Document J1krdBxBkMjxO8krwwzQrOoX

.ALLIED RESEARCH BULLETIN NUMBER RC-59 LEITE LEAD COMPARATIVE DURABILITY OF LEADING BRANDS Adams May 27, 1940 ALLIED - RESEARCH LABORATORIES CHICAGO, ILLINOIS N12S22 0007-SWP-000006829 White Lead - Comparative Durability of Leading Brands feral Statement ^ The purpose of this series of exposures was to establish any bif- r^'ferences in durability of the leading White Loads, and the effect, if any, of vuri- ' etions in the Carbonate to hydrate ratio within the Units of commercial product!; v. ' -'Test Procedure The various "Jhite Leads were ground in Linseed Oil and applied according to the standard "YThite Lead in Oil" practice, three coats on White Pine, f. vertical exposure, Chicago paint test farm. National'White Lead iu Oil whs used as the guide on each panel. Exposure Results The exposure period of the nain series as S-l/2 years, sufficient 'to evaluate the inportent durability features. The MacGregor Lead constitutes an exception, the exposure periods being 2-1/4 end l-l/ years. No. Brand Colei**- Chalkin'-- Fissure Pat "i Cracking Fl.'Ain.- 1. National 0. D. High Carbonate Etd. Considerable Her'... _ Slight Absent 2. National H.T.S. Low Carbonate Slightly Blight to Snail whiter considerable Slight Absent 3. National Carter High Carbonate '-i. Cotic.'.:r 'Normal Slight Very align "4."'' Eagle Picher 0. D. Equal Medium Carbonate Eli/ho to Cun siderf.bi iLxre 1 Slight Very sllgh 5, S-n 0 D e High Cerb&nato Equal Considerable ilorncl Slight to Slight considerable 6. a.` >- 7. S-W 0. D. Lo t / Carbonate S--7 Q. P . High Carbonate e. S-W Q. P. Low Carbonate Equal Considerable Large Equal Considerable Muracl Very Slight slightly v.-hiter Slight Slight Slight Absent Absent Absent Co.nt. on next page. 0007-SWP-000006830 sure Results - Cent. 8^ Brand, MacGregor -1/4 Irs,, S-B MacGregor 1-1/2 Yrs. 9-C MacGregor 1-1/2 Yrs. Colors CV:r.lSr.in.; Fissure pattern Cracking Slightly Considerable Irregular Slight whiter Flaking Absent Slightly Considerable Linear whiter Slight Very slig. Slightly Slight whiter Large Slight to Very sligh rectangular considerable E-Comparison against National Old Dutch Mscussion of Results No narked superiority of one Load ror another-has been found. Different lots of-MacGregor Load .a irregularity of performance. r]-- National E.I.S. Lead thd ilia S-7i similar - type of Lean, No. 8, have given some evidence of superiority druring the oi^ccur.' period, out the difference pat 3-1/2 years is not narked. CEA; AR 0007-SWP-00000S831