I have taken a test panel and poured straight fuel on it (I use 10% nitro) and left it overnite. After 24 hours the poly was a little soft, but not much. I feel that I am not going to let my planes sit with raw fuel/fuel residue on them for 24 hours, so there should be no problems. I have also done the same with clear ACRYLIC lacquer. The lacquer was also a little soft after 24 hours, but not as much as the poly. The most noticeable part was a slight "dragging" of the cloth when wiping off the Windex.

I have not tested it with higher nitro and I do spray 2 thin coats on. If you are unsure, do a test panel and see for yourself. I normally let the final coat of poly dry about 8 hours before exposing it to fuel.

I paint with latex and use the MinWax Polycrylic for a clear coat. I have not had any problems in 1 1/2 years using this method with the fuel damaging the paint.