using a marking pen. Ensure delami-
Obtain the required bolt, nut and
outer diameter shall be of suficient
size to extend a minimum of 0.060
(c) Remove NDI couplant by wiping with
inch beyond the area of delamina-
clean, water moistened wiping cloth.
tion as determined by NDI. Select
bolt grip length to ensure no more
(d) Obtain/Prepare Bolt, Nut and Washers.
than three washers per side are
DO NOT allow release liquid to come into
contact with repair or repairs details. Disbonds
may result in loss of structural integrity.
Clamp-Up Bolts and Torque Values 1
HOLE DIAMETER (IN)
Coat bolt, nut, washers and back-
Seal the backside of the fastener
ing plate with liquid release agent.
hole by securing an aluminum
Apply a second coat, waiting 15
plate with vacuum bag sealant.
minutes after each application to
Apply vacuum bag material over
ensure solvent in release agent
the aluminum plate and secure to
completely evaporates. Cure per
backside of part using vacuum bag
manufacturer s instructions.
Plug adjacent holes that may pro-
vide a leak path for the vacuum
(e) Prepare Surfaces For Adhesive Appli-
system with vacuum bag sealant.
Lightly sand around fastener hole in
the area where the vacuum cup will
Install Vacuum Cup/Perform Leak Test.
be applied and in the countersink
area using 180 grit abrasive paper
Obtain a vacuum cup and lid. If
to remove sealant, paint and other
one is not available, fabricate one
debris. Vacuum area to remove
6-3 for paint removal steps.
Apply vacuum cup, with lid installed
Clean fastener hole and counter-
on part surface over the affected
sink area using a cotton tipped
fastener hole using vacuum bag
applicator, wiping cloth and solvent.
Thoroughly clean the area with
repeated wiping until no residue is
Apply 25-30 inches of mercury vac-
left on the cotton tipped applicator
uum to cup. Ensure a minimum
or the wiping cloth. Allow the sol-
of 25 inches of mercury is attained
vent to evaporate for a minimum of
without any audible leaks. Reseal
as required to eliminate leaks and
obtain the required vacuum.