... it will eat through anything: mountains, plains, even water heaters. Clearly, this one had been ignored for quite awhile. Likely the pipe leak was a result of a faulty solder job. The "flower" you see at the joint is a combination of corrosion and mineral buildup. Sometimes, this will plug the leak -- at least until the next time the pipe is disturbed.

The cover of the tank is painted, but drip long enough, and it eats through the paint, then through the steel. And then ... Well, nobody can be certain. Under that maw of rust and fiberglass insulation, the tank may still be sound. Or not. Water pooling on the tank, or in the threads of the ports, can bring it to the point of no return.

Generally, we like saving water heaters, but it's embarrassing when one breaks right after we've worked on it. This is not one we would touch.

Best not to let it get to this point. Unions or flex lines should be checked six months after installation and tightened if there are signs of leaks. Badly soldered joints should be disconnected and resoldered.

If you don't ignore your water heaters, you won't ignore drips, either.