EVALUATION OF SUBSTITUTE SOLVENTS FOR ACETONE IN LB-2 SLURRY.
MCDONNELL AIRCRAFT CORP ST LOUIS MO
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The combination of solvents acetone, xylene and mineral spirits presently used in the LB-2 slurries has a hazardously low flash point and also an undesirably high evaporation rate. This union of low flash point and high vapor pressure restricts the use of LB-2 slurries from a safety standpoint. One gallon each of LB-2 top and base c ee coat slurry were heated at 135F to remove ee acetone. Each of the two concentrated slurries was devided into 4 equal parts, and each pair of slurries top and base coat was diluted with a different substitute solvent to obtain the proper slurry consistency. Thirty-two Nb-5Zr test coupons were diffusion coated per PS 13156. Sixteen of these coupons were given a single base and a single top coat dip, and the other half Group II were given a double base coat dip. Each group of 16 coupons were divided into 4 subgroups, one for each substitute solvent. Ththe diffusion-coated coupons were evaluated by oxidationoiiion testing at 1900F for 30 min and at 2500F for 1 hour. Author