I need some help from the expert, guru (know - it- all) most respected persons on the web.
Really, this is the best place.

I have built 2 Yost SOF boats and when coating the skin with one part polyurethane (Minwax Helmsman) I get irregular blotches where the skin touches the frame.
Dacron 8oz from Dyson over a varnished (Minwax again) and waxed frame.
The first boat it was apparent I left drips and thick areas which then penetrated the cloth causing blotching.
Second boat I did some test panels which did not blotch and thought that just making a thin first coat would work.
Unfortunately the instant I started applying the urethane (brush) small local areas blotched and over the course of the complete coating perhaps 5% of the frame area blotched - showed a much darker color where the coating soaked all the way thru and contacted the frame (I assume).

Any suggestions? I see perfect coatings on the boats in Yost's web site. I was looking for the translucent color. The first boat had no additional color, the second had a light tint mixed into the clear varnish.

Any help would be appreciated - If I try this a third time I would like a reasonable chance of success. I could always paint a solid color, just didn't want to.

Thanks, Marc