Introduction: Electrolysis for Rust Removal – Coffee Container

About: I like to design and build random things.

I’ve recently started the restoration of an old truck. As part of the restoration, I need to remove rust from many of the parts. I’ve read multiple blogs and instructables on this topic so I thought I would give it a try. For a proof of concept, I made the simple almost free version (minus the battery charger) shown here. I plan on building a large scale version similar to the others shown online in the near future.

Video of the Process:

Step 1: References

I’m not going through the detailed process or the FAQ since I think they have been covered in the referenced links pretty well. This instructable just goes through the small scale build. I strongly suggest you read the referenced material before building your own setup.

Instructables:

Other Resources:

Step 2: ​Tools/Materials:

Tools

  • Drill & Bit
  • Scissors

Materials:

  • Battery Charger
  • Coffee Container (48oz)
  • Washing Soda
  • Zip Tie
  • Plastic Sheet
  • Wire
  • Electrode (sacrificial metal)
  • Work Piece (rusty part)

Step 3: Container Build

If you follow me, you might know that I recently acquired a large trove of plastic coffee containers. I’m almost out and I’ve been told by the wife to stop bringing them home. Anyway, this container works great for small parts and was perfect for my small scale test.

Step 4: Electrode (Sacrificial Piece of Material)

There is an old railroad track running through my town that is being converted to awesome project known as “rails-to-trails”. Walking the track, you can find steel railroad spikes that have been discarded over the years. I thought these old rusted relics would be perfect test pieces. If you can’t find spikes, use steel angle brackets, rebar or any other old piece of steel that will fit on the side of the container.

Step 5: Electrode Attachment

There is an open spot in the container between the handles which is perfect spot for the spike. I drilled 2 holes in the upper side of the container for a zip tie.

Step 6: Zip Tie

Use a zip tie to attach the spike to the container.

Step 7: Protection

To ensure that the electrode and work piece didn’t make contact, I used a plastic sheet (divider from a notebook) to cover the electrode.

Step 8: Add Protection

Cover the electrode with the plastic sheet. Note that it fit nicely between the handles and was held in by friction – no fastening required.

Step 9: Mixture

Fill the container with water. This is small scale (48oz container) so the laundry soda content is pretty small as well. Using the guidelines from the references, I decided 2 teaspoons would do the job.

Step 10: Battery Charger

This version has 3 settings (6V/6A, 12V/2A, 12V/6A) and cost about $30 from Amazon.

Step 11: Hookup

Connect a wire to the work piece and then to the negative terminal. I assume you could leave the negative terminal in the water but I wasn’t sure of the material and didn’t want to damage my charger terminal. Place the work piece in the container. Make sure it doesn’t come into contact with the electrode. Connect the positive terminal to the zip tied spike. Make sure the terminal isn’t in the water. Note that I used the 12V/2A power setting on the battery charger.

Step 12: Process

For safety reasons, move the setup to a ventilated area. Turn the charger on and wait. If it is working, you will start to see bubbles coming off the work piece. I ran the test for 24 hours and most of the rust was gone. I left it for another 24 hours and the work piece turned totally black. The electrode spike had a 1/8” thick layer of rust around it as expected. Note the rust in the on the top of water. There was also a decent amount in the bottom of the container.

Step 13: Cleanup

I used a scouring pad to scrub off the black layer. It washed up pretty easily.

Step 14: Final Pictures

Here is a comparison of the two pieces after the test.

Step 15: Electrode

Notice the rust buildup on the surface.

Step 16: Work Piece

It came out of test with a black layer. I scrubbed it under running water and this is the final result. The test worked as expected.

Step 17: Paint

I have no need for a railroad spike but I spent the time “de-rusting” it so I gave it a quick coat of black paint and then gave it to my daughter to paint.