TM 1-1500-204-23-11
is used when little or no airlow is possible, such as
delaminations around fastener holes. The delaminated
area is heated to the minimum viscosity temperature
of the adhesive, and then adhesive is added to a
vacuum chamber which has been placed over the
delaminated area. The adhesive is maintained at
this minimum viscosity temperature under vacuum to
allow outgassing of air and/or volatiles, then vented
to atmosphere to force the resin into the delaminated
area. The vacuum chamber is then removed and
a fastener or clamp is installed to provide positive
pressure for curing the adhesive. NDI is performed on
the delaminated area when the repair is complete to
ensure successful injection. See igure 7-59 for details.
This repair procedure is not necessarily applicable to
a particular weapon system. The applicability of this
repair depends upon additional factors such as loading
Figure 7-58. Process Flow Diagram for Fastener
conditions and laminate thickness. Consult the system
Hole Delamination Repair (Vacuum Injection)
speciic technical manual or engineering for further
For fastener holes with delaminations open to the
guidance.
edge of the part, follow steps in 7-8(g). This method
Figure 7-59. Vacuum Injection Fastener Hole Repair
(1) Facilities, Equipment and Materials. The
following equipment and materials are required:
Heat Lamp, Temperature/Vacuum Controller, Vacuum
Cleaner, HEPA Filter, Vacuum Cup and Lid, Torque
DO NOT use oil or oil based materials
Wrench, Bolt, Nut & Washers (Local Availability),
as NDI couplants on advanced composite
Marking Pen, Silicon Carbide Abrasive Paper, Pres-
components. Use only water or water based
sure Sensitive Tape, Wiping Cloth, Spatula, Adhesive,
materials. Disbonds may result and loss of
Liquid (See System Speciic Technical Manual), Vac-
structural integrity may occur.
uum Bag Repair Materials Kit, Aluminum Sheet Stock,
0.063 inches or thicker (Local Procurement), Release
(b) Inspect damaged fastener holes using
Liquid, Cotton Tipped Applicator, Solvent, Mylar.
NDI to determine extent of delamina-
tion according to paragraph 5-2 and the
(2) Fastener Hole Delamination Repair
system speciic technical manual. Mark
Procedure.
the perimeter of the delamination on the
part surface and on a Mylar template
(a) Remove dirt, grease and aircraft luids
from repair area as described in para-
