I am new to the list, but am actually building my forth strip boat. I am using a spar urethane that has worked out well in the past. The first coat on the outside of the hull dried beautifully. On the inside of the hull it remained tacky. I tried extra heat, fan, more time. Made no difference. Finally, I scraped it off, and re-did a trial section. It remains tacky. I can take the same varnish and do a section that dried previously and it will still dry to touch in half an hour. One possibility is that the problem originally was related to too low a temp because I work with a kerosene heater in a garage, or it could have something to do with the epoxy cure. What can I do to get it to dry hard? This is driving me nuts, any help would be greatly appreciated