While on the subject of rust removal. I use washing soda (here in SA called "Electric Soda")instead of carbonate of soda (baking soda). The action is identical. The part that corrodes away is not the object you put in there to clean - but a piece of old steel connected to the positive terminal of the battery charger. This eventually decomposes and falls to the bottom of the tank. The part you are cleaning (connected to the negative terminal of the charger),is cleaned by the action of hydrogen forming under the rust or paint particles and lifting them off. Best not to be smoking when you lift off the lid. I run mine at 1 or 1.5 amps - which you can vary by shifting the positive away from the negative. This process is the safest of many ways to clean metals. I have tried both molasses and bread. Both worked - slowly, and in the case of bread - smelly. I found the paint on chemical means a bit messy. I do the rest as per Jeff49
Stationary
