Motorcycle Repair: Restoration, cushman eagle motor scooter, tank leaks

Question
I am restoring a fuel tank from a 1952 Cushman Eagle Motor Scooter. The inside was coated with a brownish material ( I assume to stop leaks). The tank leaks on the bottom front frame mount. It appears that the frame mounts were spot welded on the bottom of the tank before the two sections were joined to make the fuel tank. It is leaking at this spot weld under the tank frame mount.
QUESTION:
Should I cut the entire L bracket section out and have a new section welded in? Or should I braize around the mount to avoid messing with integrity of the Tank? Thanks for your help
Bill

Answer
Bill, I think you have to determine how strong that mount is and if it will work loose in the future. You probably can't really tell if this is just a vibration crack around the spot weld or if there is more extensive rust/corrosion underneath.

First, of course, the tank needs to be flushed thoroughly to get old fumes out of the inside. If the tank is coated you will have problems, once you fire up the torch for brazing. The coating is just a solidified plastic and will begin to melt/burn as soon as it gets heat to it. This can start a fire all on its own. Most coatings can be removed by pouring MEK inside, which is also a pretty dangerous toxic chemical, but you should try to remove the coating before making repairs.
If the leak is just a pinhole type, perhaps cleaning the tank inside and recoating it will solve the problem, at least for awhile.

Bill Silver