I'm not convinced that you necessarily have crevise corrosion as, unless you're running about with your tanks pressed up at all times, the environment is not anaeroebic. I'd investigate further as to what exactly is bubbling and, if it is crevise corrosion, I'd sand, treat with ospho, and seal with epoxy. It beats the joys of removal. The tank may well already have a coating and that may be what you're seeing fail at the welds-it's the most likely spot for any type of failure regardless.
“Scientists are people who build the Brooklyn Bridge and then buy it.”
Wm. F. Buckley, Jr.