TM 1-1500-204-23-11
Lightly sand any squeezed out iller
1
lush with part surface using 180
grit abrasive paper.
Failure to properly cure adhesive in accor-
dance with the speciied cure cycle will result in
Using the template fabricated
2
reduced repair strength may not be detectable
above, carefully locate a drill guide
by visual or nondestructive inspection. This
containing the correct drill bushing
may result in loss of structural integrity.
for the hole to be redrilled. Secure
the drill guide to the part with a
NOTE
clamp.
An optional method could be performed which
involves placing a vacuum cup over the
Redrill and countersink the
3
resin illed damaged area before curing. The
repaired fastener hole per para-
vacuum will remove any trapped air remaining
graph 6-8. If countersinking is
in the potting compound. When the air has
required, use a countersink micro
been removed, remove the cup and complete
stop to prevent countersinking too
the repair. Figure 3-25 includes a diagram of
deep.
a vacuum cup assembly.
(i)
Reinish.
Some potting compounds shrink during cure.
If using a mixture that is likely to shrink, build
Sand the area smooth with 180 grit
1
compound slightly above the part surface.
abrasive paper. Vacuum sanding
dust from repair area. Wipe with
(g) Set Filler.
clean, dry wiping cloth to remove
sanding residue.
1
Apply release ilm, a metal caul
plate and contact pressure to the
Apply inish system in accordance
2
repair using either an external
with paragraph 7-13b or the sys-
weight, clamps or a vacuum bag.
tem speciic technical manual. Use
care not to apply inish system in
Cure the repair using the cure cycle
2
fastener hole or countersink area.
from the system speciic technical
manual and paragraph o. If an ele-
d. Potting Method. This repair is applicable to
vated temperature cure is required,
repair misdrilled, oblong, and/or angled holes in addi-
use a heat lamp, heat blanket or
tion to oversized countersinks and gouged surfaces.
other heating equipment. Place a
This method uses a wet layup fabric plus a resin
thermocouple next to the repair on
illed with chopped ibers to restore damaged fastener
the same side as the heat source.
holes and part surfaces. This method is used to repair
If room temperature cure is used,
minor damage to fastener holes that extends through
remove release ilm, caul plate, and
the full thickness of the laminate. The potting method
contact pressure after a minimum
should not be used if the laminate surrounding the
of 8 hours. Allow to dwell at room
damaged fastener holes is delaminated or damaged
temperature for a minimum of 5
in other ways. Refer to igure 7-54 for the Process
days.
Flow Diagram for Potting Fastener Hole Repair.
A typical potted repair is shown in igure 7-55. This
(h) Redrill/Countersink Hole.
repair procedure is not necessarily applicable to a
particular weapon system. The applicability of this
NOTE
repair depends upon additional factors such as loading
If the resin is cured at room temperature,DO
conditions and laminate thickness. Consult the system
NOT smooth or drill the hole for at least 24
speciic technical manual or engineering for further
hours after the resin sets.
guidance.
7-89