This is a really easy method of rust removal. I have used it a lot and it works very well. I'll try and post some before and after pics over the next few days.
Regards
Stewart
Electrolytic Rust Removal
The process will remove rust, grease and paint from steel or cast iron parts. The process is extremely effective if the points below are followed. This process is self-limiting and will only remove rust.
Safety First
The bath must be inaccessible to children.
If using caustic soda, the solution must not touch your skin.
If using caustic soda, the bath should not be inside or in a closed area.
Container
Any type of container is suitable provided it will remain watertight during use. Steel containers should have a plastic sheet inserted before filling. Plastic containers must be strong (ie plastic rubbish bins tend to split). Obviously, the container size limits the size of the part to be cleaned. Large parts may be cleaned one half at a time.
Solution
Carefully and slowly add caustic soda flakes into warm water and stir until dissolved. You will need approximately two kilograms of caustic soda for 20 gallons (91 litres) of water. For smaller amounts mix one tablespoon per 1 gallon (4.5 litres) of water. Another solution that is less harmful, non-polluting and biodegradable is washing soda available at the supermaket or hardware store. (Not the same as laundry detergent)
The caustic soda or washing soda may be dissolved in cold water but allow 24 hours for your bath to start working effectively.
Electrodes
The part to be cleaned is connected to the battery charger negative. Battery charger positive is connected to a piece of steel about 3”x3” when using a 44 gallon drum. If using a steel containing make sure you line it with plastic. You virtually have to use a battery charger with an ammeter (or amps indicator) as the current flow is controlled mainly by the size of the piece of steel (positive electrode). The best method of controlling the battery charger is to initially leave the positive electrode out of the solution, turn the charger on, then carefully lower the positive electrode whilst watching the ammeter. When the ammeter shows a reasonable reading (to suit the rating of your charger) support the electrode to suit.
If you wish to clean only one or two small parts and elect to use a 2 gallon plastic garbage bin (9 litre bucket) a smaller piece of steel or large 3” nail would suffice for the positive electrode.
It is important that for both electrodes a good electrical connection is required. From time to time you will need to clean electrode connected to the battery charge positive. After a few uses it will probably need to be replaced.
Electrode Support
At least one of the electrodes should be supported from a piece of wood so that electrodes do not touch.
On completion
Parts can be left for 24 hours. Rusted areas converted by electrolysis will be black in colour. Rub down with wet and dry or wire brush. Parts will be now be very prone to rust again unless treated immediately, spray with WD-40 or paint parts.
After about a minute you should see some tiny bubbles coming from the part. Bubbles are good...
