FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 3. Fiberglass and Plastics | 3. Transparent Plastics | 3-24. Repair of Plastics
AC 43.13-1B
9/8/98
FIGURE 3-21. Stop-drilling cracks.
a. Surface Patch. If a surface patch is to
be installed, trim away the damaged area and
round all corners. Cut a piece of plastic of suf
ficient size to cover the damaged area and ex
tend at least 3/4 inch on each side of the crack
or hole. Bevel the edges as shown in fig
ure 3-22. If the section to be repaired is
curved, shape the patch to the same contour by
heating it in an oil bath at a temperature of
248 to 302 °F, or it may be heated on a
hot-plate until soft. Boiling water should not
be used for heating. Coat the patch evenly
with plastic solvent adhesive and immediately
place it over the hole. Maintain a uniform
pressure of 5 to 10 psi on the patch for a
minimum of 3 hours. Allow the patch to dry
24 to 36 hours before sanding or polishing.
b. Plug Patch. When using inserted
patches to repair holes in plastic structures,
trim the holes to a perfect circle or oval and
bevel the edges slightly. Make the patch
slightly thicker than the material being
FIGURE 3-22. Surface patches.
Page 3-20
Par 3-24