When I initially finished my kayak a couple years ago, I was burnt out and couldn't face using real varnish and having to wait a day between coats and then sand, and then clean up and re-varnish, sand again, etc., so I sprayed the bugger with several coats of Minwax Spar Polyurethane clear satin and got out paddling.

Now, I want to brush on several coats of the same poly, but I was under the assumption that I could re-coat each hour or two without sanding as I was able to do with the spray.

Upon reading the label, it says to wait 4 hours between coats and then sand with 220 grit before applying the next coat.

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?

If the answer is no, you have to sand first, then should I use wet sandpaper at 220 grit? Thanks for your help.