: Anyone interested, even in a failed experiment, can see more at my
: blog http://theancientkayaker.weebly.com/cylinder-molding.html

So I wrote up a lengthy response to this and apparently, didn't save it, let me sum up...

Very cool experiment, A result you don't want lets you know what to work towards to get a result you do want.

I would suggest elevating the jig about 6 inches and not only bending it in the Y-axis (up), but also the Z-axis (towards the floor), and then apply the epoxy to it. that would let it bend up, as you have already demonstrated, then bend in and lock it into place. that would allow you to make another one and joint them to get a hull (or deck).