TM 9-2350-261-34
R E P A I R
W A R N I N G
Fuel fumes can explode and
bum you. Before welding:
Drain all fuel. Disconnect
and cap all fuel and vent
lines. Purge fuel residue
and
fumes
b y
steam
cleaning. Purge air from fuel tank with
C02.
N O T E
Repair entire weld joint all around the
fuel compartment.
5.
6.
Drill and tap eight 3/8 x 16 UNC-2A (10
mm) deep holes on centerline of weld joint
crack about 5–1/2 inches (14 cm ) apart,
regardless of crack length.
Install eight 3/8 x 16 UNC2A (10 mm)
screws in tapped holes. Tighten screws to
144-180 in-lb (16-20 N.m) torque. Use
torque wrench. Secure with lockwire.
C A U T I O N
Do not apply sealing compound in
temperatures under 45°F (7°C). Com-
pound will not set at low temperature.
7.
8.
9.
10.
11.
Apply one layer of sealing compound
1/8-1/4 inch (3-6 mm) thick. Extend seal
about 1 inch (3 cm) on both sides of weld
joint centerline and over screw threads.
While sealing compound is still tacky, lay a
new rubber seal over centerline of inside and
outside of fuel compartment weld joints.
Allow first layer of sealing compound to set
for at least 4
layer.
Apply second
1/8-1/2 inch
1/4–1/2 inch
first layer of
Allow second
set 40 hours
used and 48
hours before applying second
layer of sealing compound
(3-13 mm) thick. Extend seal
(6-13 mm) behind edges of
sealing compound.
layer of sealing compound to
at 72°F (22°C) if class B2 is
hours if class B4 is used.
N O T E
To speed sealant setting
electrical gun type heater.
200°F (93°C).
time, use an
Do not exceed
4-4
