William, Eric,

I have suggeted this before-some said it wouldn't work, but I've done it for 15 years, and NO PROBLEM.
Get the least expensive thin CA you can, (sometimes you can get a yellowing bottle cheap from your LHS) and squeeze it in the tank/firewall area. Fuel proof up to about 20% nitro, and you can get it everywhere.
KEEP YOUR FACE AWAY FROM IT WHILE YOU ARE DOING THIS!
It will fuel proof EVERY nook and cranny.

Jetts