Hi there.

You'll probably get more coats than that out of 1 quart, and I agree that more on the deck than the hull is appropriate. I think it's hard to argue that the hull under your butt needs much in the way of UV protection. More than that, I've been thinking that varnishing the hull is 90% just for cosmetics, so as to make the hull as pretty as the deck.

Consider this: with the boat upside down, do as many coats on the hull as 1/2 of your varnish will go. Using the rest on the smaller-area deck should give you at least one more coat than on the hull.

I spoke recently with a technical advisor at Z-Spar. Surprisingly, what he advised was NOT what was on the can's label. He suggested that I could thin Flagship up to 30% (for spraying; we weren't talking about brushing) while the label said much less. Go figure.

For between-coat sanding, he suggested 220 grit production paper, and then something finer, up to 400 grit, before the final coat. If you are into wet sanding, he said that it is more coarse than the production paper with the same number, i.e., 400 grit wet-or-dry would be equivalent to something like 300 grit production paper.

Have fun,

Pete,
in Snohomish