I saw a video of a guy using electrolysis to remove some rust.

Simple 12v/6A charger, small piece of rebar, empty water jug, and a piece of wood.

My differential cover was coming off for me to change the inner axle seals, so I thought I would put it to the test yesterday/today. Results surprised me!




Before. Really really badly rusted.





During. This is after about 12 hours in the bath.





After. 18 hours. It doesn't come out clean, but this is just after some dry cloth and a wire brush.

 

Here is a shot of 12 hours looking at the cover itself.





After 12 hours. Obviously there was some oil mixed into that rust.





After 15 hours. Really flaking off.

 

Pretty cool. Unfortunately I'd only end up shocking myself...

 

Turn the power off before you touch it lol.

 

The S.S. Hunley was cleaned the same way after it was fished out of the Atlantic some years ago. Put a little salt in water and it will work faster. This is basically electroplating, I use a similar method to build up bearing journals on electric motors with a nickel solution.