Heat Cure Repair Patch Method - Piper PA-32R-301 SARATOGA SP Maintenance Manual

FUEL STORAGE (Cont.)

(4) Heat Cure Repair Patch Method

(a) Prepare the exterior cell wall and exterior patch.
1 Cut a repair patch from FT-192 material to size required to insure a proper lap over
injury in all directions. (See Limitations.)
a
b
2 Wash one square foot of cell wall surrounding injury with a clean cloth soaked with
Methylethylketone solvent.
3 Wash repair patch contact side with a clean cloth soaked with Methylethylketone solvent
4 Abrade cell wall surface about the injury and on the contact side of patch with fine emery
cloth to remove the shine.
5 Repeat Methylethylketone washings two more times, for a total of three washings for
each surface.
6 Tape a 8'' x 8'' piece of cellophane inside the cell over the injury.
(b) Position cell for patch application on repair table
(c) Mix the 80C27 cement (320 gms) with the cross-linker 80C28 (81cc), and stir mixture thor-
oughly, for five minutes.
Cement must be at a minimum of 70°F before mixing. Keep
away from water and excessive heat.
(d) Brush one even coat of mixed repair cement on the cell wall around the injury and on the
contact side of the repair patch. Allow to dry for fifteen minutes.
(e) Repeat a second mixing of repair cement and brush a second coat.
Make sure cellophane inside cell over injury remains in place
because cement will stick cell walls together without it as a
separator.
(f) After cement has dried approximately five minutes, center patch over injury.
1 Lay patch by rolling it down on surface from center to edge without trapping air.
2 Hold unrolled portion of repair patch off cemented surface until roller contact insures an
air-free union.
3 The patch may now be moved by hand on the wet surface to improve lap. Do not lift
repair patch, slide it.
PIPER AIRCRAFT
PA-32R-301/301T
MAINTENANCE MANUAL
Hold shears at an angle to produce a beveled edge (feather) on patch. (Dull side or
gum contact face of repair patch should be largest surface after beveling.)
Round corners of patch.
Do not use the first can of mixed cement for second coat.
– NOTE –
– CAUTION –
– CAUTION –
2E2
28-10-00
Page 28-13
Reissued: July 1, 1993