From The Flickr Pool: De-Rusting Old Hardware

Toolmonger reader and photo pool member Tracy posted a series of photos demonstrating the process of electrolytic rust removal — using an iron (or stainless) electrode and small amounts of electrical current to convert rust to a smaller molecule that binds to the base metal.
Tracy’s a regular reader, so if you’d like to know more, just ask in comments — or try a Google search. There’s lots of information available as rodders and restorers have used this technique for years.
Toolmonger’s Photo Pool [Flickr]
Electrolytic De-Rusting [Google]
This works wonders for old rusted tools as well. I have salvaged several sets of rusted tin snips with ERR.
This is a good site with links to more explaination.
http://www.davidbradley.net/ERR.html
Hey, my pics are on toolmonger again. cool. 🙂
This process scales up quite easily. I used to keep one of those big blue plastic rain barrels (20 gallon?) in my shop full of the soda/water solution. I used it to derust all sorts of things, including motorcycle exhaust pipes.
It’s also a good way to derust motorcycle gas tanks. You can close the fuel tap and fill the tank with the solution, then use a peice of rebar as the anode. A funnel will keep it from contacting the sides of the tank opening and a bit of electrical tape wrapped on the tip will keep it from touching bottom. No container needed.
A couple more pages of info:
FAQ:
http://www.bhi.co.uk/hints/rust.htm
The chemistry of why this works:
http://www.holzwerken.de/museum/links/electrolysis_explanation.phtml
Making a power supply for derusting out of a PC power supply:
http://buncombe.main.nc.us/~mikel/derust.html