Document jeELnbwDkEK8GzB13zxaeVv9

FORK B40 20M 6 5* -RIIIMTCD IN U. . A. > Bestwall Gypsum Company FOR Paoli Lab DA' ATTENTION OF Mr J. R. Watt ANSWERING YOURS 8 29 58 10 3 58 FROM Grand Hirddi - . OFFICE SUBJECT Carey1a 7-0 - Asbestos DICTATED BY E. Reverski - mk CC: Mr. A. H. Ten Elshof - Grand Rapids Mr. J. I. Trolley - ^rdmore The bag of new 7-D Asbestos wa received September 16, 1958. On September 22, 5 charges of acoustical plaster were made. On the 5th and last charge, the new 7-D Asbestos was used. On September 25 we sent a I4O lb. sack of both the Uth and 5th charges for your evaluation to the Faoli Lab along with a I4 lb. sample of the new asbestos.. Screen tests on the asbestos were Thru New 7-D Asbestos Stock Asbestos Specifications 8 Mesh 99.93> 99.92 (100-97) 16 Mesh 92.0* 87.22 (98-92) 30 Mesh 57.0i 50.22 (65-55) 50 Mesh 32.82 3U.62 (UO-26) 100 Mesh 23. U% 2U.82 (30-18) T.C. of Mew Asbestos - 332 cc T.C. 11 Stock " - 3l<(Lccl The color of the new asbestos, v.+v <.+- aTM* ^ T,aa a ihade darker than our regular stock, the latter havingT creamier shade when wet. This is the reverse of Carey L Co. opinion. / 1 FOR MR. WATT AMD MR. TEN ELSHOF ONLY.. T.C.s of regular acoustical plaster was 260 cc and the new asbestos acoustic was 255 cc. The 1st, lith and 5th batches of acoustical plaster were filled in l/2 thick in the lo" x l8" test panels at W/DM ratios of 300, 280 and 260 cc respectiv The remainder from each box mix was aoplied to a U1 x 71 wall Danel by trowel 1/2* thick. #1 Panel at 300 W/DLI dried out OK with very small fiscuring but one corner sagged out .and did not bond. #2 Panel at 280 '.V/DM came out perfect. This one was troweled extra to smooth out because on darbying, it took up rather fast and dragged. This compacting aided this panel. The 3rd panel with the new asbestos was struck off with the darby while still fluid and was not troweled until the 3rd day. The 3rd panel showed 3 cracks the next day. Cn the 3rd day these cracki troweled out but reappeared again but they are small and would be covered by spraying the finish coat on. SGP 0018916 YIVAHia OCT 6 1S58 OESTYvali ,, Paoli Lab 10 3 58 Due to the wood framework etc., the smaller 16" x Li8" test panels were passable whereas the lj' x 7* wall panel was not satisfactory at all. The reason the W/DJJ was cut from 300 to 260 W/DU was because the acoustic was too fluid to be applied by trowel on the wall panel. On the 1st day of standing, the panel sagged and bulged at the bottom and two slight cracks appeared. Water ran down and wetted the concrete floor. At the end of the 3rd day, all panels were troweled. The fissures disappeared on troweling but a 2 square foot area of the wall panel fell out after troweling. (The gypsum base coats were total ly"c!ry''?>n all panel*). Fissures started to appear on the panel again the bth and 5th days. By the 6th day, portions adjacent to the fissure started to bulge out. The YY/DM was decreased from bottom to top on the panel and the worst fissuring and bulging occurred at the bottom where the VY/DM was the highest. The top part of the panel was in passable shape. On the 8th day the panels were still wet so they were fanned and heated. Drying conditions in this basement laboratory are very poor. By today, the 10th day, the panels are all dry and no further fissuring appeared on the rapid drying. Throughout the 10 days of wetness, the base coat did not soften up to any extent. From the above testa, I feci that the 16" x U8" test panels will not duplicate job conditions and are not severe enough a test. Also, the acoustical plaster should be applied lower than T.C. to handle properly and to s tick to the wall. Tinney's report of September 23 showed a W/BM ratio of 365. I don't see how they could apply this with a trowel. Also, Tinney did not state how thick they applied the acoustic. I feel that l/2" is too thick to apply in one appli cation, especially with poor drying conditions. The only shipment we have made on acoustical plaster was down to Ohio so have not followed