I've used Epifanes and It dried like any other varnish for me. I have also experience what Rob described and perhaps what you are experiencing. I read that's it blush that interferes with the drying of oil based paints and varnish. Your epoxy needs a good week to cure and then you should give it a good scrubbing with an abrasive pad and detergent and water. Even then it's not a bad idea to try a small square as a test. I usually finish a boat early spring and I paddle it a few times and it's actually many weeks before I varnish since I want the weather to warm up so I can varnish in my garage in CT.

The time it didn't dry for me was on my first boat - a chesapeake LC deck. I had to wipe it down with solvent and wash it good let it dry for a week and start over. It wasn't Epifanes either.