Cleaning rust with electrolysis

The electrolysis set up before adding water.

Cleaning rust from a relic is fairly simple. First of all you need a source of DC current, car battery charger works the best. You need the simplest one, I use some Polish made, gives up to 20A. I added a photo of a very similar one, it need to be very simple, non digital, with an arrow showing the strength of current. An automatic charger will not work.

You will need a plastic bucket or other durable container.

A piece of scrap metal, I use roof iron plate, bend it inside of the bucket, so it covers the walls, it gives electricity to get to your object from all sides. It will be destroyed in the process. Never use stainless steel or something chromed for sacrificial metal. Chrome will make the solution poisonous. Use as pure iron as possible to clean iron or steel.

I prefer sheet metal instead of rods, it work more effective, gives electricity from all around.

Fill the reservoir and add Calcinated soda (Na2CO3, sodium carbonate) to the water, I get it from a chemistry shop, it allows water to conduct better than usual. Never use table salt or you will get a reenactment of Battle of Ypres, you will get chlorine gas. Using calcinated soda you get only oxygen and hydrogen coming out of the bucket. I use around 2/3 glass of crystals per bucket, You can easily add more, it depends on how strong the charger is, for 6A charger use less, for 20A more. You need to look at the arrow in the process.

Car charger.

You will have two crocodile clamps, (-) goes to relic, (+) goes to sacrificial metal. (-) can be in the solution, but if (+) gets in solution it will be destroyed. (+) usually is on  the red wire.

Attachment point on the relic needs to be clean metal, so file some small spot through the rust to get shiny metal to attach the crocodile clamp. You can make additional wires with small crocodiles on both ends to add more relics, one end attaches to some relic, another to main crocodile, relics can touch each other.

Throw relic in water, it can touch plastic, but it can't touch the sacrificial metal.

Turn on and look what happens, if you are able to regulate voltage turn it on minimal before starting. You may burn down a few fuses before you get it right, so take a charger with car fuses, they are cheap and easy to change.

Bubbles in the electrolysis bath.

For example if the charger is 6A, don't let it go over 5A, if it is too much, take away some water and add fresh water, but don't add soda. If You need more then add soda. I usually turn it on in the evening, and off in the morning. I suggest using waterproof gloves as the rust will turn into very fine black dust. Brush it with a stiff wire brush and rinse with a good amount of water to wash off calcinated soda. To save on plumbing expenses do not pour the used solution in the sink.

Dry it and coat it with something, hot wax, laquer, almost anything that prevents air to get on the relic.

Bayonet that did not get preserved after electrolysis.

All the rust came off the bayonet, but as you can see on this example it was not preserved after the process, so new rust formed almost instantly.