How to Remove Rust Using Washing Soda - Electrolytic Rust Removal

This process of removing rust from steel objects is relatively safe and environmentally friendly.

Instructions

Difficulty: Moderately Easy

Things You’ll Need:

• Battery charger
• Washing soda
• A piece of scrap steel
• Item to be cleaned
• Container large enough to hold the item with space around it

1. Add washing soda Pour enough water into the container to cover the item to be cleaned. Add about a tablespoonful of washing powder per gallon of water and stir until the powder is completely dissolved. Washing soda is sodium carbonate, and is said to be more effective than baking soda (sodium bicarbonate) which may alternately be used.
2. Anode Insert a piece of scrap steel into the container. This will be the anode, which will eventually erode in the process. I use a piece of rebar rod but any scrap steel will do.
3. Electrolitc setup First make sure the batter charger is off or unplugged. Then connect the red/positive cable to the anode. Make sure this red/positive cable clamp does not touch the water. Then connect the black/negative cable to the item to be cleaned and put it in the solution. Keep the item several inches from the anode. It is alright to have the black/negative clamp in the water.
4. Battery charge Once everything is set properly, turn on the battery charger. Small bubbles will appear at the anode and the item to be cleaned to indicate that it is working.
5. A dark scum will eventually form on the surface. Periodically turn the charger off and check on the progress of the cleaning. The length of time it takes will depend on the size of the item, current used, and how badly the item is rusted.
6. When finished the item will have loose scale and dark sludge or gunk on it. Rinse it and use a brush to scrub the stuff off and the metal should have a gray color. If not, put it back in the solution and continue the electrolysis.
7. Once the item is cleaned, oil or otherwise protect it from further rusting.
8. Larger container For larger items it helps to use more than one anode so the process removes rust evenly from all sides. Here is a photo of a larger container I made, using old bent lawnmower blades for anodes that are connected by wire.

Tips & Warnings

• Use proper eye protection and rubber gloves
• Only do this process in a well-ventilated area, preferably outside, as the water breaks down into flammable hydrogen gas and oxygen and keep it away from cigarettes or any open flame or ignition source.
• Make sure the battery charger is off or unplugged whenever the cables are being hooked up or moved, and keep the red/positive cable out of the water.