"Reynaud" wrote in message ...
Has anyone here ever built an kayak or canoe from polystyrene coated with
cloth and Epoxy?

We did it last year and you see pictures of the canoe he
http://www.boatplans-online.com/prod...?prod=Hiawatha
We have more pictures in other parts of the site.
We used polystyrene insulation foam, the blue stuff.
We did not expect any good results but we wanted to check a new panel
development software and had some foam sitting there. Once assembled,
since the warehouse guy had nothing better to do, we slapped some
resin and glass over the foam.
To get some impact resistance,we had to use more glass than on our
plywood composite hulls and the result is a boat slighly heavier than
the plywood-fiberglass version. It also cost more because you need
more fiberglass and resin.
There is no saving in weight and it cost more than marine ply plus
fiberglass . . . not a great deal but the question keeps coming up,
probably because of all the "no wood" boat ads.

That question is also often discussed in our message board and we
wrote about it in our FAQ at:

http://bateau2.com

Jacques from bateau.com