a uniform density is guaran teed throughout. In addition, because its surface is smooth it cannot become contaminated with dirt or other material which, in turn, may become radioactive. Oftentimes where exception ally high energy levels are being shielded and where the concen trated load of the quantity of lead required would be prohibitive, a combination of concrete and lead has been employed. The lead may be sandwiched as a sheet between layers of concrete or may be used on either side of the concrete. Lead cast or extruded into bricks has proven especially useful in atomic shielding because the bricks can be easily moved to areas where special temporary RADIATION PROTECTION 09 shielding is needed and can be built up to any thickness or placed in position desired. In atomic reactors or "piles" operated by the Atomic Energy Commission, cadmium, lead, concrete and distance are used to protect operating personnel from exposure to all types of danger ous radiation, chief among these being neutrons and gamma rays. Neutrons escaping from the uranium section of reactors are absorbed by a thin cadmium shield. This absorption causes the cadmium to emit gamma rays which are in turn stopped by a lead shield. Thus personnel during the loading and unloading of atomic fuel are protected from neutrons by the cadmium and from gamma rays by the lead. In one type of reactor a 4 in. shield of lead-cadmium alloy sur rounds the reaction area and fits snugly inside a concrete shield 8 ft. thick which encases the entire reactor, The lead-cadmium alloy protects the concrete from direct exposure to neutrons and gamma rays. An extra 1-ft. shield of lead bricks is located on top of the reactor to compensate for the absence of concrete. The thick lead shield at the side and bottom is constructed with ) 100 LEAD IN MODERN INDUSTRY internal copper tubing- for circulating cooling water to remove heat generated in the shield itself and the exterior of the reactor chamber. A column made of graphite bricks extends into the heart of the reactor to provide a path for thermal and slow neutrons. The end of the column protruding through the outer concrete shield is covered with a cadmium curtain and a 2-ft. lead and iron shield in which an 8-in. square opening is provided for access. The first uranium-graphite reactor, breeder of the original Atom Bomb, looked like a windowless two-story square concrete building, 30 ft. wide, 32 ft. long and 21 ft. high. On the sides of this early reactor concrete alone was depended upon for protec tion. The top of the pile was paved with 6 in. of lead, totalling about 185 tons. On top of the lead was an additional layer of 4 ft. of solid wood. Resting on this shield was a small experi mental laboratory in which operating personnel worked, secure in the trust that they were being protected from the tremen dous energy being generated beneath them by the 4-ft. layer of wood and 6-in. layer of lead. The table given below prepared by the National Bureau of Standards may be used to determine the required thicknesses for shielding from gamma ray sources in the laboratory. To use the table select the column for the energy required (use next higher if exact value is not given). The entry gives thickness in centi meters of lead for different source strengths at 1 meter for 8 hr./day to give 50 milliroentgens. Then add algebraically the correction terms for other working ranges or times to obtain the shield thickness required. Example: Shield is required for the manipulation of 500 millicuries of radioactive material emitting 1.8 million electron volts (Mev) gamma rays at a minimum working distance of 50 cm., and for 4 hr./day. Shield thickness=8.60+2.77--1.39=9.98 cm. of lead (a) (b) (c) in which a=basic entry* b=correction for danger range=50 cm. c=correction for 4 hr./day. (ft 0\ #5 At the shield face of a nuclear reactor, a cast lead entry port and lead bx-icks pi'otect operating personnel fi*om radiation' injury. Left. In a radioisotope laboratory, special purpose lead castings and lead bi'icks protect the technicians. Radioisotopes are stoi'ed in the lead *) bi'ick "hot" cave on the left. Right. Highly l'adioactive cobalt 60 is shipped in this lead lined steel container. . F l General Electric X*ltap Corp. AHix-Chalmers Mf#. Co. Left. Two million volt X-ray unit with lead collimating core for direct ing the rays. Right. Twenty-two million volt betatron with lead collimator and movable lead shield. SIk "5 Left. A sheet lead lined hospital X-ray room and door. Right. A sheet lead covered X-ray room floor with cement block-lead sandwich wall con struction. n  j J 3 J '3 J O REQUIRED LEAD SHIELDING THICKNESS FOR GAMMA RATtS r.nergv (Mev) Activity 0.2 10 me. . .. ... -0.14 20 me. ... ... -0.09 50 me. ... ... -0.01 100 me. ... ... +0.06 200 me. ... ... +0.10 500 me. ... ... +0.17 1 c.......... ... +0.23 2 c.......... ... +0.28 5 c.......... 10 c.......... 20 c.......... ... +0.47 50 c.......... ... +0.54 100 c.......... .. . +0.60 o.n -0.36 0.00 + 0.47 +0.82 + 1.17 + 1.64 + 1.99 +2.35 +2.81 +3.17 +3.52 +3.99 + 4.34 o.x -0.27 + 0.41 + 1.31 + 1.99 + 2.67 +3.57 + 4.25 + 4.93 +5.82 + 6.50 +7.18 +8.08 +8.76 1.0 - 0.11 + 0.76 + 1.90 + 2.77 + 3.63 + 4.78 + 5.65 + 6.52 + 7.66 + 8.52 + 9.39 + 10.54 + 11.40 1.3 + 0.37 + 1.57 + 3.15 + 4.34 + 5.54 + 7.12 + 8.31 + 9.51 + 11.09 + 12.28 + 13.48 + 15.00 + 16.25 2.0 + 0.78 + 2.16 + 4.00 + 5.38 + 6.77 + 8.60 + 9.99 + 11.37 + 13.21 +14.59 + 15.98 +17.81 + 19.20 2.3 + 1.15 + 2.63 + 4.57 + 6.05 + 7.52 + 9.47 + 10.95 + 12.42 + 14.37 +15.85 + 17.32 + 19.27 +20.75 Danger ni ni?e Plus 20 cm. .... . .. +0.26 50 cm. .... ... +0.11 1 m........... ... 0.00 2 m.......... ... -0.11 5 m.......... ... -0.26 10m.......... ... -0.37 Plus + 1.64 +0.71 0.00 -0.71 -1.64 -2.35 Plus +3.16 +1.36 0.00 -1.36 -3.16 -4.52 Plus + 4.02 + 1.73 0.00 - 1.73 - 4.02 - 5.76 Plus + 5.55 + 2.39 0.00 - 2.39 - 5.55 - 7.94 Plus + 6.44 + 2.77 0.00 - 2.77 - 6.44 - 9.21 Plus + 6.85 + 2.95 0.00 - 2.95 - 6.85 - 9.80 Working time, hr./day This 1 ....... ... -0.17 2 ........... ... -0.11 -4 ............ ... -0.06 8 ........... ... 0.00 24 ........... ... +0.09 Plus -1.06 -0.71 -0.35 0.00 +0.56 Plus -2.04 -1.36 -0.68 0.00 + 1.08 Plus - 2.60 - 1.73 - 0.87 0.00 + 1.37 Plus - 3.59 - 2.39 - 1.20 0.00 + 1.89 Plus - 4.16 - 2.77 - 1.39 0.00 - 2.20 Plus - 4.42 - 2.95 - 1.47 0.00 + 2.34 3.0 + 1.40 + 2.91 + 4.90 + 6.41 + 7.92 + 9.91 + 11.41 + 12.92 + 14.91 + 16.42 + 17.93 +19.92 + 21.43 Pins + 7.00 + 3.01 0.00 - 3.01 - 7.00 -10.01 Plus - 4.52 - 3.01 - 1.51 0.00 + 2.39 No t e s (1) Source activity Is quoted In mllllcurlrs or curies, whore 1 ourlo is Hint amount of radioactive material that disi the rate of 3.7 x 10w disintegrations per second. However, the table Is computed on the further assumption that each d yields one gamh i a photon of the selected energy. This will lend to Innecurncles whenever the disintegration Is complex. M calculations can he made by obvious methods when the disintegration scheme Is known. (2) The tabulation Ignores the Increased effective transmission of shields under wide beam irradiation. (3) This form of shielding table Is Intended to form a guide to rapid erection of temporary shielding striieturcs In tory. Where permanent Installations of maximum economy are planned, more detailed calculations by conventional m required. y a a a LEAD EQUIVALENTS Material Iron .. Menu (tenuity, B. per cu. cm. 7.9 Concrete: .................................... 2.2 2 parts ballast...................... .. 2 parts sand............................ 1 part cement.......................... f.cad equivalent, nun. 1 2 3 4 0 8 10 15 20 50 100 1 2 3 4 .6 8 10 15 20 50 100 F VARIOUS MATERIALS Corresponding thickness of nmlcrials, mm e-- -................. -- __________________________ X-rays excited at peak voltages of 150 kv. 11 25 37 50 200 kv. 12 27 40 55 .`00 kv. 12 20 28 35 48 60 75 400 kv. 11 18 23 28 38 45 55 75 85 80 60 50 160 150 95 75 230 210 125 100 295 275 150 120 210 150 260 185 300 220 300 RADIATION PROTECTION 103 Some common applications of lead in the development of atomic energy and in the handling of radioactive materials include: lead bricks (interlocking or ordinary rectangular), lead plates and castings, "hot" laboratory table and sink tops, storage, carrying and shipping containers, lead rubber gloves and aprons, lead glass aprons, lead glass windows, Geiger counter tube shields, lead shot, lead sheet sheathing, lead headed nails, lead plywood, lead lined cinder blocks, lead safes, and so on. X-RAY PROTECTION X-rays are widely used both by the medical profession and by industry. Since these rays can cause physical damage to per sons exposed to them it is necessary to enclose X-ray generating units in chambers made of or lined with a material which is re sistant to X-ray penetration. Since the impermeability of the shielding material is a function of its density, lead, which is the densest commonly available material, will give the greatest pro tection per unit of thickness. Lead is the least bulky and usu ally the lightest and most economical material for such shielding. Although certain types of X-ray machines intended for pro duction line operation are self contained in lead lined cabinets with automatic controls to shut off the course of power before the doors can be opened, a general X-ray department usually re quires the provision of a lead lined room. Such a room must be carefully planned and constructed with the lead lining of suffi cient thickness to keep the exposure of persons in its vicinity below safe tolerance limits. The principal factor in determining the proper thickness of lead is, of course, the intensity of the X-rays to be generated but consideration must also be given to the cumulative time of operation during the working day, the distance of the operator and other persons outside the room from the X-ray tube and the generation of scattered or secondary radiation given off by objects in the path of the useful beam. The intensity of the rays is a function of the voltage impressed on the tube and therefore it is customary to use voltage as a primary guide in selecting the proper thickness of lead required for X-ray protection. An accompanying chart gives the thickness of sheet lead protection recommended for installations of various voltages and correlates these recommendations with commercial 104 LEAD IN MODERN INDUSTRY 10.0 SHEET LEAD lb. per sq. ft. THICKNESS OF LEAD IN MILLIMETERS 9.6 24 9.2 8.8 8.4 8.0 7A 7.1 6.8 6.4 6.0 5.6 5.2 4.8 4.4 4.0 3.6 3.2 2.8 2.4 2.0 1.6 1.2 0.8 0.4 0 70 90 110 130 150 170 190 210 230 250 KILOVOLTS - PEAK Thickness of lead barrier required to reduce X-ray dosage rate of the useful beam to 6.25 milliroentgens per hour under indicated conditions. RADIATION PROTECTION 105 thickness of sheet lead. Having selected the proper thickness of sheet lead, the principal feature to watch in obtaining effective shielding is to see that no even minute space exposed to the rays is left unshielded. Thus no screw or nail holes, with or without screws or nails in them, or cracks around doors are left without being completely shut off or shielded by lead. LEAD SHIELDING CONSTRUCTION There are a number of methods of applying lead for X-ray protection. Several special devices incorporating lead are avail able for wall construction. These include sheet lead bonded at the factory to plywood, wall or other board materials on one or both sides with special lead covered strips for covering the joints and special lead headed nails for securing the material in place. Another device is a concrete or gypsum block with an unper forated sheet of lead anchored at its center. The two halves of this block on each side of the lead are about 1 in. off center so that their edges are offset by that amount. The sheet lead, how ever, extends to the outer edge all around. Thus when a wall is built up of these blocks, the lead in one block overlaps that in all adjoining blocks by 1 in. and provides a continuous lead lin ing. Other special devices include lead-lined doors and leadcovered windows glazed with glass containing a high percentage of lead. If such special methods are not used, there are a number of ways of applying sheet lead linings, all of which are satisfactory and the choice of which may depend upon the type of construc tion and other installation conditions. Some of these methods are described here. In one method sheet lead is placed against the wall surface or studs with the long dimensions of the sheets running vertically. Sheets should not exceed 36 in. in width for ease of handling and should be of such width that joints will occur over vertical sup ports. Such joints should have 2-in. overlaps. At the top, sheets should turn out at least 2 in. onto a continuous horizontal sup port. Over the lead at joints and at about 16 in. intervals, 2x4 in. wood strips or steel angles or channels are placed running from the floor to ceiling. These are secured top and bottom and 106 LEAD IN MODERN INDUSTRY at intermediate points, the spacing** of which depends on the weight of the lead but in no case should be more than 4 ft., by bolting through the lead to the wall. One or two horizontal braces between each pair of studs may be used to give additional sup port to thick linings. Lead patches are then welded or soldered to the lead on each side over all bolts. These patches should ex tend several inches in each direction beyond the bolt hole so that rays striking at an angle cannot penetrate the bolt holes. Metal lath can then be fastened to the supports and the wall finished in the usual way. Patches should be of the same thickness of lead as the lining to eliminate any possibility of leakage. 2"X4" Weed posts 'X/ a-'. Lead weid Lead weld-** Typical X-ray shielding construc tion with sheet lead. Cover doorsBrass screws 8n on center A method suitable for masonry walls is to build 2 x 4 in. wood studs into and flush with the wall at 16 in. intervals. Sheet lead with the long dimension running vertically may then be screwed RADIATION PROTECTION 107 to these studs. A perforated steel strip against the lead under the screw heads helps to distribute the load. Strips of lead may then be placed over the screw heads or steel strip and welded or soldered to the sheets on each side. Screws should be about 6 in. apart. A slight variation of this method is to screw the edge of only one sheet to each stud, allowing the edge of the ad joining sheet to overlap the screw heads and steel strip and be welded or soldered to the first sheet, thus covering the screw holes. Still another method is to use horizontal wood sleepers built into and flush with the wall at 2 ft. intervals. The sheet lead is then applied as in the previous methods, but with the long dimen sions running horizontally, the screw heads being covered as before by overlapping. Another method successfully used is to employ boards screwed horizontally to regular studs. The lowest boards are applied first to a height of about 18 in. and are then covered with a sheet of lead which is turned back over the upper edge of the top board and then turned upward about 1 in. against the studs, where it is screwed. Another tier of boards 18 in. wide is then applied in the same way, fitted down over the set-back of the first sheet of lead, and covered with lead in the same manner. The joints between the lead sheets are then soldered or welded. Sheets in all cases should be bent around corners and at inter sections so that they can be welded or soldered to the sheets on the adjoining wall to make the lining continuous. Wall sheets should be turned out several inches on the floor to insure ample lap between wall shielding and floor shielding. The lead lining should also be carried around the rabbet of door jambs so that it will overlap the lining of the door itself when in the closed position. Where pipes or wires penetrate the lead lining, they should be fitted with flanged lead elbows welded or soldered to the lead lining and so designed as to prevent passage of rays through the opening. Pipes or wires passing through the wall may be offset so that the opening through the lead lining can be backed with a large lead patch on the outside. Electric switch boxes should also be backed with lead patches much larger than the opening so that rays cannot pass through even at an angle. 108 LEAD IN MODERN INDUSTRY Protection on ceilings may be accomplished most easily by laying lead, with overlapped joints, on the floor above or on a drop ceiling. In such cases, the lining should be extended well be yond the lead walls below it. This projection of the floor lining should be enough to prevent passage of the rays through the gap of the floor construction between the lead walls and the lead on the floor above, as the rays travel in a straight line at an angle to the wall and ceiling. Lead takes paint well without special preparation, so lead lin ings may simply be painted to present a pleasing appearance. If such treatment is intended, a baseboard and a chair rail should be provided to prevent damage to the lead by being struck by feet or furniture. If a plaster finish is desired, metal lath may be applied to the supports previously described and the wall plastered in the usual manner. Wall board may also be applied to these supports. Wood floors to be laid over lead linings either in the X-ray room or in rooms overhead should be laid on floating sleepers, care being taken that no nails penetrate the lead. Ce ment floors may be laid over lead linings but if the lead is left exposed without immediately pouring the concrete, it should be protected against mechanical damage by a layer of heavy build ing paper or 15-lb. felt. In either case it is advisable to protect the lead from the action of "green" concrete by coating it with a thin layer of asphaltum. -. A terne-plate gasoline tank for a Ford car. The lead-tin alloy makes the forming operation easier and guards against corrosion during use. FoUausbt'f StrrI Corp. Installing a loose-locked, standing seam terne-plate roof. The terne alloy protects the roofing metal from atmospheric corrosion and provides an excellent base for paint. Left. Hot dip lead alloy coated steel building hardware. Right. Wiring in a Sperry Automatic Pilot. All wire terminals in this assembly have been electroplated with an alloy of lead and tin (40-60) to facilitate sol dering. ' Spraying pure lead on parts of a sheet metal exhaust system to be used for venting sulphuric acid fumes. CHAPTER FOURTEEN Lead and Lead Alloy Coatings TERNE PLATE Lead and certain of its alloys are widely used protec tive coating- materials for iron and steel. Best known perhaps is terne metal, an alloy of lead and tin, the tin content being usually between 10 and 25 percent. Uncoated, the steel is known as "black plate." It is first cleaned and pickled in dilute sulfuric acid and then passed through the alloy bath in which rolls are immersed, the resultant coated steel being known as "terne plate." Sheets requiring extra heavy coating are redipped by hand. Terne plate is produced in two grades, 1) short terne and 2) long terne. Short terne, used largely for roofing, usually carries a coating of 8 to 40 lb. per package of 112 sheets, 20x28 in. in size. They are comparatively light in weight and last for a long time if painted at intervals of four or five years. Long terne is a sheet mill product produced in larger sizes than short terne--up to 48 x 120 in. Long terne is utilized in the manufac ture of gasoline tanks and automobile body parts, in buildings _for frames and doors and other fireproof construction, and in caskets. Terne plate is used extensively for packaging paints, lubricating oils, greases and similar products. A common weight of coating on long terne plate for the manu facture of these articles is about 8 lb. per base box, a base box representing a unit of area 112 sheets 14x20 in. For roofing, valleys, eaves, troughs and conductor pipe, coatings up to 40 lb. are used. In the nomenclature peculiar to this industry coating weight refers to the total weight of terne metal distributed on both sides of 112 steel sheets 14x20 in. in size. The surface of terne plate is soft and has a greasy feel. The metal will not flake off, is very ductile and is much used for 109 f"! ! I ;j ;j ii * : }\ s : * 110 LEAD IN MODERN INDUSTRY deep drawing- operations where a corrosion resistant material is desired. Because of the unusual ductility of such coatings they are ideal for articles to be formed as the lead also acts as a lu bricant in die drawing or stamping operations. Terne coatings form an excellent base for paint and are therefore especially useful on articles that may or must be painted. Terne plate is used for gasoline tanks where any products of oxidation might clog the fuel line. In addition, it is easily soldered with non-cor rosive fluxes and welds without difficulty. - HOT DIP LEAD ALLOY COATINGS The virtues of lead and lead alloy coatings containing little or no tin have become generally recognized. Lead and lead alloy coatings have a number of advantages over other commercial coatings. The coating is highly resistant to corrosion. If some pinholes are present, as may be expected in almost any metal coating, it has been learned that they do not permit rust to pene trate or spread under the coating, although some rust discolora tion may appear in early stages of exposure. In actual practice, these pinholes become sealed by corrosion product against fur ther attack. While lead is being used successfully as the coating metal, the most widely used coating consists of lead base alloys. There are several such suitable alloys on the market. In general, they run from 90 to 95 percent lead with additions of smaller per centages of tin, usually 2.5 percent or less, the balance being other metals such as antimony, zinc, silver in some amounts. These alloys are designed to have greater fluidity in the molten state than pure lead and contain such elements as tin and anti mony because they alloy readily with both steel and lead. Also, they tend to harden the coating metal for greater mechanical wear without accompanying brittleness. Both water solution and molten fluxes are being used in lead alloy coating, with the molten fluxes apparently preferred* Zincammonium chloride or special fluxes made by manufacturers of the lead alloys are employed. It is good practice to pre-heat the articles to be coated in the molten flux at a temperature about the same or slightly higher than the lead alloy bath. This is LEAD AND LEAD ALLOY COATINGS 111 particularly true of large articles as it prevents chilling of the lead alloy and insures a well-bonded coating. Strangely enough the heavy metal, lead, results in one of the lighter weight coatings. This is because adequate protection is gained with thinner coatings than those often employed with other metals. The thickness of coating required naturally de pends to a large extent on the use to which the article will be put. It can be said, however, that lead alloy coatings weighing about 0.7 oz. per sq. ft. both sides, equivalent to a thickness of about 0.0004 in., usually give good protection against normal atmospheric corrosion. Coatings may be much thicker, never theless, to resist special conditions, or may be lighter if intended to serve only as a die lubricant or paint base, or to protect only for short periods. Lead alloy coated sheets have been employed for a number of purposes, such as building sheet metal work, duct work, and for forming into a variety of objects like ammunition boxes and deep drawn articles. In addition, lead alloy coatings are being applied to a variety of fabricated articles. Radio and radar parts and telephone pole line hardware are prominent among these. Some other articles being coated are mufflers, battery boxes, nails, condenser cans, seamless tubes and unit heater assemblies. ELECTROPLATING Pure lead or lead-tin alloys can be electroplated on iron or steel. Several different types of solutions are available, such as the fluoborate and sulfamate solutions. These are now available as powders or master solutions which are readily dissolved or di luted for use in plating, thus adding greatly to the convenience of the process. High current densities may be employed in lead plating. This process has been used for various purposes for a num ber of years. Shells coated twenty years ago have been found to be in excellent condition today. Among products now being electroplated with lead are battery hardware, bearings and bushings, nuts and bolts and many other items. The following table gives some data on various lead electro plating solutions: Plating solution: grains per liter 2 PbCO,-Pb(OH), 160 50% HF 240 ILBO, 106 Glue 0.2 2 PbCCVPb(OH), 300 50% HF 480 ILBO, 212 Glue 0.2 Pb 75 Total fluosilicate 150 Glue 0.2 Sulfamate Pb process Sp. gr. soln. 30 Be LEAD ELECTROPLATING SOLUTIONS* Anodes corroding or chemical Pb Current density ; nmp./sq. dm. 0.54 to 5.4 (av. 2.2) Voltage; volts Temp. C. 25-40 0.54-7.6 (av. 3.2) 0.54 to 8.8 0.1 to 0.2 35-40 0.5 to 4.5 (a) 3-8 (b) 9-14 25-50 (n) Still. (I> llnrrcl. Dntn from "Motnl Progress." pH 1.3-2.0 (av. 1.5) Current efficiency 100% 100% 100% 100% LEAD AND LEAD ALLOY COATINGS 113 The rate of electrodeposition of lead is high. Tabulated below are the ampere minutes per square foot required to deposit a coating equivalent to one pound of coating metal per base box, showing clearly the high rate for lead as compared with tin. The rate for lead is also high compared with other metals as well as tin. Coating per base box Electrolyte 1 lb. lead................................. Sulfamate 1 lb. tin................................... Halogen 1 lb. tin................................... Stannate Amp. min. per sq. ft. 16.2 28.27 56.54 The following table shows the time required to deposit various thicknesses of lead plating at different current densities: RATE OF DEPOSITION--ELECTROPLATED LEAD COATINGS Oz. lead Thick- ness sq. ft. inches 0.094....... 0.0001 0.188....... 0.0002 0.376....... 0.0004 0.564....... 0.0006 0.752....... 0.0008 0.94........ .. 0.001 1.88........ ... 0.002 3.76........ ... 0.004 5.64........ ... 0.006 7.52........ ... 0.008 9.4............. 0.01 18.8............. 0.02 47.0........ ... 0.05 Cathode current density in amp. per sq. ft. at 100% cathode efficiency ,----------------------------------------------- ----------------------------------------------- . 1 20 30 40 50 60 Time required in minutes (414 amp. min.---.001 in. per sq. ft.) 4.14 2.07 1.38 1.03 .83 .69 8.28 4.17 2.76 2.06 1.66 1.38 16.56 8.28 5.52 4.14 3.31 2.76 24.84 12.42 8.28 6.21 4.99 4.14 33.12 16.56 11.04 8.38 6.62 5.52 41.40 20.70 13.80 10.35 8.28 6.90 1 hr. 41.40 27.60 20.70 16.56 13.80 23 min. 2 hr. 1 hr. 55.20 41.40 33.12 27.60 46 min. 23 min. 4 hr. 2 hr. 1 hr. 1 hr. 49.68 41.40 8 min. 4 min. 23 min. 2 min. 5 hr. 2 hr. 1 hr. 1 hr. lhr. 55.20 31 min. 46 min. 50 min. 23 min. 6 min. 6 hr. 3 hr. 2 hr. lhr. lhr. lhr. 54 min. 27 min. 18 min. 44 min. 23 min. 9 min. 13 hr. 6 hr. 4 hr. 3 hr. 2 hr. 2 hr. 48 min. 54 min. 36 min. 28 min. 46 min. 18 min. 34 hr. 17 hr. 11 hr. 8 hr. 6 hr. 5 hr. 30 min. 15 min. 30 min. 38 min. 54 min. 45 min. SPRAYED COATINGS Lead coatings may be applied by spraying. The lead in wire form is fed into a spray gun which melts the metal and blows it onto the surface to be coated. Since there is no chemical bond 114 LEAD IN MODEEN INDUSTEY between the lead and base metal, the latter is first sand-blasted or otherwise roughened and cleaned in order to provide good mechanical anchorage for the coating. Pin holes may be mini mized by peening the surface after coating. Because of lead's low melting point, it is more rapidly and economically applied by spraying than are most other metals. Sprayed coatings may be built up to any desired thickness. This method is especially useful for applying protective coatings to equipment already in place, although its usefulness is by no means confined to such conditions. Spray guns may be obtained from manufacturers by those who wish to apply their own coatings. There are also many jobbing shops equipped to do spray coating for others. Co a t in g Th ic k n e s s Co n v e r s io n Ta b l e Several different methods are used to describe the thickness of lead coatings. For instance, coatings on steel sheets are some times expressed in decimals of an inch, sometimes in pounds per base box, and sometimes in ounces per square foot. Expressed in thickness reference is usually made to the thickness on one side of the sheet only, whereas weight usually refers to the coat ing on both sides of the sheet. Therefore, the following con version table should prove helpful, it being kept in mind that this table refers to pure lead and that when alloys are used some adjustment may have to be made for differences in density. COEEELATION OF DECIMAL THICKNESSES OF LEAD COATINGS -- TO WEIGHTS PEE UNIT OF AEEA Coating thickness (one side) In. Coating weight (both sides) ,---------------------------------*--------------------------------- * Lb. per base bos Oz. per sq. ft 0.00001................................... 