I'm in the process of finishing off my canoe. When I glassed the inside I did not fill the weave before the epoxy was fully set up. My question is, how much do I need to sand to get a good mechanical bond, since I'm not going to be able to get a flat surface without cutting into the glass. I could just varnish over what I've got but I do know that I'd just have varnish peeling off, so I'm thinking of filling the weave and sanding again before I varnish. Thanks