TM 1-1500-204-23-11
and strengthens the structure to withstand clamp-up
procedures. Insure that the full diameter
loads from fasteners. This type of repair can also be
of the drill bit can be reached without
used for small skin to core disbonds. The size of the
drilling into the opposite facesheet.
hole and densiied area will depend on a number of
factors such as loading conditions, laminate thickness,
(d) Vacuum the repair area and then wipe
and part weight limitations. This repair procedure
with clean wiping cloth to remove drilling
is not necessarily applicable to a particular weapon
dust.
system. Refer to the system speciic technical manual
for particular repair applications and limits. Refer to
(e) Drill the fastener size hole through the
igure 7-16 for the Process Flow Diagram for Rapid
aluminum or composite guide plate.
Densiication. Consult the system speciic technical
manual or engineering for guidance on using this
(f)
Double face tape the drilled plate over
technique.
the hole in the skin. Align the holes
using alignment pins or the back of the
drill bit.
Failing to use a guide plate will result in
elongating the hole in the laminate and result
in additional damage.
(g) Insert the core cutter through the hole
and rotate from the top skin down to the
bottom skin to disrupt the core mate-
Figure 7-16. Process Flow Diagram for Rapid
rial from the skin surfaces. Refer to on
Densiication
spoiling core and local manufacture of
an internal core cutter.
(1) Facilities, Equipment and Materials. The
following equipment and materials are required: Vac-
(h) Remove the guide plate using a putty
uum Cleaner, HEPA Filter, Drill Motor, Drill bit the
knife or similar tool, taking care not to
size of the fastener to be used, Core Cutter or mod-
damage the laminate.
iied Allen wrench that its through the fastener size
hole (local manufacture), Hand vice or pliers/vice grip,
(i)
Remove the disrupted core material
Guide plate, aluminum or composite sheet, approxi-
through the drilled skin hole using a
mately .030" thick (Local Manufacture), Injection Gun,
vacuum cleaner.
Metallic Retainer Barrel, Putty knife, Allen wrench,
Heat Blanket, Temperature/Vacuum Controller, Flash
breaker Tape, Adhesive, Paste (See System Speciic
Technical Manual), Injection Cartridge, Disposable,
Injection Nozzle, Disposable, Syringe, Solvent, Sili-
Reduced strength will result if the incorrect
con Carbide Abrasive Paper, Wiping Cloth, Double
mix ratio is used, if an excessive amount
Faced Tape.
of air is introduced into the adhesive during
mixing, or if mixing is inadequate and may
result in loss of structural integrity.
(2) Rapid Densiication Procedure Perform
the following steps for rapid densiication (See igure
6-12 and igure 7-16).
Pressure must be applied to adhesive within
the pot life of the resin. For ambient temper-
atures in excess of 90 F, decrease this time
(a) Determine the fastener location accord-
by 50%. An unsatisfactory repair will result
ing to the system speciic technical
if the resin gels before adequate pressure is
manual.
applied and may result in loss of structural
integrity. Select and prepare a heat blanket
(b) Remove dirt, grease and aircraft luids
(if required) and all necessary vacuum bag
from repair area as described in para-
materials prior to mixing resin.
(c) Drill the fastener size hole through one
(j)
Mix adhesive. Refer to paragraph 6-17
skin. Refer to paragraph 6-8 for drilling
for mixing adhesive.