0.26 0.0189 0.00005..................... 1.30 0.095 0.0001......................... 2.60 0.189 0.0005..................................... 12.90 0.947 0.001....................................... 25.80 1.89 0.002....................................... 51.60 3.78 0.005....................................... 129.00 9.47 0.01......................................... 258.00 18.92 CHAPTER FIFTEEN Soft Solders VNE of the most useful groups of alloys is the tin-lead series commonly called soft solders. With varying amounts of tin and lead, depending upon the application, these alloys have solved a wide range of metal joining problems. . The eutectic alloy of this group contains 62 percent tin and has a melting point of 361 deg. F. That is also the solidus of all except the very low and very high tin-content alloys in this group. See tin-lead phase diagram on page 188. As tin content is reduced below that of the eutectic, the liquidus rises and the plastic or freezing range becomes wider. Consequently with low- tin solders, higher soldering temperatures are necessary and care must be taken to eliminate "hot shortness" difficulties (brittleness when hot). Furthermore, the lower tin-content solders do not as a rule have as good flow characteristics and are apt to be more porous. Solders containing about 40 percent tin and 60 percent lead or 50 percent of each, with or without small percentages of antimony, are probably most widely used. Considerable work has been done recently with solders con taining less tin. These include lead alloyed with silver, with silver and small percentages of tin, and other combinations. With fluxes and soldering techniques adjusted to the particular alloys used, favorable results have been obtained in many in stances. For instance, the canning industry, using highly mecha nized methods which can be adjusted to the new solders and closely controlled, is using solder containing as little as 2 or 3 percent tin, naturally with a considerable cost saving because of the lower tin content and no loss in quality of the joints. In that and some other industries these economies have resulted in permanent use of lower tin content solders than formerly. How ever, in many applications and particularly for hand soldering 115 116 LEAD IN MODERN INDUSTRY operations, the higher tin content solders will probably continue to be preferred. Among the reasons for this are less corrosive fluxes, lower temperatures, better flow characteristics, greater strength and less porosity. The following table lists some of the familiar tin-lead solders and some of the alternates that have been recommended, along with melting point data: TIN-LEAD AND ALTERNATE SOLDERS Temperature <--------------------------<'---------------------------- . Tin 2.5 5 10 20 30 40 50 60 62 70 80 49 39 29 19 20 10 0 Composition, percent ------------- *-----------------------, Lead Anti mony Silver 97.5 -- -- 95 -- -- 90 -- -- 80 -- -- 70 -- -- 60 -- -- 50 -- -- 40 -- -- 38 -- -- 30 -- -- 20 -- -- 50 i -- 60 i -- 70 i -- 80 i -- 78.75 -- 1.25 88.50 -- 1.50 97.50 -- 2.50 Solidus ,,--------------- -------- , Deg. Deg'. F. C. 574 301 518 270 361 183 361 183 361 183 361 183 361 183 361 183 361 183 361 183 361 183 367 186 367 186 367 186 365 185 356 180 252 178 579 304 Liquidus -,------------------*--------- . Deg. Deg! F. C. 606 319 592 311 567 297 523 273 486 252 453 234 421 216 372 189 361 183 378 192 397 203 410 210 446 230 486 252 523 273 518 270 554 290 579 304 ranee ----------*------------- > Deg. Deg. F. C. 32 18 74 41 206 114 162 90 125 69 92 51 60 33 11 6 00 17 9 36 20 43 24 79 44 119 66 158 88 162 90 202 112 00 The foregoing table is not intended to include the composi tions of all available commercial solders but will give a good idea of melting points and freezing ranges of a wide variety. Solder containing in the neighborhood of 50 percent tin is the most popular general purpose solder. Somewhat higher tin con tents, about 60 to 70 percent, are used for "fine solder," particu larly where temperature requirements are critical. For wiping solder, those having tin contents around 37 to 40 percent are most generally used, although somewhat lower tin contents have been employed for this purpose in emergencies for joints not under pressure. Automobile radiator solder also falls in this group. For coatings, the low tin-content alloys are usually em- Limlr A h' }innh(>'is Cu. Left. Torch soldering the handles on stainless steel cans using tin-lead wire solder. Right. Soldering an automobile radiator with stick solder and a hot "iron.'' }! An automatic side seam can soldering machine. I SOFT SOLDERS 117 ployed, running: up to 25 percent tin for terne metal and as low as about 2 percent tin for lead alloy coatings. Since automobile body solder requires comparatively little strength and a wide plastic range, the low tin-content solders are also used for this purpose. Low tin-content solders are also frequently employed for dip soldering operations where design of the objects sol dered is such as to assure a strong enough joint. For high tem perature, high strength solder, lead-silver solder has enjoyed some popularity, particularly for machine soldering operations. In addition, solders can be obtained with melting points down to lower than the boiling point of water for special purposes where extremely low melting is necessary to avoid warping of the metal joined or for other reasons. They are usually alloys of lead and tin with either bismuth or cadmium or both (see page 133). Solder is available in a variety of forms. These include bars, cakes, slabs, wire (with or without flux cores or flux on or near the surface), ribbon, foil or sheet, drop, powder and paste. CHAPTER SIXTEEN Bearing Metals So me of the first pieces of machinery with rotating parts were so constructed that wood functioned both for shafts and bearings. Later metal replaced wood for these purposes. In 1839 Sir Isaac Babbitt obtained a patent on an alloy containing 88.9 percent tin, 7.4 percent antimony and 3.7 percent copper, for use as a bearing metal. Other alloys, many of them now lead base, have since replaced the original babbitt metal because they are less expensive and often superior. Common usage has now applied the term "babbitt metal" to a wide variety of white metal bearing alloys differing from Babbitt's original formula. In modern machinery, there is a tendency to use replaceable bearings, con sisting of a steel, brass or other strong metal shell lined with babbitt metal. Although ball and roller bearings have a lower starting friction than bearings made from babbitt or bronze, the running friction is approximately the same owing to the high internal friction of ball and roller bearings at high speeds. Furthermore, total resis tance of a vehicle is not entirely due to bearing resistance, by any means. Therefore, before an installation of bearings is made, all factors should be considered. With proper design and lubri cation, babbitt and bronze bearings may give as good or even better service than roller bearings at greatly reduced cost. Ease of replacement and ability to adjust to the alignment of the shaft are other advantages of the white metal bearing alloys. Furthermore, should lack of lubrication lead to trouble, the bearing metal can yield or melt without damaging the shaft. White metal bearing alloy compositions and properties will be found on page 201. 118 BEARING METALS 119 Bronzes are used for unlined bearings or for the backing of babbitt lined bearings. They generally consist of copper alloyed with smaller amounts of tin and lead. There are a wide variety of these alloys, but the backing used for lined railroad journal bearings may be typified by the formula 73 percent copper, 20 percent lead and 6 percent tin, balance impurities. Bronzes for unlined bearings may be represented by the formula 80 percent copper, 10 percent lead and 10 percent tin. Phosphor bronzes con tain in addition up to 1 percent phosphorus. In general industrial use, the 80-10-10 formula is probably most representative. Cop per-lead alloys containing from 25 to 40 percent lead, balance mainly copper, are also widely used for bearing linings, particu larly in aircraft. These are sometimes made by sintering copperlead powder to steel strip on one or both sides. Copper-lead bearings are said to be inferior in non-scoring to tin and lead base babbitt but superior in fatigue resistance. LEAD-BASE BEARING ALLOYS Although lead-base alloys containing little or no tin have been used for certain kinds of bearing linings for many years, only recently has it become generally recognized that, if proper pre cautions are taken, lead-base alloys can satisfactorily replace tin-base alloys in practically all applications. By lead-base alloys is meant those containing less than 10 percent tin and in many cases having a much lower tin content. They may be alloys of lead, antimony and a small percentage of tin with or without small quantities of arsenic, or they may be essentially lead hardened with the alkaline earth metals such as calcium and sodium. For light loads, bearings of the same design as those employ ing high-tin alloys may be used with complete satisfaction. For heavy loads, however, bearings should be redesigned to have as thin linings as possible. In any case, proper bonding of the lining to the shell is essential. If these precautions are observed, it is possible to use lead-base alloy linings for virtually all pur poses with excellent results at lower cost. Methods of preparation of the shell for lining with lead-base bearing metal vary to suit the condition and the metal of the 120 LEAD IN MODERN INDUSTRY bearing shell. In general, for steel back shells, the conventional methods usually used for tin-base babbitts may be employed. Another process of shell preparation which has been success fully employed on cast iron and malleable iron as well as on steel is using a molten catalyzed salt bath at a temperature of approximately 850 deg. F. Briefly, the essential steps of this process are as follows: machining or abrasive cleaning, immer sion in molten catalyzed salt bath of controlled temperature for 5 to 15 minutes, water rinse, immersion in solution of salts to dissolve ferric oxide, water rinse, etching in hydrochloric acid solution, immersion through a floating layer of molten zincammonium chloride flux into a bath of lead-antimony-low-tin tinning metal which bonds with the iron shell. The operations are carried through in rapid sequence and the result is a thin coating of tinning metal which bonds readily with the lining. A recent variation of this process involves electro-cleaning in the molten salt bath, the current being reversed during the opera tion. This eliminates the second salt bath. Other processes involve special machining and handling meth ods, chemical cleaning or other means of providing scrupulously clean surfaces suitable for the application of the tinning metal which in some methods is deposited electrolytically. Whatever the method, the tinning must be continuous over the entire bear ing if the application is to be successful. Lead-base babbitt is not recommended for use in those bronze back bearing shells where the operating temperatures may be 275 deg. F. or higher. After prolonged heating at elevated temperatures, the bond of lead-base babbitt is materially weakened when the backing material is bronze. Temperatures of this order are found in gasoline and diesel engines, but steel mill bearings, railroad car journal bearings, and many other types generally operate at much lower temperatures. The thickness, or rather, thinness of the actual bearing metal definitely influences its performance in use under many condi tions. In the automotive industry, linings as thin as 0.002 to 0.006 in. are employed. Pouring temperatures for the lead-base alloys are slightly higher than for tin-base. Lead-base alloys are being used successfully today in almost all kinds of bearing applications. Among these are automotive 4ms Heavy machinery makes use of lead-base babbitt metal for bearings. 0*n i ii t; i< i . Cierelaml (irophito Hrunz*' Oy. /,V^rrd/-.Vof/w/ ( orjj. Left. Cross-section of lead-copper-tin bearing alloy electrodeposited on steel with a lead alloy overlay bearing surface, x 100. Right. Cross-section of a bearing made from copper and lead powders sintered to a steel back ing. x 100. Oil-impregnated metal powde r sleeve, thrust, flange and self aligning bearings containing lead powder. i Automobiles use high lead content bronze steel backed bearings. BEARING METALS 121 connecting: rod, main and camshaft bearings, diesel engine bear ings, steel mill bearings, railroad car journal bearings, all kinds of electric motor bearings and a variety of other industrial ap plications. Speeds range from 25 to 3,600 r.p.m. and loads up to 2,000 lb. per sq. in. Steel back copper-lead lined bearings manufactured from powdered copper and lead provide a practical solution to the problem of casting molten copper-lead alloy by eliminating the melting and casting steps. Essentially copper and lead in the form of powders are spread upon a continuously moving steel strip, sintered in a controlled atmosphere furnace, rolled, again sintered and the lining strip stamped into bearing blanks. Up to 45 percent lead is used in this process to make bearing ma terial which reportedly possesses mechanical properties higher than those of bearing linings made by centrifugal or gravity casting methods. Iron-lead bearings containing up to 10 percent lead, an alloy that would be practically impossible to cast, illustrate another lead alloy bearing application that utilizes the advantage of powder metallurgy. The addition of lead not only adds to the effi ciency of the bearing but it is said also inhibits corrosion of the iron. Composite bearings consisting of thin lead babbitt coatings on a matrix of copper and nickel powders sintered to a steel backing show very desirable characteristics regarding resis tance to both fatigue and corrosion. Bearings made of pure silver, cast, rolled, or plated on a steel backing and then plated with lead and indium or lead and tin have been used for very heavy duty service where the extra cost is warranted. CHAPTER SEVENTEEN Ammunition If y o u have ever gone home with your limit of duck, tried your marksmanship on clay pigeons at the traps or skeet, or brought a buck crashing to earth, you will understand why Ameri cans use about 40,000 tons of lead in ammunition in a peace-time year. In the early days of this country, every section had its shot tower and lead shot was handled everywhere in grocery, hard ware and other stores. With the advent of the breech-loading shotgun, a demand arose for shot loaded in shells, and ammuni tion manufacturers were quick to realize their opportunity. Shot towers all over the country gradually disappeared, save a few preserved for historical reasons, such as one in Philadelphia erected in 1808 and probably the first built in this country, while the shot business passed to ammunition manufacturers whose shot towers are now the only active ones remaining. The method of manufacturing shot in towers is said to have been invented in 1782 by a plumber in Bristol, England, named Watts, who one night dreamed he was out in a rainstorm but that it was raining lead instead of water and the drops of lead were perfectly spherical like raindrops. The next morning he decided to try the experiment and poured molten lead from the tower of St. Mary Redcliffe Church into some water below. The trial was successful and he is said to have sold the invention for a considerable sum of money. Lead's great density has always made it the ideal metal for bullets and shot. It permits the attainment of the high momentum necessary to maximum striking power and accuracy and decreases the surface against which the air resistance can act. Shot up to 0.23 in. in diameter, nearly *4 in., is made in shot towers. Molten lead is poured from the top of the tower through a pan perforated with holes smaller than the shot desired. The necessary height 122 AMMUNITION D 123 Modem lead shot tower. 124 LEAD IN MODERN INDUSTRY of the pouring floor in the tower depends on the maximum size of the shot to be poured; the larger the shot to be made, the higher must be the pouring floor. The bottom of the pan is cov ered with a sludge of oxidized lead, so that the molten metal will ooze slowly through and form round drops. Small amounts of arsenic, up to 1 percent, are added to the lead to increase fluidity and allow it more easily to assume the perfect spherical shape desired, while from 2 to 6 percent antimony is also added to shot for long range loads to increase hardness. The smaller sizes of shot usually contain the higher percentages of arsenic and anti mony. As the drops rain down the tower, they solidify and are caught in a tank of water at the bottom so that the spheres will not be flattened on landing. In order to decrease the height of shot towers, an upward blast of air sometimes blows against the falling lead, which has the same effect as a longer fall. The maximum height used in modern shot towers is about 125 ft. After the shot is collected in the water, it is dried and mixed with graphite to polish it and then screened to eliminate odd sizes. It is next rolled down sloping glass tables which have a narrowT trough running along the bottom. The perfectly round shot gather enough momentum to leap this trough, but those slightly flattened are slowed in their descent so as to fall into the trough and subsequently are remelted. The grading operation is repeated four times. The shot is then loaded into shells and becomes ready for use. Shot greater than 0.23 in. in diameter is too large to manu facture by this method and is cast in revolving split-ring molds. The molds are placed around the circumference of a vertical ring several feet in diameter. The lead is poured in at the top and solidifies as it passes down one side until the split-ring opens and drops it out at the bottom. The smallest shot manufactured is 0.04 in. in diameter and 4,565 weigh an ounce. The largest east shot is 0.44 in. in diameter and three weigh about an ounce. For bullet cores, lead is usually extruded as wire, which is cut to length and swaged to the approximate shape of the bullet. This core is then inserted into a gilding metal (90 percent cop per, 10 percent zinc) jacket which has been drawn from a disc to the shape of the bullet. The size and shape of the cores vary , iVinrhrxtrr Repeatin'! Arms Co. Molten lead falling- through a sieve in the time-honored method of making lead shot in a shot tower. II'inrhcxter Repeating Arms Co. Left. Sloping glass tables help separate the off-shape lead shot from perfectly formed pellets. Imperfect shot lags behind and drops into a re ject trough. Right. Most lead shot goes into shells for sporting ammuni tion. jv V wv Lead bullets and bullet cores for small arms ammunition. Cutting and swaging lead wire into bullets and bullet cores. U. S. Army Compared to its use in sporting ammunition lead is not a principal wartime metal. Military ammunition applications chiefly consist of pistol, rifle and machine gun bullets and bullet cores. AMMUNITION 125 depending upon the type of bullet and the composition is usu ally between 97.5 and 100 percent lead with the balance antimony. In "ball" cartridges the entire core is lead alloy, but in tracer and incendiary bullets, the lead core is somewhat shorter than the jacket, the remaining space being filled with the tracer or incendiary chemicals. Armor-piercing bullets have a special alloy steel core which is more blunt than the jacket. The space between the tip of the jacket and steel core is filled with a small piece of lead. The lead helps the steel core to penetrate armor plate by acting as a lubricant. The modern pointed bullet has an interesting history. Origi nally, round balls were fired from smooth bore muskets, but it was recognized that pointed bullets offered much less resistance to the air and were therefore more desirable. However, a pointed bullet fired from a smooth bore simply tumbled end over end and would not stay on its course. Then it was decided to impart spin to the bullet, so rifling was tried but was not really successful for many years because bullets capable of gripping the rifling when fired could not be easily loaded down the muzzles. Various types of expanding bullets and bullets with rings around them to fit the rifling were tried unsuccessful]}'. It was not until the early part of the eighteenth century, at which time the invention of the greased patch in America made possible the remarkable shoot ing of such men as Daniel Boone and Davy Crockett, that rifles attained any real measure of success. The invention of the patch brought forth the famous Kentucky Rifle made in Pennsylvania and called "Kentucky" because of the great demand for it by settlers of the then newly opened territory of Kentucky. The deadly accuracy of the American marksmen with the long Ken tucky rifles played a very .decisive part in ruining the morale of British troops as the accuracy attained by these backwoodsmen was far ahead of that attainable by the use of any other available weapons of the time. The patch, a greased piece of cloth or buck skin, was inserted ahead of the bullet and cleaned the powder fouling from the previous shot, lubricating the bore sufficiently to allow the bullet to be seated home. Breech-loading arms, made practical by the development just before the Civil War of the cartridge case to form the gas seal at the breach, are responsi ble for the great modern development of rifles but it was several 126 LEAD IN MODERN INDUSTRY years before accuracy comparable with the best of the muzzle loading arms was obtained. After the shot or bullets have been manufactured, they need to be inserted in shells or cartridges before use. Shot gun shells consist of weatherproof paper tubes, capped at the breach end with a brass cap into which the primer is placed. Powder, wads and shot are loaded into the open end which is then closed by turning the paper over onto a ``top wad." Rifle bullets are in serted in brass cartridges containing powder and primer and the cartridge is firmly crimped to the base of the bullet. This is of course all done automatically. Today there are scores of types and sizes of bullets and shot manufactured for cartridges for the many kinds of guns, rifles, pistols and machine guns that exist. About five tons of shot are made in the United States for every ton of bullets in peace-time. Antimonial lead is used for shrapnel balls, but modern armored warfare has reduced greatly the amount of shrapnel used. Anti monial lead is also employed for practice bombs used by mili tary fliers. They are usually die-cast. Ammunition used to train airplane gunners is made from a mixture of lead powder and a plastic. The bullets shatter when they strike the target plane's special armor, instead of penetrating it. A number of chemical compounds of lead are also important in ammunition. Lead azide is probably most important as a detonator explosive, while lead sulfocyanate, nitrate, peroxide and styphnate may also be employed. CHAPTER EIGHTEEN Other Metallic Lead Products and Alloys TYPE METAL Amo n g the alloys which have contributed heavily to modern civilization are the type metals, usually combinations of lead, tin and antimony. ............... A large part of the advancement in the art of printing may be attributed to the use of lead alloys as type metal, for lead or lead alloys have been relied upon for this purpose ever since the invention of movable type in the fifteenth century. Linotype or monotype machines, marvels of ingenuity with keyboards similar to those of typewriters, cast type metal kept molten in small pots into the shape of the type desired. An alloy must be used that can be depended upon not to clog the expensive type setting machines. Type may be used directly or stereotype plates .may be made from it. Stereotypes are usually preferred for long runs, such as newspaper printing. A modern newspaper plant may use 100 tons of stereotype metal cast several times over within twenty-four hours. Stereotype plates, often curved to fit the rolls of rotary presses, are made by impressing the form of type in wet papier-mache. After this has been baked dry, stereotype metal, a lead alloy, is cast in the mold. Electrotypes are formed by making impressions in wax or in sheet lead, called impression lead, instead of papier-mache and electro-depositing copper or nickel followed by copper upon the impressed material so that a thin sheet metal replica is produced. This copper shell is re moved from the impression, fluxed, and coated on the back with a sheet of solder foil to cause a backing metal to adhere when it is cast. ' The backt ing metal is called electrotype metal. Lead base type metals or electrotypes are often chromium 127 128 LEAD IN MODERN INDUSTRY plated on the printing face so as to give a longer life; sometimes twice as much printing can be done by chromium plating. Type metal varies in composition with the use to which it is to be put. Here are some typical formulas. TYPE METALS (Percent by weight) Lead Electrotype ................ 94 Linotype ....................... 84.5 Monotype ..................... 76-72 Stereotype.................... 