Piper PA-28-161, Maintenance Manual

Page: 697 / 1104

PAGE 1
Nov 30/06 4C19
51-70-00
REPAIRS
WARNING: NO ACCESS HOLES ARE PERMITTED IN ANY CONTROL SURFACE.
WARNING: USE OF PATCH PLATES FOR REPAIRS OF ALL MOVABLE TAIL SURFACES IS
PROHIBITED. USE OF ANY FILLER MATERIAL NORMALLY USED FOR REPAIR OF
MINOR DENTS AND/OR MATERIALS USED FOR FILLING INSIDE OF SURFACES IS
ALSO PROHIBITED ON ALL MOVABLE TAIL SURFACES.
Structural repair methods used must be in accordance with regulations set forth in FAA Advisory Circular
43.13-1, latest revision. To assist in making repairs and/or replacements, Figure 1, 51-00-00, identifies
type and thickness of various skin material used.
Never make a skin replacement or patch plate from material other than type of original skin, or of a
different thickness than original skin. Repair must be as strong as original skin. However, flexibility must
be retained so surrounding areas will not receive extra stress.
1. Fiberglass Repairs
The repair procedure in this section will describe the methods for the repair of fiberglass reinforced
structures. This section describes Touch-up and Surface Repairs such as blisters, open seams,
delaminations, cavities, small holes and minor damages that have not harmed the fiberglass cloth
material. Also covered are Fracture and Patch Repairs such as puncture, breaks and holes that have
penetrated through the structure and damaged the fiberglass cloth. A repair kit, Piper P/N 766-222, that
contains the necessary material for such repairs, is available through Piper Distributors.
NOTE: Very carefully follow resin and catalyst mixing instructions furnished with repair kit.
A. 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 fiberglass 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 fiberglass 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 .062 of
an 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, make sure the 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.
PIPER AIRCRAFT, INC.
PA-28-161, WARRIOR III
MAINTENANCE MANUAL