All Corsa Forum banner

1 - 4 of 4 Posts

1,000 Posts
Discussion Starter #1
HOW TO: Rust removal using Electrolysis

How Wikipedia discribes electrolysis

In chemistry and manufacturing, electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell.

Basically its a chemical reaction that can break down certain molecules into separate atoms, making it a good way of removing rust from ferrous metals.

so science lesson over,
what you will need.

1. a plastic water tight container.
2. a 12v DC car battery charger (overnight trickle chargers are not really man enough)
3. some 8AWG amplifier cable
4. four old pieces of steel plate 1.2mm thickness works best
5.calcium carbonate (found in baking powder and washing up powders)
6. a bucket with markings in gallons

The method

firstly set up the container big enough to hold whatever it is that is being cleaned with the four sheets of steel plate, one on each side and connect together with the 8AWG cable.

then place the item to be cleaned inside the container making sure it does not come into contact with any of the four electrodes (sheet steel) and connect a piece of cable to the item (for heavy rusted items must be cleaned with a wire brush to insure good contact)

below is a diagram of what the setup should look like

once setup you now need to add enough water to the plastic tub to submerge the item being cleaned, making sure you count how many gallons of water are needed (this is where the bucket with gallon markings is handy).

once the plastic container is filled with the right amount if water you need to add the calcium carbonate, (i use vanish stain remover powder as it has a good concentration of calcium carbonate) the powder should be measured out so for every one gallon of water used one table spoon of powder must be added. this just needs to be poured in, (the water will go a milky color)

PLEASE USE APPROPRIATE PPE WHEN MIXING, SAFETY GLASSES, GLOVES AND SOME OVERALLS, (The mix is not especially dangerous but most washing powders are and irritant and splashing the mix into your eyes certainly wont do it any good.) i take no responsibility for you hurting yourself because you dint give a shit and splashed electrolyte all over your face.

the setup should look a little like this

then you need to connect the battery charger, (do not plug into the mains at this point). the positive clip attached to the wire attached to the steel plates and the negative to the cable attached to the item to be cleaned (shown in the above diagram)

now it is time to plug in the charger and turn on the power. (don't worry nothing will go bang if you've connected it all up properly)

the reaction will start and eventually you will start to see a series of bubbles start to rise from the surface of the item being cleaned, and start to create a light brown froth on the surface of the water. now its time to find something to pass the time and let the magic happen, depending on how heavily rusted the item is will depend on how long it will take, my items took around 4 hours each. don't be afraid to lift the item out every few hours to see how its getting on, (just don't use bare hands) a set of grips will do fine, the power should be switched off when doing this to avoid any surges caused by accidental contact between the part and the plates.

when the item is clean the surface of the part will be a black colour, (asif someone has just painted over the rust) remove the part and give it a good going over with a wire brush the black (reacted rust) will come away easily and leave a nice clean bare metal surface.

once done dry the item a quickly a possible and get a coat of etch primer on it before it rusts again, you may find when drying the item a orange coat of rust will appear all over the surface, just keep drying once the item is dry another quick once over with a wire brush and it will come up clean as a whistle.

here are a few photos to show my results

item before

item after drying (notice the black color on the ball joint this is what the entire surface will look like before the wire brushing, i never bothered to brush the ball joint as its being replaced.

and after dry and clean

the black marks on the hub are grease, the chemical reaction will not remove things like grease and paint, this has to be removes by other means IE a wire brush or sand blasting.

Premium Member
15,222 Posts
Really interesting guide that. Nice one.
1 - 4 of 4 Posts