80.5 Small type..................... 64 Tin 3 4 7-9 6 12- Antimony 3 11.5 17-19 13.5 24 Copper -- `-- 0-0.1 -- 0-0.5 POWDERED LEAD A number of commercial uses exist for finely divided metallic lead (powdered lead). It is available in irregular granular, spherical and flake form. The degree of fineness varies widely depending upon the use, and the powder may either be of rela tively uniform particle size or a mixture of various sizes. Lead powders are used as a constituent of bearings, brake and clutch facings, as a plastic filler, in the manufacture of rubber, free-machining steel, paints, lubricants and pipe joint compounds. High quality lubricants contain an average of 20 percent by weight of metallic lead which is introduced to a calcium base grease during agitation. In use, the grease acts as a vehicle to carry particles of lead powder to the gear or wearing surface where, under pressure, the individual particles coalesce and form a uniform layer or film of lead. An important and valuable property of such a lubricant is the fact that the extremely tenacious lead lining fills score marks, pitted or worn surfaces and thus, in effect, renews them. Once this has taken place, the lead coating itself becomes the bearing surface and since lead has excellent anti-friction properties, the result is smooth, fric tion-free, quiet operation. Lubricants containing powdered lead are especially useful in applications where gears and bearings are open or exposed to dirt, grit and abrasives. The comparatively soft film of lead is capable of absorbing such materials without injuring the bearing OTHER METALLIC LEAL PRODUCTS AND ALLOYS 129 surface. Wire rope is generally lubricated with powdered lead grease to prevent excessive squeezing of the hemp fibres and knicking of the wire strands. During the last war leaded greases played an interesting and important role in the protection of allied submarines. Ordinary greases when freed from various underwater bearing surfaces would float to the surface and form a tell-tale oil slick. To over come this, a special grease loaded with powdered lead was de veloped so that if any became detached it would sink instead of rising to give away the sub's location. Furthermore the lubricat ing characteristics and water- and corrosion-resistance were en hanced by the presence of the lead. Another unusual use of lead powder is in frangible training bul lets. The powder is mixed with powdered plastic and pressed into bullets. Such bullets resist the forces of firing but shatter when they strike the target, specially armored airplanes, which are used to train aerial gunners. Through the use of powder and by applying the principles of powder metallurgy, lead may be mixed with metals or non-metals with which it does not readily combine in any other way. Uniform mixes of materials having widely different specific gravities and melting points and other mechanical characteristics may be obtained in this way. Certain lead alloys such as solder are also sometimes used in powder form. Lead powder, the particles of which are coated with copper, has also been produced. LEAD WOOL This product consists of fine strands of metallic lead loosely wound into a rope that weighs about 1 lb. for every 2.5 ft. It is made by pouring molten lead through a fine sieve, the lead solidi fying in fine strands as it falls through the air. The strands are caught in an inclined metal trough some distance below and as they emerge at the bottom of the trough are wound loosely into a rope. Lead wool is used for the same purposes as calking lead, but since it is used in solid form without heat, it can be employed under water or in gaseous locations where heat would be danger 130 LEAD IN MODERN INDUSTRY ous or impossible. It is also employed for plugging oil wells to prevent water seepage and for other calking purposes. When calked, the individual strands lose their identity and the wool becomes a solid mass of lead. To calk deep joints, the lead wool should be placed in the joint one strand at a time and calked before another strand is placed on top of it. This assures solid calking clear through the joint. MOLDS AND DIES Lead, which itself is so easily molded, is used for molding other materials, largely because of this very reason. Examples are found in molds for plastics, for rubber hose, and in impression lead used in the printing trades, as well as in dies for stamping aluminum. Molds for plastics are sometimes die-cast of lead alloy, the molds being produced in quantity, remelted after use and recast for use again. However, molds for plastic articles of simple design are made in another ingenious way. A pattern or group of patterns of the finished article is made of polished steel and attached to a steel plate. These patterns are lowered into a bath of molten lead, the adjacent lead solidifying as a shell around the cold steel patterns, which are then withdrawn from the lead kettle and plunged into water. The patterns are removed from the lead, leaving a smooth lead mold into which the plastic can be cast. After the plastic has solidified, the lead mold is knocked off and thrown back into the melting pot for re-use. In the manufacture of rubber hose, a rubber tube is first ex truded, around which is braided one or more plies of strong cord, and a rubber cover applied. Lead is then extruded around the hose through a fluted die, just as cable sheath is extruded around cable. From 12,000 to 18,000 ft. of lead covered unvulcanized hose, depending on size, are wound on huge reels and vulcanized at one time. This is accomplished by the application of high pressure steam on the outside and hot water running through the inside of the hose pressing it against the lead mold. Air under pressure is sometimes used instead of water. The hose takes a permanent form corresponding to the impression on the inside of the mold, which is either corrugated or smooth. After vulcanization, the lead is stripped off, remelted and used again. OTHER METALLIC LEAD PRODUCTS AND ALLOYS 131 Antimonial lead is often used for male dies in sheet metal or plastic stamping operations. The female die is usually a zinc alloy. The advantages of lead alloy dies is that they can be easily and cheaply cast as compared with steel dies, and are particularly suitable for short or experimental runs, or where designs may change rapidly. The metal can of course be re-used. An interesting application of lead is as a mold or pattern for producing extremely thin-walled articles of other metals. For instance a lead rod may be extruded and a thin layer of copper electroplated onto it. When the copper plating has reached the desired thickness the lead is melted out, leaving a thin-walled copper cylinder or tube. Such devices are widely used in radar. For making large precision castings low melting lead alloys are used for the model instead of wax. Oftentimes the wax models for this method of casting are made in lead alloy molds. Impression lead is described in an earlier section on Type Metal. PACKAGING Lead foil, collapsible tubes and seals all play important roles in modern packaging. Lead collapsible tubes usually contain small percentages of antimony and may or may not be lined or coated with tin, the tin amounting to only a few percent. They are used for paste products, such as mucilage, shaving and dental cream, and colors-in-oil. Lead foil naturally does not permit destructive light rays to pass through it and also protects against moisture. In fact, through the use of low melting lead alloys, lead foil may be sol dered by an extremely simple process so that it seals the package hermetically. Being soft, lead foil bends readily without cracking. Taking advantage of the flexibility and water-proofing char acteristics of lead foil, the military Ordnance Department uses lead foil backed up on silk cartridge cloth for packaging various ordnance material. X-ray film is customarily packaged in lead foil to protect the photo-sensitive film from light rays. X-ray film for both dental and industrial radiography use is also backed up with lead foil 0.0025 in. thick. A new type of camera, a unique development which produces completely developed and 132 LEAD IN MODERN INDUSTRY printed pictures in 60 seconds, uses lead foil to prevent leakage of the special chemicals contained in capsules within the camera as well as to shield them and the film from stray light. Many kinds of packages are closed with tamper-proof seals, often made of lead. These are found on money bags, freight cars, express packages and elsewhere. A newer development is the use of lead seals for closing moisture-proof plastic packages. These are sometimes merely lead rings, which are slipped over the gathered end of the pliable plastic envelope and crimped tightly together. The soft lead thus seals the package tightly without damaging the plastic. These rings can be pried open and re-used when necessary. LEAD FOIL In addition to its use as a packaging material, foil made from lead and lead alloys has found extensive use in the manufacture of paper-wound condensers and mica condensers for use in vari ous electronic circuits including television and radio sets. Foil in this case is 0.0004 in. thick and is used because of its excellent electrical characteristics and the ease with which it may be soldered. Lead foil is used in metallic packing. It is a familiar sight at Christmas time as a Christmas tree decoration in the form of tinsel, a lead alloy foil containing 1 percent antimony and 1 percent tin. A recent application for lead foil 0.01 in. thick and 1/2 in. wide is as a tape for wrapping coaxial cable used in television transmission. LOW MELTING ALLOYS Lead is a constituent of a number of extremely useful low melting alloys in which it is usually combined with bismuth, tin, cadmium or a combination of these metals. Some of these alloys melt at a temperature lower than the boiling point of water, and ' those containing appreciable amounts of bismuth expand slightly upon solidification. Low melting alloys are employed for many purposes; in safety devices such as sprinkler systems and boiler plugs, for special solders where high temperatures cannot be used, for molds, patterns, punches and dies, for anchoring punches in T0^ The Texas Co. Hell Telephone Laboratories Left. Manufacturing leaded lubricants containing lead soaps as well as powdered lead. Right. Sealing a wiped cable joint with a special lowmelting lead alloy. Left. Three 2; in. lead anchors on a bolt for fastening machinery to concrete. Right. Collapsible tubes and the lead blanks from which they are made by impact extrusion. Left. Metallic packing made from shredded or wrinkled lead foil. Right. Lead wool being used for balancing airplane propeller blades. Lord Baltimore Press Left. Lead alloy type metals are chiefly linotype and electrotype. Right. Lead base die cast parts for a fire extinguisher. Jlarblette Corp. (A) (B) (C) (A) Dipping a steel die in molten lead. (B) Removing the lead mold from the die. (C) After filling molds with molten plastic, the finished plastic piece is removed and the mold remelted for reuse. Lockheed Aircraft Corp. Left. Each pair of drive wheels of steam locomotives are counterbal anced with as much as 2500.1b. of lead enclosed in the solid sections of the wheels. Right. A hard lead punch (upper) and zinc alloy die (lower) as used for forming sheet metal in airplane manufacture. OTHER METALLIC LEAD PRODUCTS AND ALLOYS 133 punch plates, for bending tubing, and for the addition of lead and bismuth to aluminum and other metals and alloys to obtain free-cutting materials. The use of matrix alloy, for instance, saves many hours of highly skilled machine work in anchoring punches in intricate dies such as lamination dies. Similar alloys are excellent for forming dies and punches for relatively short runs and for experimental models. They are quickly and inexpensively made from almost any kind of pattern. Hardening by freezing in liquid nitrogen temporarily gives some lead alloy dies the properties of steel dies. Tubes are bent without deformation by pouring low melting alloy into the metal tube to be bent and quenching rapidly in cold circulating water to solidify it. After bending, the alloy is melted out by submerging the tube in boiling water. LOW MELTING ALLOYS Melting temperature Alloy Deg. F. Matrix ........................... 248 Bending (Wood's metal) 160 Mold and pattern.......... 255 Anatomical .................. 140 Lipowitz......................... 158 Eose's .................. .......... 212 Eutectic ......................... 203 Eutectic ........................ 198 Deg. C. 120 71 124 60 70 100 95 92 Pb -28.5 -25 -44.5 17 --26.7 -28 -32 -40 Composition Bi 48 50 55.5 53.5 50 50 52.5 52 Sn 14.5 12.5 -- 19 13.3 22 15.5 -- Other 9Sb 12.5Cd -- 10.5Hg lOCd -- -- 8Cd LEAD HEAT TREATING BATHS Molten lead baths are widely used for the heat treatment of steel at temperatures between 650 and 1,700 deg. F. Lead is the only metal so used commercially and has a number of advantages over salts used for the same purpose. For the thermal properties of lead, see page 185. The following table gives the heat content of lead at various temperatures : 134 LEAD IN MODERN INDUSTRY HEAT CONTENTS OF LEAD Temperature Deg. F. 400 .................................................................. 600 .................................................................... 621, solid ......................................................... 621, liquid ....................................................... 800 .................................................................... 1,000 .................................................................... 1,200 .................................................................... 1,400 .................................................................... 1,600 .................................................................... 1,700 .................................................................... Heat content B.t.u. ... 11 ...17 ...18 ...28 ...34 ...41 ...48 ...55 ...62 ...65 Lead's greatest advantage, perhaps, lies in its high heat con ductivity which results in rapid heating, high output, uniform temperature throughout the bath, and high thermal efficiency. Lead does not decompose but does tend to oxidize. This is usually minimized in practice by covering with a layer of charcoal, coke or other suitable material. These carbonaceous coverings protect the lead from oxidation by the reducing effect of CO gas generated as they burn. Molten salt coverings, such as mixtures of sodium chloride, sodium carbonate and potassium carbonate are also employed. These result in exceptionally clean work and low lead loss, but are expensive. Among the other advantages of lead are that it has no appre ciable chemical action on the pot material and it does not absorb water as do most salts. Furthermore lead does not tend to pit or decarburize the steel treated in it. Lead has a high specific gravity and arrangements must be made for submerging the work in it. If all conditions are not right, there is some tendency for lead to adhere to the stock. This occurs particularly when the lead bath is operated at low temperatures, below 850 deg. F. At higher temperatures with suitable coverings remarkably clean work results. Adherence is best prevented by avoiding oxidation of the lead as much as possible. Sulphur and tin in the bath also promote adherence. Adherence is sometimes prevented by dip ping the stock in a hot saturated brine solution before dipping it in the lead, leaving a light deposit of salt on the stock. This method can be used up to 1,475 deg. F., the melting point of sodium chloride. In difficult cases the stock is dipped in molten OTHER METALLIC LEAD PRODUCTS AND ALLOYS 135 caustic soda immediately after removal from the lead, and is then quenched in water. Three types of pots are used for lead baths--cast iron, cast, welded, or pressed steel, and special alloys such as high or low nickel-chromium steel or chromium steel. Pot design is impor tant, all corners, particularly below the lead level having large radii and abrupt changes in pot thickness being avoided. Electri cal heating apparently results in longer pot life, but good results can be obtained with gas or oil firing if the furnace is properly designed with respect to location of burners and vents, adequate combustion space, vent area, length of flame travel, location of splash brick and height of combustion chamber. Liquid lead pool electrode furnace. Lead or lead alloy compositions are being used as a liquid electrode in electric salt furnaces for heat treating purposes. The liquid electrode principle is simple and, in practice, has demon strated several advantages over ordinary electric salt furnaces. A pool of molten lead alloy lying in the bottom of the furnace chamber contacts a source of electrical power on one end and a molten salt bath on the other. The flow of current between two such electrodes in the same salt bath creates the heat necessary to keep both the salt and the lead alloy molten. The greatest advantage of the lead pool furnace is that "over-the-side" elec trodes which tend to corrode badly at the salt line can be dis pensed with. Other advantages are easy sludge removal and lower power consumption because the usable heat treating area of the furnace is the only area heated. To avoid steam eruptions which may be dangerous to operators 136 LEAD IN MODERN INDUSTRY through splashing of molten lead, all material should be thor oughly dry when dipped into the molten bath. Lead baths are especially useful for local hardening and tempering, and in fact are probably the only kind suitable for such work. Lead baths may be operated by either batch or continuous methods, the batch method generally being used for tempering and both methods for hardening. Molten lead is also used in the bottom of galvanizing pots or in the outer compartment of double galvanizing pots to distribute heat more uniformly and prolong the life of the pots. MISCELLANEOUS ALLOYS A variety of lead alloys are mentioned in other sections of this book, either under the process of manufacture employed with them or the uses to which they are put. Thus antimonial lead is used in storage battery grids, cable sheathing, for pipe and sheet and for castings. Both lead foil and collapsible tubes usually contain small percentages of antimony and both may be coated with tin by rolling lead and tin together during manufac ture. Shrapnel contains antimony up to 12 percent and bullet cores may have up to 2.5 percent antimony in the composition. Shot usually contains from 0.5 to 1 percent arsenic and 2 to 6 percent antimony. Foil for condensers may have as little as 4.5 percent tin or as much as 50 percent in some cases, whereas foil for making tinsel contains from 1 to 4 percent tin. A few typical alloys are listed here. MISCELLANEOUS LEAD ALLOYS . /"" ~ 1 Lead Battery grid metal.... 93-88 Percent by weight ------- - -- A--- -- -- Antimony Tin Copper. 7-12 0-0.25 -- Shrapnel ....................... 88 12 . -- -- Bullet cores ................... 100-97.5 0-2.5 -- -- Shot ............................... 100--93 2--6 -- ---- Cable sheaths............... 100-99 0-1 ---- Collapsible tubes......... 100-97 0-3 ---- Condenser foil ................ 92--48 2-3.5 4.5-50 -- Tinsel ........................... 97.5-05 <1.5 1-4 -- Machine brass ............. 1--4 -- -- 88-62 Metallic packing......... 100-96.5 0-2 0-1.5 -- Packaging foil............. 98-88 1-2 1-10 -- i ,, Other -- -- -- 0.5--1As -- -- -- -- 10-35Zn -- -- OTHER METALLIC LEAD PRODUCTS AND ALLOYS 137 LEAD WEIGHTS Because lead has the highest specific gravity (11.34) of the common metals, it is frequently used for counterbalances, weights and ballast. An additional advantage for this purpose is the ease with which it may be fabricated into almost any desired shape. Thus lead weights not only concentrate the greatest weight in the smallest practical volume but may also be made in the most convenient shape without difficulty. The low melting point makes lead easy and economical to cast, and where the design is such as to make other methods of fabrication preferable, weights may be extruded or stamped from sheet. The uses of lead as weights or balances are too numerous to mention. A few are balances for machinery, locomotive and train wheels, automobile wheels, anti-aircraft guns, divers' equip ment, industrial trucks, airplane control surfaces and propellers, naval ballast, fishing sinkers and seine weights. Lead weighs approximately 707 lb. per cu. ft. or 0.41 lb. per cu. in. The television tube shown here being welded together contains up to 30 percent lead by weight. Lead, introduced to the glass batch as an oxide, also gives brilliance to the fine "crystal" glassware on the right. Left. Lead-bearing glazes are widely used on artware, tile and other pottery products to give,brilliance, luster and smoothness. Right. Spray applying a water-suspended leaded glaze on a vitreous china plumbing fixture prior to firing. The Elertrir Stnrur/e Hatter;/ Co. Litharge, red lead and black oxide form the "paste" shown being applied to storage battery .grids. Standard Oil Co. fX. J.) Litharge is important in the "sweetening" of certain gasolines. It is mixed with caustic soda to form sodium plumbite "doctor" solution. Dur ing treatment the litharge is converted to lead sulphide, then oxidized and re-used. CHAPTER NINETEEN White Lead Ba s ic c a r b o n a t e w h it e l e a d , or simply white lead, is the oldest and most widely used of the lead pigments; it is the only white pigment which will produce a durable exterior paint if used alone without other pigments. Alone, or in combination with other pigments, the use of white lead in paint is so widespread that this subject is discussed in greater detail in another section (see page 151). White lead is also used in glazing pottery and enameled ware, in putty, in the manufacture of orange mineral and in other industries. The composition of basic carbonate white lead is often indi cated by the formula 2PbC03-Pb(0H)2, which corresponds to a combined lead carbonate content of 69 percent. The range in composition of commercial white leads is from 62 to 75 percent. At 62 percent lead carbonate content, the formula of basic car bonate white lead is more closely represented by 4PbC03- 2Pb(OH)2-PbO. If the total lead carbonate content exceeds 75 percent, the quality of the pigment suffers since the presence of uncombined lead carbonate is indicated which, by itself, is a poor pigment. The recently developed white leads of low lead carbonate con tent (62 to 66 percent) and greater basicity are characterized by finer particle size, higher hiding power and greater paint thickening power. Possibly the most outstanding characteristic of white lead is its remarkable chemical affinity for paint vehicles; it becomes an integral part of the paint film and actually reinforces the paint, resulting in a tough, flexible film, unusually resistant to embrittle ment. . White lead is manufactured in this country by several different methods: the Carter, Euston, Sperry, Thompson-Stewart and 138 WHITE LEAD 139 other processes. The Old Dutch process, most widely used some years ago is no longer employed. In the Old Dutch process, thin, perforated discs or "buckles" of metallic lead about six inches in diameter were placed in earth enware pots with a small amount of dilute acetic acid, and the pots placed on moist spent tan bark. The fermentation of the tan bark produced heat (up to 180 F.) and also gave off carbon di oxide. The heat caused the acetic acid to evaporate and its fumes attacked the lead buckles, which had since been oxidized, and formed a coating of basic lead acetate. The carbon dioxide from the tan bark decomposed the basic lead acetate, thus producing basic carbonate white lead. The Carter process is basically the same as the Old Dutch proc ess except that the metallic lead is blown with steam or air to a fine powder and treated with acetic acid, air, water and carbon dioxide gas in large, revolving wooden cylinders. Under these conditions, the corrosion of metallic lead into white lead proceeds at a much more rapid rate than in the Old Dutch process which required approximately 3 to 4 months for conversion. In contrast only 12 to 14 days are needed in the Carter process, principally because the particles of blown, Carter-process lead are very small. In the Euston process, metallic lead is treated with lead acetate solution in the presence of air to form basic lead acetate from which white, lead is precipitated by suitably controlled contact with carbon dioxide gas. In the Sperry process, the lead acetate solution is obtained by the electrolytic decomposition of a metallic lead anode in an elec trolytic cell, white lead being precipitated almost instantaneously from the lead acetate by sodium carbonate present in the solution. The Thompson-Stewart process for the manufacture of white lead is a fairly recent development. The chemical reactions in volved are essentially the same as in the Carter process. How ever, the reaction rate is controlled until all the metallic lead has been oxidized to lead oxide (PbO) and this reacted with acetic acid, water and C02 to produce basic lead carbonate. , Basic lead sulphate, also called basic sulphate white lead or sublimed white lead, finds its main use in paint. As a paint pig ment it has the same properties as basic carbonate white lead. A 140 LEAD IN MODERN INDUSTRY fine, opaque, amorphous white powder, it is usually represented by the formula Pb0-PbS04. It is used extensively in the mixed paint industry. Prior to 1930, basic lead sulphate contained 4 to 6 percent zinc oxide. Commercial basic lead sulphate now being produced by either the fume or chemical processes does not contain zinc oxide. The two fume processes now in use differ chiefly in the raw materials used. In one, the pigment is manufactured in a Scotch Hearth type of furnace by feeding galena concentrates with the proper fluxes directly into the furnace. The lead and sulphur are sublimed and, in the gaseous state, oxidized to form basic lead sulphate. The gases and fume are cooled, depositing the pigment as a fine powder which is collected in a cloth filter bag. In the other fume process, it is produced by the atomization of lead in the presence of an excess amount of air and sulphur di oxide. In the chemical process, sulphuric acid is added to a litharge slurry, precipitating basic lead sulphate. The product, because of the controlled conditions possible with this process, more closely approximates the theoretical composition of basic lead sulphate than that produced by other processes. White Lead-Varnish Cement. This unusual cement is made by mixing paste white lead with a good grade of varnish to a heavy brushing or troweling consistency. A typical composition con sists of If to If gallons of varnish and 100 lb. of heavy paste white lead. Uses for this product include the mounting of canvas murals on the walls of public buildings, cementing canvas deck ing in place on boats or porches, applying metal letters to glass, and setting marble. In the latter, white lead-varnish cement is particularly advantageous because the joints can be made prac tically invisible by applying the cement in very thin layers (less than tV in. thick) without impairing its adhesive characteristics. CHAPTER TWENTY Lead Oxides LITHARGE Lit h a r g e --lead monoxide (PbO)--is one of the most widely used and commercially important of all metal chemi cal compounds. It has a buff color, is made in either flake or powdered form and in a wide range of particle size. It contains roughly 93 percent lead and 7 percent oxygen by weight. Litharge is made by melting pig lead in reverberatory or cupel furnaces in the presence of air. The product of the reverberatory furnace is usually powdered litharge; of the cupel furnace, flake litharge. From 24 to 36 hours are generally required for the process. Some litharge is also made by burning lead to a fume in the presence of oxygen. Obviously it is possible to obtain a litharge suitable for practically any application providing the re quirements are known. As a matter of fact, the various grades used commercially are generally known by the uses to which they are put. Storage batteries account for the largest consumption of lith arge. Battery litharge is very pure and is used, with red lead, to form the active material on the plates (see page 31). Glassmakers' litharge is either in powdered or flake form. Par ticle size is not important since it is melted with other materials such as silica and potash to form complex silicates which make an exceptionally tough glass. Glass high in lead exhibits much greater resonance and by increasing the refractive index of the glass, it also adds to its brilliance. It imparts to glass lead's power of stopping X-rays, and glass with a high lead content is therefore used for X-ray room windows. Litharge for this pur pose should be of high purity to avoid discoloration of the glass which might result from impurities such as iron. What has been said of glassmakers' litharge also applies to potterymakers' and enamelers' litharge, since it is used as a constituent of the glaze for pottery or enameled ware. 141 X 142 LEAD IN MODERN INDUSTRY Colormakers' litharge is in powdered form. It is dissolved in acetic or nitric acid and used to produce chrome yellow and chrome green color pigments. Rubbermakers' litharge is finely powdered and serves as an accelerator, toughener and controlling ingredient in the manu facture of rubber. Recent work has shown it to be particularly useful in the compounding of synthetic rubber and syntheticnatural rubber mixtures. For instance, in Buna S stocks, it has been shown that the product has excellent aging and physical characteristics with a rapid rate of cure and an extremely wide curing range. Varnishmakers' litharge, usually in powdered form, is used to give proper drying qualities to varnish by the formation of lead soaps. As a catalyst, litharge promotes more rapid polymeri zation of fatty acids in the oils used in varnish making. Oil refiners' litharge is finely powdered. It is dissolved in caus tic soda and employed to break up some of the complex organic sulphur compounds in the petroleum products. Lead sulphide forms and settles out, removing the sulphur. Although the foregoing are the principal uses for litharge, this interesting compound has many other applications. For example, added to red lead paint (about 10 percent litharge by weight in the top coat), it makes a harder film for painted surfaces sub ject to continued soaking under water, as in water tank painting. Litharge is added as a stabilizer to improve high temperature and high pressure characteristics of petroleum lubricants. Litharge--Glycerin Cement. Litharge when combined with glycerin also makes a useful quick-setting, acid-resisting cement for joining metals, ceramics, etc. The accompanying tables give data which may serve as a guide in using litharge-glycerin cements. Colormakers' litharge is recommended for this purpose and should be fresh, as aged litharge retards the setting time. Since water speeds up the setting of these cements, any water taken up by the glycerin, which it has a tendency to do, speeds up the setting. As can be seen from the table, for fastest setting some water should be used in the mix. However, for maximum strength, the mix should be free of water. These cements will safely stand temperatures up to 350 deg. F. in use. Glycerin or LEAD OXIDES 143 the desired mixture of glycerin and water is usually added to the dry litharge to make only enough cement at any one time to be used up within the short pouring and setting time. UTHARGE-GLYCERIN CEMENT COMPOSITIONS AND CHARACTERISTICS Formula Pouring Time Setting Time Tensile Strength Paste After 4 Months, Condition Lb. per Sq. In. 100 cc. glycerin 1 lb. litharge 1 hr. 19 min. 3 hr. 48 min Fairly viscous 626 90 cc. glycerin 1 lb. litharge 40 min. 1 hr. 50 min. Fairly viscous 668 80 cc. glycerin 1 lb. litharge 86 cc. glycerin 1 lb. litharge 14 cc. water 19 min. 8 min. 43 min. 18 min. Very viscous Fairly liquid 662 394 80 cc. glycerin 1 lb. litharge 20 cc. water 5i min. 154 min. Fairly liquid 411 RED LEAD Red lead (Pb3OJ is another lead oxide of great commercial importance. It is bright orange-red in color and contains about 91 percent lead and 9 percent oxygen by weight. It is manufac tured by heating powdered litharge at a carefully controlled temperature, lower than for the manufacture of litharge. The litharge takes up more oxygen and forms red lead. A part of the litharge usually remains unconverted in the form of minute cores in the red lead. "True red lead" is the actual Pb304 in the com mercial pigment. "Pure red lead" may contain some unconverted litharge but is otherwise free from impurities. Red lead is made in a wide range of true red lead contents up to 98 percent true red lead. For some purposes high true red lead content is desirable. An example is ready mixed or paste red lead for paint, as any appreciable amount of litharge pres ent may cause the paint to harden prematurely in the can because of the drying action of litharge. On the other hand, a low true red lead content is often specified for battery red lead since it is usually mixed with litharge anyway to form the paste for the plates. 