HONEYCOMB CORE.Repairs to damages
completely through the sandwich structure may be
accomplished either by the scarfed method (similar to
the repair described for damage extending into the
core) or the stepped method.
The scarfed method is normally used on small
punctures up to 3 or 4 inches in maximum dimension
and in facings made of thin cloths (which are difficult
to peel). The stepped method is usually employed on
larger repairs to facings composed of thick cloths.
The scarfed method of repair for punctures is the
same as that used for damage extending into the core,
with the exception that the opposite side of the
sandwich is provided with a temporary mold or block
to hold the core in place during the first step. See
view C in figure 14-13.
After the first facing repair is cured completely,
the mold and the shim (temporarily replacing the
facing on the opposite side) are removed. The repair
is then completed by repeating the procedure used in
the first step. When this facing is cured, the surface
should be sanded down to the original contour and the
repair area lightly sanded in preparation for
When you use the stepped method of repair, the
damaged area is first trimmed out to a round or oval
shape or to a rectangular or square shape (preferably
having rounded corners).
Figure 14-12.Foam-type core repair.
Figure 14-13.Scarfed repair method.