Document vgdLdGndM8JrxaLLNqYexdGq

#i? * SWP 471 ' * e: . Mr. . V. fasig and Mr*-Van Loo Inspected the panel and/or house tests of the national Lead Company (basic silicate white lead house paints suy) tend 'tide Ktsnisn Pigasnt feowtioa at Seville, K. X. and of the du tait Pigment Division at YiU&gton, Delaware* A report was prepared and distributed. | Exposures '10518-59 CS,- |i and F were essoined after two years' exposure south and north vertical!** Chicago and south vertical in Florida. The paints involve studies! ef basic silicate white lead (both national and Eagle-Fieher) time1 basic silicate replaces (1) lead sulfate at equal fctaj using H SOS sine ea&de for 412 dry, (2) replacing basic carbonate white lead in a conventional 5Q5S lead - SO^ zinc oxide 1556 Ti02 - 2556 ex tender top coat pigmentation. Basic silicate was also substituted for equal volume of lead carbonate in lax 4JXj and in Mtf-401 sineless primer. .The Chicago panels are difficult to evaluate because of the gen eral cleanness even on the north. The principal failure is erosion. The SUP top coats made with basic sulfate 'white lead axe tee most pronounced in this respect. In general the 111 401 primer is inferior to Rex 450. National's 45-1 basis silicate white lead gives poor results in Mff 401. In the straight .top coat comparisons, there is vexy little choice as to the special materials* The Florida panels are imeh more varied in results and the major conclusions mat be based on them; this applied to dirt as well as film integrity. Rex: 471 with Rex 450 normally lodes bad in this series because f a spotty surface Hairing (poor atem-up). Bagle-Picher's material al most invariably deans up without this prolonged spottiness, but while National's is just as clean in some cases, it is no better than tee regu lar in other cases. ; Bote shear a "yellow* Him, however, and are not satis factorily white, fhb only eases of serious failure (more than a very slight microscopic cracking) are found cm paints Which contain Eagle-Picher aad National basic tflMlte substituted for tee basic sulfate content of tee leaded zinc osdfie menially contained. lew apis! basic sulfate white lead shows up poorly teen substi tuted for the BOWL gkamalty contained. Faints in teich tee basic silicates have bean used to pskiaee tee BCHL continue to perform equally well with the standard S9P. This difference in performance may possibly be ascribed to tee use of . paw'.aiac ( XX 505) in tea first case and a -fused loaded sine in the second. In tee Florida exposures W 401 is only very slightly inferior to Rax 450 and the silicates in W 401 are equivalent at this inspection to BOWL N39111