"Bart" wrote in message
ups.com...
Boat and yacht decks and hulls are commonly cored to
save weight.

What are the various types of core material?

Airex foam
End-grain balsa
Plywood
Metal honeycomb


What are the characteristics of each?

Airex: a near-perfect core material, won't absorb water, quite rigid,
fairly lightweight, far cheaper than balsa or honeycomb, provides insulation
factor.

End-grain balsa: very lightweight, expensive, labor-intensive, low-tech,
will absorb water, quite rigid, some insulative properties.

Plywood: cheap, heavy, absorbs water like a sponge, very rigid, good
backing for major hardware like winches, cleats, did I mention cheap?

Honeycomb: rigid, very expensive, won't absorb water, but if damaged during
construction water can flow into the cells, no insulative properties, high
tech and the lightest in weight of the bunch.

There are probably others, but less significant in terms of commonality.

Max