Playing with electricity: rust removal using electrolysis

After putting my 1965 Giulia TI restoration on hold following my little medical issue I finally got the ball rolling again once winter had set in.

I decided to start with what I was most familiar with; the rear suspension. Having rebuilt the front and rear suspension on my daily driver Spider a few years ago, I knew what to expect. I also have great factory manuals to refer to. BTW, these workshop manuals are available to all ARCO members and cover most popular 105/115 and 116 model ranges.

I proceeded to remove the rear suspension and differential from the car. After taking all the components apart I proceeded with removing all the surface rust and prepping for paint. Half shaft tubes were a little time consuming because of their shape and the parking brake backing plate because of the amount of rust. But the components I was dreading most were the coil springs. Not very easy to wire wheel and sanding by hand was going to be a very long process.

Dismantled differential and suspension components

That’s when I remembered watching a video on Youtube about rust removal through electrolysis. Components were cheap and easy to acquire so I decided to give it a try.

The build is pretty simple. You need a large container made out of non-reactive (and non-conducting) material, some metal for the sacrificial anode, washing soda (not baking soda) and a battery charger.

I used a 20L plastic pail for my container, some rebar for the anode and found washing soda at Canadian Tire. I decided to cut my 6ft rebar into 4 X 18 in. lengths. I wire wheeled the pieces of rebar to ensure they were on bare metal. I then drilled 2 holes in the 4 quadrants of the pail to attach the rebar using steel wire making sure that the wire was going to be above water level. Final step was connecting the anodes together by running wire outside of the pail. Voilà, the assembly was complete.

Complete assembly in use

Next step was to fill the pail with water. I then added about ½ cup of washing soda and stirred thoroughly making sure the soda was completely dissolved. Using a piece of wooden dowel I suspended the coil spring in the pail of liquid making sure it didn’t touch the bottom or the anodes. I connected the negative lead of the battery charger to the coil spring and the positive lead to one of the rebar. I then braced myself half expecting an explosion and plugged in the battery charger. Lucky for me there were no explosions. Unfortunately, there were also no tell-tale bubbles from the coil spring to indicate that the electrolysis was under way. I added a bit more washing soda and still nothing. I took out the coil spring and wire wheeled a small section to allow the lead to make proper contact with the metal. Put the spring back in the solution, plugged the charger again and SUCCESS! After a few seconds the coil spring started to bubble away.

I left the whole thing brew overnight. Next morning I rushed outside even before my morning espresso to have a look at the results. All the rust had lifted away leaving a smooth rust-free surface. The coil spring being too long to fully fit in the pail, I turned it upside down and continued the process. The next day I had a beautiful coil spring ready for paint. Absolutely no effort required.

Left: Before, Right: After

I did the same process for the 2nd spring. Although I did get great results, it took much longer because the anodes had become coated with rust. I quick pass on the wire wheel would have fixed that problem.

Anode covered in rust

I am truly impressed by how easy and effective this method is. Best part is that it doesn’t use any expensive and toxic chemicals. The used solution is non toxic being water, washing soda (which is mined from the ground) and iron oxide.

Some important things to remember; this reaction generates oxygen and hydrogen. It’s important to use a well ventilated area. I put mine in an outdoor car shelter. The process generates enough heat that the solution will not freeze even in -20C weather.

Some modern chargers will detect batteries and not give out current unless plugged into a battery. In this case you need to connect the charger to the battery and the battery to the anodes.

As always, use proper caution when working with water and electricity.

Not that I’m hoping to find more rusted out parts on my car but having done this little experiment, I will no longer be disheartened when I do.

I do hope this article is useful to you and please share your experiences with this process.

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