Electrolytic Rust Removal and Mopeds

Many times, you'll find yourself with a crusty part that you either don't want to or can't use. In this instance we-re talking about a crankshaft. I've cleaned up several cranks using this method, and it's far better than acid or abrasive - it requires no removal of material. I've used it on many tanks as well - I just finally decided I should do a writeup.

You'll need:

• An inert non-metallic container
• A 12v power source
• leads
• water
• baking soda
• ventilation
• sacrificial iron anode (do not use stainless or alloys - use only plain steel)
• A crusty part

Simply fill the container you are using with warm water and dissolve in about 2-3 tablespoons of baking soda per gallon of water. Attach the negative side of your power source to the part you are cleaning (cathode). Attach the positive side to the sacrificial metal (anode). Make sure that the lead is not exposed and that current is only flowing through the part and the sacrificial anode - not through your connectors to the anode and cathode. In this case, I wrapped wire around the threads of the crank, then insulated it in electrical tape. For the sacrificial anode, choose something long enough so you don't have to put your lead into the solution (rebar and angle iron work well).

It is IMPERATIVE you get the polarity correct or you will rust your part and clean the worthless piece of metal. Also make sure that the two metal objects do not touch.

Plug in your power source and let er rip. Even with the worst things, I find 12 hours does about as much as is going to be done with a strong 12v power source. Please be aware that this setup will produce hydrogen and oxygen gas (it dissociates water) which is flammable. As such you should do it in a ventilated area or better yet outdoors.

The same setup can be used in gas tanks, but the anode cannot touch the tank wall (the tank is the cathode). Once again, electrical tape works well. I've wrapped the end of a piece of rebar in tape and stuck it into tanks before.

Before

The setup

After

Here are some pics of the first crank I ever did... this was 5 years ago.