I think the big thing with the epoxies, is that the longer you have to work with the epoxy (5 min, 12 min. etc.) the longer it will have to permeate the pores in the wood, which increases adhesion. When you are fuelproofing a firewall, for instance, you need to use a slow epoxy that will take it's time and work itself into the wood and form a good bond. Otherwise, it will fairly easily peel off.
Good luck,
Curtis