I really must apologize. It has been a number of years since I have painted urethane over enamel and I plain got mixed up. The reducer used in the urethane paint is much stronger than enamel or old lacquer for that matter, it will eat through the underpaint and lift---bad! So use 1 part clear and 1 part hardener and you will be ok. Remember do a small test panel first to ensure the paint will not lift. No if memory serves me, I'm in the middle side of 60, you can really pour on or I should say heavy coat the clear mixed this way and it should not run. I have intentionally orange peeled the paint and it flows together nice. Takes a long time to cure unless you use heated lamps, then paint it like normal don't lay it on really thick. Medium coats will work fine. And the finish is smooth like glass.