REPAIR INSTRUCTIONS USING FIBER GLASS MATERIAL
The procedures given under Structural Repairs are used
for repairing various types of damage to the fiber glass
laminate cracks, large and small fractures, panel
separation, etc. that can affect the structural soundness
of the laminate.
Cracks, Small and Large Fractures
Cracks, small fractures and large fractures are identified
as follows: A crack is an obvious separation extending
completely through the laminate (Figure 18). Cracks,
which result from stress beyond normal operation, can
occur in the center of the laminate or extend from the
Figure 18. - Crack
Small fractures are punctures that are 3 inches or less in
size (Figure 19).
Figure 19. - Small Fractures
Large fractures are punctures that are 3 inches or more
in length (Figure 20).
Figure 20. - Large Fractures
Cracks, small fractures and large fractures are repaired
following the same basic procedure. All require backing
patches or backup strips. These are simple laminates
that are formed to the shape of the surface being
repaired and bonded with epoxy cement to the back side
of the repair area. The backing patch serves two
It provides the foundation on which the exterior
surface is built up and formed to match the
It provides the mechanical strength needed to
keep a repair structurally and visually intact
during normal operation and use.
A repaired laminate must be as strong as the original
material surrounding it. If it is not, the repair will not last
and is likely to crack around the edge of the patch.
In addition to the backing patch, large fractures will
require additional mat laminations which are used as a
filler in building up the surface to the original contour.
Perform the steps listed under Preparation Procedure
(page 5), then proceed with the repair as follows:
Using a tapered bit or a saber saw, remove the
cracked and flaked fiber glass surrounding the
damaged area. For cracks, remove enough
material so that there is an open gap at least 1/8
inch wide (Figure 21). For small and large
fractures, cut away as much material as is
required to provide a solid edge (Figures 22 and
WARNING - WEAR GOGGLES AND RESPIRATOR
WHEN CUTTING, GRINDING OR SANDING.