I've been very happy with Bristol Finish. I'm in my fourth year of North Carolina coastline sun and salt and it's holding up very well. I will be doing some recoating this winter. It's a %$@%%^ to put on but I think it's worth it. Call them up and see what they say about using it on existing varnish. I seem to recall it is feasible. But they'd tell you for sure. Joe ----- Original Message ----- From: Tom Jenkins To: For and about Montgomery Sailboats Sent: Thursday, September 27, 2012 7:24 PM Subject: M_Boats: varnish Hate to get off the interesting thread about teeny motors, but I have another question; what resists UV best on a boat in the sun: standard spar varnish, or urethane spar varnish? Additionallly, I now have numerous coats of regular varnish in good shape, and I wonder if the urethane would go over the regular without sanding to bare wood (which I ain't doing). Thanks, Tom Jenkins