> Don't know, but canvas is a great absorber of water and I've never seen a
> boat that doesn't get some water inside. Most advocates of canvas suggest
> that the coating should be sufficiently thinned to fully penetrate the
> cotton when applied from the outside. Raw canvas mildews and rots fairly
> easily. The space between the skin and the stringer rarely gets a chance to
> dry out.

I found that I could not thin Elast-o-Seal enough to penetrate #10 14oz. canvas, I thinned to 50% and they recommend no more than 10%. The fibers swell and stop penetration. I've heard that it penetrates polyester nicely though.

Mike