Speaking of moisture getting into the tanks, I once watched a tank monkey put all of the tanks in the water, aluminum tanks tend to float bottom up, then attach the fill whips and open the valve. This blows the water that was between the k-valve and the whip into the tank. That might explain why I only got a few years out of my first set of 72’s.
There was (RIP) also a NJ LDS that wasn’t doing PM on their compressor and had a reputaion for pumping water into tanks