I was told that 1 quart of varnish would be enough for my canoe. I have varnish two seat frames times four and four gunwales times three. I have one coat on the inside of my boat and only have one quarter of the can left. I did not thin the Interlux Varnish at all and I think that was and expensive mistake. What should have I done and what do you use to thin varnish? Thanks Trav