Brian
I think you can fair it with Epoxo 88 if not too large of an area. I have used this stuff on aluminum before. Great adhersion, sand and cold tar/zinc chromate afterwards. Maybe this would be a less expensive alternative? Be sure to wire brush & clean the pitting areas real good first before you mix it. You only have 6 mins to work with so a little at a time. Maybe a pressure test would be in order.
A new tank might be your best bet..................Good Luck
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