I'll second the polyurethane trick that Ed shared. Where I had trouble was placing the cloth on the plane and keeping it in place. I thought I was clever and sprayed a light dusting of 3m77 spray adhesive on the float. Then I smoothed the cloth in place. Then I brushed on the polyurethane. BUT I used solvent-based PU and not Water-based. The solvent dissolved the 3m77, and the cloth bubbled at the corners.
Still, once it was done, it was strong and light, and easier to work with than sticky epoxy that is racing toward the end of its pot-life.