Piper SARATOGA PA-32-301 Maintenance Manual page 300

PIPER AIRCRAFT
PA-32-301/301T
MAINTENANCE MANUAL
REPAIR PATCH (HEAT CURE METHOD).
1. Prepare the exterior cell wall and exterior patch first. Cut a repair patch from FT-192 materialto the
size required to insure a proper lap over the injury in all directions. (See Limitations.) (Hold shears at an angle
to produce a beveled edge (feather) on the patch.) Round corners of patch. (Dull side or gum contact face of
repair patch should be the largest surface after beveling.)
2. Wash one square foot of cell wall surrounding the injury, and the repair patch contact side with a
clean cloth soaked with Methylethylketone solvent.
3. Abrade cell wall surface about the injury and on the contact side of patch with fine emery cloth to
remove the shine.
4. Repeat Methylethylketone washings two more times, for a total of three washings for each surface.
5. Tape a 8" x 8" piece of cellophane inside the cell over the injury.
6. When all the above preparatory work has been done and the cell has been positioned for patch
application on the repair table, mix the 80C27 cement (320 gms) with the cross-linker 80C28 (81cc), and stir
mixture thoroughly, for five minutes.
- NOTE -
Cement must be at a minimum of 70°F before mixing. Keep away
from water and excessive heat.
7. 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.
8. Repeat a second mixing of repair cement and brush a second coat.
- CAUTION -
Do not use the first can of mixed cement for this coat.
9. Allow cement to dry approximately five minutes, and then center patch over injury. Lay the repair
patch by rolling it down on surface from center to edge without trapping air. Hold the unrolled portion of the
repair patch off the cemented surface until roller contact insures an air-free union. At this time, the repair
patch may be moved by hand on the wet surface to improve lap. Do not lift the repair patch, slide it.
- CAUTION -
Make sure the cellophane inside the cell over the injury remains in
place, as any cement will stick the cell walls together without the
cellophane as a separator.
10. Cover one smooth surface each of two aluminum plates (plates must be larger than patch), with
fabric-backed airfoam, fabric side out. Tape airfoam in place. Foam must cover edges of the plate for
protection. Use a cellophane separator to prevent the cement from sticking in the wrong place.
11. Fold the cell adjacent to the patch and place prepared plates one over repair patch and one on
opposite side.
28-12-12
2B7