Document 2jgyGmrNYk7Xpx5RjbkBDM8yp

y.V/.; Ho ass Paints < mm mpmt 10* Dr .Patv'-nt 'i<'. 5 .* xv Mr 3* Gw ffrw 0* Shay Ape*. y* 0, <fctS0U list* 14 P* Singleton e e ( Philadelphia Laboratory mill I Septei&H&r 29 1949 *' fPf . "MDEXED *-/f/-> yet MJM&Mmm fhs moisture Taper permeability of 4 different interior paint systems has* beam determined in response to questions fro the .field and to evaluate- S^iddaE* m7apor Barrier" System* flas results are .reported as .grains of water per hour per square foot per inch of mercury difference in vapor' pressure*' .Since our_ tests are run under different conditions than those specified by {D~S99~4$?) or TAFPI (1?440) our data cannot fee coopered with their' results or specif1cations* JwS<,f 4u and IAPH oper ate with a 4$ - 50 $ relative humidity difference,. while the Philadelphia Laboratory method approaches 100$ difference*. Itfe have no data to show that a change in relative humidity produces a proportional change in the rata of vapor passage* fhe four systems' and their vapor passage in grains are* fi) Gliddea*s Spred "fapor Barrier* system X w l^i'C \Z\ DuPont .Semi-Bloes 'emulsion*' 1*36 13) DuPont interior Gloss enamel and aifcyd primer sealer* *17 l4l DuPont Interior Gloss enamel and emulsion First Beater *16 fho systems ways pratsared bv applying the taints, to tin plated sheets and I'emoying tto dry fils tf amalg&mtlon* Bach .system conciof three coat:, one of the specified primer and two of the .topc-oat* In the ca*o of the semi-gloss emulsion, z third coat of the same material served as the primer.* All costs were applied at appK'Osdm&tely 400 $00 $q ft* per gallon.:* 13J fhe BXiddca system consists of'the Spred Primes5: Sealer and Spred Satin, which are both water emulsions of what appears to he" D-:,,? l-tex' 512**1 {a hutadime-'Ctyv-ene copolymer ai^l*-iou} * It ie olainsl that this system will pass only" %4& grains of water Taper 1/ th-:. TAPPX wathod :fbw ms&wm rats usually accepted few rnpor barriers ie X to I>i/4 grains*' discrepaaey bofcmm tteir slsia aeeardirig of $APfg of 'k$ grains 4a&~oar result of 1*42 grains -is proetmafeiy due to tin difference in tin aetked* / 1* Letters M y# Liagletoa to 4, W* lliff '.lO/l6/%6 Zm notebook '356fl* page 96*$f ' PHILADELPHIA' iABOHATOET ^o i i s t o i jfMsmjts DUP030003155