Document B5azKy13Z5rDmg0Bo5qNaJ7DX

Cross Inflex: cc Release Letter Ho, 93.0 Letter 5/3/49 to E, S, Nickerson Mr, I, W, Iliff, - Lab, MTo C, R. E. Markle, Mr. Stuart Graves, ** Mr, W# F, Singleton, rt Mr, A, C. Krause, * MBM0RAH3XM REPORT HO, M-247: Philadelphia laboratory May IS, 1949 IB ML LABORATORY LI FIELD TOT #1236 - "DHLtK" SCREEN TmM&m&re fnwuf RESIDENCE OF MR, E, S, NICKERSON. --wrmu mmwm "Dulux" Screen Enamel, 28-666, was recommended for field trial in Release Letter No, 910 dated October 24, 1945 and for'full sale in Release Letter No0 910-a on October 29. 1947, However, in April 1948 the laboratory recommended the withdrawal of the re lease of this product beoause of the severe staining obtained on Mr, E.o So Nickerson8 screened porch in Wilmington even though it hud been properly applied by experienced men. On the basis of recent test fence exposure results it was decided to field test a higher zinc dust content soreen enamel. Daring the period May 2 to May 12, 1949 the product was applied on Mr, Nickerson* porch, TJpoa removing the molding on the screen it became evident that a great deal of the staining on this porch was iron staining caused by the corrosion of tin-coated iron staples which had been used to tack down the copper screens. These staples were spaced less than two inches apart over the entire area of the porch and a sizeable amount of rust had collected under the moldingB over a period of years. The screens are all millmade and therefore it was not suspected that iron tacks would be used in connection with copper screening, {Painting of the copper screening behind the molding had been demonstrated by a previous tost to be unnecessary), Most of the staples at the bottom edge of the screens wore rusted through completely. The screening up near the eaves was protected from the weather and the staples were in relatively good condition. At this point it became obvious that in order to carry out a proper field test it would be necessary to remove the iron staples. It was decided to replace most of the old screening with new wire since the old wire had previously been coated three times and was fairly well plugged up over 75$ of the area, Mr, Krause and the writer accomplished the following work on this field test. Pleas refer to the attched diagram for details, 1, Removed all moldings and replaced iron brads with brass where necessary. 2 2. Removed 95$ of tbs old copper screening and replaced with either new copper or aluminum soreening as required for the test* 3* Removed all of the iron staples except as noted 0 4. Coated inset of frames with zinc dust enamel to cover iron staples which had broken off in the wood, -I 5 Coated the inside edge of all moldings* 4 6* Repainted all the frames with 301-875, #40 Outside White with the exception of the four pillars and facings on the side of the porch which w coated with Trim & Trellis White t p-87-pl4732o It was necessary to practically disassemble most of the sec tions of the porch in order to perform the work* It should be noted that after a reasonable period of ex poser 0 we can expect staining on sections B, 1, $, and G since these seotions oontain either new or old iron tacks for purposes of the testo At the completion of the test Mr. Krause commented that the control 28-666 had better application properties than P-28-R- 28577 probably because of a lower zinc dust content* The writer observed that both enamels covered better over weathered soreening than over new copper or aluminum screening which already is pro tected with a clear finish. It may be necessary to cut down some what on the amount of zinc dust in P-28-R-28577 in order to improve the application properties* The following table corresponds to the figures in the ttaohed diagram: Behind Behind Code iSorsaa Taoks Screen Molding Enamel A Maw Cu B Mew Cu Cu Mo Fq NO Mo P-28-R-28577 No P-2S-R-28577 B.i Mew 0u F Mo . No 28-666 0 1 Yr, Old Cu Cu No D New Cu Cu Yes Dx Mow Cu Cu Yes E Old Gu Fe Mo F Old Cu Fe MO Yes P-28-R-2S577 Yes P-28-R-2S577 Yes 28-666 Yes P-28-R-28577 Yes {P-28-R2857?"bottam - * G old cu Fa NO Fe Mo only) Mo P-28-R-28577-side & 1 Mo P-28-R-28577 H Alum0 1 Alum* Al Yes Yes P-28-R-28577 Al Yes Yes 28-666 Samples of the stain have been collected and will be analyzed for iron and oopper content* BWJfcpp ATTmh . DUP030003119 (b, fATM 1 ' Porch* ~ An Centra. $ ovi , Pm 0 n't OtP CO C 3)00 V I yfr , 6i. t? F otj> Co 0*c.K 0, A 6 as5*.8*-focboU A/ew/ to wevo co t>, f/E:\AJ Cw 3,8-to* < p A/v*/ to V & OUV Cv w HHH | ^ A* A t *--------- - V ------ ----- -4 $ I PC' ^ HH At- At* H At H HI At At At HH At 0L H At H HX At At At ^8- (9(9^0 IrfiyW~i?MK DUP030003120