If you go with epoxy it usually only takes a few drops of alcohol to thin it.
Epoxy brushes, same as flux brushes used by plumbers, cost a lot
http://www3.omnimodels.com/cgi-bin/w...I=GPMR8060&P=7 are 30 cents each
http://www3.omnimodels.com/cgi-bin/w...I=GPMR8062&P=7 are 15 cents each
I bought a bucket of cheap paint brushes at a Hobby Lobby store that work well for this stuff. They were on the children’s art aisle and cost was 4 dollars for 144 brushes. This was a couple of years ago so they may or may not still be available.
If you want color on the wood, Top Flite LustreKote seems to be pretty fuel proof.
Cub Yellow
http://www3.omnimodels.com/cgi-bin/w...I=TOPR7518&P=0
Primer
http://www3.omnimodels.com/cgi-bin/w...I=TOPR7527&P=0