Electrolysis

This is one of the neatest things I've stumbled across, and it works for more than just gas tanks! So, the inside of this tank was obviously rusted, being a '71 and sitting for god knows how many years. I decided to try the electrolysis method I had seen others do. Well, it definitely works, and very well. Here is a picture of 1/2 the rust that came out of the tank (did it twice).