I was hoping Paul would join this thread. I'm going to be at that stage soon (hope). Personally i do like the idea of using a 'tougher' final finish, but I am suspisous because many of my past 'good' ideas (based on 'thiking rather than experience) havn't always turned out so good.

I have to say that no matter how glad I was to have the benifit of Paul's thinking on this I remain unconvinced (for me, and not in any sense of my thinking being right for anyone else). I would like to see if there is anything more to this issue. I mention my thoughts after reading Paul's comments not to try to 'counter' them but just to see if a more full aring of this is possible.

2 points Paul made don't matter for me: My epoxy has had more than enough time to harded and I will have time to let the varnish dry. I guess part of it is a matter of degree as to what will scratch varnish and what will leave the poly seemily unmarked. Undoubtedly some scratches will scratch both materials. I appreciate what has been pointed out about the time savings if the poly will look good for a year or more longer. And that is another part of the relative matter of the final finish marring how long before even the poly starts looking ragged is a mtter of judgement being in the eye... But even with all these variables I still like the forgivingness of using varnish and do not want something that is hard but scratched to work with. I DO see Paul's good point about "SO what if it's hard, you just need to sand it and the next coat fills in ANY scratches, so what's the diff?"

Anyway I don't have anything to go on but my thinking (often flawed) and my gut here and appreciate anyone out there who can share what they thik here or have had experince with. This BB has been so great to help make me as good a builder as I am ... Which is WAY better than I would have ever been without it!

Joe

: I've used varnish, and I'm planning to switch to polyurethane.

: My wood floors have polyurethane on them and they stand up to the wear and
: tear of sand, high heels, kids and dogs. Varnish would not last that long,
: so I'd be redoing the floors more often. similarly, I expect to need to
: revarnish every year or two, while with polyurethane I might go 3 or 4
: years. That is a time savings.

: While both may scratch, the softer varnish has wide and deep scratches. I'd
: prefer to have shallow and narrow ones, if I have any at all.

: The varnish takes a long time to dry. Eventually it gets plenty hard -- but
: it does not become the "armor plate" I want to protect an epoxy
: which is still getting harder and stronger months after it has been
: applied.

: I don't see what difference it makes on how hard the coating is realtie to
: sanding it off. The only time I'd want to completely remove the finish
: (varnish or Polyurethane) would be to patch a hole in the glass, and for
: that a 60 grit sanding belt will remove varnish, or polyurethane just as
: fast, and the glass cloth barely slows it down. The sharp grit on
: sandpaper will cut either material. Sticks on a (soft) muddy shore will
: make an impression (n a pressure mark) in varnish.

: For refinishing you don't need to totally remove existing finishes. the
: sanding simply scrufs them up to provide some "tooth" so the
: next coat can lock into it.

: I see varnish as a weak coating that simply filters out UV. I see
: polyurethane as an enhancement that toughens the outer layer of flexible
: and soft epoxy. In both cases, though, these fluids flow into the
: "scratches" produced by my sanding of the epoxy and by filling
: them they replace the matte finish with a glossy one.

: If I was working with polyester resin I wouldn't use either. I'd use a gel
: coat. Some people are using polyester gel coats with UV filtering
: materials over their epoxy/glass work instead of polyurethane or varnish.

: Just some thoughts on this.

: PGJ