On May 20, 4:34*am, "Bob La Londe" wrote:
I have been looking at aluminum boats for the last couple years now with an
eye towards how they are built. *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?

I was building aluminum plate boats in the 5.6metre-7metre range for
about a year, these were fairly expensive high quality fishing boats
with water ballast keels and various layounts including cuddy cabins
and walkarounds. These were plate aluminum boats, using materials up
to 6mm (1/4") so they were fairly rigid, but still had only a single
hard chine in the hull where the V bottom joined the side plates, then
a "step" in the sides. You can see the boats here;

http://www.barcrusher.com.au/

They are not overly complex to make, though a good aluminium MIG with
synergic pulse is a huge help. Try Fronius (my preference) or Kempi,
but dont expect too much change from $10,000. The forming/cutting
tools are very basic. Any tungsten tipped blad for woodworking is
good for aluminum. You can use common woodworking table saws, drop
saws etc. The machine used for putting the step in the side panesl is
not expensive, its just a simple offset roller, you can buy cheap ones
for a few hundred dollars. You then mark the sheet with a marker
where you want to have the step, then roll it by hand. Very basic.

Knowing where to put the mark is the real skill same with shaping
the side/bottom sheets, the shape you cut them to is quite complex and
not easily worked out. Expect to waste some materials ($$$) if you
havent done this before and have no design/CAD knowledge. The
simplest way to get a feel for it is to make scale modesl with
cardboard. Dont try to be real fancy here, 10 minutes/model is
enough. Just mark out on cardboard, cut, and tape. See what
happens. Remember you'l need a very good fitup at this scale for it
to translate to a weldable product at full scale.

Best Regards,
Shaun