Document n9rY91Z3zqjmR7MQ4G8aNgOMz
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TORT COWS
April 29# 1959
Ptoli Lab*
Mr* L V* Rodanborn
LIOH? AC0U37ICAL PLA3T2H
J* R* Watt - nd
Rot Zoehae Flattering Company
oat Kossrs# A* L* Merer Ardraoro
0. 8* Abbey
J* 0* Wise - twin Citieo
Warren Irlah m m
II* J* Zslsi - Ft* Dodge
Refer to your lottor of 4/23/59* Results of aialjsla nadt oa the gypsua baaoooat aro aa follows!
Combined water Insoluble 90}
16*20
jBP
2Hoeast
?
Veraioullte and otbor Aold insolubles Linastons (by difference)
74*1 :o;7
Baaod on aa eatinated weight of 9 lbs. oul ft* for the vercleullte* there la approximately two eubic foot por 100 lbs* plastor* High 11 catena ooatoat Coy difforanoo) indloatoa 9 10 percent lino or limestone was addod* Baaoooat was not Tory hard but doubt if it has mioh to do with tbo bond falluro*
la ny opinion# tho bond falluro was in aUprobability duo to addition of lino to tho aoouotloal plastor* Aa mentioned provioualy# tho addition of only about ono poreont lino affoota tho gel strongth of tho olay binder# It eausoa tho aooustioal plastor to *vator out* and bo abort working* It also tends to kill tho Conning action* Aa you know# at tho tins wo wore told lino was added on the job wo wore skeptical and requested a final report on tho Job*
In answer to your question# wo fool that tho addition of lino should bo prohibited insofar aa possible* Any plasterer
should bo advised that ho addt lino at hia own risk and that vo will aooopt no responsibility in easa of failure*
This lo tho flrot instance wo know of whore lino was added to the aooustioal plastor*
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