TM 1-1500-204-23-11
3
Replace the lid and reseal with vac-
NOTE
uum bag sealant.
Position the heat lamp(s) such that the thermo-
Apply 25-30 inches of mercury
4
couples are not in the shadow of the vacuum
vacuum and hold until no more air
cup.
bubbles escape or until 8-10 min-
utes pass, whichever occurs irst.
(g) Heat Repair Area.
Monitor the adhesive continuously
during the 8-10 minute period by
Perform a heat survey of the repair
1
looking through the lid. If excessive
area per paragraph 6-18g. Adjust
foaming of the adhesive occurs,
the position and number of heat
control the foaming by alternately
lamps to obtain a part temperature
disconnecting and reapplying the
of 125 5 F. After successfully
vacuum hose to the cup, but do
completing the heat survey, pro-
not vent the cup to atmospheric
ceed with the repair.
pressure. In no case exceed 10
minutes.
Heat the repair area to a tem-
2
perature of 125 5 F using heat
lamp(s) as described in paragraph
After the 8-10 minute vacuum
5
6-19h. Monitor the temperature
dwell, disconnect vacuum hose
of the repair area using thermo-
and vent the cup to atmospheric
couples. To prevent early gelation
pressure by activating the vacuum
of the adhesive, ensure the repair
connector plunger. Leave the cup
area temperature does not exceed
vented to atmosphere for 5 min-
130 F. Maintain 125 5 F part
utes.
temperature throughout the injec-
tion procedure.
Reconnect the vacuum hose and
6
apply 25-30 inches of mercury vac-
uum. Hold for 5 minutes. Monitor
the adhesive and control foaming
per step 4 above.
Reduced strength will result if the incorrect
mix ratio is used, if an excessive amount
After the second vacuum dwell,
7
of air is introduced into the adhesive during
disconnect the vacuum hose and
mixing, or if mixing is inadequate and may
vent cup to atmospheric pressure
result in loss of structural integrity.
by activating the vacuum connec-
tor plunger. Remove the vacuum
Pressure must be applied to adhesive within
cup, backup plate, bagging ilm
the pot life of the resin. For ambient temper-
and sealant tape.
atures in excess of 90 F, decrease this time
by 50%. An unsatisfactory repair will result
Clean up excess adhesive on part
8
if the resin gels before adequate pressure is
surface using clean, dry wiping
applied and may result in loss of structural
cloth. Do not wipe inside fastener
integrity. Select and prepare a heat blanket
hole.
(if required) and all necessary vacuum bag
materials prior to mixing resin.
(h) Prepare a small quantity (30 grams) of
liquid adhesive per paragraph 6-17.
DO NOT exceed the torque values listed in
table 7-5 or damage to part may result.
(i)
Perform Vacuum Injection.
Failure to properly cure adhesive in accor-
Remove lid from vacuum cup using
1
dance with the speciied cure cycle will result in
care not to affect the cup to part
reduced repair strength may not be detectable
seal.
by visual or nondestructive inspection. This
may result in loss of structural integrity.
Pour the prepared adhesive into
2
the fastener hole until illed. Pour
remaining adhesive into cup.
(j)
Cure Adhesive.
7-97
