RE: fuel proofing?
Nothing wrong with thinned epoxy EXCEPT that it's alot more ($$$) than a clear POLYURATHANE that you can get at any K MART,WALMART, MENARDS or any hardware store.That's right-it's cheaper & works just as well.
And when your muffler comes loose you will find out why it's a MUST to seal raw wood with the epoxy or polyurathane.