> Does anyone have any exprience using aluminum extrusion for a box-beam
> instead of wood? I'm thinking that buying the 2x4 extrusion will save me
> some work by not having to build a box-beam. Would I have headaches
> attaching the frames to the beam?

> Another reason for using aluminum is that I will be building my stripper
> in my apartment's living room. Last winter, in my living room / workshop I
> had some panels of my Pygmy Arctic tern warp due to the moisture in my
> apartment (from showering, cooking, etc.) and am worrying that a wood beam
> may warp. The 2x4 that I used to ensure a flat, straight keel warped
> pretty severely.

> Thanks, Dean

I've used a 2" X 4" aluminum box beam for both the base of my canoe strongback and for the centre beam for kayaks. They can be a little expensive unless you have a friend that sells non ferrous metals. I simply used a quick set epoxy to glue cleats to the roughened surface of the beam and then used a heat gun to break the epoxy bond when the planking was finished and the forms were to be removed, The system worked fine but rather than go to the expense, just use a box beam as shown in Nick's book. It takes less than a sheet of plywood and if constructed well it shouldn' warp.