Actually I don't have any concern with the strength and flexibility, this would just be varnish which has shown to flex just fine on Dacron. I did a few tests on a "boat like" shape and beat it with a screw driver and a hammer and did not get any separation until I hit it hard enough to penetrate the skin (with the sharp end).

However a very sharp knife went thru it like butter. Varnish, paint, and 2 part urethane made the skin more rigid and the knife cut it easier than just uncoated Dacron. The knife had been sharpened to where it would shave the hair off your arm - my conclusion was that I should not use a knife on a boat! Some of those videos showing a knife not cutting dacron must have used a pretty dull knife.

I'll post a picture of the finished boat, to show the rolled gunwale. I have a little concern it will not show up well since the color will be as bright of a yellow as I can get. My friends request.