Document 27QEDZj2EbRLwkmRB1mnKorp

#150 - Durability Studies of Zinc Sulphide Pigment Combinations Panels 2280-4 C were examined after a full 6 years' exposure at Chicago* There are duplicate sets - vertical and 45 exposure. They consist of 5-coat self-primed work'on Ponderosa pine siding. Wardway.'s Coverall Buff of 1958 is the basic formula, with, both stock paint and our laboratory reproduction represented, TJiis formula uses about 21# each of New Jersey Zinc11 s Cryp tone MS-130 and 55/65 leaded zinc, plus about. 28# each of 20 L asbestine .and Metronite (caleium-magnesiua-carbonate-silicate) j three special lots' of Coffeyville ZnS (Mg) blends are substituted for the Cryp tone MS-150, Though originally of primary importance, the four ZnS (Mg) comparisons have developed practically po difference in performance. In fact, there is no choice between the paints except for slightly greater fading and more dirt on the part of the. Wardway stock guide. Between the vertical and 45 exposures, however, there is a striking difference. The former are free, from failure (except slight ero sion) and have excellent color with a minimum of dirt, while the 45 panels are nearly black with mildew and dirt, and are in an advanced stage of ' failure. A combination of cracking and erosion has exposed considerable' wood, and a great deal of wood-checking has resulted. The logical conclu sion is that while this tint is very satisfactory tip to 6 years of normal south exposure at tills locality, no chances can be taken with it under severe exposure conditions. It should be noted, however, that a previous report showed these 45 panels still without significant failure and look ing good at 40 mouths. . $86' - Durability of Pigments with Special Reference. to Beaded Zinc and 111116 Lead- ' _________. . A special report was written on exposures 4500-4633 C, Cof,,,` F'and mimeographed as a supplement to previous reports. Various competitive zinc oxides, white.leads and leaded zincs- are compared, based on (a) Rex 471 Gloss Tftiite of 1-4-40, (b) Rex 575 Colonial Yellow of 1-5-40 and (c) a spe cial 25$ lead titanate formula of Rex 375. Complete results cannot be pre- .sented here. The report i essentially routine at about 5-1/2 years' e^osure, since it follows one prepared in April, 1944 at some 7 months less (ex?osure time and "will be followed by a final report in about a year. The panels are all qedar, primed with Rex 450 Undercoater and exposed vertical south. Mechanically-mixed leaded zincs are seen to be definitely-inferior in durability to co-fumed. In these mechanical mix tures. St, Joseph #46 Zinc Oxide stands out as consistently poor, with Azo ZZZ-53 one of the best. National acicular basic lead sulphate is also outstandingly poor, with the other, white leads tested nearly identi cal. Qzlo 35/65 leaded zinc seems to have a slight advantage over Azo'. 55 L and Lehigh SO and 635. 0007-SWP-000006881 -4-. M. VAH LOO Cont. #86 --Pont. The. essential differences '.in the tint group are found between the lead titanate and regular.(non-chalking titanium) types.- The slowcleaning Chicago .panels show both as .bad due, to heavy adherent chalk and dirti A general vie?/, leads to the conclusion that lead titanate holds a slightly better color and is cleaner, up to the point where self-cleaning should reach its peak. Thereafter, the regular will clean quite thoroughly, but lead titanate holds its dirt more stubbornly. #163' - One Coat House Paint .- ' Panels 9148-9154 C and F were prepared for exposure during the month. The paints were described in the December report. They are vari ations of the regular* One Coat House Ppint CH 4697 with no lead titanate, but conparing the following micas: Alsfbronz #19, AA Mica, AAA Mica, Kraft* s C. 1000 and G 3000 Micas, and Concord.India Mica. Panels 9158-9169 C,and F were prepared for esqposure, This series is divided into two groups. The first compares regular One Goat House Paint CH 4897 -with its zinc oxide content of 25*8$, with a special with 30$ zinc oxide content, also another Special with no lead titanate. The second group includes special formulations for superior whiteness and self-cleaning.' ' /' / #77 - Mildew Inhibitors Formulas have been given to-the factory for the manufacture of a number of mildew resistant paints using phenyl mercuric oleate, phenyl mercuric naphthenat,' and tetrachloiphenol. - These paints are to be ex posed in house teats at Lafayette, Louisiana,-.as.'soon as the paints can be manufactured. The phenyl mercuria.naphthenate will be introduced as Nuocide 321 in concentrations of 0.02$ and 0.04$ Hg based on the point solids. Phenyl mercuric oleate vd.ll be used in a concentration of 0,04$ Hg based -on the paint solids and tetraehlorphenol at the usual concentra tion of 3$ based on the total weight of the paint, .' Exposures 7250-63 F,.FI were examined after 16 months* Florida exposure, vertical south. .These tests comprised various fungicidal agents in Rex 63Q57 Mildew Resistant Treated Gloss Whites tetraehlorphenol, 2052 dry, the regular agent in this formula, and 1/1000 and 1/2000 parts (by weight of paint) of phenyl mercuric borate, phthalate, salicylate, gluco nate, nitrate and' oleate. Rex 471 Gloss Ihite was used as gride: the pri mer was Rex 450 TJndercoater on all panels, which were both cedar and yallor pine. In spite of our special request that these panels be exposed in a place favorable to mildew growth, very little mildew has formed. This is probably due to the relatively low humidities and the 50$ of normal rsin-r fail during the past year. . 007-SWP.00000s882