I used Sterling LPU (paint not clear) on the bottom of boat #3 a couple of years ago and had great results. I thinned it to their recommendations and used an old but decent 3" varnish brush. The first coat developed a couple of sags so I decided to re-read the lit. They recommended brushing out vertically, which I did the second time around. It looked a bit strange initially, but after ~1/2 hour it leveled out to a beautiful finish. I had to work fast, but not unreasonably so, at 70-75deg. It still looks great after weekly use including a fair amount of abuse on the rocks of Palos Verdes and elsewhere. It is just starting to wear through at the bow, but the rest dosen't look much the worse for the wear.