144 LEAD IN MODERN INDUSTRY The two biggest uses for red lead are in the production of storage batteries and metal protective paints. In storage bat teries, red lead, like litharge, is an active ingredient on the plates (see page 30). The oxide is preferably fine but, as stated does not need a high true red lead content because it is usually mixed with litharge. Red lead has long been recognized as the leading pigment for metal protective paints, particularly primers (see page 160). The true red lead content used in paints is generally in the neighbor hood of 95 to 97 percent and the pigment is extremely fine. Red lead has a number of other uses quite similar to the appli cations of litharge. Principal of these is its use as an ingredient in the mixes for glass, glazes and vitreous enamels. Red lead for this purpose is of high purity but does not have to be particularly fine nor have a high true red lead content. The latter depends largely on the other ingredients of the mix, which determine how much oxygen has to be added by the red lead. Red lead is added to certain greases for use as a drill stem lubricant in oil well drilling operations. It is also used as an anti-galling agent on threaded joints subject to high temperature service such as on locomotives and boiler installations. OTHER OXIDES At least two other lead oxides are of commercial importance. They are the peroxide or dioxide, Pb02, and orange mineral, Pb304. The first is a strong oxidizing agent employed in the manufacture of dyes, matches, rubber substitutes and other prod ucts. Incidentally it becomes the principal ingredient on the positive storage battery plate after forming (see page 30). Orange mineral has the same chemical composition as red lead, and is manufactured from basic carbonate white lead, or from litharge, by a process similar to that used for red lead. It differs from red lead principally in its color and tone. It has a brilliant vermilion color and is used largely by color makers and manu facturers of printing inks. Black oxide, a mixture of litharge and finely divided metallic lead, finds its main use in the storage battery industry. CHAPTER TWENTY-ONE Tetraethyl Lead ^ ^ .............. ^ ^ * ^ JLe t r a e t h y l l e ad --Pb(C2H3)4--is a heavy, colorless liquid used almost exclusively as an important ingredient in gasoline. It is the active component in the "anti-knock compound" which oil companies use to improve the anti-knock quality of aviation and automotive gasoline. The addition of only a few cubic centimeters of tetraethyl lead, often referred to as TEL, effects a substantial improvement in the anti-knock value or octane rating of a gallon of gasoline. The higher the octane rat ing of gasoline, the more power it can produce without knocking. High test or premium gasoline was first placed on the market in 1923, but it is only in the last fifteen years that the volume of lead used in its manufacture has reached important proportions. Premium gasoline for automobiles contains from 2 to 3 cc. of tetraethyl lead. Even ordinary gasoline contains lead but in lesser amount, from 0.5 to 1.5 cc. per gallon. Present day auto mobile fuel is composed of a blend of cracked, thermal or cata lytic, straight run fuels and tetraethyl lead. Through the past twenty years, as the anti-knock quality of automotive and aviation gasolines has been improved, the effi ciency of engines has made corresponding progress. Today a gal lon of gasoline produces approximately 50 percent more useful power in a suitably designed engine than in the average automo bile of 1925. It is estimated that an automobile engine designed with a compression ratio of 12 to 1 will give approximately 50 percent more miles per gallon at 40 miles an hour than a 1940 model with a compression ratio of 5.25 to 1. In aviation, the increase in power produced by improvements in fuels and engines has been spectacularly large. This extra power has been used to provide extra speed and improved economy. 145 146 LEAD IN MODERN INDUSTRY Tetraethyl lead is made from pig lead, salt, hydrogen, alcohol and refinery gases in the manner shown in the flow diagram. pig lead salt hydrogen sodium' chlorine ->- lead-sodium alloy tetraethyl lead hydrochloric acid alcohol ethyl chloride refinery gases -methylene The reaction may be represented by the chemical equation: 4PbNa+4C2H5Cl Pb (C2H5) 4+4NaCl+3Pb The pig lead is melted and mixed with sodium under a blanket of nitrogen to form a lead-sodium alloy. It is then solidified and ground. The alloy is reacted with ethyl chloride to form tetra ethyl lead. This is steam distilled and otherwise purified and then blended with ethylene dichloride, ethylene dibromide and dyes to form the anti-knock compound. CHAPTER TWENTY-TWO Other Industrial Lead Compounds Al t h o u g h the chemical compounds of lead which ac count for the largest tonnages of metal have been described in considerable detail, a number of other compounds are also of commercial significance. Lead chromates--yellow, orange and red--are valued both for their color and protective properties. The normal chromate, PbCr04, is made by precipitation from solutions of lead acetate or lead nitrate to which potassium or sodium bichromate has been added. The resulting precipitate has a brilliant yellow color and is known as medium chrome yellow. To obtain a paler yel low known as lemon chrome yellow, a little sulphuric acid or sodium sulphate is added to the solutions which causes some white lead sulphate to precipitate intimately with the lead chromate. Orange chrome yellow is the partly basic lead chromate and is obtained by dissolving an alkali, such as caustic soda or soda ash, in the bichromate solution before adding the bichromate to the lead solution. American vermilion, also known as Chinese scarlet and chrome red, is basic lead chromate usually made from white lead instead of from a lead acetate solution. Between chrome red, which is a deep red of an orange tone, and lemon chrome yellow, lie many other gradations of color which are really mixtures of the different lead chromates. They are obtained by varying the conditions of manufacture described under the different lead chromate pigments. Chrome green, the most important green pigment, is a mix ture of yellow lead chromate and Prussian or Chinese blue. It is made by precipitating the chromate in the presence of finely divided Prussian blue (ferric-ferrocyanide). 148 LEAD IN MODERN INDUSTRY Blue lead, also referred to as basic lead sulphate-blue, is slategrey in color and consists of basic lead sulphate, small amounts of lead sulphite, lead sulphide, and zinc oxide plus a trace of car bon. It owes its color to the carbon present. It is manufactured in a specially constructed Scotch Hearth furnace from which it rises as a fume, is collected in bag filters, and retained as an extremely fine blue-grey pigment. The princi pal use of blue lead is in the manufacture of paint for the pro tection of iron and steel surfaces. Metal protective paints com pounded with blue lead are described beginning on page 171. Blue lead is also used in the compounding of special lubricants, elec trical and mechanical rubber stocks where, in the latter case, it acts as an accelerator. Lead azide--Pb(N3)2--has become a standard detonator ex plosive, being used in place of the more dangerously sensitive detonators previously employed. It is a fine, cream-colored com pound. Its sensitiveness and efficiency are less affected by ab sorption of moisture than other commonly used detonators, its hygroscopicity at 30 deg. C. and 90 percent relative humidity being only 0.03 percent. It is practically insoluble in water. It is not easily decomposed by heat, having been stored, in tests, for 15 months at 80 deg. C. with no noticeable impairment in sensi tivity or brisance. It is more readily detonated by flame than by shock or friction, so when used in a detonator to be exploded by a firing pin, it has a covering or priming charge of a suitable sensitive explosive. It may be stored under water or alcohol and when spilled, may be destroyed by washing with a solution of ammonium acetate. Lead arsenate is an essential insecticide for the protection of crops and large tonnages are used annually for that purpose. Several different lead arsenates are used as shown by the table on page 204. Litharge is the raw material employed for the manu facture of commercial lead arsenates. It may be dissolved i:. arsenic acid in the presence of acetic or nitric acid as a catalyst, or may be converted to lead acetate or nitrate and allowed to react with sodium arsenate. The latter method results in a mix ture of mono- and dibasic lead arsenate and should not be used if the product is to be mixed with lime-sulphur solutions. s A variety of lead compounds are used for plasticizing vinyl plastics (left) and stabilizing rubber as well as plastics (right). "v Military equip ment powered by reciprocating gaso line engines such as these airplanes must use high lead content gasoline to operate at maxi mum efficiency. V. S. Xary Fueling a modern commercial airliner with high octane leaded gasoline. Ethyl Cory. Two "old-timers" and two later model cars line up for a fuel economy run._ The event proved the remarkable gains in fuel economy made during a 25-year interval, due in large measure to the continual rise in tetra ethyl lead content of gasolines. OTHER INDUSTRIAL LEAD COMPOUNDS 149 The importance of lead arsenate and its contribution to modern agriculture cannot be underestimated, for it has brought about control of some of the most dangerous and damaging plant pests. Lead silicates are used extensively as frits in the ceramic in dustry. There are many types of lead silicate frits including both the monosilicate and bisilicate. They meet the demand for lead bearing material that can be used in glazes, enamels and glass without fritting and supply part of the silica, as well as the lead to the batch. Basic silicate white lead is a compound of lead commonly used in the ceramics industry. As manufactured, it has a composition closely approximating 3Pb0-2Si02-H20. The method of manu facture involves the initial preparation of anhydrous lead silicate by fusing pure silica sand with litharge. The granulated anhy drous silicate may be hydrated by ball milling with water under controlled conditions. Basic silicate white lead has many desir able pigment properties similar to both basic carbonate and basic sulphate white lead. It is chemically reactive with paint vehicles and yields elastic films which are stable. As a pigment, basic silicate white lead is used to its greatest advantage in metal pro tective paints for submerged exposure. In both fresh and salt water it greatly increases the corrosion inhibitive properties of mixed pigment paints. It is also used as a stabilizer in the com pounding of vinyl plastics. Basic lead silicate--a new paint pigment--is a complex salt of lead oxide and silica. It is made from litharge and silica cata lyzed with a small amount of sulphuric acid. The resulting pig ment has a core of unconverted silica with a surface coating of the complex basic lead silicate salt. Important reasons for using lead pigments in house paints are their chemical reactivity with oil and their ability to stabilize the breakdown acids of the ve hicle. Development of this pigment was based on the theory that, by concentrating the active material on the surface of each pig ment particle, this reactivity would be retained with a pigment of lower weight per unit of volume. Lead stabilizers. A whole series of lead compounds, most of them of too complex structure to describe in detail here, are used as stabilizers in vinyl plastics. These plastics, when exposed to 150 LEAD IN MODERN INDUSTRY light and heat, are subject to deterioration unless they contain a stabilizer to react with decomposition products and arrest the reaction. Lead stabilizers are among the most economical and efficient to use and in some cases the only effective stabilizers. The lead stabilizers include certain basic sulphates and phos phites, complex silicates, and organic compounds like the salicyl ates and basic stearate, phthalate, maleate and so forth. Miscellaneous lead chemicals. Many other chemical compounds of lead are of considerable commercial importance, while others have characteristics that make them interesting possibilities. A list of a large number of lead compounds and some of their properties begins on page 203 and includes those which have already been described elsewhere in more detail. CHAPTER TWENTY-THREE White Lead Paints JLh e manufacture of paint is an industry of huge pro portions and consumes an increasingly great variety of natural and manufactured chemical compounds. Despite the hundreds of raw materials used in paints, lead in the form of pigment con tributes more valuable properties to paint than any other single ingredient as will be explained later in this chapter. For this reason the prospective user of paints, exterior paints in particu lar, will do well to make certain that the paint he purchases con tains either a substantial quantity of white lead or is of the pure white lead type. White lead, the oldest white paint pigment known to man, was employed by the ancient Egyptians, Greeks and Romans. Several descriptions exist, dating from before the Christian era, of meth ods of making it from metallic lead and vinegar or wine. The Old Dutch Process, by which the pigment was usually made until re cently, is essentially the same in principle as the method used by the ancients. Most of the newer methods replacing the Old Dutch Process, which required 90 to 120 days for conversion, differ pri marily in that they reduce the conversion period to 12 days or less. Manufacturing details for the various types of white lead pigments are described in detail beginning on page 138. The early history of paint itself antedates any reliable written records. It is known to have been used by the Egyptians as far back as 2500 B.C.; the ancient Hindus and the Hebrews before the time of Moses also were well acquainted with the art of paint ing for decorative purposes. The Greeks were probably the first to recognize the importance of protecting their structures with paint. Remains of their edifices are often found showing evidence of its use. Paint is now called upon to serve many purposes. Primarily, of 161 152 LEAD IN MODERN INDUSTRY course, it is to protect and to beautify, but time has brought in creasing responsibilities and greatly enhanced its value and ser viceability. Well painted buildings, both inside and out, go hand in hand with improved sanitation. In exterior house paints the liquid or vehicle part of the paint is composed principally of linseed oil and other vegetable oils having the same type of fatty acid glyceride chemical structure. White lead has a natural affinity for these oils possessed by no other white pigment. Actual chemical compounds, commonly referred to as lead soaps, are formed between the white lead and vegetable oils, greatly reinforcing the paint film. Lead soaps are made up of flexible crystals with a long spiney structure. Under a microscope, they look like cockleburs, with the spines of adjacent crystals intermeshed. This intertwining or meshing forms a felted mat which reinforces the film and in creases its coherence and elastic strength to an optimum degree. White lead stabilizes paint, retarding its decomposition. With out a reactive pigment, a house paint film would have a relatively short life in outdoor service. As the paint slowly weathers, the vehicle breaks down to form acidic compounds such as formic, hydroxyacetic, propionic and related destructive organic acids. These liquefy or soften the film. Active lead pigments in a paint neutralize these products of decomposition as the film ages and form stable insoluble lead salts. In this way, the film is stabilized and its durability greatly improved. Lead plasticizes paint, increasing its flexibility. In reality a paint film is a plastic, although it is not generally referred to as such. And, like many plastics, it would become hard, brittle and inflexible if it did not contain a plasticizer. Such a paint would crack easily under normal stresses, not only spoiling its appear ance but also greatly reducing its protective value. White lead pigments permit the proper formulation of paints that provide flexible films not only after application, but throughout the life of the paint. Lead soaps act as plasticizers. In multiple pigment paints their effect is supplemented by other soaps usually present in the film. The inherent reactivity of white lead and resultant lead soap formation also increases the elastic strength of a paint film. The paint film is reinforced mechanically as a result of chemical re WHITE LEAD PAINTS 153 actions. As the films containing- the reactive lead pigments age they increase in toughness to an optimum degree. The lead soaps improve the adhesion, cohesion, flexibility, distensibility and the other factors that contribute to long life and improved protective ability of the paint film. White lead pigmented paints possess high water repellency. Water attempts to dissolve and emulsify portions of a paint film causing it to swell and soften. This tends to break its cohesive bond and is probably the greatest single cause of loss of adhesion. Paints containing lead pigments are highly resistant to water; they absorb only a fraction as much water as non-lead paints. A paint should preserve the surface over which it is applied, re main attractive for the longest possible period and eventually pre sent a satisfactory surface for repainting. Ready-mixed house paints containing substantial percentages of white lead or pure white lead paints have repeatedly demonstrated their ability, in actual use, to outlast paints made from other pigments or com binations of pigments. Paints based on white lead slowly wear away, leaving an even, slightly chalky surface which enhances ap pearance throughout the life of the film and presents an excel lent surface for eventual repainting. It does not crack or scale, whereas paints that do must be scraped or burned off before re painting. This adds another item to the already high cost per year of maintenance with inferior, rapidly deteriorating non-lead paints. Aside from technical reasons, the preponderance of evidence in favor of white lead-containing ready-mixed paints and pure white lead paints is being increased daily. Performance alone dictates the use of white lead. Almost any paint will look well a year after application--or even two years. The real test of an exterior paint only begins then. Paints containing substantial percentages of lead, properly applied, will usually remain in excellent condition at least four or five years, often much longer. Briefly, white lead adds more desirable qualities to paint than any other white pigment and has practically no undesirable quali ties to nullify its advantages. It is one of the few chemically re active pigments, and authorities are agreed that high percentages of reactive pigments are essential to durable paint. Its reaction, moreover, takes the most beneficial form, providing maximum re- ii : ,^'i It l i I 154 LEAD IN MODERN INDUSTRY inforcement of the film. The hiding power of white lead is good and its brushability excellent. White lead, too, improves the ad hesion of paints which in large measure accounts for its wide ac ceptance in primers. Among the other characteristics which white lead contributes to paint in good measure are mixing and grinding ease, package stability, leveling, drying, whiteness, film strength, flexibility, tint retention, gloss and, of course, weather resistance. One other characteristic, foolproofness, deserves special men tion. To the user this characteristic of white lead means that in accuracies in thinning or inexpert application will have little or no effect unless greatly exaggerated. To the specifier or formulator, it means greater latitude in the remainder of the paint in gredients without getting into trouble. This is an invaluable asset of any paint. White lead for paint is marketed in several different forms. In dry form, it is used by manufacturers to make ready-mixed paint. For public use, then, it may be (1) an ingredient of ready-mixed multiple pigment paints, (2) a linseed oil paste (white lead in oil), or (3) a ready-mixed paint in which the pigment portion is entirely white lead. White lead paints for generations have preserved many colonial landmarks through the rigorous climate of the Atlantic seaboard. Several current government house paint specifications require the inclusion of substantial quantities of white lead for both priming and finishing coats. The profitable application of white lead in paints is not confined to exterior use. Pure white lead paints can be utilized to advan tage for interior decoration, particularly in public and traditional buildings where elaborate decoration is used and it is very ex pensive and inconvenient to repaint often. In spite of frequent and repeated cleaning white lead paints maintain their original brightness and luster. For this reason many hotels use white lead paints exclusively in their rooms. Pure white lead paints may be easily tinted to practically any color desired. The professional or amateur decorator is not limited to a choice of a few standardized colors. The following are suggested proportions for formulating white lead-in-oil paints for exterior use on wood. WHITE LEAD PAINTS 155 NEW WOOD Materials First Coat White-lead soft paste *. ........ 100 lb. Raw linseed oil.............. Turpentine .................... ........ 2 gal. Liquid drier .................. Gallons of paint.. ........ 9g Second Coat 100 lb. 1 gal. li gal. 1 pint 61 Third Coat 100 lb. 31 gal. .... 1 pint 61 PREVIOUSLY PAINTED WOOD Materials First Coat White-lead soft paste *___ .... 100 lb. Raw linseed oil....................... Turpentine............................. Liquid drier........................... Finish Coat 100 lb. 31 gal. 1 pint Gallons of paint............ .... 71 61 * If white-lead heavy paste is used, add one quart of turpentine to all formulas. The following- are typical formulations for high quality readymixed multiple pigment exterior primer and house paints. PRIMERS The following primer formulations are designed as adherent undercoatings to provide a sound surface for subsequent finish coats. A substantial proportion of white lead was included in these formulas to assure the formation of paint films having a high degree of elastic strength and water resistance, primary requisites for durable house paint primers. EXTERIOR PRIMER Bl White Lead..................................................... Rutile Non-Chalking Titanium Dioxide... Magnesium Silicate * ........ .......................... Litharge f ...................................................... Pounds Non-Vol. Pounds 553.7 74.6 292.1 9.2 GaUons 9.8 2.1 12.3 0.1 Raw Linseed Oil............................................. . 165.0 Ester Gum Cold Cut (10 lb.)..................... . 22.7 Low Acid Heat Bodied Linseed Oil (Z2-Z4) . 147.8 Cobalt Naphthenate (6%)........................... Mineral Spirits ....................................... .. 165.0 37.6 147.8 2.8 215.5 21.3 4.7 0.4 0.4 33.1 1498.3 102.0 Pigment = 62.0% Vehicle = 38.0% P.V.C. = 36.7 Pig./Gal. Paint = 9.1 lbs. Consistency = 80:2 K.U. 156 LEAD IN MODERN INDUSTRY Pigment Analysis Percent White Lead..........................59.6 Rutile Non-Chalking Ti tanium Dioxide ........... 8.0 Magnesium Silicate.........31.4 Litharge............................. 1.0 Vehicle Analysis Percent Vegetable Oil.................... 55.0 Resins................................. 4.0 Thinner and Drier...........41.0 100.0 100.0 10% silica may be used to cut gloss if desired. ___ . , , ,, , . t The 9.2 lbs. litharge may be replaced by 35.4 lbs. (3.7 gals.) of lead naphthenate (24%) and compensation made by adjusting the mineral spirits content. EXTERIOR PRIMER Bz ** Pounds Non-Yol. Basic Carbonate White Lead............................ Basic Sulfate White Lead.................................. Rutile Non-Chalking Titanium Dioxide * ........................................................... Barytes t ............................................................... Magnesium Silicate............................................. Litharge J ............................................................. Raw Linseed Oil....................................... 159.8 Bodied Linseed Oil (Z-4)....................... 143.3 Ester Gum Cold Cut (10 lb.)................. 22.0 Cobalt Naphthenate (6%).................................. Mineral Spirits ................................................... Pounds 267.2 267.2 105.8 244.4 173.4 10.6 159.8 143.3 36.4 2.5 208.2 Gallons 4.7 5.1 3.1 6.6 7.3 0.1 20.7 17.1 4.6 0.3 31.8 1618.8 102.0 Pigment = 66.0% Vehicle = 34.0% P.V.C. = 39.7 Pig./Gal. Paint = 105.5 lbs. Consistency = 86 2 K.U Pigment Analysis Percent Basic Carbonate White Lead ........................ 25.0 White Basic Lead Sulfate. 25.0 Rutile Non-Chalking Ti tanium Lead................. 9.9 Barytes ............................. 22.9 Magnesium Silicate.........16.2 Litharge ........................... 1.0 Vehicle Analysis Percent Vegetable Oil .................... 55.1 Resins............. .................... 4.0 Thinner and Drier...........40.9 100.0 100.0 * Anatase type permitted. ' .. t About 10% silica may be used to replace barytes and/or magnesium silicate to con trol gloss. J The 10.6 lbs. litharge may be replaced by 40.8 lbs. (4.3 gals.) of lead naphthenate (24%) and compensation made by adjusting the mineral spirits content. ** This formula approximates Fed. Spec. TT-P-25a. Photomicrograph illustrating the meshing effect of spiney lead soap crystals formed by the reaction of white lead with fattv acids in the paint film. 4 Experimental paint films with varying lead pigmentation, after stripping, soaking and drying. As the lead con tent increases disinte gration is materially reduced. *y.; 1l ``i *{ '- , di' 'I; 4 Lead Non-lead Lead Non-lead f test ?a.n!l\ exPosed 30 months in Florida (left) and 36 months m Chicago (right) show how properly lead-pigmented house paints retain their elasticity, toughness, staying power and appearance. S 0^i If #* IH-' I Historic Baron Von Steuben head quarters erected in 1700atSouth Bound Brook, N. J., is pre served both inside and out with pure white lead paint. I i mmf* A typical private home protected and beautified by lead base exterior mixed pigment white paint. A typical New England landmark, the Congregational. Church at Litch field, Conn., is painted with white lead. WHITE LEAD PAINTS 157 HOUSE PAINTS The following are white and tint base formulations stabilized with substantial proportions of white lead. Carefully balanced formulas of this type provide long term protection, maintain exeellent appearance and offer excellent surfaces for eventual re painting. HOUSE PAINT BS--WHITE White Lead..................... Zinc Oxide ..................... Anatase Free-Chalking Titanium Dioxide * ..................... Magnesium Silicate___ Pounds Non-VoL Total Pounds 296.0 262.0 140.0 225.0 Raw or Refined Linseed Oil............ .............. 282.0 Bodied Linseed Oil (Z-2 to Z-3)............... .. 124.0 Lead Naphthenate (24%).............. Manganese Naphthenate (6%)___ Mineral Spirits............... 282.0 124.0 6.7 1.2 158.0 Gallons 5.o 5.6 4.3 9.5 36.5 15.5 0.7 0.2 24.2 Pigment = 61.7% P.V.C. = 32.4 1494.9 102.0' Vehicle = 38.3% Pig./Gal. Paint = 9.2 lbs. Consistency f Pigment Analysis Percent White Lead..................... . 32.1 Zinc Oxide....................... . 28.3 Anatase Free-Chalking Titanium Dioxide.... . 15.2 Magnesium Silicate ... . 24.4 Vehicle Analysis Percent Raw or Refined Linseed Oil ............... . 49.3 Bodied Linseed Oil (Z-2 to Z-3) .... . 