Hi! I'm finally getting close to completing the construction of the fuselage in my LT-40 build but have a question. I know I need to fuel proof the fuel tank compartment behind the firewall, but have a few questions:

1) Do I also need to fuel proof the engine mounting area (forward of firewall), or is this protected by the covering material?
2) I had thought to use a fuel proof paint, but when I went to the my LHS, they didn't know what I was talking about. I know I can use thinned epoxy for the same purpose, but as I have never done it before, was a bit uneasy about that (afraid I would thin it too much and end up with a rubbery mess). Anyone have suggestions?

Thanks!