feetup wrote:This is not intended to hijack the thread, but I have been thinking about water born finishes for a while. I have used varathane diamond coat successfully for a number of non-boat projects, and have used water based instrument lacquers on a number of guitars now and get excellent results now that I have learned some of it's tricks.
I had thought to ask about the varathane exterior water based finish for boat use, but sailors tend to be traditional and I was afraid I might get a strongly negative response. The literature seems to claim excellent UV resistance, but I was a bit concerned about how brittle it might be.
Tim J
The UV protection from exterior Varathane Diamond Coat is only so-so. Used on its own, you won't be happy with the results. The UV will damage the lignin in the wood, and cause the finish to lift in flakes.
Watco Teak Oil (made by Flecto - the makers of Varathane) has instructions on it for overcoating with Varathane. The Teak Oil is I believe basically varnish, thinnned with Tung Oil, so it hardens up after a day or two. It has good UV protection in it from the varnish. Used in conjuction with the Varathane, it gives good results (at least for our climate).
The procedure is to put on 2 heavy coats of Teak Oil about 30 minutes apart. You then wait 15 minutes, and wipe the excess off. After 3 days, you put on 4 coats of exterior Varathane. These can go on 4 hours apart, so I usually do it on one day on the weekend - say 8:00, 12:00, 4:00 and 8:00. The varathane is dry to the touch in about an hour, fully hardens in 10 days.
With the small amount of brightwork on my boat, I can sand the wood and oil it after work one day, and get the Varathane applied on the weekend.
The next year, I just give the brightwork a scuff, then I oil and varathane the hole piece as before. Any part that has scratched or flaked ends up looking pretty good, as the scuff knocks the loose stuff off, and the oil gives the wood a similiar colour to the rest.
I am currently building some new spashboards for the boat. If you would like, I can take some pictures of it for you, so you can see what the finish looks like.