21.7 Thinner and Drier......... . 29.0 100.0 100.0 * The free-chalking anatase titanium dioxide max be replaced in whole or in part by semi-non-chalking anatase to reduce chalking and erosion with some increase in dirt collection. t The consistency of this paint will vary depending upon the raw materials used. The oil content may be altered slightly to improve working properties. HOUSE PAINT BA--TINT BASE Pounds Non-Vol. White Lead................................................................... Zinc Oxide....................................... Rutile Non-Chalking Titanium Dioxide.................. Magnesium Silicate......................................... .... Total Pounds 296.0 262.0 112.0 251.0 Gallons 5.5 5.6 3.2 10.6 158 LEAD IN MODERN INDUSTRY Raw Linseed Oil................................................ 282.0 Bodied Linseed Oil (Z-2 to Z-3)..................... 124.0 Lead Naphthenate (24%)........................................ Manganese Naphthenate (6%) Mineral Spirits ......................... 282.0 124.0 6.7 1.2 158.0 36.5 15.5 0.7 0.2 24.2 Pigment = 61.7% P.V.C. = 32.3 1492.9 102.0 Vehicle = 38.3% Pig./Gal. Paint = 9.2 lbs. Consistency * Pigment Analysis Percent White Lead................. ... 32.1 Zinc Oxide................... ... 28.4 Rutile Non-Chalking Ti- tanium Dioxide ... ... 12.2 Magnesium Silicate .. ... 27.3 Vehicle Analysis Percent Raw Linseed Oil----- ........ 49.3 Bodied Linseed Oil (Z-2 to 25-3) ........................... 21.7 Thinner and. Drier..____ 29.0 100.0 100.0 * The consistency of this paint will vary depending upon the raw materials used. The oil content may be altered slightly to improve working properties. HOUSE PAINT Bo--WHITE Pounds Non-Vol. White Lead .................................................... ............. Zinc Oxide.......................................................... ...... Anatase Free-Chalking Titanium Dioxide *............ Magnesium Silicate..................................................... Raw or Refined Linseed Oil........................... 320.0 Bodied Linseed Oil (Z-2 to Z-3)................... 105.0 Lead Naphthenate (24%)......................................... Manganese Naphthenate (6%)................................ Mineral Spirits............................................................. Total Pounds 243.0 302.0 130.0 300.0 320.0 105.0 6.9 1.2 124.0 Gallons 4.5 6.5 4.0 12.6 41.4 13.1 0.7 0.2 19.0 Pigment = 63.5% P.V.C. = 33.8 1532.1 102.0 Vehicle = 36.5% Pig./Gal. Paint = 9.6 lbs. Consistency f Pigment Analysis Percent White Lead................. ... 24.9 Zinc Oxide ................. ... 31.0 Anatase Free-Chalking Titanium Dioxide .. ... 13.3 Magnesium Silicate .. ... 30.8 Vehicle Analysis Percent Raw or Refined Linseed Oil ......................... ........ 57.4 Bodied Linseed Oil (Z-2 to Z-3) ...................------- 18.8 Thinner and Drier.......... 23.8 100.0 100.0 The free-chalking anatase titanium dioxide may be replaced in whole or in part by semi-non-chalking anatase to reduce chalking and erosion with some increase in dirt collection. t The consistency of this paint will vary depending upon the raw materials used. The oil content may be altered slightly to improve working properties. WHITE LEAD PAINTS 159 HOUSE PAINT B6--TINT BASE Pounds Xon-Yol. White Lead ................................................... Zinc Oxide ................................................... Rutile Non-Chalking Titanium Dioxide.................. Magnesium Silicate..................... ............... Total Pounds 243.0 302.0 105.0 325.0 Raw Linseed Oil............................... ........... ... 320.0 Bodied Linseed Oil (Z-2 to Z-3).............. ... 105.0 Lead Naphthenate (249&)......................... Manganese Naphthenate (6%)................. Mineral Spirits ........................................... 320.0 105.0 6.9 1.2 124.0 Gallons 4.5 6.5 3.0 13.6 41.4 13.1 0.7 0.2 19.0 1532.1 102.0 Pigment = 63.59c Vehicle = 36.59c P.V.C. = 33.8 Pig./Gal. Paint = 9.7 lbs. Consistency * Pigment Analysis White Lead ..................... 24.9 Zinc Oxide ....................... 31.0 Rutile Non-Chalking Ti tanium Dioxide ............. 10.8 Magnesium Silicate.........33.3 Vehicle Analysis Raw Linseed Oil.............. 57.4 Bodied Linseed Oil.......... 18.8 Thinner and Drier.......... 23.8 100.0 100.0 * The consistency of this paint will vary depending upon the raw materials used. Tin* oil content may lie altered slightly to improve working properties. CHAPTER TWENTY-FOUR Metal Protective Lead Paints RED LEAD PAINTS Red l e a d has long been the most important pigment in the production of metal protective paints, particularly metal primers. In fact for more than a century pure red lead paint has been considered the standard priming coat for the protection of iron and steel against corrosion and rust. However, modern research has not only brought about improve ments in red lead pigment and pure red lead paint, but also has developed a variety of multiple pigment paints, containing red lead as the principal pigment, which are designed to meet specific conditions. While pure red lead and linseed oil paint gives out standing service where there is ample time for drying, it is now possible to formulate red lead paints which will meet exacting requirements for quick drying, low cost, light weight, salt or fresh water exposure, or other conditions as the formulator or specifier may desire. Properly formulated multiple pigment or pure red lead paints adhere tenaciously and form impervious films resistant to water, many corrosive gases, and air. Red lead has a strong affinity for linseed oil, forming lead soaps in the paint. These strengthen the film, which is tough and elastic when dry, so that it can ex pand and contract as the surface expands and contracts with temperature changes. Furthermore, red lead effectively inhibits the anodic solution of steel through its oxidizing character and buffering action. The basic character of red lead also minimizes the destructive action of low molecular weight organic acids resulting from the breakdown of Oleoresinous vehicles after prolonged exposure to weathering and adverse environmental conditions. 160 METAL PROTECTIVE LEAD PAINTS 161 Both, in impartial competitive tests and in actual performance, red lead paint has proved its worth. For instance, the Corrosion Committee of the Iron and Steel Institute of Great Britain in its 1943 report stated, "As regards to the paints themselves, the priming coat should be of an inhibitive character. So far no paint tested by the committee has proved superior to red lead for this purpose." In May, 1949 a report was published by the American Iron and Steel Institute on a study of paints for enclosed structural members in steel housing construction. This comprehensive re search project was carried out at the Battelle Memorial Institute. The following was among the conclusions reached after exposing thirty-four different paint systems to continuous immersion in water, contact with air at high humidity and alternate wet-dry conditions: "Considering all factors in rating the various coat ings, System C (red lead) appears to be outstanding. It has a good blister rating, affords excellent protection to the base metal, as evidenced by low weight loss and slight visual evidence of attack on the steel and, as previously mentioned, penetration and undercutting at the damaged zone are either negligible or slight." But even more conclusive than such statements are the pro tective jobs red lead is actually performing. It is the priming coat of paint on such bridges as the San Francisco-Oakland Bay, Brooklyn, and George Washington Bridges; the majority of state highway departments use red lead primers on steel; by far the majority of railroads use red lead for priming steel struc tures; millions of tons of ships including the U. S. Navy have been primed with red lead paint; and far more than any other paint it has been depended upon for the first coat on steel struc tures of all kinds. The use of red lead paints is included in the latest recommen dations of the American Water Works Association for both the exterior and interior of steel water tanks. Recommended Prac tices include the following statement: "The outside prime coat or patch coat shall comply with Federal Specifications TT-P-86a, Type I, which require the use of red lead in linseed oil weighing not less than 25 lb. per gallon." With reference to steel tank interiors this same bulletin says, "All interior surfaces of the 162 LEAD IN MODERN INDUSTRY tank shall be painted with (or touched up with) paint comply ing with Federal Specifications TT-P-86a, Type IV, with all subsequent amendments, if any." This specification calls for a red lead base paint containing a highly water impervious and chemically resistant spar varnish vehicle. Red lead is available as a dry powder, as a paste, or as readymixed paint in which the pigment is all red lead or a mixture of red lead and other pigments. The following formula is typical of pure red lead and linseed oil paint made from paste red lead: Paste red lead Raw linseed oil Turpentine .. Liquid drier . Total paint .. 100 lb. li gal. , li pt li pt 4i gal. Pure red lead and multiple pigment red lead paints are avail able in ready-mixed form, either untinted or tinted to offer con trast between coats. Red lead paint specifications based on practical experience are available to meet a wide variety of drying requirements, surface conditions and exposure environments. Red lead has proven adaptable to successful formulation with a wide variety of fast drying, durable synthetic resins developed in recent years. These include alkyd, phenolic and vinyl type vehicles. Extensive research work is being continued by the Lead In dustries Association, government agencies and others toward the development of improved red lead paints to meet a diversity of requirements. The Lead Industries Association is prepared to give technical assistance to formulators, specfiers and users of metal protective paints. White lead base paints, tinted as desired, are frequently used as finish coat paints over red lead primers. Where a me tallic finish is desired, aluminum finish paints containing alkyd or. phenolic type synthetic vehicles, have been used very suc cessfully over red lead paints for steel structures exposed to the atmosphere. A number of typical formulas for straight red lead and multi ple pigment red lead base paints follow, together with the type of exposures for which they are. recommended and other com ments pertinent to their proper usage. METAL PROTECTIVE LEAD PAINTS 163 ATMOSPHERIC EXPOSURE Primers based on the following formulas are indicated for use on bridges, similar structural steel and other ferrous metal surfaces. They are suitable for priming and body, either in the shop or field, where good resistance to the corrosive effects of the usual atmospheric environment is required. The vehicle solids, consisting entirely of linseed oil offer the best means of wetting the metal and obtaining an intimate bond between the paint and the surface, despite the presence of limited amounts of corrosion products found impractical to remove. PAINT B7 (Federal Specification TT-P-86a, Type I) Percent Pig me n t : Red Lead (97% Grade)........... ___ 99.7 Aluminum Stearate................... .... 0.3 Pounds 1860.0 5.5 Gallons 25.96 0.66 . 100.0 Ve h ic l e : Raw Linseed Oil......................... ___ Pale Heat Bodied Linseed Oil (Z-2 Viscosity) ................... .... Mineral Spirits........................... .... Drier * .......................................... ___ 49.0 17.0 29.0 5.0 262.0 90.8 154.5 26.4 34.80 11.60 23.80 3.18 Pigment = 77.8% Vehicle = 22.2% * Federal Specification TT-D-CDla, Type I. 100.0 2399.2 Wfc/Gal. = 24 lbs. PV = 36% 100.00 The following primer formulas were designed for the priming and general maintenance of structural steel where work sched ules call for an overnight dry and complete removal of rust and mill scale is not feasible. A vehicle composed of a blend of lin seed oil and synthetic resin has proven to be a successful com promise under these conditions. Since the vehicle is a compro mise, its wetting and penetrating characteristics are limited. Consequently it should only be applied to surfaces freed of loose mill scale and corrosion products. 164 LEAD IN MODERN INDUSTRY PAINT B8 (Federal Specification TT-P-86a, Type II) Pig me n t : Percent Red Lead (97% Grade) ..................... 65.0 Iron Oxide (85% Fe,03) ..................... 16.0 Magnesium Silicate ... ..................... 14.5 Mica ............................... ..................... 4.2 Aluminum Stearate ... ............ .. 0.3 Pounds 746.0 184.0 168.0 46.0 3.5 Gallons 10.30 4.96 7.13 1.95 0.42 100.0 Ve h ic l e : Alkyd Resin * ............... ..................... Raw Linseed Oil........... ..................... Mineral Spirits............. ..................... Lead Naphthenate Drier (24% Pb) . Cobalt Naphthenate Drier (6% Co). 57.0 28.0 14.1 0.6 0.3 327.0 163.0 83*o 4.2 1.7 40.96 20.90 12.80 0.44 0.20 100.0 1726.9 100.00 Pigment = 66.4% Vehicle = 33.6% Wt./Gal. = 17 lbs. PV = 38% * Medium oil length linseed modified glyceryl phthalate alkyd (34% phthalic anbydride), 50% solution in mineral spirits. PAINT B9 Pig me n t : Percent Read Lead (Fed. Spec. TT-R-191a, Type I, Grade C).. ..................... 75.0 Iron Oxide........................................... 24.7 Aluminum Stearate-----..................... 0.3 Pounds 1240.0 407.0 5.0 Gallons 16.80 11.70 0.70 100.0 Ve h ic l e : Raw Linseed Oil.......... Alkyd Resin * ..................................... Lead Naphthenate Drier (24% Pb). Cobalt Naphthenate Drier (6% Co) . 33.6 0.8 0.3 358.0 184.0 4.6 1.8 46.30 23.80 0.50 0.20 100.0 2200.4 Pigment = 75% Vehicle = 25% Wt./Gal. = 22 lbs. PV = 32% * D. S. Maritime Commission Specification 52-MC-501, Type IL 100.00 The. following synthetic vehicle paint was formulated for thoroughly cleaned iron and steel surfaces and for touch-up work where drying within a six-hour period is desired. It is intended for use on smooth steel, particularly as an industrial primer for articles fabricated at the factory, such as railroad cars, window sash, air conditioning conduits, etc. It is also well Practically all metal surfaces, interior and exterior, of ships such as the Queen Mary are primed and maintained with red lead base paint. The exteriors of gas holders and water tanks are customarily primed with red lead paint. Water tank interiors are protected with a special red lead base paint. Wide World Painters applying red lead to New York's Queensboro Bridge. Most of the world's steel bridges are primed with red lead base paint. United Xat ions The United Nations Building flanked by the Empire State and the Chrysler Buildings each have their steel framework protected by red lead base paint. METAL PROTECTIVE LEAD PAINTS 165 suited as a fast drying- g-eneral maintenance primer for touch-up work on thoroughly cleaned steel. PAINT BIO (Federal Specification TT-P-86a, Type III) Percent Pig me n t : Red Lead (97% Grade)................... . 99.7 Aluminum Stearate......................... . 0.3 Pounds 1275.0 3.5 Gallons 17.20 0.46 Ve h ic l e : 100.0 Alkyd Resin* .................................... . Aromatic Petroleum Spirits........... . Cobalt Naphthenate (6% Co)----- . Antioxidants and Wetting Agents. . 84.0 14.5 0.3 1.2 522.5 90.0 1.9 7.6 67.50 13.70 0.20 0.94 100.0 1900;5 100.00 Pigment = 67.3% Vehicle = 32.7% Wt./GaL = 19 lbs. PV = 38% Medium oil length linseed modified glyceryl phthalate alkyd conforming to the requirements of Federal Specification TT-K-266, Type III. MARINE ATMOSPHERIC EXPOSURE AND INTERMIT TENT SEA WATER IMMERSION Paints made according to the following formulas are suitable for priming iron and steel surfaces on the topsides of ships, bridges situated along the seacoast or over tidewaters, dock structures and other atmospherically exposed marine installa tions. These primers dry fast enough to permit recoating in six hours under normal drying conditions. Since these paints con tain synthetic vehicles they should be applied only over thor oughly cleaned surfaces. PAINT Bll (Bureau of Ships Paint Formula No. 116, Primer, Exterior, Maintenance, June 1, 1949) Pig me n t : Percent Founds Red Lead (Fed. Spec. TT-R-191, Type I, Grade B)................. 55.0 380 Zinc Yellow (Fed. Spec. TT-Z- 415) 10.1 70 Mica (Navy Dept. Spec.52M3). 9.4 65 Indian Red (Fed. Spec. TT-I-511, Type I) .................................. 1.5 10 Magnesium Silicate (Navy Dept. Spec. 52M2, Type A)........... 23.1 160 Aluminum Stearate (Navy Dept. Spec. 52A12) ..................... 0.9 6 Gallons 5.13 2.33 2.77 0.23 6.70 0.71 166 LEAD IN MODERN INDUSTRY Ve h ic l e : Alkyd Resin Solution (Fed. Spec. TT-R-266, Type I, Class A) *. Dipentine (Fed. Spec. TT-D-376) Paint Thinner (Fed. Spec. TT-T- 291, Grade I)......................... Lead Drier (Fed. Spec. TT-D- 643, Type I)........................... Cobalt Drier (Fed. Spec. TT-D- 643, Type II)......................... 64.9 3.9 29.6 0.8 0.8 415(290.5) 25.0 190.0 4.7 4.7 52.00 3.52 29.20 0.49 0.59 100.0 1330.4 103.67 Alkyd Besin Solution (Federal Specification TT-K-266, Type I, Class A) : A solution of a soy oil-modified alkyd resin containing not less than 23% phthalic anhydride and a fatty acid content of 60-75%. The specification calls for the following characteristics: Non-Volatile = 69-71% Viscosity (Gardner-Holdt) = T-Z2 Acid Number = 5-10 (on solids) The following anticorrosive red lead formulations are intended especially for paints for priming and undercoats on ship boat topping areas and on parts of marine structures undergoing intermittent sea water immersion by tidal action. These for mulas are also well adapted for surfaces exposed to marine atmospheric environments. These quick drying paints contain straight synthetic vehicles and should be applied only to thor oughly cleaned surfaces. PAINT B12 Pig me n t : Percent Red Lead (97% Grade)..................... 52.8 Zinc Yellow......................................... 10.0 Zinc Oxide, Lead Free....................... 7.9 Mica, Graphitic ................................. 15.1 Raw Sienna ....................................... , 3.9 Magnesium Silicate........................... 10.0 Aluminum Stearate........................... 0.3 Pounds 330.0 62.8 49.8 94.3 24.9 62.8 1.9 100.0 Ve h ic l e : Oleoresinous Varnish Vehicle *___ Aromatic Mineral Spirits........ .. Lead Naphthenate (24% Pb).......... Cobalt Naphthenate (6% Co)........ Manganese Naphthenate (6% Mn). Anti-Skinning Agent f ..................... 61.9 37.1 0.7 0.1 0.1 0.1 391.3 234.5 4.3 0.7 0.7 1.0 Pigment = 49.8% ' Vehicle = 50.2% 100.0 1259.0 Wt./Gal. = 12.6 lbs. PV = 35% Gallons 4.50 2.15 1.07 3.88 0.93 2.65 0.23 52.32 81.50 0.44 0.08 0.08 0.17 100.00 METAL PROTECTIVE LEAD PAINTS 167 * Description of Oleoresinous Varnish Vehicle : A long oil modified phenolic varnish formulated as follows : Modified Phenolic Resin..............................................100 lbs. China Wood Oil...................................... 34 gallons Alkali Refined Linseed Oil......................................... 16 gallons Mineral Spirits .......................................................... 45 gallons V. M. and P. Naphtha................................................ 15 gallons Dipentine ..................................................................... 5 gallons Cooking Procedure: Run resin, china wood oil and 10 gallons of alkali refined linseed oil to 500*F. Hold for body (40 minutes for laboratory batch) : Add 6 gallons of alkali refined linseed oil and all of the heavy bodied linseed and heat to 475*F. Hold for 10 to 15 minutes. Take off fire, cool and reduce to viscosity of G-H (Gardner-Holdt). Properties: Non-Volatile = 60% by weight Viscosity = G-H (Gardner-Holdt) Color = 6 L-6 Acid Number = 7.3 f An anti-skinning agent of the aliphatic oxime type. CONTINUOUS IMMERSION IN SEA WATER The following formulation has been designed for use with antifouling paints for the protection of steel ship bottoms and continuously immersed marine structures. This primer can be used with a variety of antifouling paints. One example of a high quality bottom paint system is this red lead-coumarone anticorrosive primer applied over clean steel in multiple coats to a dry film thickness of 3 mils and followed by the application of 6 mils of antifouling paint such as Navy Cold Plastic 105, Maritime Commission Specification 52-MC-403 or Military Specification MIL-P-15931. If desired the anticorrosive paint can be applied on phosphate treated steel surfaces. The anti corrosive paint may be applied by brushing or spraying. A mini mum drying period of six hours should be allowed between coats and before application of the antifouling paint. PAINT Bis Pig me n t : Percent Red Lead (97% Grade)..................... 47.0 Zinc Oxide............................................ 8.3 Zinc Yellow.......................................... 8.8 Mica (325 Mesh)................................. 8.3 Magnesium Silicate ........................... 0.4 Aluminum Stearate ........................... 0.4 100.0 Ve h ic l e :* Coumarone-Indene Resin (M. R. 127137C.) f ...................................... Coumarone-Indene Resin (M. R. 515 C.) t ........................................ 25.4 8.7 (Continued next page) Pounds 332.0 58.1 62.2 58.1 192.0 3.1 166.0 * 57.0 Gallons 4.51 1.24 2.08 2.46 0.37 0.37 18.12 6.22 168 LEAD IN MODERN INDUSTRY Ve h ic l e * (con't) : Percent Liquid Coal Tar (Navy Dept. Spec. 52T5a) ........................... ............. 8.9 Zinc Resinate ....................... ............ 3.2 Chlorinated Rubber............. ............. 6.3 Hi-Flash Naphtha............... ............. 31.7 Aliphatic Petroleum Spirits (Boiling Range 105-260F.) ... ............ 15.0 Pine Oil................................. ............. 0.8 Pounds 58.1 20.8 41.5 208.0 98.5 5.2 Gallons 5.87 2.17 3.03 28.50 16.69 0.67 100.0 1360.6 100.00 Pigment = 51.9% Vehicle = 48.1% Wt./Gal. = 13.6 lbs. PV = 35% * This vehicle may be prepared by heating the coumarone resins and liquid coal tar together to a temperature of 445"F.. adding the zinc resinate and holding temperature until it is all melted in. All of the petroleum spirits and SO gallons of the required Hi-Flash naphtha may then be added. The chlorinated rubber can then be dissolved into the remaining Hi-Flash naphtha at room temperature. The chlorinated rubber should be blended in with the remainder of the ingredients only after the coumaronecoal tar-resinate mixture has cooled to 140F. or less. To avoid decomposition, the chlorinated rubber should never be heated above 140'F. Although the above method is preferred, the vehicle may also be prepared by cold cutting the indicated ingredients. t A coumarone-indene resin with a melting range of 127-1 """C. t A coumarone-indene resin with a melting range of fi-lo'C. Note: Only dark colored finishes should be applied over this primer since bleeding through of the coal tar may occur. However this does not affect its protective per formance. The following anticorrosive paint consists of a red lead pig mentation incorporated into a vinyl chloride-acetate copolymer resin binder. The well known corrosion inhibitive characteristics of red lead and the excellent water impermeability and high abrasion resistance of vinyl resins are combined in this paint. The inherent heat and light stabilizing effect of lead compounds makes red lead an especially valuable pigment for use in vinyl type vehicles. The red lead-vinyl anticorrosive paint, applied as part of a conventional vinyl anticorrosive-antifouling system, is particu larly well suited for the protection of metal surfaces immersed in or exposed to sea water. This vinyl anticorrosive paint also offers long term protection for ferrous surfaces exposed to fresh water, and highly corrosive atmospheric environments. A suggested basis for an outstanding system for marine ser vice or for highly corrosive atmospheres consists of 0.3-0.5 mil of a metal conditioner 1 followed by a total of 4 mils of a red lead- 1 As the name implies the metal conditioner is intended primarily to pro vide a firm bond between the metal surface and subsequent coats and assure good adhesion. It is necessary to follow the metal conditioning treatment METAL PROTECTIVE LEAD PAINTS 169 vinyl anticorrosive paint applied in three sprayed coats (double pass for each coat). This should be followed with suitable top coats. For details regarding the composition and uses of vinyl antifouling paint reference can be made to Military Specification MIL-P-15931 or U. S. Coast Guard Specification CGS-59P-3a. Other types of finish coat paints can also be used depending upon color preference and exposure environment. For maximum serv ice the metal surface should be freed of surface contaminants by sandblasting or other equally effective means. PAINT BlU (This formula conforms with the requirements of Military Specification MIL-P-15929 or U. S. Coast Guard Specification CGS-52P-4a) Percent Pig me n t : Red Lead (Fed. Spec. TT-R-191, Type I, Grade C)......... ...............100.0 Pounds 213.53 Gallons 2.92 100.0 Ve h ic l e : Vinyl Resin * ....................... ............. Trieresyl Phosphate ........... ............. Toluene f ............................... ............. Methyl Isobutyl Ketone f.. ............. 19.36 1.94 39.35 39.35 142.35 14.24 289.45 289.45 12.29 1.44 43.41 39.94 100.00 949.02 100.00 Pigment = 22.5% Vehicle = 77.5% Wt./Gal. = 9.5 lb. PV = 17.5% * A copolymerized vinyl chloride-acetate resin meeting the following composition requirements: 89.5 to 91.5% (by weight) of vinyl chloride, 5.8 to 7.0% (by weight) of vinyl alcohol and 2.0 to 5.5% (by weight) of vinyl acetate. Such a resin is typified by Carbide and Carbon Corporation's VAGH. t For application in extremely hot weather 6.0 to 8.0% of the methyl isobutyl ketone may be replaced with cyclohexanone and 6.0 to S.0% of the toluene may be replaced with xylene to reduce the volatility. Note: For the purpose of differentiating between coats or to minimize contrast the above formula can be modified to a brown color by including 0.25% lampblack by weight of the total pigment. CONTINUOUS IMMERSION IN FRESH WATER The following formulation was designed primarily as an anti corrosive paint for total immersion in fresh water. It is a fast, hard drying red lead base paint incorporating a highly water impermeable and chemically resistant spar varnish vehicle. This paint is included in the recommended practice of the American with priming anticorrosive paints which are essential to the satisfactory per formance of metal protective paint systems. For details regarding the com position and use of the metal conditioner reference can be made to Military Specification MIL-P-15328 (SHIPS) or U. S. Coast Guard Specification CGS-52P-7. 170 LEAD IN MODERN INDUSTRY Water Works Association 1 for the priming of water tank in teriors. A dry film thickness of approximately 6 mils (3-4 coats) is suggested for this type of application. This paint is also suitable on iron and steel surfaces exposed to the atmosphere, particularly under conditions of high hu midity. In addition to its excellent water impermeability, this paint also has good resistance to alkaline environments. Water storage tanks, structural work on dams, equipment in bottling plants, laundries and mines are typical of steel surfaces on which this paint is effective as a protective coating. This paint drys to a tack free film in 4 hours under normal conditions. Clean steel surfaces, free from rust and mill scale, are re quired to insure the best performance of this paint. PAINT B15 (Fed. Spec. TT-P-86a, Type IV) Pig me n t : Percent Red Lead (97% Grade)............. .... 85.0 Diatomaceous Silica................... ___ 8.0 Magnesium Silicate ...................____ 6.6 Aluminum Stearate................... .... 0.40 Pounds 950.0 89.6 74.0 4.4 Gallons 12.85 5.36 3.10 0.53 100.00 Ve h ic l e : Phenolic Varnish *..................... .... Aromatic Petroleum Spirits... .... Dipentine ..................................... .... Antioxidants ............................... .... Lead Naphthenate (24% Pb).. .... Cobalt Naphthenate (6% Co).. ___ Manganese Naphthenate (6% Mn). 74.0 22.4 2.75 0.5 0.23 0.06 0.06 432.0 129.7 16.0 2.2 1.4 0.3 0.3 57.70 17.70 2.26 0.27 0.15 0.04 0.04 100.00 1699.9 100.00 Pigment = 65.9% Vehicle = 34.1% Wt/Gal. = 17 lbs. PV = 41% * Phenolic Varnish : Phenolic Resin (100% para tertiary amyl phenol-formaldehyde resin).. 20.25% Tung Oil (F. S. JJJ-O-353)............................................................................. 39.75 Mineral Spirits (F. S. TTT-T-291a, Grade 1)............................................. 