TM 55-1730-229-34
AG 320A0-MME-000
TO 35 C2-3-473-2
TM 1730-34/1
NOTE
e. Repair Combustion Chamber Cap.
Repair damaged insulation material on
Ensure inside flow surfaces are
combustion chamber cap (9, figure 9-6)
as follows:
free of excess weld.
(b) Fusion arc weld cracks using
(1) Cut away any loose material
around damaged area.
Hastelloy X weld rod (AMS5798) with gas
backup in accordance with MIL-W-6858.
(2) Thoroughly clean area with
methyl-ethyl-ketone (MEK) TT-M-261 or
(7) Repair hot spot in combustion
Dry with clean, lint-free
equivalent.
chamber as follows:
cloth .
(a) Hand machine to remove hot
spot.
(3) Apply primer B (SS4155, Gen-
eral Electric Corp., Waterford, NJ
12188) by wiping, brushing or spraying
(b) Fabricate flush patch from
to a thickness of 0.1 to 0.3 millimeter.
Hastelloy X (AMS5536) 0.032 inch stock.
Air-dry for 1 hour.
(c) Deburr combustion chamber
(4) Mix insulating compound (TBS-
and flush patch.
758A Resin and TBS758B Catalyst, General
Electric Corp., Silicone Products BUS-
(d) Clean weld areas with a
stainless steel wire brush and wipe
iness Dept., Waterford, NJ 12188) as
Thoroughly mix 10 parts of
follows.
clean with acetone 0-A-51C or equiva-
resin and 1 part of catalyst. Addition
lent.
of the catalyst should be held within
10 percent of the specified amount.
(e) Position and fusion arc weld
patch with continuous weld using
Mixed compound will have a 4 to 6 hour
application life at 77F (25C) dur-
Hastelloy X filler rod (AMS5798) with
gas backup in accordance with MIL-W-
ing which time the compound is most
6858. Weld may extend 0.03 inch maximum
easily applied.
above surface.
(5) Apply insulating compound as
(f) Perform fluorescent pene-
follows.
Trowel compound onto cleaned
trant inspection on all welded areas.
area. Total thickness of insulation ma-
terial after repair shall be 0.20 to
0.40 inch.
(6) Cure insulating compound as
Regulate air pressure to keep ero-
Curing techniques can range
follows.
sion of base metal to a minimum.
from a simple passover with a hot air
Keep nozzle in motion to prevent
gun application to radiant heat sources.
The selection of equipment for the heat
blast from dwelling on one spot.
generating source is dependent upon the
(g) Peen all over to clean with
configuration of auxiliary power unit
Recom-
glass beads Screen No. 100-230, 130 grit
when the compound is applied.
Class IV, Size AF or AG, (Potters In-
mended cure conditions are; 5 minutes
dustries, Inc., 600 Industrial Rd,
at 300F (149C) or 10 minutes at
NJ 07072 or equivalent) .
Carlstadt,
280F (138C) or 1 hour at 250F
Clean area of glass beads.
(121C).
Once the applied coating has
9-20
