(h) Apply a uniform coat of barrier
adhesive (item 2, table 2-11 ) (1, figure 2-32) in one
direction over previous coat of repair adhesive (2) to
within no more than 1/4 inch of repair area of O.D. Use
a brush. Remove any excess adhesive from unbuffed
area. Use dean cloth (item 16, table 2-11) dampened
with acetone (item 3, table 2-11). Wear gloves (item 4,
table 2-11). Allow barrier to dry to touch.
Figure 2-32. Applying Adhesive Over Previous Coat
(i) Apply a second coat of barrier
adhesive (3) over first barrier coat (1) at 90 °
application of first coat. Use a brush (item 6, table 2-
11). Allow second coat to air dry for approximately 30
(j) Prepare repair adhesive as in steps
(e) and (f).
surface with gloved fingers wet
with acetone, lightly touch only
Insure acetone does not contact
barrier cement previously applied,
as the barrier cement is soluble in
acetone. Damage to the barrier
cement can result in the barrier
(k) Prepare a new batch of adhesive
(item 1, table 2-11) and carefully apply a uniform
(liberal/heavy) coat of adhesive mixture (1, figure 2-30)
over previous coats of barrier adhesive to within no
more than 1/18 inch of O.D. of buffed edge area. Use
a brush (item 6, table 2-11). Smooth surface with
gloved fingers wet with acetone (item 3, table 2-11) and
remove any excess adhesive from unbuffed area Use
dean cloth dampened with acetone (item 3, table 2-11).
Wear gloves (item 4, table 2-11).
When performing interior loose
seam damage repair, do not apply
fabric patch. Proceed to para (m).
(I) Cut a fabric patch (item 8, table 2-
11) that is 1/8 inch larger all around than the area of
barrier coverage. Dampen patch with acetone (item 3,
table 2-11), shake out excess solvent and lay the patch
into the wet adhesive. Using gloved finger and brush,
work out all air. Allow to air dry for 30 minutes.
(m) Apply a light coat of adhesive (item
1, table 2-11 ) over the fabric patch and out to the
maximum area having barrier adhesive. Do not apply
adhesive to unbuffed areas.
Do not flex fuel cell in repair area.
(n) Allow finished repair to set for 1
hour before moving fuel cell.
(o) Allow finished repair to air cure for
24 hours at room temperature of 70 °F (33°C) minimum
Visually inspect repair for workmanship,
no loose edges, no voids and adhesive fully cured.
Repair Fuel Cell Interior Plies.
Acetone, barrier cement, repair
adhesives and its components are
flammable and toxic. They can
irritate skin and cause bums. Use
only with adequate ventilation and
purifying respirator for organic
vapors. Keep away from heat or
open flame. Wear safety glasses,
gloves and protective clothing to
avoid contact with skin, eyes and
clothes. I contact occurs, flush
areas with water and get medical
attention for eyes.
Change 2 2-50