40.00 100.00% Cooking Procedure: Heat all the resin and oil to 465F. in 40 minutes. Hold the batch at this temperature long enough (35-40 minutes) to obtain the desired viscosity when thinned to the specified solids content. Water-cool and thin with mineral spirits.Oil Oil Length ___ 25 gallons Non-Volatile __ 59-61% Viscosity (G-H). F-H Color (Hellige). 9 Wt./Gal................. 7.5 lbs. Drying Time: Set to Touch. 2hrs. Print Free .. 8hrs. i Tentative Recommended Practice for Inspecting, Repairing and Repaint ing Elevated Steel Water Storage Tanks, Standpipes and Reservoirs, A.W.W.A. 7H.2-T, 1949. METAL PROTECTIVE LEAD PAINTS 171 BLUE LEAD PAINTS Blue lead, also referred to as basic lead sulphate-blue, is a pigment which consists of basic lead sulphate and small amounts of lead sulphite, lead sulphide, zinc oxide plus a very small amount of carbon. The principal use of blue lead is in the manufacture of paint for the protection of iron and steel surfaces. Its pleasing blue-grey color, extreme fineness and unusual hiding power, in combination with excellent rust inhibitive qualities, make blue lead an excellent pigment for use in paints intended for rust prevention. Blue lead is marketed in dry form and in paste form, that is, ground in linseed oil. The paste-in-oil and the dry pigment meet Federal Specification TT-B-486 and ASTM Standard D405-41. In ready-mixed paint as a primer for iron and steel, it is covered by Federal Specification TT-P-20 and in many State Highway and other specifications. Blue lead exhibits the same affinity for linseed oil and con stituents of vehicles used in paints as shown by other lead pig ments. It has excellent paint film forming properties, giving a film which retains its flexibility over a long period of time. It imparts this characteristic to mixed pigment paints containing, for example, zinc chromate, basic silicate white lead, zinc oxide and certain inert materials such as magnesium silicate and diatomaceous earth. While blue lead shows good performance in atmospheric ex posure it excels in combination with basic silicate white lead in damp and humid exposures and in fresh and salt water exposures. The following formula is typical of pure blue lead and linseed oil paint made from blue lead oil paste. Blue lead in oil................................................................ 100 lb. Raw linseed oil.................................................................. 2 gal. Turpentine (or equivalent)......................... ................. li pt. Liquid drier................................................................ .. 2 pt. Total paint ................................................................ .. 6i gal. A number of typical formulas for straight blue lead and mul tiple pigment blue lead base pigments follow together with the type of exposure for which they are recommended. 172 LEAD IN MODERN INDUSTRY READY-MIXED BLUE LEAD BASE PAINT FOR ATMOSPHERIC EXPOSURE PAINT B16 (Fed. Spec. TT-P-20) Percent Pig me n t : Blue Lead .................................... .......... 100.0 Pounds 1475.51 Gallons 26.12 Ve h ic l e : Raw Linseed Oil......................... ........ Mineral Spirits......................... ........ Pb Naphthenate 24%........................ Co Naphthenate 6%................. ......... 90.20 7.32 1.88 0.60 512.55 41.49 10.63 3.47 66.01 6.33 1.11 0.43 100.00 2043.65 100.00 Pigment = 72.2% Vehicle = 27.8% Wt./Gal. = 20.44 lbs. PV = 28.35% Note: This formulation is a standard linseed oil, rust inhibitive, ready-mixed paint, conforming to Federal Specification TT-P-20. For a dry film thickness of 1.5 mils, the spreading rate is 980 sq. ft. per gallon. Drying time, 15 hours, dust-free; 18 hours, re-coat. BLUE LEAD PRIMER FOR ATMOSPHERIC EXPOSURE PAINT B17 (Fed. Spec. TT-R-266, Type III) Percent Pig me n t : Blue Lead ................................................ 54.0 Zinc Chromate .................................. .... 18.0 Lead Free Zinc Oxide...................... ... 8.0 Magnesium Silicate..................... ... 15.0 Diatomaceous Silica..................... ... 5.0 Pounds 463.3 154.5 68.9 128.5 42.9 Gallons 8.20 5.36 1.46 5.41 2.21 100.0 Ve h ic l e : Raw Linseed Oil........................... ... *Alkyd Resin Solution................. ... Mineral Spirits.................................. ... Pb Naphthenate 24% Pb............... ... Co Naphthenate 6% Co................. ... 30.3 60.4 7.5 1.3 0.5 177.1 354.1 44.2 7.3 3.0 22.81 46.60 6.79 0.78 0.38 100.0 1443.8 100.00 Pigment = 59.4% Vehicle = 40.6% Wt./Gal. =: 14.44 lbs. PV =: 35.0% Note: For a dry film thickness of 1.5 mils, the spreading rate is 690 sq. ft. per gallon. Drying time, 4 hours, dust free; 8 hours, re-coat. BLUE LEAD PRIMER FOR FRESH WATER IMMERSION PAINT B18 Percent Pig me n t : Blue Lead .............................................. ... 80 Basic Silicate White Lead............ . .. 20 Pounds 927.97 231.99 Gallons 16.43 4.80 100 METAL PROTECTIVE LEAD PAINTS 173 Ve h ic l e : Varnish* ......................... ................. 99 Guaiacol ............................ ................. 1 578.41 5.93 78.14 0.63 100 1744.30 100.00 Pigment = 66.5% Vehicle = 33.5% Wt./Gal. = 17.44 lbs. PV = 35.0% Note: For a dry film thickness of 1.5 mils, the spreading rate is 640 sq. ft. per gallon. Drying time, 2 hours, dust-free; 4 hours, re-coat. * Varnish is a S3 gallon china wood oil phenolic (100% para tertiary amyl phenolformaldehyde resin) 55% solids by wt. Body B-C. Weighs 7.4 lbs./gal. BLUE LEAD PRIMER FOR INTERMITTENT OR TIDE LEVEL SEA WATER IMMERSION PAINT B19 Percent Pig me n t : Blue Lead ............................... ........... 60.0 Basic Silicate White Lead... ........... 15.0 Lead Free Zinc Oxide............. ........... 10.0 Magnesium Silicate............... ........... 7.5 Diatomaceous Silica............... ........... 7.5 Pounds 441.42 110.42 73.57 55.14 55.14 Gallons 7.81 2.29 1.57 2.32 2.84 Ve h ic l e : 100.0 Varnish * ................................. Mineral Spirits....................... ........... Guaiacol ................................... ........... 9.6 0.9 545.25 58.51 5.51 73.66 8.92 0.59 100.0 1344.96 100.00 Pigment = 54.7% Vehicle = 45.3% Wt./Gal. = 13.45 lbs. PV = 31.2% Note: For a dry film thickness of 1.5 mils, the spreading rate is 570 sq. ft. per gallon. Drying time, 2 hours, dust-free; 3 hours, re-coat. * Varnish is a 25 gal. china wood oil phenolic (100% para tertiary amyl phenolformaldehyde resin) 55% solids by wt. Body At. Wt. 7.40 lbs. per gal. BLUE LEAD PRIMER FOR CONTINUOUS SEA WATER EXPOSURE PAINT B20 Pig me n t : Blue Lead........................... Basic Silicate White Lead Lead Free Zinc Oxide----Magnesium Silicate........ Diatomaceous Silica........ Percent ... 60.0 ... 15.0 ... 10.0 ... 7.5 ... 7.5 Pounds 510.24 127.56 85.04 63.78 63.78 Gallons 9.03 2.64 1.81 2.69 3.29 Ve h ic l e : Varnish* ----Mineral Spirits Guaiacol ......... 100.0 ... 90.9 ... 8.2 ... 0.9 541.62 48.88 5.35 72.52 7.45 0.57 Pigment = 58.8% Vehicle = 41.2% 100.0 1446.25 Wt./Gal. = 14.46 lbs. PV = 34.9% 100.00 Note: For a dry film thickness of 1.5 mils, the spreading rate is 590 sq. ft. per gallon. Drying time, 1 hour, dust-free; 2 hours, re-coat. Varnish is a 15 gal. phenolic (100% para tertiary amyl phenol-formaldehyde resin) 55% solids by wt. Body A. Weighs 7.47 lbs. per gal. CHAPTER TWENTY-FIVE The Safe Handling of Lead and Its Products Wh il e , like nearly everything we use in modern liv ing, lead if improperly used and handled may be a health hazard, its properties have been recognized for so many years, its use has been so widespread and its toxicology has been studied so extensively that methods for handling lead and its products with complete safety are well understood. In spite of all this, how 1: ever, erroneous and alarming statements are still made from time to time and unfounded prejudices still persist. To result in lead intoxication (lead poisoning), the lead must gain entrance into the human system in measurable quantity, usually by one or both of two means: (1) inhalation of vapors, fumes or dust or (2) ingestion of lead compounds introduced into the mouth on the fingers or with food, tobacco, etc., or swal lowed as a result of being trapped in the upper respiratory tract. Of the two, ingestion is by far the less important and is most often associated with children chewing on objects coated with paints containing lead. However, since most inside paints and paints used by manufacturers on children's furniture and toys contain no lead, a hazard usually exists only if children are allowed to chew outside painted surfaces, like porch railings, or if parents inadvertently repaint furniture with outside house paint. Pica (abnormal appetite in children) or teething may cause them to chew on painted surfaces and also on many other substances which may be injurious to health. The average healthy adult normally ingests with his food and drink minute quantities of lead. He inhales air containing a small quantity. But only a fractional portion of ingested lead is actually absorbed into the body, most of it being eliminated by normal body processes. The human system can tolerate lead to this extent without disturbing the individual's sense of well- 174 THE SAFE HANDLING OF LEAD AND ITS PRODUCTS 175 being. To produce lead intoxication or poisoning, an abnormal and extended exposure to lead must take place. As it is not practical in all industrial operations to eliminate completely the possibility of lead exposure, a maximum allowable atmospheric limit has been established: a concentration of 1.5 mg. of lead per 10 cubic meters of air. In other words, when the air of workrooms regularly contains not more than 1.5 mg. of lead per 10 cubic meters of air, no cases of disabling lead intoxi cation can be expected to occur among the men who regularly work there. Certain principles have been laid down which are helping im measurably in the prevention of lead intoxication in industrial operations where lead is used. Probably the one factor which has contributed most is the adoption of good housekeeping methods. These should include encouraging personal cleanliness on the part of the workmen, providing showers and clean lunch rooms, keeping floors well swept and preventing careless handling of materials. Processes have been revamped in many instances to reduce the duration of exposure. Newer equipment is being constructed with exhaust devices as integral parts. Lead fumes are being suppressed and collected by a variety of fume scrubbers and similar devices to prevent atmospheric pollution. Exposures which are necessarily hazardous are being localized in specific areas where they can be controlled. Many large companies manufacturing lead products maintain qualified physicians, industrial hygienists and nurses on their staffs. Regular inspections are made of all departments where lead or its products are handled to check the lead content of the air as well as the functioning of special equipment such as res pirators, exhaust fans, hoods, fume scrubbers, etc. They also check periodically the lead absorption of all workmen exposed to such conditions. Many small plants retain a hygienist or medical man on a part-time basis for this purpose, often in con junction with other companies in the same area. Lead intoxication can be cured and recovery is usually com plete, leaving no disability. In all cases treatment for lead in toxication must be undertaken by a properly qualified physician and should be administered only after it has been determined 176 LEAD IN MODERN INDUSTRY beyond doubt that the illness is actually due to excessive lead absorption. This point cannot be stressed too highly in view of the fact that most symptoms of lead intoxication are very similar to those of other illnesses, such as appendicitis or simple colic, and are oftentimes confused by individuals not fully acquainted with the characteristics of true lead intoxication. A complete history should be taken in each case, in order to certify the cause, nature, degree and duration of the exposure and a complete diag nosis, including analyses, is necessary. Detection of lead absorp tion may be by such methods as examination or analysis of the blood or analysis of the feces or urine for the presence of lead. But no one of these alone can be relied upon as a sure means of detection. Two or more methods should always be used in com bination to check the findings. The treatment is seldom compli cated and many excellent published works are available on both diagnosis and treatment, for example, the publication "Occupa tional Lead Exposure and Lead Poisoning," obtainable from the American Public Health Association, 1790 Broadway, New York 19, N. Y. at 75^ per copy. Detailed information on this subject is available from the office of the Lead Industries Association. i s' #A, *\ CHAPTER TWENTY-SIX Specifications for Lead, Lead Alloys and Lead Products Th is chapter contains a tabulation of many govern ment, commercial, and other standard specifications for lead, its alloys and products. Abbreviations used in this chapter refer to standards or specifications as identified below: A.A.S.H.O. A.S. A.S.A. A.S.T.M. A.W.W.A. C.S. ......... F.S. American Association of State Highway Officials, 1220, National Press Building, Washington 4, D. C. Army Specifications obtainable from Office of Chief Engineer, Washington 25, D. C. Standards approved by the American Standards Association, 70 East 45th St., New York 17, N. Y. Standards and Tentative Standards published by the American Society for Testing Materials., 1916 Race St., Philadelphia 3, Pa. Standards and Tentative Standards published by the American Water Works Association, 500 Fifth Ave., New York 18, N. Y. Commercial Standards representing voluntary standards of the trade, prepared under the proce dure of the National Bureau of Standards and published by the United States Department of Commerce. Obtainable from the Superintendent of Documents, U. S. Government Printing Office, Washington 25, D. C. Federal Specifications published by the Federal Specifications Board and obtainable from the Superintendent of Documents, U. S. Government Printing Office, Washington 25, D. C. 177 178 LEAD IN MODERN INDUSTRY L. I.A. M. C. M. S.S. N. S. S. A.E. T. D. T.V.A. Standards published by the Lead Industries Asso ciation, 420 Lexington Ave., New York 17, N. Y. Maritime Commission Specifications set up for U. S. Maritime Commission, Washington 25, D. C. Standards published by the Manufacturers Stand ardization Society of the Valve and Fittings Indus try, 420 Lexington Ave., New York 17, N. Y. Navy Specifications obtainable from Bureau of Sup plies and Accounts, Navy Department, Washington 25, D. C. Specifications prepared by the Society of Automo tive Engineers, 29 West 39th St., New York 18, N. Y. Treasury Department Specifications obtainable from the Procurement Division, Treasury Depart ment, Washington 25, D. C. Specifications established by Tennessee Valley Authority, Knoxville, Tenn. American Society for Testing Materials Standards are issued under fixed designations; "T" indicates Tentative. All specifica tions and standards are subject to revision from time to time, hence, when ordering it is important to request the latest date of issue. JF I > 3 > 3 3 .3 . 3 SUBJECT METALLIC LEAD Calking lead F.S. QQ-L-15G Hard lead fittings Lead pipe Lead traps Pig lead Sheet lead WW-P-325 WW-P-325 QQ-L-171 QQ-L-201 LEAD ALLOYS Bearing alloys QQ-M-101 Car and tender journal bearings, lined Copper-lead bearings Lead- and tin-base alloy die castings Soft solder Wiping solder QQ-S-G71a CHEMICAL ANALYSIS Bismuth in pig lead Iron in lead- and tin-base alloys Lead alloys, spectro Lead- and tin-base solder Pig lead Pig lead, spectro Bed lead, dry White metal bearing alloys A.S.A. K16.1 A.S.T.M. B29 B23 B67 111 02 B32 E58 E67 E49 E46 E37 E25 D49 E57 OTHER L.I.A.; A.W.W.A., C.S., 94 L.I.A. L.I.A.; C.S., 95 L.I.A.; C.S., 9(5 S.A.E. 10,110,11,1 15 S.A.E. 48, 480, 481- S.A.E. 1A-6A S.A.E. lb to Gb t* SUBJECT F.S. iEAD PAINTS Blue lead Chrome green, exterior Chrome yellow Exterior, titanium-lead-zinc Exterior, white lead and oil Internat'l orange Olive drab enamel Paint, marine ext., basic lead chromate Paint, marine ext. red lead Primer, shop for underwater metal surfaces Primer, exterior (undercoat for wood) Protective painting for metals Red lead base paints TT-P-20 TT-P-71b TT-P-53 TT-P-102 TT-P-104 TT-P-59 TT-E-485b TT-P-25a TT-P-86a Repainting elevated steel tanks (red lead) White and tinted (lead and zinc base) LEAD COMPOUNDS Aviation gasolines Litharge Tests for lead in gasoline Tests for tetraethyl lead in gasoline A.S.T.M. OTHER D910 D810 D526 T.D., 356 T.D., 358 T.V.A., C-44 A.S., C.E.-ll M.C. 62-M.C.-18 A.A.S.H.O., M71 Bu. Ships 116 M.C. 62-M.C.-20 M.C. 62-M.C.-20 A.A.S.H.O., M72 A.W.W.A., 7H.2 A.A.S.H.O., M7 N.S., 52-L-10b 3' ^ > SUBJECT LEAD PIGMENTS Basic carbonate white lead Basic sulphate white lead Blue lead;basic sulphate Chrome green, dry Enamel; drum coating exterior Enamel, O.D. rust inhib. Lead chromate (yellow and orange) Lead titanate Leaded zinc oxide Red lead F.S. TT-W-251b TT-W-261a TT-B-486 TT-C-235 TT-E-485a TT-C-290 TT-Z-321 TT-R-191a LEAD COATINGS Lead-alloy coated iron or steel Lead-coated copper sheets Lead- and lead-alloy- coated copper wire Lead on steel, electrodep. Terne-plate (long) Terne-plate (roofing) QQ-T-191 QQ-T-201 MISCELLANEOUS Allow, cone, of lead and certain inorg. empds. Batteries, storage W-B-131b A.S.A. K23.1 K47.1 K48 K24 A.S.T.M. D81 D82 D405 D606 D80 D83 A267 B101 B189 B200 OTHER A.S. 3-181A Z37.ll SUBJECT MISCELLANEOUS (cont'd) Cable, armored and lead- covered-armored Corrosion, alt. imm. Corrosion, total imm. Die castings Leaded-rubber (Roentgen opaque) Packing, metallic, flexible Tacking, metallic and non- metallic, plastic . Packing, metallic, flexible, condenser tube Prep, of metallographic spec. Treads; safety, metallic F.S. J-C-71 ZZ-L-151 IIH-P-126a HH-P-13ta HH-P-128 RR-T-661 A.S.T.M. B192 B185 B102 OTHER E3 CHAPTER TWENTY-SEVEN Properties of Lead and Lead Alloys In o n e form or another lead is associated with nearly every phase of our daily life. Its practically innumerable applica tions depend not upon one single property or characteristic but upon many different properties inherent in the element. It is employed in some instances primarily for its weight, in others because of its resistance to corrosion or its softness and mallea bility or its atomic structure or its ability to alloy readily with other metals to change or modify its properties. The various properties, comparative figures and other pertinent data that apply to lead and lead alloys are consolidated in this chapter to serve as a handy source of reference and as a guide to the proper use of the metal. General Properties Color ................................ Bluish gray Patina .................................. .On atmospheric exposure lead takes ... on a silvery gray patina except in industrial atmospheres where it changes to dark gray to black Atomic number.................... .82 Atomic arrangement ...... Cubic face-centered Length of lattice edge..........4.9389 A Atomic weight..................... 207.21 Specimens of lead are known having atomic weights differing considerably from that given above. Such varieties are derived from radioactive ores or produced in atomic pile reactions. Lead isotopes vary in atomic weights from 201 to 216. 183 184 LEAD IN MODERN INDUSTRY Atomic volume....................................18.27 Valence................................................ Usually 2, sometimes 4 or 1 Weight and Density Density: Cast lead, 20 C................................. 11.34 g. per c.c. Rolled, 20 C..................................... 11.35 to 11.37 g. per c.c. Just solid, 327.4 C......................... 11.005 g. per c.c. Just liquid, 327.4 C....................... .10.686 g. per c.c. Density of molten lead in g. per c.c.: Temp. C. 327.4 331 345 356 Density 10.686 10.663 10.642 10.632 Temp. C. 411 416 459 486 Density 10.583 10.558 10.507 10.475 Temp. C. 529 555 577 580 Density 10.423 10.382 10.360 10.354 Temp. C. 650 694 717 731 Density 10.265 10.219 10.200 10.188 Density, vapor (Hydrogen 1), calcu lated ...............................................103.6 Weight: Cast lead, 20 C., calculated...........0.4092 lb. per cu. in. equivalent to..................................707 lb. per cu. ft. Rolled, 20 C. (density 11.37), cal culated ......................................0.4103 lb. per cu. in. <p""\ I equivalent to................................. 709 lb. per cu. ft. Liquid, 327.4 C., calculated___ _ .0.3854 lb. per cu. in. equivalent to .................................. 666 lb. per cu. ft. Sheet lead, 1 ft. square by ^ in. thick ....................... ............... .approximately 1 lb. '. *r Volume of 1 lb. cast lead, 20 C., i calculated ..................................2.44 cu. in. ( Thermal Properties *4, /i Melting point, common lead...............327.4 C. (621 F.) Melting point, chemical lead...............325.6 C. (618 F.) Elevation of melting point for each 150 atm. increase in pressure.........1.2 C. (2.16 F.) Recrystallization temperature...........below 0 C. for 99.999% Pb 125 C. for chemical lead Casting temperature 790 to 830 F. J > > 3 3 3 J THERMAL DATA * Antimony Composition Mean specific heat, 60 F. to melting point, point, B.t.u./lb./F .................................... Heat in solid at melting point, B.t.u./lb........ Latent heat of fusion, B.t.u./lb...................... Total heat in liquid at melting point, B.t.u./ 0.054 59.7 70.0 Lead 0.032 18.0 9.9 Type Tin Babbitt Babbitt metal 75-10-15 80-10-10 86-3-11 Pb-Sn-Sb Pb-Sn-Sb Pb-Sn-Sb P 0.069 26.9 24.9 0.039 15.8 26.2 0.038 . 20.5 17.4 0.036 15.3 21.5 129.7 Mean specific heat of liquid, B.t.u./lb./F. .. 0.054 Average pouring temperature, F .................. 1,320 Total heat in liquid at pouring temperature, B.t.u./lb............................................................ 138.0 27.9 0.032 720 31.1 51.8 0.060 650 63.8 42.0 0.038 625 48.2 37.9 0.037 820 46.0 36.8 0.036 620 41.6 Mostly based on data taken from Industrial Gas Series, "Combustion,"' American Gas Ass'n,, 1932. 186 LEAD IN MODERN INDUSTRY Boiling point at different pressures: Pressure, in atmospheres. 0.14 Boiling' point, C ........ ........ 1325 Boiling point, F ................ 2417 0.35 1410 2570 1.0 1525 2777 6.3 1873 3403 11.7 2100 3812 Vapor pressure: Temperature, C ........... 808 1000 1200 1365 1525 1870 2100 Pressure, mm.Hg.......... 0.08 1.77 23.29 166. 760. 6.3 atm. 11.7 atm. Specific heat (eal. per g.): Temp., C. -150 -100 - 50 0 Specific beat 0.02805 0.02880 0.0298 0.0303 Temp., c. 50 100 200 300 (solid) 327.4 Specific heat 0.0309 0.0315 0.0325 0.0338 0.0340 Temp., c. liquid 327.4 378 418 459 Specific heat 0.0333 0.0338 0.0335 0.0335 Latent heat of fusion........ .. .6.26 cal. per g. or 11.27 B.t.u. per lb. To melt 1 lb. of lead heating from 20 C. requires.......... 7100 g. cal. or 28.2 B.t.u. Latent heat of vaporization. .202 cal. per g. Relative thermal conductivity (silver 100) ....................... 8.2 Thermal conductivity (cal./cm.2/cm./C./sec.) : Temp.. C --247.1 -160 0 0.117 0.092 0.083 Temp., C 100 200 300 0.081 0.077 0.074 Temp., C 400 500 600 0.038 0.037 0.036 Heat contents of lead in B.t.u. at various temperatures up to 1700 F. appear on page 134. Coefficient of expansion: Linear ( -- 190 to 19 C. mean).............. 0.0000265 per deg. C. Linear (17 to 100 C. mean).................. 0.0000293 per deg. C. or 0.0000163 per deg. F. Cubical (liquid at melting point to 357 C.) ................................................ 0.000129 per deg. C. Cubical (17 to 100 C.)........................... 0.0000879 per deg. C. PROPERTIES OF LEAD AND LEAD ALLOYS Expansion of sheet lead: 187 EXPANSION IN INCHES (A graph showing the expansion of antimonial or "hard" sheet lead ap pears on page 88.) Increase in volume from 20 C. to liquid at melting point................................... 6.1 percent Decrease in volume from liquid at melting point to 20 C., calculated................... 5.8 percent Increase in volume on melting................... 4.01 percent Decrease in volume on solidification.........3.85 percent Shrinkage on casting taken in practice as ^ to in. per ft. Coefficient of heat transfer (theoretical overall value) for bonded lead covered copper pipe: where: u X, 1 , 1 ,Y K T hx T h2 ^ K, , - U = theoretical overall coefficient of heat transfer, B.t.u./hr./sq. ft./F., K = conductivity of lead wall per inch (use 240), Ki=conductivity of copper wall per inch (use 2680), X = thickness of lead wall in inches, Y = thickness of copper wall in inches, hi=steam film (use 1000), and, h2=liquid film (film 800). 188 LEAD IN MODERN INDUSTRY Tin-lead phase diagram: Tin. percent 0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 55.0 60.0 62.0 65.0 70.0 75.0 80.0 85.0 90.0 95.0 100.0 Lead. percent 100.0 95.0 90.0 85.0 80.0 75.0 70.0 65.0 60.0 55.0 50.0 45.0 40.0 38.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0 . A Soloidpus. 621 . 518* 361 * 361* 361* tt tt it tt it it a u it tt it tt it it tt it 450 B Liquidus. F 621 594 570 550 531 511 491 477 460 441 421 399 374 361 367 378 387 399 410 423 435 450 ' (B-A) Pasty range. F 0 76* 209* 189* 170 150 130 116 99 80 60 38 13 0 6 17 26 38 49 62 74 0 * These are preferred values for engineering purposes but are not equilibrium values. At equilibrium the eutectic limits are 19.5--98 percent tin. PROPERTIES OF LEAD AND LEAD ALLOYS 189 A Antimony-lead phase diagram: c 700 600 ' 500 Liq uid 400 327 Pa ity Pnsiy -- 200 /3.5 -a 1.2 100 Pb 10 20 252 Solid 1 30 40 50 60 70 Weight percentage antimony. 80 1200 -i 630 i j 1000 i L 1 1 r 800 L fi-i 600 t i i i 400 90 Sb Eutectics of lead: Melting point of eutectics of lead with other metals: - Other metal Silver ................... Arsenic ................ Gold....................... Barium ................. ...Ba Bismuth ............... ...Bi Cadmium .................Cd Magnesium.......... ...Mg Palladium.................Pd Platinum............... ...Pt Antimony............. ...Sb Tin......................... ....Sn Zinc ...................... ...Zn Percent by weight 2.3 2.8 15 4.5 56.5 17.4 3 5 5 12.5 62 .5 Temp., *C. 304 292 215 291 125 248 250 265 290 251 183 318 190 LEAD IN MODERN INDUSTRY i.i Low Temperature Properties At low temperatures soft solders that contain a high per centage of lead retain their ductility and increase in impact 0^ strength. When the percentage of tin reaches 50 percent, serious embrittlement and decrease in impact strength occur. Tin con ! tents up to 15 percent have no serious embrittling effect. The tensile strength of solder alloys and the breaking load of soldered joints increases proportionally .as the temperature is lowered. m ! The solder containing the most tin (50 percent) shows the great est increase in strength and the solder with the most lead (97.5 percent) shows the least increase in strength. i; Unalloyed lead shows no visible or otherwise detectable effects at temperatures in the range of those to be encountered in the if Arctic, for example, therefore no special care is required for the li maintenance of lead or high lead base alloys. Lead base bearing alloys could be expected to behave in a manner similar to that ji of the various solder alloys. ^*5 The Bureau of Standards has reported the following results \ i from some of their investigations, all based on pure lead. i CAST LEAD *% Temperature, Tensile strength. Elongation, F. psi percent Brinell Impact Room ..................... 3000 33 4.3 2.3 --300 ........................ 6200 40 9.0 3.8 ROLLED LEAD V 59 --------- ..... 3600 52 -- -- -- 4 ..................... 7200 40 -- -- -- 40 ..................... 13300 31 -- -- i !I --103 ..................... 15200 24 -- -- Mechanical Properties Hardness, Moh's scale......................... 1.5 Brinell number, 1 cm. ball, 30 sec., 100 kg. load: Common lead....................... .3.2 to 4.5 Chemical lead......................................................................4.5 to 6.0 PROPERTIES OF LEAD AND LEAD ALLOYS 191 Influence of temperature on Brinell hardness (chemical lead): Temperature, C ............................. 25 Hardness .................................. 5.3 100 3.6 150 2.6 Ultimate tensile strength: Common lead..................................1400 to 1700 lb. per sq. in. Chemical lead ............................2300 to 2800 lb. per sq. in. Effect of temperature on tensile properties (lead annealed at 100 C.): TempAerature 'C. F. 20 68 82 180 150 302 195 383 265 509 Tensile strength, lb. per sq. in. 1920 1140 710 570 280 Elongation, percent 31 24 33 20 20 Reduction in area, percent 100 100 100 100 100 Tensile strength and elongation: (Laboratory rolled specimens, room temperature, pulling speed i in. per min. per in. of test section) Grade of lead Tensile strength. lb. per sq. in. Common (99.85+0.13 Bi)............... ......... 1931 Corroding (99.99+0.006 Bi)........ ......... 1904 Common (99.98+no Bi)................. ......... 2093 Chemical (99.92+0.06 Cu)............. ...... 2961 Chemical (Commercial sheet)----- ........ 