This is the used tank (as seen in my avatar). It decided to spring a leak.
Upon further inspection I discovered previous owners quality work in leak repair. Looked good until i put it on the bike and let the gas thru the leak. Now i know why i got a good deal on it. Can only blame myself for not inspecting closer.
Nevr would have broken if the thing was mounted properly... Never put one of those tanks in a bind...shim and check...not draw tight... or...Weld and repair!!! BTW, that looks like a 5 gal bob tank...what FX is that on??
Welded many a tank tab back on and my favorite is the stud mount on the inside that cracks. How are you cleaning the inside of the tank before welding ?
Myself, I've always used some Tide Liquid laundry detergent and really hot water. May have to do this a couple of times until the gas smell is gone. Then a couple rinses with hot water again to get the soap out and weld away.