I'm working on my 2nd Yost boat, a Sea Otter R. I expect to do a sewn-on skin. My combing will be Yost-style plywood buildup with rigid ring on the frame, as that's what I'm comfortable at building.

I see sew-up skins are stitched onto the combings (which float? I have a hard time grasping this). So, how are the stitch holes in the combing riser sealed? This is probably of extra importance with a plywood riser. Or, should I be considering a some method other than stitching to the combing?