Piper SEMINOLE PA-44-180, Maintenance Manual

Page: 554 / 881

MINOR SCRATCH AND CRACK REPAIR
1 . Remove wax, oil, and dirt from around damaged area with acetone, methylethylketone, or equivalent and
remove paint to gel coat.
2 . Scrape damaged area with a fine blade knife or a power drill with burr attachment to roughen bottom
and sides of damaged area. Feather edge surrounding scratch or cavity. Do not undercut edge. (If
scratch or cavity is shallow and penetrates only the surface coat, continue to step 2, b.)
3. Pour a small amount of resin into a jar lid or on a piece of cardboard, enough to fill damaged area.
Mix equal amount milled fiberglass with resin, (use a putty knife or stick. Add catalyst per kit instruction,
to resin and mix thoroughly. Use a hypodermic needle to inject gel into small cavities not requiring
fiberglass millings mixed with gel.
4. Work mixture of resin, fibers, and catalyst into damaged area. Use sharp point of putty knife or s t i c k
to press it into bottom of hole and puncture any air bubbles. Fill scratch or hole above surrounding
undamaged area about 0.062 (1/16) of an inch.
5. Lay a piece of cellophane or waxed paper over repair to block air and start cure of gel mixture.
6. Allow gel to cure 10 to 15 minutes until it is rubbery to touch. Remove cellophane and trim flush with
surface, using a sharp razor blade or knife. Replace cellophane and cure completely for 30 minutes to
an hour. Patch will shrink below structure surface as it cures. (If wax paper is used, check wax is
removed from surface.)
HOLE REPAIR
1. Rough up hole bottom and edges with electric burr attachment or rough sandpaper. Feather hole into
surrounding gel coat, do not undercut.
2. Pour out a small amount of resin, add catalyst, and mix thoroughly (use a cutting motion rather than
stirring). Use no fibers.
3. Using tip of a putty knife or fingertips, fill hole to about one-sixteenth of an inch above surrounding
surface with gel coat mixture.
4. Lay cellophane over patch to start curing process. Repeat step f, trimming patch when partially cured.
5 . After trimming patch, immediately place small amount of gel coat on cut edge of patch and cover with
cellophane. Use a squeegee or the back of a razor blade, squeegee level with area surrounding patch.
Leave cellophane on patch for 1 or 2 hours or overnight for complete cure.
6. After repair has cured 24 hours, sand patched area using a sanding block with fine wet sandpaper.
Finish by priming, sand again, and apply color coat.
FIBERGLASS FRACTURE AND PATCH REPAIRS
1. Remove wax, oil, and dirt from damaged area with acetone, methylethylketone, or equivalent.
2. Use a key hole saw, electric saber saw, or sharp knife to cut away ragged areas. Cut back to sound
material.
3. Remove paint three inches back from damaged area.
4. Use 80-grit dry paper and working inside the structure, bevel edges to approximately a 30 degree angle
and rough-sand hole and area around it. Feather back for about two inches all around hole to roughen
surface for strong bond with patch.
5. Cover a piece of cardboard or metal with cellophane. Tape it to outside of structure. Completely
cover hole. Cellophane must face toward inside of structure. Repair to a sharp contour or shaped a r e a
requires a sheet of aluminum formed to a similar contour to be placed over area. The aluminum
must be covered with cellophane.
6. Prepare a patch of fiberglass mat and cloth to cover area two inches larger than hole.
7. Mix small amount of resin and catalyst, (enough for one step) per kit instructions.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
51-12-03
Page 51-06
Revised: June 20, 1995
2L14