I tried an epoxy on a cracked plastic Shindaiwa tank, didn't work. I finally took a soldering iron, tank empty of course, and melted it back together, fixed it.
/ whats the best way to fix a crack in a fuel tank?
I have repaired more than a few plastic tanks with polyurathane caulking. Clean with thinner and glob the caulking generously to cover the damage or cracked area. Also a good idea to stop drill a crack at both ends.
One brand is FLEXTRA and if you can't find that brand windshield adhesive (sold in tubes) would do the same work.
On a steel tank steam it thoroughly, blow lots of air thru it to remove any vapors and braise the split or hole.
Acid core solder and a hot soldering iron can also fix a steel tank.
For a pin hole type of leak you could use leather or plastic washer with a self tapping metal screw.
Most plastic tanks are PVC and epoxies just will not adhere no matter how rough you sand the surface.
Hot soldering iron and blending the PVC and or adding PVC (aka hot glue gun sticks) also works.
/ whats the best way to fix a crack in a fuel tank?