Electrolytic Rust Removal
Jim Becker, October 2002
Required materials:
The set-up is as illustrated above. The NEGATIVE lead of the charger is connected to the part you want to clean. The POSITIVE lead is connected to the iron anode. Preferably, the entire part being cleaned will be submerged in the electrolyte at one time. The negative clip from the charger can be submerged. Submerge as much of the anode as possible in the electrolyte. Do not submerge the charger's positive clip.
Mix the electrolyte solution using one tablespoon of washing soda or TSP per gallon of water. Water that is lost to evaporation or electrolysis can be replenished without adding more TSP.
Watch the ammeter to make sure current is flowing. Any adjustments you make to increase the current flow (to the limit of the charger) will make the process go faster. Moving the electrodes closer together or increasing the surface areas will increase the flow. Occasionally cleaning the anodes will help as well.
After the rust is gone, there will be some black residue remaining on the part. Wash any remaining electrolyte off the part. You can then scrub off the black reside with a wire brush etc. Immediately coat the part to prevent rerusting.
Web references:
http://users.interconnect.net/nlindsey/rusty2l/electrolysis/electrolysis.htm