|Where major bits are
affixed to an EPS foam board, be they fin boxes, foot straps, mast bases, etc,
such bits need to be anchored in such a way as to remain attached :) and do
so without leaking. The hardware, or inserts, that are installed in the
boards for this purpose are almost exclusively made from some reinforced plastic or another,
inexpensive to manufacture to reasonably close tolerances. Only problem is
that the Epoxy used to hold the board together does not bond to plastic
well. Which is why manufacturers mold some sort of ridged tooth design into
the perimeter of these inserts, in order to achieve a mechanical connection.
With EPS foam having the holding power of a marshmellow (and that's an
insult to the marshmellow), some sort of intermediate medium needs to be
introduced. Enter Divinycell PVC foam, or high density Urethane foam.
Surrounded by such structural foam, we can safely ignore the fact that the
Epoxy still will not bond to the face of the insert, since it does securely
bond to the closed-cell foam immediately adjacent.
Time and time again I find leaking and/or loose inserts
to have been installed without the benefit of such cartridge of structural
foam. Maybe, an insert destined to support a water bottle can safely be
installed directly into the EPS. Maybe. But anything that will see bigger
loads will need extra support!