compound curves in plywood

"The point loads in fiberglass airplanes are carried through strong
bulkheads, bonded very well to the body. I don't think what your describing
has that.

If the use of a single layer of wood is used to be the core, instead of
foam, and the same thickness of fiberglass is applied, as it would be in the
fiberglass and foam plane, there should not be a problem. Is this the
intent?"

Yes! The cedar strips are simply space, rather than strength. The rigidity
comes from the 1/4" thickness of the cedar strips, plus the thickness of the
multi-layer epoxy coverings. My kayak has 3 layers of cloth on the
exterior, plus epoxy resin..The cedar strip is used for beauty and the
"plastic" ability to conform to compound curves. The strength comes for the
thickness of the cedar times the layers of epoxy - really like a foam
aircraft. Although additional strength could be gained by cross laminating
2 layers of cedar strips, it would also add to the weight - and the change
of delamination between layers may increase. Just as in foam airplanes,
bulkheads of other means of transferring stress from a single point to a
much larger area are necessary.

I have built a stitch-n-glue boat, also, but could never get the beautiful
compound curves that I could get from the cedar strips. There is a limit to
the bending.

I do think, though, that it would not be difficult to simply make a mold of
the shape desired and take very thin skins and make your own plywood,
conforming directly to the desired shape, much like the paper mache ugly
animals we made in grade school. Compound curves allow great strength with
thin materials.

Colin