: Building a foam cored composite hull, be it carbon or glass, does
: not require a mold. Just female stations and form stringers.
: Very simple stuff, really.

: You learn to do this by building something small, like bulkheads
: and then move to more complex forms. I know all sorts of
: builders who will not build a stripper of any kind because they
: perceive it to be too complex and fiddly compared to stitching
: together plywood. A foam cored boat build is no more complex
: than a wood stripper, yet, there is a lingering perception that
: it's difficult.

: There are raw beginning boatbuilders who are constructing F-22
: folding trimarans in 3/8" foam core with glass laminates
: and the boats are turning out beautifully. There's absolutely no
: reason why a canoe, or kayak, could not be built by a beginner
: with similar results.

Hi Chris,
I was involved in building a foam core boat years back (pre-CF days, CF was only for military tech) and there are some differences. The mold/framework to lay the foam had more pieces, the cross-sectional mold-frames and stringers. The foam was stitched to the stringers rather than to the molds as in wood strip.
The core was a bit thicker than would be needed for a kayak, much less 'floppy' but still needs more of a framework to support it.

Strength in compression was determined by the foam density, we used higher density foam along the keel-line and high stress areas and lower densities elsewhere.

Fairing this was messier than a wooden core, the sandings get 'static cling'.

Other than a few things, not much difference overall. But you have availability, cost, appearance, intended usage, etc effecting choice of materials. So far, wood is easily available compared to foams, likewise CF.
For some reason, kayak builders prefer wood cores, something to do with individuality of appearance of the kayak as an inherent component of the structure, foam core doesn't give that level of individuality as an inherent component. Painting designs on the surface would hide the prettiness of CF. :)

Then there's the "Ooo, pretty" response. Not something you get universally with CF but you do with wood core. That, I think, is a vital aspect of strip building for us. Put a foam/CF kayak beside a wood strip kayak and watch who and how many go "Ooo, pretty". :D Plus, timber smells nicer than foams.

There is also the point of 'scavenging' materials, kind of harking back to building from what is easily available locally. A kinda expression of survival ability.

Mike Savage
South West Cork