Document Rax36beb5r4KXjEo74Jj04YYB

PH*:JAli:ICP V-l & U-S/ICP c- Subject: Painting on Plastered Salle and Gelling*. Gentlemen: X. In reply to your letter of September 19th, wa h*ve the following to offerj 2. It is our opinion that in etsny cases the discoloration of paint. on plastered . or ceilings: 1* closed by improper drying of the wslls. . fps.is Sb, ;r: ;|^n:cr;:#/:gypstj' base:, ts;-i*sed, ' believe that it is due to the action of thealfcaii contained m the llae of the finleh coat on the paint ^ sise. P refer you to Bureau of Gtapdarde fei8$0$fe taper Bo, 274, U8e of United States boveinwent SpeClflcatiCnpaints and Paint liaterials*. Thl* publication nay be obtained from the Superintendent of Doeuients* qoremiient printli&ipllee*. lashingtCEC, IM1* at a ecsf of tn::oe*its a copy* page cl dir-usti papert / Too such emphasis cannot be laid oaths ..thcrcc#*: drying of all .plaster* concrete censa^-yctc'** before painting. It must be remeaberedthat enCb.vetrcCtcreS: when aes contain auch water and unlefsJhiff^^ bdlMli- - tions of temperature and hicmldlty; Is thorough drying the eater remaining In the.- eal"Sn^^yyentually ` seriously injure any - paint oentliijipi^ out that a wall any appear to beiiifcjSiijiitt still be damp in the interior. gwe^e^Plp^rly dried* new structures of this kind way hence it is advisable when the structureM#j^^w|n d year old, even if it is known to be dryMmnpplfr.npfore paint ing, an aqueous solution of sine pounds orystallised slno sulphate to 1 galI5%fof,jjifer|. Alio* N 3608 B. of Q. and M. - 2 ,September 28 1328 this to dry thoroughly before applying paint. 4. it is noted that the plastered surfaces are painted tiro ox three months after the piaster is applied* Apparently the plaster Is frequently applied directly to the tile or brick wall, lie aery muoh question the advisability of atteamting to paint piaster that is applied directly on brick wall. The plaster should have air apace back of it eo as to assure drying, Of course It is presupposed that the building is properly designed, and constructed to prevent water seepage from the bad of the piaster after the plaster hae dried. 5. Bureau of Standards' Circular so* 151, "fall plaster: Its ingredients, preparation and properties*, obtainable from the Superintendent cf Documents at a cost of fifteen cents per popy, contains considerable information regarding specifications ad general plastering practice which may be of interest to you. 6. in regard to the painting procedure, it is noted that you propose to use lead and oil paint for the second and third coats, there is nothing better that can be need these coat*. The specification for the first or primer ;qoat;jn indefinite. Thefeisno reason why if. lead-and..-.. ' * * " ` is used f|r third coats, that it should 7. You are referred to technologic paper So. 27^ page Jd, for a^formule for primer coats for plaster, using mbits- !!$*." 6. ve are enclosing a copy of our better circular which lists tbe Dureaue publlcations on paint and, vflhieh end givee inforfcation *&Vo 'hos .tbef-'aay be cbtaieed^PKI"' also enoloee United States aovefhment master specification* for gypsum plaster, quicklime end hydrated lime for struc tural purposes. Enclosure; (; 0 (P 1*0 59, O -KjV Speoifioations. ^lgOA) as0 ;' George K* Buxgessi^pir