Repairing a cub

The gas tank has a 1 inch hole in the top. I was thinking of cutting a square hole where the existing one is and somehow welding another piece of metal there. Someone told me to do this and fill it back in with bondo before painting. Has anyone done this and how has it turned out? Thanks in advance for any help.

Welding the gas tank. Can be done. Remove the tank from the tractor. Rinse out with water - rinse until all traces of fuel are removed. Let the tank air dry with the sediment bowl and cap off for several days. You want to remove all of the fuel fumes. Vacuum cleaner on exhaust for several hours will speed up the drying out process.

I used to teach metal shop and we (students) have welded up many gas tanks. Form a patch larger than the repair hole yet smaller then the filler opening. Put a small hole in the center of the patch. Stick a long piece of wire through the small hole in the patch, crimp the wire below the patch. Fish the wire through the filler hole and back up through the hole to be repaired. Pull the patch tight to the hole. Braze or wire weld the patch to the hole.

For a novice, clean the tank as described, then refill the tank full of clean water, with just a little air right under the patch (patch on top) so you only have a small volume to explode if your cleaning was insufficient.

This also works well on 55 gallon drums you want to cut the top off of or weld a nozzle into.

Your JB weld idea will probably work. If you are an accomplished with soldering that would be an option to consider also.