Experiment 8: Electrolytic Rust Removal

Electrolytic rust removal is very helpful for removing rust from ferrous objects, as it does not damage the underlying metal and is quite a good "lazy" method.  I had some rusty railroad spikes (no, I did not steal them from an active railroad - October Sky), so I tried this method on them using my lab power supply from Experiment 7: ATX Computer Power Supply Conversion.  To actually remove the rust from the spikes, I poured one gallon of water and one tablespoon of washing soda (not baking soda or baking powder) into a bucket and stirred.  For my anode, which connected to the +12V terminal and is eventually eroded away, I used a flattened out wall of a steel soup can.  The cathode, which the rust is removed from, was obviously my railroad spike.  After I connected the +12V and GROUND terminals, I made sure that the leads got good connections to the electrodes by testing for a voltage drop with my voltmeter.  The voltage should drop if the electrolysis is actually running.  Every so often I turned the spike around to ensure that the anode had a good "line of sight" to all the surfaces.  Note that while it is fine for the black GROUND wire to be submerged, you will destroy your positive lead if you submerge it.  Once I saw that all the corrosion on the spike had turned black, I took it out of the bucket and scrubbed it off with a bristle brush.  After that, I washed it with hot water to warm the piece, and after drying it with towel, let the stored heat dry off the residual water.  I got some very nice results, so here are the before and after pictures: