Piper Arrow IV, Maintenance Manual

Page: 484 / 752

FIBERGLAS REPAIRS.
The repair procedure in this manual will describe the methods for repair of Fiberglas Reinforced Structures,
Fiberglas Touch-Up and Surface Repairs such as blisters, open seams, delamination, cavities, small holes and
minor damages that have not harmed the fiberglas cloth material, Fiberglas Fracture and Patch Repairs as
puncture, breaks and holes that have penetrated through the structure and damaged the fiberglas cloth. A repair
kit, part number 756 729 will furnish necessary material for such repairs, and is available through Piper
Aircraft Dealers.
—NOTE—
Very carefully follow resin and catalyst mixing instructions
furnished with repair kit.
FIBERGLAS TOUCH-UP AND SURFACE REPAIRS.
1. Remove wax, oil and dirt from around the damaged area with acetone, Methylethylketone or
equivalent and remove paint to gel coat.
2. The damaged area may be scraped with a fine blade knife or a power drill with a burr attachment to
roughen the bottom and sides of the damaged area. Feather the edge surrounding the scratch or cavity. Do not
undercut the edge. (If the scratch or cavity is shallow and penetrates only the surface coat, continue to Step 8.)
3. Pour a small amount of resin into a jar lid or on a piece of cardboard, just enough to fill the area being
worked on. Mix an equal amount of milled fiberglas with the resin, using a putty knife or stick. Add catalyst,
according to kit instruction, to the resin and mix thoroughly. A hypodermic needle may be used to inject gel
into small cavities not requiring fiberglas millings mixed with the gel.
4. Work the mixture of resin, fibers and catalyst into the damaged area, using the sharp point of a putty
knife or stick to press it into the bottom of the hole and to puncture any air bubbles which may be present. Fill
the scratch or hole above the surrounding undamaged area about 1/16 inch.
5. Lay a piece of cellophane or waxed paper over the repair to cut off air and start the cure of gel mixture.
6. Allow the gel to cure 10 to 15 minutes until it feels rubbery to the touch. Remove the cellophane and
trim flush with the surface, using a sharp razor blade or knife. Replace the cellophane and allow to cure
completely for 30 minutes to an hour. The patch will shrink slightly below the structure surface as it cures. (If
wax paper is used, ascertain wax is removed from surface.)
7. Rough up the bottom and edges of the hole with the electric burr attachment or rough sandpaper.
Feather hole into surrounding gel coat, do not undercut.
8. Pour out a small amount of resin, add catalyst and mix thoroughly, using a cutting motion rather than
stirring. Use no fibers.
9. Using the tip of a putty knife or fingertips, fill the hole to about 1/16 inch above the surrounding
surface with the gel coat mixture.
10. Lay a piece of cellophane over the patch to start the curing process. Repeat Step 6, trimming patch
when partially cured.
11. After trimming the patch, immediately place another small amount of gel coat on cut edge of the patch
and cover with cellophane. Then, using a squeegee or the back of a razor blade, squeegee level with area
surrounding the patch, leave the cellophane on patch for one or two hours or overnight, for complete cure.
12. After repair has cured for 24 hours, sand the patched area using a sanding block with fine wet
sandpaper. Finish by priming, again sanding and applying color coat.
FIBERGLAS FRACTURE AND PATCH REPAIRS.
1. Remove wax, oil and dirt from around damaged area with acetone, methylethylketone or equivalent.
2. Using a key hole saw, electric saber saw, or sharp knife cut away ragged edges. Cut back to sound
material.
3. Remove paint three inches back from around damaged area.
4. Working inside the structure, bevel the edges to approximately a 30 degree angle and rough-sand the
hole and the area around it, using 80-grit dry paper. Feather back for about two inches all around the hole. This
roughens the surface for strong bond with patch.
51-10-03
Page 51-04
December 1, 1978
2I13
PIPER AIRCRAFT
PA-28RT-201 / 201T
MAINTENANCE MANUAL