Electrolytic Rust Removal

Electrolysis can remove rust like magic. I had read about this several times, and finally decided to give it a try on a recent project. I was restoring an older cuckoo clock and found that the battery had been left in, and severely corroded the battery tabs. These small rusted parts would be perfect for my initial attempt at electrolytic rust removal since first of all they were obviously rusted, and secondly they were in a fairly delicate state which prohibited any other type of cleaning.

This was a small setup, and could easily be modified into a large one for bigger parts. I could easily see a 10 gallon fish tank and battery charger for cleaning up some vintage tools.

Items Needed.

Plastic container

Baking soda

electric supply

wires

water

scrap steel or iron ( rebar? )

hopefully this is at least somewhat informative, as the process is both amazing and simple.

Making my first INSTRUCTABLE was harder than playing home chemist. ...enjoy

Step 1: Get a Heavily Rusted, Corroded Item.

This is a fantastic way to remove rust and oxidation from steel and iron. It is not recommended for brass, aluminum, copper or exotic metals and alloys.

Step 2: Get Ready to Combine Items

You need a non conductive container. In plain terms...plastic or glass. I used the bottom half of a soft drink bottle.

Step 3: Make Your Electrolytic Solution

Put your water in the container

To the water add baking soda. I used roughly 1 tablespoon per gallon of water.

Step 4: Add Electricity

since i was cleaning a small part I only needed a small supply of electricity. I chose a 9v battery

From the battery I ran a hot/positive and cold/negative lead

larger items in a bigger solution vat would need a larger supply of current. A common household battery charger would be ideal.

Step 5: Making Your Anode

Your anode is your sacrificial lamb in this process, and gets connected to the positive/red/hot side of your electric supply. The amazing process of electrolysis will erode the anode away over time. I used a scrap nail for this. Again small parts here.

I think in a large setup a piece of flat steel or maybe some rebar would work well. You want surface area here for best results.

Step 6: Connect Your Part

Now the part to be cleaned gets connected to the cold/black/negative terminal of your electrical supply

Step 7: Put It Together

Anode into the electrolyte solution ( water & baking soda)

Step 8: Part Goes In

finally the rusted part goes into the solution.

Step 9: The Magic Begins

you will see an immediate bubbling from the rusted part and the anode.

Step 10: Just Watch

bubbles are good, it means it is working as it should.

Step 11: Grand Finale

The rust and corrosion just flake away as the bubbles do their magic work

Step 12: Enjoy Your Final Result

I went from totally rusted, non conductive battery tabs to almost shiny ready to use perfectly conductive tabs.

* the black film can easily be cleaned off with a slight abrasive such as a scotch brite pad

* make sure you treat the newly cleaned metal asap since it will easily and quickly begin to rust again.

Comments

[armorer243]

Well written instructable! I will also recommend washing soda for the elctrolyte instead of baking soda. I have used both and although the baking soda works, washing soda works a bit better. I did a restoration on a South Bend metal lathe and used electrolysis for not only rust removal but grease, oil, paint, and general grime and grit removal as well. Just keep the nonferrous metals out of the bath and it works great. Thanks for the write up!

[wobbler]

I've actually used it to strip paint off and clean diecasts as well with no issues, though it might need a couple of goes depending on what type of paint and some types of paint it doesn't work with. Never tried it with aluminium though but that's because I've never needed to. It does clean brass though really well and it comes out looking polished.

Although it's often referred to as electrolysis and people often think the rust is being transferred, what is actually happening is that at the positive the water is releasing oxygen, which is why it rusts and at the -ve it is releasing hydrogen. Because the hydrogen doesn't react with the objects on the -ve, this then effectively shot blasts the surface and anything attached to the surface is blown off by the bubbling hydrogen. That's why it also works with brass and the donor still goes rusty!

[reitaka18]

Great instructable, thank you.

One question, what do you do with the water afterwards? Can you use it again for other rusty things? or do you need to start over?

Thanks

[wobbler]

Bit of late reply, but I reuse the water. It will look really scummy while it's in use but the rust and gunk just settle to the bottom to leave the water clear again. I just leave it there and put in other things when needed. I never bother replacing the soda either, seems to be OK.

[wobbler]

Great Instructable.

Old soup or beans cans make a cheap and easy to use donor. Just cut them out into a flattish plate using tin snips. You can also make a flap out of the bottom to hang over the side of a bucket and then attach the +ve wire to that. I use crocodile clips to attach the power, but attaching them outside of the water to the can has the advantage of not rusting up the wire or clip.

If you setup a bucket just for this, you also don't need to get rid of the water every time as the gunk will just settle to the bottom and you can just bin the tin and reuse it. It's also easier that sandpaper, etc., gets into nooks and crannies, cheaper than paint stripper and environmentally friendly enough to just throw down a drain.

There's a bit more about how I use it in my G.I. Roe project.

[KenC138]

Hi, I love this instructable. I have played a little with this before but it was for hho or brown gas(hydrogen gas). I am trying to remove some small rust spots from an old metal purse frame (making my own case with it) and I’m not sure what it is made of, it seems to be Crome plated. My thought is to use the electroplating to remove the rust spots. Then turn around and electroplate the whole frame again to seal the frame to prevent future rust. My question is....

-How do I remove the rust without damaging the existing Crome coat on the frame (again I’m not sure what it’s made of)?

-Would it be more advisable to solder additional frame work before or after? The concept behind this is a Faraday cage/RFID blocking for cards ect. (Yes I am aware that this will likely block incoming and out going signals-that’s kinda my point)

-How to possibly re-electroplate/Crome (after removal of rust) the frame over the existing Crome?


I apologise, my question at the beginning seem to be much more simple at the beginning but as I kept typing it quickly became more complex. I really appreciate any help or directions on this.

Thank you
Ken

[DavidS1168]

Worked completely, thanks for the tip. I used a Professional power supply that probably was overkill but the 32v 3A did the cleaning very fast !!!

[mrygula]

you could put a piece of brass in there and coat your cleaned metal with it

[wold630]

Great info, thanks for sharing!