All those integral shapes provide rigidity in very light sheet material.
These boats are typically riveted, or welded in extremely controlled
environments.

For a homebuilt, you will probably weld, using much thicker material; I
understand that most welders can do good work in 3/16 plate, the talented in
1/8, and only very very expert can weld material lighter than that with much
success.

These thicker plates require less framing or complex bending than the thin
material.

For a full discussion, take a look at Pollard's Boatbuilding with Aluminum:
http://www.amazon.com/Boatbuilding-A.../dp/0070504261

Have fun!
Sal's Dad



I have noticed a lot of them will have 'V's
folded or stamped into the hull along the length for strength. I don't
see
anyway that a backyard builder could do this practically. Would a home
built aluminum just be built with a structural frame with pieces going in
both directions like a wood boat?



They may allso be there to help longnitudnal stability or for spray
control.

A V mounted above the water line sweeping with the lines of the hull is
almost always there for spray control. I think they even call it a spray
rail.

You can get the strenghth by rivetting or welding on
stringers made from aluminum angle.on the inside or bend some flat
stock 3 times to make a V shaped piece. that could go on the inside or
outside of the hull.