TM 1-1500-204-23-11
3
Apply paste adhesive to bottom
(g) Dry repair area as described in para-
and sides of replacement core
graph 6-6 using a heat blanket to
using a spatula. (See igure 7-15,
remove subsurface moisture.
View C). If damage is through both
(h) Prepare repair area for bonding by
skins, apply adhesive to sides of
lightly hand sanding with 150-180 grit
replacement core only.
abrasive paper as described in para-
graph 6-7. Vacuum sanding dust from
Carefully insert replacement core
4
repair area and wipe with clean wiping
into repair cavity. Ensure part and
cloth. Handle prepared surfaces wear-
replacement core ribbon directions
ing powder free latex gloves until patch
are aligned. Push core against
bonding is complete. If patch is not
opposite side skin inner surface or
to be bonded immediately, cover with
metal plate as applicable.
clean barrier material and secure with
tape to prevent contamination.
Visually inspect part core to
5
replacement core sidewall area
(i)
Fabricate repair patch(es) according to
for adequate illing of adhesive. If
paragraph 7-4 and the system speciic
voids or gaps exist, ill a sealant
technical manual. Any of the meth-
gun with adhesive and inject more
ods; cocured, cobonded or secondarily
adhesive into gaps/voids.
bonded may be utilized for skin repair.
6
Place a metal caul plate on top of
(j)
NDI Patch Bond(s).
replacement core. Apply external
weight (3-5 pounds) on top of caul
Visually inspect adhesive squeeze
1
plate (See igure 7-15, View D).
out at patch edge as described in
Remove excess adhesive by wip-
ing with a clean wiping cloth.
2
Perform NDI of patch to skin and
patch to iller bond areas to verify
bondline integrity.
Failure to properly cure adhesive in accor-
(k) If appropriate repair lightning mesh per
dance with the speciied cure cycle will result in
paragraph 7-12 and the system speciic
reduced repair strength may not be detectable
technical manual.
by visual or nondestructive inspection. This
may result in loss of structural integrity.
Using a heat lamp or heating blan-
7
ket, (if applicable), cure the paste
DO NOT sand into laminate near patch edge
adhesive according to paragraph
when sanding adhesive squeeze out.
6-19 and the system speciic tech-
nical manual or the manufacturer s
(l)
Reinish.
recommended cure cycle per engi-
neering direction. Allow the repair
1
Sand area smooth with 180 grit
area to cool. If room temperature
abrasive paper. Vacuum the sand-
curable, allow it to set until machin-
ing dust from repair area. Wipe
able (approximately 8 hours).
with clean, dry cloth to remove
sanding residue.
Remove weight and caul plate.
8
Apply inish system in accordance
2
Remove the release ilm (and metal
with paragraph 7-13b or the system
plate, if installed).
speciic technical manual.
(f)
Trim the top of the cured core lush with
e. Rapid Densiication. Rapid densiication of
either the original core or the part mold
line, depending on the type of repair
sandwich structure is necessary when the structure
being performed. The inished surface
requires repair with fasteners or modiication to install
should be left comparatively smooth
external equipment, such as an antenna. It is applica-
and match the contours being repaired.
ble to honeycomb, foam or X-Cor/K-Cor sandwich
See igure 7-15, View E.
structures. The procedure is similar to potting the core
7-29