On Sat, 1 Sep 2012 14:29:47 -0400, iBoaterer wrote:

I am using tool boxes now. We were trying to go another way but the
32" width seems to be a problem in a dock box and we want a height
suitable as a seat with a cushion.
We have a trick box across the back too but next time around I am
thinking about a leaning post with storage under it and no box across
the back. Since all of the aluminum will be custom made I want the
boxes first.

I'm thinking to get just exactly what you want, you'll have to build it.

===

Yes, and it wouldn't be all that difficult for anyone who is halfway
handy with wood working tools, epoxy and fiberglass. I'd start by
laminating a few sheets of 1/4 inch exterior ply with one layer of
relatively light weight glass on each side. It's easy to get the
panels dead nutz flat that way and much easier to laminate than after
it has been built into a box.

Evaluate the panels for stiffness; laminate extra layers of glass on
each side as needed for strength/rigidity but remember that the sides
and bottom do not require extreme stiffness.

Use the pre-laminated panels, cut out the pieces you need for the box,
seal the edges of all pieces with epoxy, and then tack the whole thing
together using clamps or light weight fasteners. Next step is to
thicken some epoxy and filet all of the inside corners with something
like a 1/2 inch radius (being careful to keep everything in square
alignment). Cover the filets with one or two layers of 3 inch
fiberglass tape/epoxy and let the whole thing cure.

You should now have a very strong and rigid box assembly that can be
filled/sanded/finished/painted the way you want. Make a cover using
the same technique as the box, sizing it to overlap the edges by some
small amount. The top will need to be stiffer than the sides and
bottom if you are going to use it for seating.