Due to reading reports on this board about troubles getting a good clear wet-out on Raka 5 0z. satin cloth, I tested several fabrics in preparation for glassing my next kayak. My samples were 2 layers of 3.25 satin, 2 layers of 3.75 s-glass, 1 layer of 3.75 s-glass, 1 layer of 5 oz., and another sample of 5 oz. to be hit with a heat gun after wet out. The plywood base was pre-sealed. All of the samples wet out perfectly and look the same. I saw absolutely no evidence of the grid that some have described, not even while the initial wet-out was progressing. Using the heat gun on the second 5 oz. sample made no visible difference. My shop temp was 60 and resin (MAS slow) temp was about 70. I plan to weigh and measure the stiffness of each sample later on.

My shop temperatures are cooler than what Larry suggested to me on the phone, so I was expecting some trouble. So why are other people having trouble? The only significant variable I can think of is the resin.

My impression of the open weave s-glass is that it is coarse, just like open weave should be I guess. More resin accumulated on the squeegee than from the other samples, which suggests that it will need more fill and lead to a heavier boat. It looks as clear as the other fabrics at this point, but a better test will be to put on some fill coats and look at it in bright sunlight.

At this point I it looks like the deck outside will get the 5 oz satin. I'm still waffling about the s-glass. The ideal cloth for a light, tough boat would be a tight weave s-glass, which I have not found yet.

Below is a close-up of the 5 oz. sample with one thin fill coat.

Cheers,
Ted