b. Frame. Make certain the frame is free of dirt,
oil, grease, or other foreign matter, and bare metal
is exposed for welding. Remove necessary com-
ponents before welding.
c. Tank Cleaning. The tank must be free of
explosive vapors and thoroughly cleaned before any
repairs are attempted; drain the tank of all con-
tents and open filler plug, allow filler to remain
open for several minutes. If compressed air is
available, blow out the tank. Clean the tank interior
with solvent and dry thoroughly. Precautions and
procedures outlined in TB-ORD 1047 will be
adapted to the tank. Areas of the tank to be sub-
jected to severe heat must be cleaned to the bare
metal; use a stiff stainless steel wire brush or other
suitable tool for this purpose. Pay particular at-
tention to the seams; heat from a welding torch
tends to volatilize tetraethylened deposits, causing
toxic fumes. The tank exterior must be cleaned of
all dirt, sand, oil, or other foreign matter with a
solution of trisodium phosphate and water; rinse
with plain water and dry. Remove paint from any
area to be welded.
6-20. Protective Finish
All normally painted exterior surfaces of the tank
must he protected by enamel at all times. A primer
and semi-gloss enamel shall be used. The primer
should comform to specification TT-P-666, and the
enamel to specification TT-E-529. Use standard
Army olive drab color 2430.
6-19