any jobs on it. So far, we have not heard of the plaster in Ohio being reused. It is now months old. SGP 0018917 Paoli Lab Mr. J. P-. Hatt 8 29 58 10 3 58 CCt Mr. A. U. Ten Flshof - Orand Rapids Mr. J. 1. Trolley - Ardmore Orand Rapids Carey's 7-D - Aabeatoa E. Reveraki - mk Tha teg of new 7-D Aateotoo waa received September 16, 1956. On September 22, 5 chargaa of aeouatlcal plaeter war* made. On tha 5th and laat charge, tha nan 7-D Asbestos ana used. On Septeafcer 2$ wa aant a LO lb. aaek of both tha lith and 5th chargaa far jour evaluation to tha Paoli Lab along with a li lb. sample of tha new aabaatoa. Soraan teata on tha aabaatoa warai Thru New 7-D Asbestos Stock Aabeatoa Specifications 8 lEsah 99.9% (100-97) 16 Ueah 95 ;sr 87.2* (98-92) 30 Mesh1 TfSr 50.2* (65-55) 50 Hash w 3lu6* (LtO--2 6} 100 Meah TOTT- 2U.8* (30-18) T.C. of Haw Aabeatoa - 332 ec T.C. " Stock - 3U0 ee Tha color of tha new aabaatoa, both wet and dry, waa a ahade darker than our regular atock, tha latter having a oraanier ahade whan wot. Thia la tha ravaraa of Carey & Co. opinion* FOR MR. WATT AMD MR. TEN ELSHQF ONLY T.C.a of regular aeouatlcal plaatar waa 260 cc and tha new aabaatoa acouatie waa 255 eo. Tha 1st. Istb and 5th tetehea of aeouatlcal plaatar ware filled in 1/2" thick in tha 16" x ItB" teat panala at H/DU ratioa of 300, 280 and 260 cc reapeetiva The remainder fren each box nix waa applied to a It* z 7* wall panel by trowel 1/2" thick. #1 Panel at 300 !0)I( dried out OK with very assail flaauring but one corner aagged out and did not bond. #2 Panel at 280 K/DH oaaa out perfect. Thia one waa troweled extra to aaooth out becauae on darbying, it took up rather faat and dragged. Thia compacting aided thia panel. Tha 3rd panel with tha new aabeatoa waa atruck off with the darby while atill fluid and waa not troweled until the 3rd day. The 3rd oanel ahowed 3 cracka the next day. On the 3rd day theae cracka troweled out but reappeared again but they are small and would be covered by spraying the finish coat on. SGP 0018918 2 Paoli Lab 10 3 58 Due to the wood framework eto* tha nailer 16" x L8" teat pnala were paaaabla whereat tha L* x 7* all panel wae not eatlafaetory at all. The realon tha w/DM was out fron 300 to 260 W/DM wax because the aeoustlo was too fluid to be applied b]r trowel an the vail panel* On tha 1st day of standing* the panel sagged and bulged at the botton and two alight cracks appeared* Water ran down and vetted the concrete floor* At the end of the 3rd day* all panals were troweled* Tbs fissures disappeared on traveling but a 2 square foot area of the wall panel fell out after trdeeling. (The gypew base coats were totally dry on all panels)* fissures started to appear oo the panel again the Itth and 5th days* By the 6th day* portions adjacent to the fissure started to bulge out* The W/DM was decreased Area botton to top on the panel and the worst fissuring and bulging occurred at the botton where the W/DU was the highest* The top part of the panel was in passable shape* On the 8th day the panels were still wet so they were fanned and heated* Drying conditions in this baaenent laboratory are eery poor* By todgjr* the 10th day* the panels are all dry and no further fissuring appeared on the rapid drying* Throughout the 10 days of wetness* the base coat did not often up to any extent* Fron the above tests* 1 feel that the 1& x IIS'1 test panels will not duplicate job ceoditiona and are not severe enough a test* Also* the acoustical plaster should be applied lower than T*C* to handle properly and to a tick to tha wall* Tinney'e report of Septeaber 23 ahoned a W/btl ratio of 36$. 1 don't see how they could apply thia with a trowel* Alao* Tinnay did not atate how thick they applied the acoustic* I feel that 1/2" is too thick to apply in one appli cation* especially with poor drying conditions* The only shipnent we have aede on acouatical plaster waa down to Ohio ao have not followed any jobs an it* So far, we have not heard of the piaster in Ohio being reused* It is now b nontha old* SGP 0018919