Document LKp93oOyME06XED8MxDbe9223

NATIONAL GYPSUM COMPANY RESEARCH LABORATORIES 0*^ If :-.jL Copies to: File No. 6a - 6004 - REPORT TO THE DIRECTOR OP RESEARCH FROM 391 Renort No. Date__ Juno 28, 1949 AcoustlcrJ ___ TITLE: On the Job ^plication of Snraying Wool for Acoustical Treatments'. . REQUESTED BY: WHAT IS WANTED: F. L. Ilaralt A description of the application and evaluation of Sprains '.tool on the 3ob. WHY WANTED: To determine the possibilities of using these mixtures for sprayed acoustical treatments. REPORT: 1. :ix containing Anoslle fibers sprayed very veil onto a rib lath ceiling, no sections dropped off, nor did any blisters fom. 2. ::ix containing asbestos fibers 4T-4Z did not spray on satisfactorily, soae sections dropped off. . 3. *-ater usage for the /exsite nix cverroed 1/2 lb. per lb. of material. She nix containing 4T-4Z fibers required an excess of water, 4. The sprayed material resulted in r. rough finished surface. 5. Asbestos floats in.rovod the texture slightly, but contributed to dustiness* ' . 6. Coverage at 5/8" thick rvereged 2800 oq. ft. per ton, this is equivalent to 2330 c . ft. per ton rt 3/4* thick. ?. Perfection Paste Povder shipped from Chicago did not perform as veil as paste pcvder shipped from Dunellen, IJ. J. 707984 Report No. 391 Page IJo. 2 Intro (faction Pour different fomulas of spraying ,*ool were replied to the rib lath coiling in the auditorium of the new Junior High School on Shroyer Hoad in !!ontgbmery County, Ohio,, by cur acoustical applicator Myron Cornish & Co. of Dsyton, Ohio. Formulation .. . . Ifunber X-2 A-2 X-3 A-3 . (percentages) Perfection paste Powder 88 8 8 Asher,too Anosite Floats (7?JT) Miner?! Uool 10 10 55 15 15 55 ny?ex Type A 77 72 77 72 The nixG3 were fornulated at the Alexandria Plant using the cement mill. Annllc&tlon The materials containing Anosite fibers sprryert on readily, with nc sections dropping off, nor blister:, forming. The spraying rate, at 5/8 thick averaged 2 1/2 lbs. per ninute, viiich is comparable to the Limpet application rate. * hhen tamped, a rough surface resulted. The replication of a fine finish coat, did help onoothen the surface, but not as smooth as Limpet. The water usage for the Anosite nix averaged 0.5 lbs. per lb. of material. This wan considerably less than used for the 3tarch, wool nix previously spiled. Type X wool nix appeared' to use slightly more water than did Otype A wool mix, but this was only visual, since work could not be stopped' to check the actual water usage. The nass when dried adhered very veil to the netel lath. KK# 707085 Report ITo. 391 Pcgc -jo. 3 The Explication of the nix using the shorter asbestos fibers hT-hZ, did not perform satisfactorily. An excessive amount of water had to he used resu? ting in a vet nans. The initial bond was poor, end some sections dropped off the ceil inn. '.hen dried, the materiel speared to be as satisfactory an the sprayed Anooite nix. All of the sprayed wool '*?. covered -*ith a thin coat of Limpet. The Linpet adhered very veil to the wool, end tsnped to a smooth finish. The binder used was Perfection Prate Powder Shipped fron Chicago. Its bonding action though satisfactory, did not perform as veil as paste powder previously used fron Panel len, 1?. j. i'.v ^/w- Wiiu... is equivalent to 2330 nr. ft. jjer ton at 3/i* thick. improve tne texture ulig'.tly. Recommendations . 1. The floats should bo :renovod fron the fornila, since the increase in dust, and the possibility of Asbectosis outveigh the alight increase in surface smoothner.r. 2. b*ith the posnibility of purchasing the Anosite fibers at a lower cost, the Anosite content of the fornulr 3houl.d be increased 2 ,'5. this wold help compensate for the rernval of the floats. 3. The new fornnlr. should be T^rpe X mineral wool Amosite fibers. . Perfection Paste Po'/der (Dunellei, U. J.) The new formula would be advantageous in manufacturing since wool is nornclly sacked i0 lbs. to a bag, and no adjustments of weights *uld be required \hm making 100 lb. batches. fart ^proved for Distribution 7G7986