: What I'm wondering is, if I wait only, say, 2 hours between coats could I
: re-coat without sanding and get a good chemical bond, like we do with
: epoxy that is re-coated within a short time period?

Minwax® Helmsman® Spar Urethane (Clear Gloss)

I used a MinWax polyurethane varnish that dried in 4 to 6 hours, so I could get a complete coat on in a day, hull and deck, and one day I did two coats with no sanding between coats. I had 7 total coats. I use Rehd’s method of hand wiping, which went on very fast and easy and virtually eliminated runs. About 15 minutes wiping time. I use paper towels dipped in the varnish which didn’t tear up and leave a residue. I use Rob Mack’s idea of not using above 220 wet grit sandpaper between sandings. That give a mechanical bond to the last layer of varnish and knocked off any high places in the varnish, yet I didn’t spend a lot of time doing needless sanding. The last coat was Rob Mack’s use of a foam brush to get a thicker last coat and then tipped of with that brush to eliminate runs and bubbles. I wore throw-a-way rubber gloves so there was never a mess from the hand wiping of the varnish. This system worked out well for me.

John