: : What if I made a cheap knockoff of the Kahuna by feathercraft? I'd need
: properly sized ribs made of plywood instead of their "injection
: molded polycarbonate", and instead of the aluminum stringers, used
: PVC conduit pipe (I got some of this stuff and abused it mightily with a
: hammer with no material failure - the grey stuff not white plumbing PVC.
: No way that aluminum or wood could have withstood that attack so well).
: Then I could make a skin of the recently mentioned PVC material used on
: billboards, or scraps from a truck tarping company.

I thought the same way about the PVC tube - After a material test with the hammer I bought a few lengths of 16mm and 22mm PVC and a few lengths of 15mm wood rod (I think it's somew sort of pine) I then made up some 'ribs' and tested the deflection at various spacings. The PVC was so flexible that I would need far too many ribs to be practicable. I will be going for the dowel for the stringers.

I will still use the PVC, however. Heat it up with a heat gun, and expand it with a tapered dowel and you get really snug slip on fittings. It seems tougher than the original pipe also.

Considering cost, the difference between the dowel and 22mm PVC was minimal, and would be lost if I needed extra PVC to compensate for the flex.

Good luck!