2454 Chemical (Extruded) ..................... ........ 2200 Resistance to bending: Elongation, percent 34.4 37.7 43.0 42.2 57.0 48.0 (Extruded strips under 200 lb. per sq. in. stress subjected to alternate 90 reverse bends over 5-in. rolls, 11 cycles per min.) Grade of lead Cycles to failure Common ..................................... ... 72 Chemical ..................................... ... 103 Corroding................................... ... 54 Elongation, percent 49 52 35 192 LEAD IN MODERN INDUSTRY Maximum allowable fibre stress in extruded pipe: Temperature C. F. 20 68 30 86 40 104 50 122 60 140 70 158 80 176 90 194 100 212 110 230 120 248 130 266 140 284 150 302 247 477 327 621 Equivalent steam gage lb. per sq. in. 0 6 14 24 37 54 535 -- Maximum allowable fibre stress, lb. per*-sq. in. _ 6 percent Chemical antimonial lead lead 200 400 190 370 180 340 172 310 162 280 153 254 144 222 136 195 127 165 118 137 110 110 100 80 90 50 80 -- --0 0-- To calculate safe working pressure of lead pipe, use formula P= 2 ST D or T= PD 2S where P=safe working pressure in lb. per sq. in. S=maximum allowable fibre stress from above table. T=thickness of pipe wall in inches. D=inside diameter of pipe in inches. For mechanical or structural reasons, it is sometimes wise to allow additional wall thickness above that derived from this formula. Likewise in chemical installations where considerable corrosion may be anticipated, extra allowance should be made. For. calculating the safe working pressure of circular ends of thin-walled cylinders use T= PD 4S Elastic limit.......................................... 200 lb. per sq. in. Young's modulus.................................. 2,000,000 lb. per sq. in. Bulk modulus........................................ 0.44 x 1012 dynes per sq in. PROPERTIES OF LEAD AND LEAD ALLOYS Poisson's ratio of transverse contrac tion to longitudinal extension under tensile strength................................0.4 to 0.45 Compressibility, 20 C., per unit vol ume per megabar..................... .. 2.2 to 2.5 x 10" 19S CREEP Creep, room temperature: Creep, percent per hour Stress. Ib. per sq. in. 200 300 400 Common lead 5 x 10-s 3.5 x 10-4 11 x 10-4 Chemical or copper lead 0.4 X 10"5 1.5 x lO-*5 * 3 x lO-5 Creep, 150 deg. F., chemical or copper lead : Stress, lb. per sq. in. 200 300 ' 400 Tensile stress, lb. per sq. in. 100 200 300 400 500 600 700 800 i Lead 0.2 0.8 1.7 4.0 -- -- -- ---- Creep, percent per hour 6 x 10-4 50 x lO-4 230 x 10-s Creep, percent in one year Lead -4-2.0 tin -- 0.6 1.1 2.0 3.3 _ --^ . _. Lead 4-0.75 antimony -- 0.4 0.6 1.0 1.4 1.9 2.5 ' ..- _ ' Lead 4-0.04 calcium -- 0.2 0.3 0.5 0.7 1.0 1.3 1.7 FATIGUE Fatigue limit (50,000,000 cycles) extruded___ 215 lb. per sq. in. Metal Lead ............................................... Lead+0.026 percent calcium .. Lead+0.038 percent calcium .. Lead+0.04 percent calcium .. Lead+0.041 percent calcium .. Lead+0.06 percent calcium .. Lead+1 percent antimony Lead+2 percent tin ....... Lead+0.06 percent copper ... T . r 0.045 percent tellurium -ueaa+^o.06 percent copper Endurance limit at 5 x 107 cycles, lb. per sq. in. .. 215- 400 .. 685- 840 .. 820-1500 .. 1120 . 300-1000 . 800 . 600 Endurance limit at 107 cycles, lb. per sq. in. 470 1038 1180 725 1000 194 LEAD IN MODERN INDUSTRY Electrical Properties Electrical resistivity: Temp.. *C. 20 40 60 80 100 120 140 160 Resistivity, micro-ohms per c.c. 20.648 22.084 23.645 25.285 27.021 28.787 30.582 32.468 Temc.p., 180 200 220 240 260 280 300 320 Resistivity, micro-ohms per c.c. 34.413 36.478 38.542 40.697 42.791 44.946 47.938 54,761 Temc.p., 330 340 360 380 400 420 440 460 Resistivity, micro-ohms per c.c. 96.735 97.867 99.000 100.255 101.418 102.563 103.716 104.878 Temperature coefficient of electrical resistivity: Temp., C. 20- 40 40- 60 60- 80 80-100 100-120 120-140 140-160 160-180 Temp. coef. of elec. resist. 0.00336 0.00341 0.0033d 0.00332 0.00311 0.00302 0.00299 0.00293 Temp., C. 180-200 200-220 220-240 240-260 260-280 280-300 300-320 320-330 Temp. coef. of elec. resist. 0.00291 0.00275 0.00273 0.00251 0.00246 0.00322 0.00665 0.0554 Temc.p., 330-340 340-360 360-380 380-400 400-420 420-440 440-460 Temp. coef. of elec. resist. 0.00116 0.000576 0.000570 0.000577 0.000561 0.000559 0.000558 Specific electrical conductance: at 0 C...................................................... 5.05 x 104 cm.-1 ohms."1 18 C......................................................4.83 melting point....................................1.06 Atomic electrical conductance, calculated. 1.139 x 10 Relative electrical conductance (copper 100) ...................................................7.82 Relative electrical resistance (copper 100) . ................. ........................... 1280 Lead is diamagnetic Magnetic susceptibility, per g., 18-330 C..................................................-0.12 x 10" 300-600 C................................................. -0.08x10* Electrolytic solution pressure: ions of Pb -f +.........,................ .............. 6.3 x 10-5 atm. ions of Pb ++ + +.............................. .... 3.0 x 10~74 atm. PROPERTIES OF LEAD AND LEAD ALLOYS 195 Electrochemical equivalents: Valence 2 4 Mg. per coulomb 1.0736 0.5368 Coulombs per mg. 0.9314 1.8628 G. per amp. hr. 3.8651 1.9326 Electrodeposition, to deposit 1 lb. of lead re quires.................................................... 117 amp. hr. Electrode potential of lead at 25 C.: with normal calomel electrode....................... 0.403 v. with normal hydrogen electrode................... 0.122 v. Thermoelectric strength against platinum----- +0.44 mv. per C. Galvanic or electrochemical series: In the following list, each metal is electropositive to all that precede it, i.e., two metals in contact in the presence of an electro lyte form a galvanic couple which tends to cause the more elec tropositive to be dissolved by electrolysis: Column headed "cobalt" follows column ending "Indium." CORRODED END (Anodic, or least noble) Caesium Lithium Rubidium Potassium Calcium Sodium Magnesium Magnesium alloys Beryllium Aluminum Manganese Zinc Aluminum 2S Chromium . Gallium Aluminum 17 ST Iron or steel Cast iron Chromium--iron (Active) 18--8 Stainless (Active) 18--8--3 Stainless (Active) Cadmium Indium Cobalt Nickel (Active) Inconel (Active) Tin Lead-tin - Lead-antimony Lead Brasses Hydrogen Antimony Bismuth Arsenic Copper Mercury Bronzes Copper-nickel Monel Silver solder Silver Graphite Palladium Platinum Gold . PROTECTED END (Cathodic, or most noble) 196 LEAD IN MODERN INDUSTRY Miscellaneous Properties Optical constants, solid lead, for A. of 0.589 p. (yellow): Refractive index ..................................... 2.01 Absorption.................................................. 3.48 Reflection.................................................... 62 percent Stopping power, s, for alpha rays is approximately proportional to the square root of atomic weight, w: s (air 1)................................................ 4.27 Vw (air 1)................................................ 3.78 Coefficient of absorption of beta or gamma rays is approximately proportional to the density. For thickness of lead for radiation protection see page 100. Velocity of sound in lead..................... .......... 122,700 cm. per sec. equivalent to................................................. 4,026 ft. per sec. Surface tension: at melting point 327.4 C............................... 444 dynes per cm. 350 C................................ 442 dynes per cm. 400 C................ 438 dynes per cm. 500 C................................ 431 dynes per cm. Comparative Data Metal Atomic weight Aluminum .......... 26.97 Antimony . .......... 121.76 Arsenic -- .......... 74.91 Bismuth .. .......... 209.0 Cadmium . .......... 112.41 Calcium .. .......... 40.08 Copper ... ...... 63.57 Iron ----------- ............ 55.84 Lead.......... ............ 207.21 Nickel .... ............. 58.69 Silver .... .............107.88 Tin ............. ............ 118.70 Zinc............. ............ 65.38 Specific gravity 2.70 6.62 5.73 9.80 8.65 1.55 8.94 7.70 11.35 8.85 10.5 7.30 7.14 Melting point / ' *....... V C. F. 659.7 1214.6 630.5 1166.9 850.0 1562.0 271.0 519.8 320.9 609.6 810.0 1564.0 1083.0 1981.4 1535.0 2795.0 327.4 621.2 1452.0 2640.0 960.5 1760.9 232.0 449.6 419.45 787.0 Hardness, Moh's scale 2.0 3.3 3.5 2-2.5 2.0 1.5 2.5-3 4-5 1.5 4-4.5 2.5-3 1.5 2.5 PROPERTIES OF LEAD AND LEAD ALLOYS 197 PROPERTIES OF EXTRUDED ANTIMONIAL LEAD ROD Antimony, percent 0 1 2 8 4 5 6 7 8 9 10 11 12 18 14 Tensile strength, lb. per sq. in. 1740 2920 8200 3100 8100 3150 3300 3240 3330 3400 3700 3800 3800 4000 3930 Elongation, percent 110 58 56 55 58 59 65 68 75 76 64 74 65 57 48 Brinell hardness 4.0 5.1 6.5 7.7 8.9 9.9 10.7 11.4 12.4 12.8 13.7 13.7 14.3 14.6 14.6 Note: These properties may vary considerably depending upon temperature of ex trusion, rate of cooling and time of aging. PROPERTIES OF COLD ROLLED ANTIMONIAL LEAD SHEET (95 percent reduction) Antimony, percent 4 6 8 Tensile strength, lb. per sq. in. , .............. A , -- ............... 1 day after As cold rolled heat treatment * 4020 11670 4100 12650 4650 12350 Elongation, percent -A As cold rolled 1 day after heat treatment * 48.5 6.3 47.0 3.2 31.3 4.7 Brinell hardness Antimony. percent 4 6 8 Aged without Aheat treatment 1 day 104 days 75 years 8.1 8.6 8.3 8.6 9.0 9.0 9.5 10.1 10.0 Heat treatedA * and aged 1 day 104 days 75 years 24.3 22,8 18.4 23.5 21.2 17.4 26.3 24.0 19.9 Heat treated at 235* C,, quenched and aged at room temperature. TENSILE STRENGTH OF LEAD-CALCIUM ALLOYS Percent 0. 0.04 0.08 0.12 .......... 0.16 0.20 0.24 Cast and aged -- 5250 7500 8200....... 7750 7350 6900 Tensile strength, lb. per sq. in. Quenched and aged 2250 5150 7250 8000 7000 6200 5800 Quenched 2000 3000 3750 4600 5100 5400 4500 > .... ..... > ------- ---"'I - ) --~ O 3 s=s^*-ra^3 Anti mony, percent 0 1 2 3 4 5 6 7 8 9 10 11 12 12.5 13 14 Density 11.35 11.26 11.18 11.10 11.03 10.95 10.88 10.81 10.74 10.66 10.59 10.52 10.62 10.42 10.38 10.30 PROPERTIES OF CAST LEAD-ANTIMONY ALLOYS Liqutrius, F, 621 612 602 Solidus, F. ---- : 603 659 Tensile strength, 11). per s<l. in. 2500 3400 4200 Elongation, percent 45 16 16 Brincll hardness 4.0 7.0 8.0 Expansivity coefficient 0.0000293 0.0000288 0.0000284 590 516 4700 15 9.1 0.0000281 678 495 5660 22 10.1 0.0000278 665 44 6360 29 11.0 0.0000275 552 44 6840 24 11.8 0.0000272 539 44 7180 21 12.5 0.0000270 627 it 7420 19 13.3 0.0000267 515 a: 7680 17 14.0 0.0000264 505 it ; 7670 15 14.6 0.0000261 496 tt 7620 13 14.8 0.0000258 489 tt 7480 12 16.0 0.0000256 485 41 7380 11 16.1 0.0000254 492 41 7280 10 15.2 0.0000253 506 u, 7000 9 15.3 0.0000251 2 y ) > > 0 3 0 0. 0 ?tricnent 5 10 15 20 30 40 50 60 Density at 20" C., g. per c.c. 11.0 10.7 10.4 10.1 9.7 9.3 8.9 8.6 Balance lend. PROPERTIES OF LEAD-TIN ALLOYS Tensile strength, lb. per sq. In. .A at 25" O. nt 150 C. 3200 1500 4100 2100 4900 2000 6400 1900 6200 1900 6600 1900 7000 1900 7200 1800 lOlongntlon, percent A. at at 25 C. 150" C. 55 65 45 35 15 20 25 70 40 120 60 140 60 145 60 140 Itcduction of area, percent ---------at nt ' 25 C. 150" C. 75 90 50 70 25 30 50 60 75 90 75 95 60 95 40 100 Brinell Thermal hardness. conduc- chill tlviiy, castings watts per nt 20 C. cm. per C. Elecirlcal resistivity, microhms per cm. 8.0 0.35 19.5 11.5 0.36 18.9 12.0 0.37 18.2 11.7 0.38 17.8 12.4 0.39 17.0 13.0 0.41 16.2 14.3 0.45 15.5 10.7 0.49 15.0 (1 2 2 2 2 2 2 2 2 > 'J LEAD-TIN-ANTIMONY ALLOYS Lead (by dlf.), percent 88.0 86.5 81.8 76.8 72.6 65.7 85.2 82.0 75.1 71.0 66.8 79.6 77.1 66.4 66.0 70.1 68.8 64.1 72.2 65.0 64.2 Tin, percent 4.1 8.6 13.1 14.8 22.1 28.7 4.6 8.9 14.7 18.6 23.0 4.5 8.6 19.0 - 18.9 4.6 9.1 13.9 4.5 10.0 5.9 Antimony, percent 7.9 4.9 6.1 8.4 5.3 5.6 10.2 9.1 10.2 10.4 10.2 15.9 14.3 14.6 15.1 25.3 22.1 22.0 23.3 25.0 29.9 Mechanical Properties1 Yield point, lb. per sq. Id. Tensile strength, lb. per sq. in. 4,800 5,400 4,800 7,220 6,010 7,500 6,300 6,900 N.O. 5,400 6,610 8,400 8,990 13,820 8,660 14,400 8,400 14,400 8,990 11,400 8,400 12,000 6,900 11,690 Broken in machining 7,800 12,000 7,800 12,000 Broken in machining 10,180 10,180 9,600 11,400 7,800 Broken in machining 8,400 12,580 Elongation, percent 1.5 3.0 2.0 1.0 -- 1.6 10.5 13.0 6.5 1.5 1.0 4.0 -- 1.5 <-- -- -- 1.0 Compression load required to compress to half length 28,448 N.O. N.O. N.O. 19,920 N.O. 28,200 24,640 N.O. 20,150 C. N.O. N.O. 26,000 23,980 S.C. 21,720 S.C. 28,000 S.C. 21,950 * 22,400 * 19,700 * 18,590 * 14,500 * N.O.--Not observed; C.--Cracks In compression test piece; S.C.--Slight cracks In compression test piece; --Failed presslon to half length. 1 O. W. Kills, Note on Lead-Tln-Antlinony Alloys, J. Inst. Metals,, 1018, v. 10, No. 1, p. 151. )3a J 3 >oa3 COMPOSITION AND PHYSICAL PROPERTIES* OP WHITE METAL HEARING ALLOYS Specified nominal composition of alloys i1 g CCJJ Alloy ,S 8 grade6 !-i No. 1. .91.0 No. 2..89.0 No. 3..83.33 No. 4. .75.0 &+* o9 5+ 2* -4 4.6 7.6 8.33 12.0 c -COo4 J p, i-i < .... 10.0 |2 O {X o 4.6 3.5 8.33 3.0 . l l b sa m 7.34 7.30 7.40 7.02 Compositions of alloys tested c s* 00.9 89.2 83.4 75.0 *aoExi 8ac CO, 4.62 7.4 8.2 11.0 *a ua> na> <av, none 0.03 0.03 10.2 O, Q> 6 04 4.50 3.1 8.3 3.0 Yield point, pal.' o oM 4400 6100 6000 6550 ool-t 2050 3000 3150 2150 John son's appar ent clastic limit. psl.f OO O 2450 3350 5350 3200 1050 1100 1300 1550 Ultimate strength in compres sion, psi.s OO o 12850 14900 17000 10150 6950 8700 9900 0901) Brinell hard ness6 t----> o- i oo 17.0 24.5 27.0 24.5 8.0 12.0 14.5 12.0 Melt ing point is c 5 (J $& aa 433 223 460 241 404 240 363 184 Tern- pera- turc of com plete lique faction JS c r* O O Os0 700 37 009 35 792 42 583 30 No. 5..65.0 No. 0. .20.0 No. 7.. 10.0 15.0 15.0 15.0 18.0 2.0 63.5 1.5 76.0 .... 7.70 05.6 0.33 19.8 0.73 10.0 14.1 14.0 14.5 18.2 63.7 75.0 2.0 6060 2150 3750 1500 15050 0750 22.5 10.0 358 181 505 29 1.6 3800 2050 3550 1800 14550 8050 21.0 10.5 358 181 531 27 0.11 3560 1600 2500 1350 15050 0150 22.5 10.5 404 240 514 26 No. 8.. 5.0 16.0 80.0 .... 10.04 No. 10.. 2.0 15.0 83.0 .... 10.07 6.2 14.0 79.4 2.05 15.7 82.0 0.14 8400 1760 2060 1200 16000 6150 20.0 0.12 3350 1860 2250 1200 15460 5750 17.5 0.6 459 237 522 27 9.0 408 242 507 20 No. 11.......... No. 12.......... No. 15. 1.0 15.0 10.0 15.0 85.0 10.28 90.0 .... 10.07 82.5 0.5 10.05 0.09 0.11 194..89 84.7 89.4 0.19 8050 1400 2750 1100 12800 6100 15.0 7.0 471 244 504 26 0.12 2800 1250 2250 950 12900 6100 14.6 0.5 473 246 498 25 21.0 13.0 479 248 638 28 No. 16.. 10.0 12.5 77.0 0.6 0.88 No. 19.. 6.0 9.0 80.0 * 10.60 *e 27.6 18.0 471 244 495 25 . . . , * .... .... . . 16000 6100 17.7 8.0 402 239 495 25 in. in length nnd 0.6 in. In diameter, mnehined from chill castings 2 In., in length nn diameter. The Brinell tests were made on'the bottom face of parallel machined specimens cast in a 2-fn. diameter by 0.025-ln. deep steel m temperature.^^ g wag discontinued in 1940. d The0 sneSflcTLravfty'inultipHed'lJy 0.0301 couals the density in pounds per cubic inch. .. S s*Ln,.!? vfeld Mint were taken from stress-strain curves at a deformation of 0.126 percent reduction of gage length. f TnLnn" anmrent elastic limit is taken as the unit stress at the point where the elope of the tangent to the curve is times Its slope a e lli^idtimauTstrength vsducs were taken as the unit load necessary^to produce a deformation of 25 percent of the length of the specimen These vXcs are the avernge Brinell number of three Impressions on each alloy using a 10-mra. ball and a 600-kg. load applied for 30 sec. From A.S.T.M. Standards, Designation B 28-48T. Appendix. > it. COMPOSITION AND PROPERTIES OF LEAD ALLOYS FOR DIE CASTING ASTM Designation %Co mp o s it io n Lead ............................................ Tin............... Antimony ........................................................ Copper, max......................................... ......... Arsenic, max................................................... Zinc, max............. ............................................ Aluminum, max.............................................. No. 4 4 to 6 14to 16 0.50 0.16 0.01 0.01 No. 5 79to8891to 91 9.25 to 10.75 0.50 0.15 0.01 0.01 Hearing Alloy 80 5 15 "C.T." Metal 85 to 87 0.65 12.50 0.65 Pr o p e r t ie s a n d Co n s t a n t s Tensile Strength, p.s.i.................................. 13,800 Impact Strength, Izod, ft. lb.................... 0.6 Elongation, % in 2 in.................................. 10.5 Brinell Hardness...................................... .... 23.2 Specific Gravity .......................................... 10.24 Weight, lb./cu. in......................... 0.370 Melting Range, F........................ 459-493 Solidification Shrinkage in./in.................... 0.002 . Corrosion Resistance.................................. Good Bearing Qualities......................................... Good 12,500 0.4 2.0 24.1 9.73 0.351 464-614 Good Good 9,100 0.8 3.8 23.2 10.12 0.365 462-500 Good Good 9,800 0.2 5.5 18.0 10.38 0.379 473-504 Good Fair CHAPTER TWENTY-EIGHT Physical Constants of Lead Compounds h e r e are literally hundreds of compounds of lead, both inorganic and organic, many of which are important con tributors to modern living. The manufacture, use, and physical constants of some of the more familiar lead compounds have been described in detail in earlier chapters of this book; the rest of them will be covered here. The available data for practically all inorganic lead com pounds, lead salts of organic acids and organic lead compounds are presented in the following tables. Molecular weights are rounded off to the nearest hundredth. Specific gravity is given at 20 C. referred to water at 4 C. with other temperatures indi cated by superior and inferior figures. The normal specific grav ity is numerically equivalent to density in grams per milliliter. The boiling point is stated at normal atmospheric pressure (760 mm. of Hg) unless otherwise indicated by a superscript. The tables begin with the inorganic compounds of lead and lead salts of organic acids and on page 217 take up the organic compounds of lead. )3 3 3 33 333 Name Lead l<cad ortlionnllmonate Tx>nd pyroantlmonate I,end arsenate, baste Lend arsenate, baste (.cad arsenate, baste bead dlarsenate (Schultcnlte) PHYSICAL CONSTANTS OF LEAD COMPOUNDS INORGANIC COMPOUNDS OP LEAD Formula Fb PMSMMi PbjSbjOr lOPbO 3As20s-3n,0 Pbc(PbPn)e(AaO) Crystalline form Motceutar color weight Index or refraction 207.21 Cubical. Silvery hluc-wlitic soft inctat. 303.15 Orange yellow ponder. Specific gravity 11,3437* 11.28816 ItaPb 11.298* UPb. 0.B8 V Melting point c 327.43 to 327.5 Rolling point C 1525 . * Cold water Insol. Insol. 709.94 Dark yellow powder. 6.72 . . Tnsol. 2076.81 Hexagonal crystals. 6.86 **** . *aa 2401.62 7.08 .... 2Pbs(AsO1)i2Pb(On)l10naO 2461.62 White solid. 7.1 a a PbltAsO, 347.13 Monocllnlc leaf 1.90 1.97. 5.79 Dccompd. Loses at 720. 11,0 at 220. Insol. A Hot water Insol. - ' " ... Alcohol, acid, etc. Sol. In UNO,, hot cone. n^O, and ncetlc acid. U re . Insol. **** Slightly aol. Insol. In dll. acids. Very slightly sol. In IICI. Sol. In nNO, and caustic alkalies. In ni an co P sa so na P m tw ar P o p ac ar T ta m d w se A ar a a as so o a o m le sh It w Lead meta-arsenate Lead monoarsenata rb(AsOa)s Pb(H5As0i) Lead orthoarsenata Pb{As04) Lead orthoarsenate Pb,(As0),0 5H,0 Lead orthoarsenate, basic SPbO Pbs(AsO<)t Lead orthoarsenate, basic BPb0Pbs(Aa04),0'6H,0 Lead pyroarsenate PbiAsjOr Lead orthoarsenite rbs(AsOj)jXH,0 453.03 Hexagonal tablets. 6.421" 480.00 Trlcllnlc crystals 4.46 1.74 to 1.82. 809.45 White crystals. 7.80 808.53 White solid. 7.00 2015.52 White solid. .... 2024.53 678.24 White rhombic crystals. Rhombic crystals BO. 203. 8.04 6.8514 872.45 White powder, X18 bulky. 5.85 Dccompd. at 140. 1042 slightly decompd. at 1200. 862 802 .... .... .... Dccompd. Dccompd. Decompd.............. Very slightly .... sol. . Sol. In adds and P fixed alkalies. le o na Sol. in 1IN0, ami A caustic alkalies, ar ar ac as so or ar od m le sh it w Sol. in HNOa and caustic. A ar ar ac as so o a od m le sh it w .............. P m w co .............. Pr m tw ar Insol. Insol. Decompd, .... Bol. In IfCl or He IlNOs- Insol. In no acetic add. Sol. In HNOa and Pp died alkalies. lea of ) .> O O 3 I 3 <3 yus Name Lend nzldc Lead metaborate Formula Ph(N3)3 Pb(B03)3II30 Lead borofluorlde Lend bromate Lead bromide Pb(BF)a rb (BrOj)9*II2O PbBrj Lend bromide, basic PbOPbBrjlIjO PHYSICAL CONSTANTS OF LEAD COMPOUNDS--Continued INORGANIC COMPOUNDS OF LEAD--Continued Crystalline form Molecular color weight Index of refraction 201.20 Colorless needles. `Specific gravlly .... 310.87 White cryst. ponder. 5,598 anliydrous. Mclllng Rolling point point c "C Explodes .... at 350. Loses water at 180. Cold water 0.023' Insol. A not water 0.00TM Insol. Alcohol, acid, etc. Very sol. In ace tic acid. Insol. In Nil,OIL Sol. In acids. In sol. In alkalies or ale. 380.85 Prismatic crystals. .... 481.00 Colorless monoclinlc crystals. 5.53 .... .... Dccnmpd. .... at 180. Partially decompd. .... 1.38" Sol. Partially decom posed by ale. - 307.04 While rhombic crystals. 0.00 373 010 to 0.4554 4.71' Sol. In acids and 018. 0.8141" KBr. Slightly sol. In Nils. In- sot. In ale. 008.24 Rhombic crystals. 0.22" Lead sub-hromtde Lead carbonate (Cerussltc) Lead carbonate, basic (White lead) (Ilydrocerusslte) rbBr PbC03 2PbC0a-Pb(0n)a 287.13 207.22 775.07 Colorless rhombic crystals. 1.801: 2.070: 2.078. While hexagonal crystals of amor phous powder. 2.09:1.01. 8.0 0.14 Decompd. .... at 315. Decompd. 0.00011" Insol. Decompd. Insol. Sol. In nrhls anil T alkalies. Insol. In o Nila and nlc. a Sol. In acids and flxed alkalies. Slightly sol. In aqueous COj. In sol. In ale. A ( l h m ) > I33 33 33 lend carbonate, basic 4PbCOa-2Pb(OII),PbO Lead chlorate, anhydrous Pb(CI09) Lead chlorate PbtClOsh'HsO Lead perchlorate Pb(C10,)5sns0 Lend chloride (Plumbous chloride) (Cotunnltc) PbCIa Lead snbchlorlde Lead oxychloride (Mntlockltc) Lend oxychloride (Lnurlonltc) Lend oxychloride (Parnluurinnltc) Lend oxychloride (Mendlpitc) Lend oxychloride Lend oxychloride PbCI PhClaPbO or PbjOCIj PI) (Oil) Cl I'bClj Pb01120 rbCls2PI>0 PbCI- 3PbO PbCI24Pb0 1774.55 White. .... 371.12 White monocllnlc 374.12 crystals. 1 392.14 Pcllivpicnt while 4.037 monocllnlc crystals. 2.0460.17 ltlinntblc crystals. ; 278.12 White rhombic crystals. 2.100: 2.217: 2.200. 5.80 to 5.85 242.67 501.33 Tetragonal while 7.21 crystals. 2.04: 2.15. 510.35 Ithnmhlc crystals. 0.24 510.35 724.54 947.75 1170.00 Colorless to white monocllnlc prisms. 2.140. Ithnmhlc yellow crystals. 2.24: 2.27:2.31. Vellovv solid. Yellow solid. 0.05> 7.08 .... .... Dccompd........... Dccompd........... Dccompd. .... at 110. Insol, Insol. Very sol. .... 151.3 171 Dccompd........... at 110. 409.720 .... 5.01 854TM"""- 0.673 3.34m Dccompd........... at 524. Dccompd. ..., at M2. Dccompd........... at 150. 003 0.0005' Insol. .. .... .... Insol. Insol. 0.0050' 0.0774 Got. In acids and flxed alkalies. In sol. In nlc. Sol. In ale. Sol. In ale. Sol. In ale. T b a A c o b w a S n w a liz Slightly sol. In dilute IICI or Nll<i. Insol. in ale. T ca o o c sc w 2 a c F 1m Sol. In alkalies H or boiling coned. h IICI. s A to le Sol. hi alkalies and coned. IICI. Do so i Name Lead oxychloride Formula PhCl27PbO Lend oxychloride (Pendedlte) Lend oxychloride (Loreltolte) Lend oxychloride (Fledlcrlte) Lend tetrachloride (Plumbic chloride) 5 5) Lead chloride sulphide (Lead eulphochlorlde) Pb0 2PbCl3 erborbcij 2PbCI2Pb0II20 rbci4 PbCI2-3PbS Lend chlorite Pb(C102)2 Lend chlorobromlde Lead chromate (Chrome yellow) (Crocolte) PbClBr FbCrO p h y s ic a l Co n s t a n t s o f l e a d c o mp o u n d s --continued INORGANIC COMPOUNDS OF LEAD--Continued Crystalline form Molecular color weight Index of refraction 1840.59 Yellow crystalline solid or powder. Specific grarity Melting Bolling point point C *C Cold water Insol. Solubility In 100 ml. of -A___________________________ _ 1H Hot Alcohol, water acid, etc. . F m te w 779.42 Hexagonal crystals. 1517.33 Tetragonal. 7.0 797.447 Monocllntc crystals. 5.88 849.04 Yellow oily liquid. 3-18) 995.93 Red. .... - 842.12 Yellow monocllntc crystals. 822.57 823.22 Yellow monocltnlc crystals. 2.31:2.37. 5.74 6.12 Dccnmpd. at 150. -15 Explodes at 105. .... .... Explodes at 126. Dccompd. evolving Cl2. Insol. 0.005 Same as for cold water. Decompd. 0.42100 Sol. In coned. IICI. Dccompd. by acid or alkali. Insol. In dll. acid. dot In alkali hydroxides. D c e w to P a s P s w a 844 Dccompd. 0.000058 Insol. 8nl. In adds and P alknllcs. Insol. In ta acetic add or b Nils. k Lead chromate, basic Pb2(01I)2Cr04 564.45 Red amorphous or 6.63 cryst., solid. to May he orange. 6.86 920 .... Insol. .... 1.019 g. In 100 R ml. of 2NKOII. w Sol. In acids and a alkalies. >3 >3 >O0 > Jjcnd chromate, basic (Chrome red) Lead dlchromate Lead cyanate PhO-rbCrOi PbCTjOj Pb(OCN)* Lead cyanide Lead cyanide, basic Lead cyanlmlde Lead ferrlcyanlde Lead ferrite Lend fcrrocyanlde Pb(CN)a rb302(CN), PbCN3 Pb8Po(CN)Sj-6Hatt Pb(FeOj)a Pb2Fe(CN)-8H,0 Lead fluoride PbFa Lead tetraftuorlde Lead fluorochlortde Lend fluoslllcate rbFi PbFCl PbSIFe-20,0 846.43 Red cryst. ponder. 6.63 to 6.86 423.23 Red crystals. * 291.25 White cryst. needles. .... 259.25 Yellowish white powder. T05.67 White solid. .... .... Green amorphous .... compound. 1153.62 882.89 Ulnck-brown to reddish monocllnle crystals. Hexagonal. l.OST satd. soln. 680.43 Yellowish-white powder. .... 245.21 White rhombic crystals. 8.24 283.21 261.651 Tetragonal crystals. 885.30 Cnlorlcss monocllnlc crystals. .... .... .... .... .... Dccompd. .... .... .... .... Dccompd. .... at 120. 1530 decompd. at 750. Dccompd. at 100. ... * .... 855 1200 .... .... 601 .... Dccompd. .... Insol. Insol. Decompd. .... Insol. Slightly sol. Slightly sol. .... Sol. .... Insol. Sol. In adds and Bo alkalies. wit of Sol. In acids and alkalies. Tre nat trat from of Sol. In ItCN. Act alk nitr Sparingly sol. In Tre KCN. soln nid Insol. In oil. Slightly eol. ..** Insol. 0.084s .... .... Sol. Slightly decompd. at 100. .... Sol. In lINOj or Tre alkalies. sol rlcy .... Slightly sol. In Tre lleSOv Decompd. sol by alkalies. Insol. roc In dll. acids. .... Sol. in 1IN0) or Tre UjSOt. Insol. in sol acetic acid, ND. ride or IIF. .... Fus and IIF .... Very sol. Tre hyd and .) ) y k) ,vs>ii iranrauwi y$ >o Name Lead fluoslllcate Lead dihydride Lend tctraliydrlde Lead hydroxide Lead hydroxide Lead hydroxide Loadlodate Load parnpertodate Lead parnpertodate Load mono-lodlde PHYSICAL CONSTANTS OF LEAD COMPOUNDS--Continued INORGANIC COMPOUNDS OF LEAD--Continued Formula rhSlF,-4n20 phn2 riiii. Pb(on>3 Pb20(On)3or 2Pb0H30 3Fb01I20 Pb(I03)3 PhHIOs PhlHOs-HjO rhi Crystalline form Molecular color weight Index of refraction 421.33 Monncllnlc crystals. Specific gravity *** 209.23 Gray powder. 211.24 241.23 Gaseous compound ll'iuedcd by liquid air. \11ille amorphous solid. .... .... 404.44 Cubical crystals or white amor phous powder. 687.65 Cubical crystals. 7.592 7.592 557.05 While solid. .... 415.14 Crystals. .... 433.15 Amorphous. 334.13 Pale yellow solid. .... -- Melting Rolling point point "C *C Decompd........... at 100. Decompd........... Dccompd. .... by heat. Decompd........... at 145 Into Pbo and I120. Dccompd........... at 145 Into I'bO and lf20. Decompd........... nt 130. Dccompd........... at 300. Dccompd........... nt 130. Loses water at 100. Dccompd. at 300. .... .... Solubility InA 100 ml. of Cold water Rot water Alcohol. acid, etc. .... .... Cry dll. Ph Attacked by fused KNO.i under con ditions where finely divided lead Is only attacked. Act foi plu .... 0.0155s .... Slightly sol. Sol. In acids and alkalies. Insnt. In acetic add. He In hyd Sm by lith 0.014 Slightly eol. Sol. In UNO*, al Ad kalies or acetic ide acid. 0.014 0.0012s Insol. Insol. 0.01 .... 0.003s Tnsol. Insol. .... Sol. In adds and Sam alkalies. mi eon diti Slightly sol. In Ac HNO.i, Insol. In lod Nils or acetic sol acid. Sol. In dll. HNO.i. Ac aci ide of Sol. In dll. UNO.,. Ac rio lea Ac did ) > i> 3 3 3 ) 3 3 Load dl-lodlde I.cad Iodide, basis Lead Iodide, basle Lead lonlde Lead molybdate (Wulfenlte) Lead nitrate ' Lead nitrate Lead nitrate Lead nitrate Lead nitrate, basic Pbl3 rbOPbTj Pbr2Pb0II20 PbNH PbMo04 Pb(N03)2 461.OS Yellow hcxngonal powder. 6.16 684.20 * 702.28 Rhombic crystals. 6.83s0 222.23 Roddlsli-bronn substance. 867.16 Yellow-white fpowder or octa- ledral plates. 8.7 331.23 Colorless cubical or inouocllnlc crystals. 1.782. 4.83 402 954 (393) (900) Pccompd........... at 100. 1008 Dccompd........... at 470. 0.044" 0.41'00 Sol. In KI or al- I'p kallos. Insol. In sol ale. alk > Insol. 38.8 .. .............. Tr sto tlo ac cry . .............. By sto po an In .............. Ac lon In .... 138.8100 Decompd. by Ad coned. ll2SO. a s Sol. In acids or mo KOII. Insol. In ale. 8.77s* In 43% Dis ale. Sol. In Nils wh or alkalies. 2ri)ON2Osl.8njO 881.44 White monocllnlc crystals. 4Pb0 N203 N20s-2H,0 1112.80 White rhombic crystals. 