> 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

Dean,

If you rip a 2 x 4 in half, flip it over and glue it back together, it will not warp easily, all warpage forces will be counteracted by approximately equal warpage force.

Or use the plywood box beam descriped in Nick's book.

Mike