I'm nearing the end of the woodworking phase for my Greenland kayak, so I'm well into researching what varnish to use. I'll be ordering nylon fabric soon, so thats what it has to be compatible with. I've already ruled out water borne poly products, based on msgs I've read on this bulletin board. I'm avoiding two part mixes, since they all seem to have faster working times then I'm comfortable with my first time.

In a research trip to the local "big box" hardware stores, the three oil based, outdoor finishes I found are:

Minwax Helmsman Spar Urethane
Zinsser Bulls Eye Spar Varnish
Cabot Spar Varnish

Only the Cabot's stuff said anything about "flexibility", and claimed to be "better than polyurethane".

Anyone have any experience with any of these three? Or other recommendations?
I'm not opposed to going mail order... these three were just locally available.

thanks!
cjk