2PbO-N2Oo HaOorPb(OH)N03 872.43 While rhombic crystals. .... 8.93 Pb(OH)NOs 280.23 Rhombic crystnls. 8.93 Pccompd. at 100. Pccompd. .... at 100. Pccompd........... Pccompd........... at 180. By sto tio ni tro cry .... Fairly sol. 19.4* * Sol. Sol In acetic acid, alkali hydroxldes, IIC1 and liNOj. Sol. In acids. He lea Bo nit ) > > 3 3 33 *0 Name Lead nitrite (Lead subnitrite) Lead monoxldo (Litharge) Lead monoxide (Massicot) (Masslcotlte) Lead dioxide (Lead peroxide) (Plattnerlte) Lead sesquloxlde (Mctaplmnbatc) Lead oxide ' (Itcd lead) (Minium) (Orthoplumbate Lead suboxide PHYSICAL CONSTANTS OF LEAD COMPOUNDS--Continued INORGANIC COMPOUNDS OF LEAD--Continued formula 3l'bONnO,n20 A rarlable componund. rbo Crystalline form Molecular color velght Index or refraction T63.68 Light yellow powder. Specific gravity ** 223.21 Yellow tetragonal crystals. 2.665:2.535. 9.53 Melting point *C 4 Bolling point 'C 888 .... Solubility In 100 ml. of i---------------------- -------------------------- > Cold Bot Alcohol. water water acid, etc. Very sol .... Sol. In dll. BNOa. Dec trite ride In 0.0017 Sol. In alkalies, nea lead acetate. ber NHCI, CaCI5, nac SrClj. air. PbO rbOi PbsOa or FbO-PbO] Pb30 PbjO 223.21 233.21 Yellow rhombic crystals. 2.51: 2.61:2.71. Brown tetragonal crystals. W 2.3. 8.0 3.875 .... .... Dccompd........... at 200. 162.42 Red-yellow amorphous powder. **** Dccompd........... at 360. 685.63 Cryst. scales or red amorphous powder. 2.4 n. 9.1 (4.6) Dccompd........... at 500. 430.42 Black amorphous 8.842 powder. Decompd. .... Into Fb . and PbO. 0.0023** Insol. Insol. Insol. 5.3 10-**. Insol. Insol. Decompd. Insol. Sol. In alkalies. Mo at air. Sol. In dll. HCI and BNOa IIjO*. Slightly sot. In acetic acid. Insol. In ale. Act dlx ll20 or pre Als the phu scr lea Sol. In acids or Ad alkalies. chl sol tic Sol. in acetic Ile acid, hot HCI or con HNOj -HjOs. In sol. In ale. Insol. Insol. Sot. In adds or for alkalies. pp du at ) > J > J 3 <3 3 O l.cad phosphate, basic PbO PbalPO,)* head phosphate, basic 2PbO FbjtPOalj l.rad phosphate, basic head hypophosphate head orthophosphate 5PbO PbatPOi)* PbFOj FbatPOjIj head diorthophosphate PblIPO liCad mono-orthophosphate Pb(n2P0), I.end pyrophosphate head pyrophosphate PbjPjO; Pb2Pa0rIIa0 head metaphosphate Pb(P03), Mad phosphide PbPB head hypophosphlte rb(II2P02>a 1034.85 While solid. ... 082 1400.0 White solid. .... 040 1927.05 White solid. 318.23 811.67 Colorless hexagonal crystals or white powder 1.070:1.930. 6.9 to 7.3 800 ........................ 1014 .... 303.24 Rhombic or mono- 5.661** cllntc eryst. solid. 461.28 Cryst. needles. .... Decompd........... **** 588.46 606.48 White rhombic crystals or amorphous. Rhombic solid. 5.8" .... 385.25 Colorless crystals or white powder. I 862.31 Black unstable solid. .... .... 337.31 White cryst. powder. .... 824 .... 806 .... anhydrous. 700 .... to 800 Heated In .... vacuo to 400 decom poses. ........................ In ch tio or In ch tio or Insol. Insol. 0.000014* Insol. .... .... Decompd. Decompd. to Pb.3 to Pbs (F04), (PO4)* Insot. Decompd. Insol. Decompd. Very slightly sol. Attached by water. .... -- Ac po lea 60I. In UNO* or alkali hydroxides. Insol. In acetic acid or ale. Fp ta lea sm so 10 Sol. In HNOa, Pp KOII. NaOII or le Nil,Cl. dl at Sol. in ROD, NaOh, UNO, or hot coned. HC1. Insol. In 50% acetic acid. D ph H cr Sol. In nNOa or Fp KOn. Insot. In so acetic acid. ro Sol. In nNOa, KOn or Na,PaOr. Readily decompd. by acid. Fp so Ns In Fp tra of plm Decompd. by dll. Tr acids. In alk Slightly sol. .... Ac me alk on }J 3 33 3 330 Name Lead orthophosphite Formula PMIPOa toad platfnocynnlde Lead selcnate PbPt(CN)4 PbScOr Lead eelenlde . (Clousthallte) Lead silicate or Lead metnslllcate (Alamoslte) Lead orthodlslllcate (Baryslllte) Lead slllcofluorlde PbSe PbSlOa PbaSljOr PbSIFa21Ts0 Lead sulfate (Anglcslte) (Plumbous) Lead sulfate, basic (Lanarklte) PbSOj rbso.riio PHYSICAL CONSTANTS OF LEAD COMPOUNDS--Continued INORGANIC COMPOUNDS OF LEAD--Continued Crystalline form Molecular color weight Index of refraction 287.24 White powder. Specific gravity .... Melting Bolling point point "C "C Dccompd. 506.45 850.17 Yellowish white cryst, powder. White rhombic crystals. .... 0.37V 286.17 Lend grey cubical 8.10 crystals. 283.27 Colorless or while 0.49 monocllnlc crystals. Dccompd. .... 1005 760 # 582.54 885.83 Trigonal white solid. 2.070:2.050. Colorless crystals. 0.53 to 6.707 .... .... .... .... . * 303.27 White monocllnlc 8.2 or rhombic crystals. 1.877: 1.882: 1.804. 520.48 White monocllnlc crystals. 1.93: 1.09:2.02. 8.92 1170 977 .... . Cold water Insol. Solubility In 100 ml. of A Hot water Alcohol, acid, etc. Insol. So). In UNOa. Ppt sal of d soln Insol. Insol. Insol. Insol. Insol. .... Insol. Sol. In coned, acids. Act len selc sal Sol. in UNO., or Act hot coned. liCl. alk sol. Dccompd. by acids. Insol. In ale. Mad litha by tate cate Am Sol. 0.0028 0.0044** .... 0,0050* Very slightly sol. Sol. In coned, acids, tartaric acid or ammo nium salts. Insol. In acetic acid. Slightly sol. In Il,S04. Hea com dro bein the add Act fate on nitr Acti air r to >> bead sulfate, basic rbSO-3PhO bead sulfate, basic Pb(ltS04)2II20 bend persulfate PhSaOsSnsO (bead peroxydlsulfate) bond sulfide (Galena) bead sulfite PbS PbSOs bead ammonium sulfate Pb(NIb)3(S04) bead potassium sulfate PhKz(SOi)j bead tellurtde (Attolte) I/cad thiocyanate PbTe Pb(CN8) bead dlthlonate bend thiosulfate Pb%0-4na0 PbS20s 972.90 Yellowish white solid. 419.39 Cryst. solid. 453.38 Deliquescent cryst. solid. .... .... .... .... Decompd. .... 239.27 Cubical blue gray metallic crystals. 3.912. 7.5 287.27 White powder. -- 1114 Decompd. 435.41 .... .... 477.52 .... .... 834.82 Tln-whltc cubical 8.19 crystnls. 823.37 Colorless mono clinic crystals. 3.82 917 Decompd. at 190. 489.39 Trigonal solid. 1.035:1.053. 819.33 White crystals or powder. 3.22 6.18 Decompd. Decompd. O.OOOl' Very sot. 4.4 10-" Insol. bess sot. thun sul fate. 0.05" Treat stloch tion o Slightly sol. In Roll Mj SOi. sulfur Very sol. Decompd. by alkalies. Electr IlaS04 cell w with t C. I highe Pb03 .... Sol. In acids or Rubble hot dll.1IC1. In- lead s sol. In K01I or Is a d ale. lead, will or bl Insol. Decompd. by HNOa, 1ICI, II5SO4. Slightly sol. In IUSOj. Insol. in acetic add. 1'ptd. alkal sol. Decompd. at 100. .............. Add propo moni sol. Decompd. at 100. .............. Add propo slum lead .............. Actio kail of so Sol. Sol. In KCN8. Pptd. lINOa or alkali lead hydroxides. monlu 115.0"" 0.03 Sol. in acids or NajS203. Disso NnjS of w Pptd. late s thios Name Lead-sodium thiosulfate Formula PbS20t-2Na2320s PHYSICAL CONSTANTS OF LEAD COMPOUNDS--Continued INORGANIC COMPOUNDS OF LEAD--Continued Crystalline form Molecular color weight Index of refraction 835.56 Small white heavy crystals. Specific gravity .... Melting Bolling point point C "C .... .... t Cold water .... Solubility In 100 ml. of A Hot water Alcohol, acid, etc. .... Sot. in thiosul fate solns. Lead metatitanate licad tungstate (Rnsplte) Lead tungstate (Stolzltc) Lead metavanadate PbTlOs PbWO PbW0 Pb(VOa)a Ammonium ehloroplumbate (NH|)2PbCl Calcium plumbate Ca2Pb0t4H20 Hydrochloroplumble acid HsPbCIa Potassium plumbate K2Pb033H20 or K3Pb(0H), 303.11 Yellow to white rhombic prisms. 7.62 455.13 Monocllnlc crystals. 8.46 455.13 405.11 Colorless tetragonal 8.32 crystals. 2.2G9: 2.182. Yellow powder .... 458.03 Yellow cubical cryst. solid. .... 423.43 Colorless crystals. 421.07 Dark brown snln. In coned. HCI. .... -- 387.45 .... .... 1123 .... .... .... .... .... .... Dccompd..................... at 120. Free acid .... decomposes with PbCL and HCI. Insol. Insol. Insol. Insol. Insol. .... Slightly sol. .... BoL .... Sol. .. Dccompd. by HCI Into PbCI2 and T102. Decompd. by hot IINOj. Insol. In NHOH. Sol. In KOH. In sol. In HNOj. Dccompd. by HCI. Sol. In dll. UNO,. Dccompd. by cold coned. H28O4, yielding PbCI*. 216 Pyromorpblte PbCI, 8Pb,(P04>s 2713.08 Hexagonal cryst. 8.8 1150 .... .... J I > ) > J > 217 Sodium phimbltc Na=PbOa 285.20 .............. .... .... .... Sol. .... .............. E c p :o Lead abletale Pb (C20TT2BO2) 2 bead acetate, anhydrous, Pb(tyi30a)a norma! bead acetate, normal (Bugnr of lead) Pb(C2lt302)2 3II20 bead acetate bead acetate, basic Pb(C2If902)2 10!t20 Pb2(C2lf!t02)a0H bend acetate, monobasic l'li(C2ll302)3 Pb(0ll)2 llaO farad acetate, dibasic Pit(C21f303) a-2Pb (OH) 2 Lead acetate, trlbaslc Ft) (tyi.iOa) 2-3PbOJf20 810.03 ORGANIC COMPOUNDS OF LEAD Rrown, lustrous translucent lumps or tine yellowish white ponder. Tnsol. 323.30 White trlcllnlc 3.251^ 280 .... 44.3TM crystals. 370.35 White ninnocllnlc 2.55 crystals. 111.570. Loses .... 31I20 at 76. Anhydrous at 280. 45.64 505.46 Rhombic crystals. 1.680 22 ___ Sol. 608.58 White. Very sol. 584.54 White monncllnlc crystals. 807.75 White microscopic needles. .... .... 1012.90 White ponder. .... ..... . . . .... .... Very sol. 5.55 .... . . . . . .. 221.20TM Insol. In most solvents. Spar ingly sol. In lin seed oil. P a a a a H l 200,0 Slightly sol. In ale. a s l 80b -- 18.2 .... Insol. In ale. R d s Slightly sol. In ale. S l o g a a Sol. In ale. 'A w m Sol. In ale. A a o t T a a f 3 f ) > 3 3 3. Name bond tetra-sectate liead benzoate bead butyrate bead Isobutyrate j bend caprate Lead eaproate bead caprylate (bead octoate) bead cerotate I.ead citrate Formula l`b(02ns03)4 Pb(C7Hc02).> !M> rb(c*ir7o2)2 Pb{C4II702)a pb(c10n,(1o2)!i PHYSICAL CONSTANTS OF LEAD COMPOUNDS--Continued ORGANIC COMPOUNDS OF LEAD--Continued Crystalline form Molecular color weight Index of refraction 413.30 Colorless monocllnlc crystals. Specific gravity OOOt) Melting point c 175 Rolling point -c 467.45 White cryst. powder. ' 381.85 White tlscous mass. .... .... boses water at 100. .... .... 381.40 White prisms. .... 100 .... 549.72 .... 103 to 104 / Cold water Solubility in 100 ml. of -A not water Alcohol, acid, etc. M Decomposes Into PbOj and acetic acid. .... Dccompd. by ale. Add Sol. In chloro acid t form. Sol. In hot coot. accllc add. 0.16TM 0.31'" Action benzoa soln. Insob .... Sol. in IINO.,. Intera acid salt I *cnt. 9.1TM .... Action acid o ide. Insob Insol. 0.0029TM in ether. Treat soln. with a caprtc Pb(C,DuO,)j Pb (CsIIigOj)] 437.51 .... 73 to 74 493.61 Wlilte leafs. .... 83.5 to 84.5 * Insol. Insol. 1.09TM In ether. Treat lead a ale. s add. Sol. In ale. 0.0938TM In ether. Treat of lea an a capryl PbCCjolIsjOa)* Pb3(C,II60T)2 3U,,0 998.50 White needles from benzene. 1053.88 White cryst. powder. .... .... 112.5 to 113.5 ...... . i* Insol. Sob .... .... Insol. In ale. or Treat ether. lead a ale. s add. Action trate of lea fJ f > >a > 219 Lead enanthate Lead cthoxlde rb(o,nMoa) pb(oc2nB)a Lead cthylsulfate Lead tetraethyl Pb(Cs!lcS04)2-2Il.j0 PbyiB)4 Lead hexaethyl dl (Hexacthyldi plumbane) (Dlplumblc hexaethyl) (Lead trlcihldc) Lead dlcthyldlpropyl) Pbi(CsBi)i PblCslIgMCan,), Lead dlethyldl-Isobutyl Pb (CaIfs) *(IsoCUp) x Lead trlcthylmonomethyl Pb(c2n5)3(cn5) I.cad trlcthylmonopropyl Pb (Calls) a(C>Hj) Lend trlethylmonolsobulyl Pb(c3ir,)3(isocng) Lend trlethylmonoamyl Pb(c,ir,)3(cBir,,) (.end trlethylmonolsoamyl Pb(C3IIB)3(lsoC3nM) 405.50 White leafs. 297.33 Light yellow friable powder. .... 493.45 Colorless liquid. 323.45 Colorless liquid 1.5218**. 1.059 588.78 Liquid. 1.471 01.5 -130 Hydro lyzed by water. Bol. 198 to Insol. 202 or 152tmm. Slightly sol. .... Insol. In ale. Hea exces acid ........ ... Susp ot l ale. strea pass with raeu acid Inte ethy hydr v In ether. Sol. In all or ganic solvents, f Insol. In dll. ale. or dll. alkali. Acti dide allo lead alky Deeompd. Insol. 351.38 Liquid. 379.42 Liquid. 309.40 Liquid. 337.37 Liquid. 351.38 Liquid. 385.4 Liquid. 885.4 Liquid. 1.529"4 * 1.458V 1.712*4* 1.505M 1.530s*:* 1.482" 1.500":* Tre loy pro Tre loy Iso Act me lead Tre loy pro Tre loy Iso Tre loy am Tre loy Isoa J 3 3 3 3 3. 3 3 jin ijiiniiiwiwmi'iiu jumuft--I 220 Name bond formate U`ad lactate Leadlaurate head Hgnoccrate Lend llnolcate I-cad malate l-cad mellssatc Dead totramethyl head dlmethyldlcthyl Formula Pb(cno2)a Pb{C,,irB03)s C12H33O3) g Pb{cMn,,o2)2 Approximate I*b(ClflIf3102)2 Pb(C4n,o,)-3n2o Pb(Crun0102)a Pb(Ctls)4 rb(ciy!.(c2n5)2 PHYSICAL CONSTANTS OF LEAD COMPOUNDS--Continued ORGANIC COMPOUNDS OF LEAD--Continued Crystalline form Molecular color weight Index of rcfrnetlon 207.25 White lustrous rhombic crys tals. 1.789: 1.852:1.877. 385.31 Heavy white cryst. powder. Specific gravity 4.50 to 4.03 .... 805.82 Chalky white powder. .... Melting Bolling point point C "C Dccompd. .... .... .... 104.7 .... 942.45 White powder. .... 117 .... 788.07 Yellowish-brown .... plastlc-Ilke mass. 303.33 White powder. .... 1138.82 White powder. .... .... .... .................. 115 .... (O 110 207.35 Colorless liquid 1.5128. 1.0051^ -27.5 110.TM 295.22 Mould. 1,790 Solubility In 100 ml. of Cold water 1.0> Hot water 20'0* dccompd. Alcohol,' scld, etc. Insol. In ale. Ma Roll le formic Sol. .... 0.009" .... Insol. .... Insol. Insol. Slightly sol. Insol. .... Insol. Insol. .... Sol. In hot ale. Action or sodi sol. loa 0.007'* In ether. Action rate or ale. on tate so Very sol. In boil ing benzene. Slightly sol. In ale. Insol. In ether. Action of lead golns. acid o nocerate Sol. in hot lin Treat s seed oil or hot In ale. turpentine. salt or Action ate on salt. Sol. In boiling toluene, acetic add. Slightly sot. In hot benzene or chloroform. Insol. In ale., ether. Action of mel ale. s acetate. In ether. Action dide o alloy, lead ct alkyl.. Action methyl lead-sod tf '1 >J J. ) head dlmethyhllpropyl i*b(cir:!)3cc3ii7)9 head dlmcthyldl-lsohutyl I'D (CI?;,) 3{IsoCir,,) 2 Lead dlmcthyldl-lsoamyl I'D (CIIa)a (IsoColIti) a l/rad tiimcthylmonoethyl Ph(CIIa),,(C2IIS) l.ead trimcthylmonopropyl l'h(Ciy,(C3II7) t.cad trlmcthylmonohutyl PbiCJIaiat^Ho) Lend trlnicthylmonolsohutyl I'D (CIi3) 3 (lsoC^lIo) Lead trlmclhylinonnisoamyl Pb(Clti).i(lsoC5Un) Lead myristate rh(C,4lt02)a Lead 2-naphthalcncsulfonate Lead naphtlmnalc Lead nonylntc Pb{C,oIlTS03)a Pb(Ci;II(|Oi) Pb(CoH,,02>j Lead aleate Pb(CieIIM02)a 323.35 Liquid. 351.38 Liquid. 370.42 Liquid. 281.308 Liquid. 205.32 Liquid. 300.40 Liquid. 300.40 Liquid. 323.54 Liquid. 601.03 lViillc powder. 1.623I 1.504" .... ----- 1.430" .... .... 1.880 .... ----- 1.760'V- .... 1.664V .... .... .... 1.068 V . ...................... 1.524*** .... .... 107 ___ 621.64 White cryst. powder. * *** 421.38 .... .... .... 621.416 Solid. .... 05 .... 770.10 White powder. . .... .... -- -- .... .... .... 0.005" Insol. Insol. ** * Insol. ...... -- *** 0.006" .... .... .... Treat le loy wit propyl .............. Treat le loy wit Isobuty Treat le loy wit Isoamyl ........ V* Action methyl lead so .............. Action propyl lead-so .............. Action butyl Io sodium .............. Action Isobuty lead-so .............. Treat l loy wi Isoamy 0.004" in ate. 0.010'` In ether. Treat l hot ale soln. acid. Sol. In ale. Interac lead s dium sulfona Sol. In vegetable Patente oil, turpentine, mineral spirits. Intel ac acid o nonylat lead sa 8.46" In ether. Pptd. Sol. In petroleum lead s ether. Slightly soln. o sol. In ate. I r t f I f I > >> 22? PHYSICAL CONSTANTS OF LEAD COMPOUNDS- -Continued ORGANIC COMPOUNDS OP LEAD--Continued Name l.ead oxalate Formula I'bCs04 find palmltate Pb(CiH3i0g)t l.ead phenolate (head pbenate) (Lead carbolate) Lead pentachtorphennte Pb(0H)0Cn8 rb(0c,ci)a Lend tetrachlorphenate Pb(0Cell2Cl<)t Lend 2-chlor6-phenylphenate Lead phenol-sulfonate (Lead sulfocarbolate) Pb(0Cn3Cl-CeHs):, Pb(CoH<(01l)803)i SHgO Lead tctraphenyl (ColIolePb Lead phthalate Pb(OOCCoII)j Crystalline form Molecular color Specific weight Index of refraction gravity 205.23 neaty white powder. 5.28 718.03 Chalky white powder. .... 317.32 Yellowish to graywlilte powder. 738.80 White solid. 608.89 White solid. 614.25 White solid. .... -- .... .... 643.61 White lustrous needles. 515.61 White needles. .... Melting Bolling point point "C "C Hecnmpd........... at 300. 112.3 .... .................. .................. .................. .................. **** * 227.7 .... 1 Cold water A not water 0.00010'* 0.005** 0.007" Insol. Belatlvely Insol. Relatively Insol. Belatlvely Insol. Sol. .... Alcohol, acid, etc. Man Sol. In HNOs, Died alkalies. In sol. In ale. Spar ingly sol. In acetic add. Pptd. soln. of ammoniu Bo). In ale. Boll a 0.148s0 In ether. palmitic soln. w acetate Boll phe arge. Sol. In ale. Sol. In bensene. Treat th of p add wi salt an Action monolo sodium Beactlo carbona water s anhydri Lend phthalocyamlne Pb(CHCfN*)4 Green. Insol. Insol. In oil. Heat and me ocyamln Inorgan pound. J j a > tl 223 Lead plerate Lead propionate Lead tetraproplonate Pb(C6H*N30,)t n2o Pb(C,Hs02). PbtCsH.Ojh Lead salicylate Lead stearate Lead tannate Lead tartrate d Lead tartrate, dl Lend dltldofurate Pb(CsHo0a)'H:0 Pb(CisH*jOt)t Approximate Pb(C,,H,Oe)i I'b(d-C<ntOj) Pbldl-Cr^O,) ' ' Pb(C<IfaOCSS)s 681.43 Yellow eryst. needles. 353.35 515.85 Colorless cryst. powder. Solid. 2.831" .... **** 451.10 White cryst. solid e TT4.14 White to yellow powder. .... 849.63 Brownish yellow, .... odorless, tasteless amorphous powder. 355.28 355.28 Rhombic crystals White cryst. powder. 8.871" 2.53" 493.60 Loses water at 130. Explodes 0.88" Insol. Sol. Insot. Slightly sol. .............. Ac ad .............. Int plo lea be pio sa Sol. In ale. Ac on Sol. In hot ale. fp so at co Slightly sol. In Fp ale. Sol. In adds. so to ac 0.0025" O.0074100 Sol. In I1N03, or KOH. Insol. In ale., acetic acid or ammonium acetate. Pp or so Index Allowable concentrations, lead and lead compounds, 175,181 Alpha particle, 97 American Association of State High way Officials, spec., 177 American Society for Testing Mate rials, spec., 177 American Standards Association, spec., 177 American Water Works Association, spec., 177 Ammunition, 122 Anchors, lead, 1,16, 25, 92 Anglesite, 5 Anti-galling agent, 144 Anti-knock fluid, 145 Antimonial lead (hard lead) Cast, properties, 198 Castings, 25 Composition, 43 Corrosion resistance, 43, 56, 58 Extruded, properties, 197 Fittings, spec., 179 Safe working pressure, pipe, 50 . Sheet, properties, 197 - Antimony-lead phase diagram, 189 Architecture, 87 Armored cable, 38, 182 Army Specifications, 177 Arsenates, lead, 148, 204 Atmospheric exposure, lead, 54 Atomic radiation shielding, 98 Atomic reactor, 99 Atomic structure, lead, 183 . Automotive Engineers, Society of, spec., 178 Aviation gasoline, spec., 180 Azide, lead, 15, 148, 206 Babbitt metal, 118,185 Ballast, 137 Basic carbonate white lead, 138, 181 Basic lead silicate, 149 Basic lead sulphate, 139, 181 Basic lead sulphate-blue, 148, 171, 180 Basic silicate white lead, 149 Basic sulphate white lead, 139,181 Batteries, storage, 27, 181 Application, 32 Construction, 31 Grid metal, 136 History, 28 Operation, 29 Battery grid metal, 136 Bearing metals, 118,179 Bearing shell preparation, 120 Beta particle, 97 Betts process, 10 Bismuth in pig lead, spec., 179 Black oxide, 30, 144 Black plate, 109 Blast furnace, 8, 9 Blue lead, basic sulphate, 148, 171, 180 Blue lead paint Atmospheric exposure, 172 Fresh water immersion, 172 Marine exposure, 173 Sea water immersion, 173 Body solder, 117 Boiling point, lead, 186 Boiling points, lead compounds, 203, 204 Bonded lead, 46 Brass, leaded, 136 Brick-lead linings, 47 Bullets Armor-piercing, 125 Cores, 124, 136 Incendiary, 125 Training, 126, 129 Burning, lead (welding), 2, 44, 72 Rod, 73 Speed, 74 Cable Armored, 38, 182 Coaxial, 39 Gas filled, 40 Lead covered, 36 Manufacture, 38 225 226 INDEX Cable--Continued Plastic jacketed, 42 Press, 20 Sheathing, compositions, 37, 136 Telephone and television, 39 Cage construction, 44, 46 Calcium-lead, 37,197 Calking lead, 1, 79,179 Composition, 81 Carbonate, lead, 5, 138, 181 Carter process, 139 Caskets, lead, 2 Casting temperature Antimony, 185 Bearing alloys, 185, 201 Die casting, 26 Lead, 184,185 Tin, 185 Type metals, 185 Castings, 25 Cerrusite, 5 Chemical construction, 44 Chinese scarlet, 147 Chrome green, 147, 180, 181 Chrome red, 147 Chrome yellow Lemon, 147, 180, 208 Medium, 147, 180, 208 Orange, 147, 180, 208 Chromium plating, 43 Cleaning lead surface, 95 Cleats, architectural, 90 Coatings, lead and lead alloy, 109 Electrodeposited, 111 Hot dip, 110 On copper, spec., 181 On iron, spec., 181 Specifications, 181 Sprayed, 113 Terne, 109 Thickness, 114 Coaxial cable, 39, 132 Collapsible tubes, 21,131,136 Color, lead compounds, 204 Commercial Standards, 177 Comparative data, metals and alloys, 196 Composition Chemical construction, 43 Pig lead, 70 Concentration, ore, 5 Consumption of lead, 4, 11, 13 Continuous softening process, 9 Conversion table, teme plate, 114 Copper-lead bearings, 179 Corrosion Atmospheric, 54, 56 Chemicals, 58 Construction, 44 Conversion of corrosion rate, 52 Immersion corrosion, spec., 182 Bate interpretation, 51 Besistance, 51, 58 Sea water, 54, 56 Soil, 57 Waste and vent, 57 Counterbalances, 21, 137 Creep, 193 Crystalline form, lead compounds, 204 Density, metallic lead, 184 Vapor, 184 Desilverizing, 10 Detonators, 148 Dezincing, vacuum, 10 Die castings, lead alloy, 179,182, 202 Drill stem lubricant, 144 Drum traps, 84,179 Elastic limit, 192 Electrical properties, 194 Electrochemical series, 195 Electroplated lead, rate of deposition, 113 Electroplating, of lead, 111, 181 Electrolytic solution pressure, 194 Electrotypes, 127 Elongation, 191 Enamel, drum coating exterior, spec., 181 Euston process, 139 Eutectics, lead, 189 Expansion, antimonial sheet lead, 88 Coefficient, 87, 186 Soft sheet lead, 187 Explosives, 15,148, 206 Extruded products, 19 Fatigue, 52,193 Federal Specifications, 177 Fibre stress, maximum allowable, 192 Fine solder, 116 INDEX Flashing, Open valley, 91 Parapet wall, 91 Roof, 89 Vent pipe, 82 Wall, 89 Floor flanges, 26, 82 Flotation process, 5, 8 Fluxes, 110 Foil, 24, 131, 132, 136 Condenser, 132, 136 Packaging, 131, 136 Forms and fabricating processes, 18 Frits, 149 Galena, 5 Galvanic corrosion, 54 Gamma radiation, 97 Gamma ray shielding, 101 General properties, 183 Glass, glazes and vitreous enamels, 138, 141, 144 Gooseneck, spec., 77 "Green" cement, 90 Green imitation bronze finish, 95 Grid metal, battery, 136 Hard lead (antimonial lead) Cast, properties, 198 Castings, 25 Composition, 43 Corrosion resistance, 43, 56, 58 Extruded properties, 197 Fittings, spec., 179 Safe working pressure, pipe, 50 Sheet properties, 197 Hardness, lead, 190 Harris process, 10 Heat contents of lead, 134 Heat transfer, 187 Heat treating baths, 133 Heating coil formula, 49 . History, 1 .......................... Homogeneous lining, 46 Horizontal seam, 89 Hot dip lead alloy coatings, 110 Hot shortness, 115 House paints, 151 Primers, 155 Tint base, 159 White, 158 Impact extrusion, 21 Imports, 4 Impression lead, 127 Index of refraction, lead compounds, 204 Inorganic lead compounds, 203 Insecticides, 148 International orange, spec., 180 Iron in lead- and tin-base alloys, spec., 179 Isotopes, lead, 183 Lead-antimony phase diagram, 189 Lead-asbestos vibration pad, 93 Lead brides, 98 Lead burning (welding), 2, 44, 72 Rod, 73 Speed, 74 Lead-cadmium radiation shielding, 99 Lead-calcium, 37, 197 Lead chromate (yellow and orange), 147, 180,181,208 Lead coatings, 109 Electrodeposited, 111 Hot dip, 110 On copper, spec., 181 On iron, spec., 181 Specifications, 181 Sprayed, 113 Teme, 109 Thickness, 114 Lead concentrates, 5, 8, Lead in gasoline, test for, spec., 180 Lead intoxication, 174 Lead monoxide, 141, 212 Lead peroxide, 144, 212 Lead poisoning, 174 Lead production, 4 Areas, 7 Lead-rubber (Roentgen opaque), spec., 182 Lead salts of organic acids, 203 . Lead silicate, 214 Basic, 149 Frits, 149 White lead, 139,181 Lead-silver solder, 117 Lead-sodium, 146 Lead sulphate, 5, 214 Basic, 139 Blue, 148, 181 White lead, 139,181 228 INDEX Lead sulphide, 5, 8, 215 Lead-tellurium, 43, 49, 53 Lead-tin alloys, properties, 199 Lead-tin-antimony alloys, properties, 200 Lead-tin phase diagram, 188 Lead titanate, 181,216 Lead wool, 81, 129 Leaded glass, 141 Leaded lubricants, 128 Leaded zinc oxide, spec., 181 Liquid electrode furnace, 135 Litharge, 16, 180 Battery, 141 Colormakers', 142 Enamelers', 141 Glassmakers', 141 Manufacture, 141 Oil refiners', 142 Potterymakers', 141 Eubbermakers', 142 Vamishmakers', 142 Litharge-glycerin cement, 142 Litharge-red lead paint, 142 Low melting alloys, 132 Low temperature properties, 190 Lubricants, leaded, 128 Manufacturers Standardization So ciety of the Valve and Fittings Industry, spec., 178 Maritime Commission Specifications, 178 Matrix alloy, 133 Mechanical properties, 190 Melting point Lead, 184 Lead alloys, 133 Lead compounds, 204 Metal powder bearings, 121 Metal protective paints, 160,180 Metallic packing, 136 Metallographic specimen, prepara tion, spec., 182 Miscellaneous Alloys, 136 Lead chemicals, 150 Properties, 196 Mine production, 4 Mining, 5 Districts, 4 Moisture proofing, 2 Molds and dies, 130, 133 Molecular weight, lead compounds, 203 Navy Specifications, 178 Neutron, 97 Oakum, 79 Old Dutch process, 139 Olive drab enamel, spec., 180, 181 Orange mineral, 144 Ores, 5, 8 Organic lead compounds, 203 Ornamental lead, 94 Packaging, 131 Packing, spec., 182 Paint Blue lead, 148, 171 Exterior, 152 Marine ext., basic lead chromate, spec., 180 Marine ext., red lead, spec., 180 Beady-mixed, 154 White lead, 151 Parkes process, 9 Patina Gray, 95, 183 Green, 95 Pattinson process, 10 Physical constants, lead compounds Inorganic, 204 Organic, 217 Pica, 174 Pig lead, 18, 179 Grades and composition, 70 Spectro. analysis, spec., 179 Pipe Ancient, 2 Chemical, 48 Hangers, 85 Heating coil, 49, 50 Lead-covered, 48 Lead-lined, 48 Manufacture, 19 Plumbing, 81, 179 Press, 19 Safe working pressure, 192 Service, 75, 77 Soil, 80 Specifications, 75 Wall thickness, 76 Weight per ft., 76 INDEX 229 Plastic molds, 16,130 Plasticizers, 152 Plumbing, 81 Plumbing and water distribution, spec., 75 Plumbum, 2 Pneumatic calking hammers, 80 Pouring temperature Antimony, 185 Bearing alloys, 185, 201 Die casting, 26 Lead, 184,185 Tin, 185 Type metals, 185 Powdered lead, 128 Power cable, 41 Primers Blue lead, 171 Red lead, 160,180 White lead, 155 Putty, 138 Radiation protection, 97 Railroad journal bearings, lined, 179 Recrystallization temperature, 184 Red lead, 1, 143 Paints, 160,180 Primer, atmospheric exposure, 163 Primer, fresh water immersion, 169, 180 Primer, marine exposure, 165 Primer, sea water immersion, 167 Pure, 143 Specifications, 179, 181 True, 143 Reducing bends, 84 Refining processes, 9 Reverberatory furnace, 10 Roasting, 9 Rolled products, 22 Roofing, 3, 87 Battens, 89, 91 Rubber hose Manufacture, 130 Press, 20 Safe handling, lead and lead prod ucts, 174 Safe pans, 1, 85 Safe working pressure, lead pipe, 78, 192 Scotch Hearth furnace, 148 Sea water exposure, lead, 54 Seal of Approval, 75, 81, 82 Sealing solder, 40 Seals, 131 Secondary lead, 11 Service pipe, 75, 77 Sheet lead Lining, 44 Manufacture, 22 Specifications, 179 Weight and thickness, 23 Shielding Atomic, 98 Construction, 105 Equivalents, 102 Gamma ray, 101 X-ray, 104 Shot gun shells, 126 Shot, lead (also see bullets), 2, 122, 136 Shot tower, 123 Shower pans, 85 Shrapnel, 126,136 Shrinkage on casting, 187 Sintering, 9 Smelting, 8 Soaps, lead, 128,152 Society of Automotive Engineers, spec., 178 Soft solder, 115, 179 Soil corrosion, 57 Soil pipe, 80 Corrosion, 57 Solder Body, 117 Fine, 116 Lead-silver, 117 Low tin, 71,115 Sealing, 40 Soft, 115, 179 Tin-lead and alternate, 116 Wiping, 116,179 Soldering, 2, 71 Solubility in alcohol, acid, etc., lead compounds, 204 Solubility in water, lead compounds, 204 Specific gravity, 184 Lead compounds, 203 Specific heat, 186 230 INDEX Specifications, 179 Spectro. analysis, lead, spec., 179 Sperry process, 139 Sprayed coatings, 113 Stabilizers, 16,142,149,152 Stamping dies, 131 Statistics, 4,11 Stereotype metal, 127 Storage batteries, 27,181 Applications, 32 Construction, 31 Grid metal, 136 History, 28 Operation, 29 Stress corrosion, 52 Sublimed white lead, 139 Surface tension, 196 Tellurium-lead, 43, 49, 53 Tennessee Valley Authority, spec., 178 Tensile strength, 191 Terne plate Long, 109, 181 Roofing, spec., 181 Short, 109 Tetraethyl lead, 145 Tetraethyl lead in gasoline, test for, spec., 180 Thermal conductivity, 186 Thermal properties, 185 Thompson-Stewart process, 139 Tin-lead alloys, properties, 199 Tin-lead-antimony alloys, properties, 200 Tin-lead phase diagram, 188 Tinsel, 132, 136 Titanium-lead-zinc, exterior paint, spec., 180 Traps and bends, 82, 179 Presses, 21 Standards, 84,179 Treads, safety, 182 Treasury Department, spec., 178 Type metal, 127,185 Composition, 128 Vapor pressure, 186 Vents and wastes, 57, 81 Vermilion, American, 147 Vibration isolation, 92 Wastes and vents, 57, 81 Water closet floor flanges, 26, 82 Weight and density, 184 Weights, 1, 137 Welding, lead (burning), 2, 44, 72 Speed, 74 Rod, 73 White lead, 138 Paint, 155,180 Paste, 154 White lead-varnish cement, 140 White metal bearing alloys, 201 White and tinted paint, spec., 180 Wiping, 71 Wiping solder, 116,179 Wool, lead, 81, 129 X-ray shielding, 103 Yarning, 81 Young's modulus, 192 Zinc-ammonium chloride flux, 110, 120