Outboarder had an article..many many years ago cut a patch out of the tank in a location that is hidden by the flywheel, and pound the dents out.. re-weld patch back in place. It will take time and patience but results can be amazing….
Or so they say, lol. I don’t see why an otherwise-solid tank couldn’t withstand 40 psi.. but dang, wear some protective gear, including heavy-duty eye and ear protection. The freakiest part for me, is the ‘playing of the torch’ flame.. aluminum tends to get really soft, really quickly.. and not in a very controllable fashion.
My thoughts are at 40 lbs and if you don’t have ALL sides and ends blocked in..this thing will look like a balloon. Especially after you add heat and soften the material. Jay Walls when holding a workshop, explained using only 9 lbs, and went so far as to say, Not 8, not 10 but 9 lbs of pressure. I personally have not used air.
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