Repairing Fuel Cell.
Internal Blister Repair.
Acetone and repair adhesives are
flammable and toxic. Keep away
from heat, sparks and open flame.
Wear safety glasses, gloves and
protective clothing to prevent
contact. Wear a NIOSH approved
air-purifying respirator for organic
ventilated area. If contact occurs,
flush areas with water and get
medical attention. If ingestion
occurs get medical attention at
(a) Cut the blister open. The cut should
resemble a "T' or "Y'. Remove any fluid inside of blister.
(b) Clean interior area of blister using a
piece of clean cheesecloth (item 16, table 2-11)
dampened with acetone (item 3, table 2-11). Wear
gloves (item 4, table 2-11).
surfaces of the blister using emery cloth (120 grit) (item
17, table 2-11).
(d) Clean buffed areas. Use a clean
piece of cheesecloth (item 16, table 2-11) dampened
with acetone (item 3, table 2-11). Wear gloves (item 4,
Repair adhesive is flammable and
should be kept away from any
Adhesive materials should be kept
containers in a cool, dry place.
(e) Prepare repair adhesive (item 18,
table 2-11). Repair adhesive is shipped as a two
component kit. Part number 22-20556 (shelf life 6
months) is the masterbatch and part number 22-20555
(shelf life 12 months) is the catalyst solution. Stir each
component well before mixing. Mix the two parts
together and thoroughly blend as follows: 90% of 22-
20556 (Masterbatch) to 10% of 22-20555 (Catalyst) by
weight. Stir mixture for 10-15 minutes. The adhesive
now should be labeled "PU-459". Maximum shelf life
after mixing is 6 hours.
The adhesive should be used
sparingly. Two (2) thin, even
coats will provide better adhesion
than two thick, puddled coats.
Acetone is used as a solvent for
cemented surface appears dry to
touch, it may be freshened or
made tacky again by application
of this solvent.
(f) Brush-coat buffed surfaces of blister
with one coat of adhesive (item 18, table 2-11) and
allow to dry 20-60 minutes.
To determine if adhesive is tacky,
test it by pressing a knuckle
surface and withdrawing it (if
practical). Proper tackiness is
achieved when a few threads of
adhesive stick to the knuckle.
This procedure is referred to as
the knuckle test.
(g) Apply a second coat of adhesive
(item 18, table 2-11) to buffed areas and allow to dry
until tacky. Adhesive can become tacky within 2 to 4
minutes, depending on ambient temperature and
humidity. Perform knuckle test.
(h) Press cemented surfaces together.
(i) If necessary to restore tack to the
cemented surfaces, use a piece of dean cheesecloth
(item 16, table 2-11) dampened with acetone, lightly
wipe over cemented areas. Allow solvent to evaporate
10 to 20 seconds or until cemented areas become
Change 2 2-57