I have just put the 3rd coat of varnish on my Guillemot Coastal and found there are a few spots on the deck where something strange happend to the varnish. The majority of the boat dried to a high gloss as I expected, however, there are a few spots where the finish is dull and flat. The varnish also remained tacky on these spots for a couple of days. It seems to have dried now. The first two coats went on fine. I'm using Z-Spar Captains varnish.

My procedure has been to wet sand with 320 grit paper, wipe down with a sponge and damp cloth, and then wipe with a tack cloth.

What could have contaminated the deck and caused the varnish to do this, or is it the varnish? The only thing I can think of is that I may have wiped these spots harder with the tack cloth and left some sort of residue. Anybody have any ideas?

What should I do about it? Just try another coat? Remove the varnish with a solvent and try again (Ugh!)?

Thanks.