07-09-2021, 09:01 AM
The tank is repairable, with the right skills of a good experienced welder/fabricator.
First, any residual fuel vapors need to be neutralized or evacuated with compressed air before any drilling/grinding or welding.
The mounting ring is 2mm thick. It was drilled, stamped, and six 6mm "bolts" dropped into holes and tack welded in place. The mounting ring is then spot welded in place in 6 locations onto the bottom of the tank.
If you drill through the stud, you are basically drilling through the bolt's head, about 2.5-3mm thickness, not the mounting flange itself. If you were able to thread it, using a bottoming tap, you would have at most 2-3 threads catching.
The raised portion of the mounting ring needs to be perfectly flat and even to let the gasket seal properly, so remember not to apply much force with the centerpunch or the drill bit.
I would recommend very carefully cutting out a section of the flange with a cutting wheel so you can put the piece in a vise and properly replace the bolt and weld it in, before welding the section back into rest of the flange. That ensures it is flush and level.
First, any residual fuel vapors need to be neutralized or evacuated with compressed air before any drilling/grinding or welding.
The mounting ring is 2mm thick. It was drilled, stamped, and six 6mm "bolts" dropped into holes and tack welded in place. The mounting ring is then spot welded in place in 6 locations onto the bottom of the tank.
If you drill through the stud, you are basically drilling through the bolt's head, about 2.5-3mm thickness, not the mounting flange itself. If you were able to thread it, using a bottoming tap, you would have at most 2-3 threads catching.
The raised portion of the mounting ring needs to be perfectly flat and even to let the gasket seal properly, so remember not to apply much force with the centerpunch or the drill bit.
I would recommend very carefully cutting out a section of the flange with a cutting wheel so you can put the piece in a vise and properly replace the bolt and weld it in, before welding the section back into rest of the flange. That ensures it is flush and level.