I have an old canvas-covered canoe with interior ribs. The canvas is rotting. I'd like to replace it with epoxy. Any recommended techniques for this?

Concern: difficult to glass the inside of the boat because the ribs are constantly in the way--could I get away with glassing the ribs, then adding glass to the sections between when the first lay-up was still green? After all, the boat was built originally with nothing more than canvas on the outside.