riverman wrote:

Hmm, I don't see an obvious easy solution to this, but what you're
envisioning doesn't look good. I once saw a royalex boat that was too close
to a campfire reach the temperature where it lost its cohesive stability.
The hull suddenly had the consistency of freshly cooked lasagna noodles, and
it was was impossible to hold it in shape with our hands while it cooled and
got rigid. We flopped it down rightside up on the ground, and to this day it
still has a completely flat bottom because of that. If it had landed on a
stick, that would have just gone right through the bottom.

Sounds like Royalex is a tradename for polypropylene. Is it?
Polypropylene has a very low melting temperature, but is otherwise
strong, lightweight and durable.