Just a couple of quick useful things:

[Lucky]

"SEAL ALL"  available  at hardware stores will patch fuel tanks & welch plugs.

fiberglass is fine to patch fuel tanks with, Marine fuel tanks have been made of fiberglass for years. Ethanol degrades fiberglass resin (sorry Inane...)  ask any boat yard about it, you'll get an earful!

--Lucky

[Walt_M.]

Thanks Lucky, I have some seepage on the roach and I don't want to weld it.

[sunburnedaz]

Thanks Lucky, I have some seepage on the roach and I don't want to weld it.

Why not weld it? I have always thought that the best way to join 2 bits of metal was welding. Well really my preferances kind of go.

1. Welding
2. Brazing
3. Mechanical fasteners
4. Soldering
5. Epoxy
6. Glue (The right kind for what you are doing non of this crap like wood glue on plastic)
7. Tape

I even picked up a plastic welder and have plastic welded sport bike farings back together better than new.

[inanecathode]

JB weld works just fine on the tanks. I've had it on there for a couple years and quite a few thousand miles, not a seep.
The patch that was on there was leaking though. Some kind of tank sealing putty. Gas just seeped right through it.