Introduction: Electrolysis for Rust Removal – Coffee Container

Picture of Electrolysis for Rust Removal – Coffee Container

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

Picture of 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.


Other Resources:

Step 2: ​Tools/Materials:

Picture of ​Tools/Materials:


  • Drill & Bit
  • Scissors


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

Step 3: Container Build

Picture of 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)

Picture of 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

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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

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

Step 7: Protection

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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

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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

Picture of 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

Picture of Battery Charger

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

Step 11: Hookup

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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

Picture of 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

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

Step 14: Final Pictures

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

Step 15: Electrode

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Notice the rust buildup on the surface.

Step 16: Work Piece

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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

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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.


TunerGeek made it! (author)2017-01-23

I made this with a 5-gallon paint bucket, and spent some time today cleaning it after considerable use. I wire-brushed the sacrificial rebar - after letting the buildup dry out - and replaced my five-piece 12-gauge bare copper rebar connecting wire with a one-piece, 14-gauge one, attached by hose clamps. I also use a piece of 1x3 pine to suspend my electrolizing parts in the water/washing soda solution, with eyehooks. The 1x3 is fitted with a length of 6-gauge copper I had left over from a plumbing project (ground wire to jump the water meter, per code) as a bus... I connect the negative lead from the battery charger to it, and one to five 16-gauge jumpers to the submerged part(s) from it. The battery charger line is *not* connected in my supplied photo, but do note the bends in the 14-gauge connector, which is held in place by hose clamps (which simplifies disassembly for cleaning the sacrificial rebar.)

JordanC4 made it! (author)2016-10-30

This instructable is awsome! I used s nearly identical setup; part of a steering column for the anode, half a 591ml bottle for a shield, and an automotive battery charger set to 10a, but used baking soda as I wasn't able to find wash soda.

I removed corrosion from 14 brackets for fender flares i got from a wrecker. After a wire brushing and primer I finished them with spray on bedliner, they will never rust again!

Check out the anode and thanks for the instructions.

mtairymd (author)JordanC42016-10-31

Thanks. Glad it worked out!

gobs1 (author)2016-06-02

Could you harvest the red rust to use in a thermite reaction?

nabzim (author)gobs12016-06-05

I think it would work. Theres one thing that I think would be important in order for it to work ; you would need do dehydrate the rust. Just let it dry out in the sun, then pulverize it, then heat it up for a while on a stove (to vaporise the remaining water molecules). In fact i may try this myself, since you just made me realize that electrolysis could be a pretty good source of iron oxide for use in thermite...

astrong0 (author)gobs12016-06-02

Red rust it chemically fe3o3. Black rust is fe3o4. You need that extra oxygen to get the thermite to really get going. I've done it with the red stuff but it's not quite the same. If you add it to boiling water you can convert it to fe3o4. Or just buy it.

nabzim (author)astrong02016-06-05

I think you have a typo there, its Fe2O3.

astrong0 (author)nabzim2016-06-05

Oops. Nice catch. Those damn number 2's just scamper away sometimes.

WayneA13 (author)astrong02016-06-03

Why are you talking about "Thermite"?

astrong0 (author)WayneA132016-06-04

Because the person that I replied to was asking about thermite.

andysuth (author)gobs12016-06-02

You may wish to reverse the electrolysis cell, and use a different electrolyte, and use a ferritic electrode you don't mind rusting away to nothing. Just saying.

Parvat (author)2016-06-02

Hi, could I use baking soda (sodium bicarbonate) instead of whasing soda (sodium carbonate)? It´s difficult to found round here. Thanks!

astrong0 (author)Parvat2016-06-02

I personally use magnesium sulphate for my electrolyte. It's Epsom salts, you can use regular table salt BUT IT WILL MAKE CHLORINE GAS! Be smart. You are just making the water conductive, not adding spices for an improved flavour.

rkrishnan7 (author)astrong02016-06-04

If it is just a matter of increasing water conductivity, you can use common salt, but the chlorine gas can be really nasty.

doctaven (author)Parvat2016-06-02

You can make washing soda(sodium carbonate) by heating sodium bicarbonate in an oven for an hour. Or in a crucible with a propane torch.

-- --

WayneA13 (author)doctaven2016-06-03

None of that is necessary, your local pool store, or online stores, sell products for raising the pH of pools, that are 100% sodium carbonate, also known as soda ash. They usually have names like pH+, PH Up, or something similar.

The process is 200 degrees Fahrenheit for about one hour. The products are dry sodium carbonate, carbon dioxide, and water vapor.

WayneA13 (author)Parvat2016-06-03

Go to a pool store, or order online, a product called pH+, it is sodium carbonate, also known as soda ash.

krieglers made it! (author)Parvat2016-06-03

I use soda ash that you use in a swimming pool for the process too

goroberts56. (author)Parvat2016-06-02

I believe the "bicarbonate" component is the reason it cannot be used. Sure it's cheaper and abundant but for this process stick with the "mono-carbonate" version. Fewer side affects and better results.

Cheese Queen (author)2016-06-02

A couple points: you want your work piece suspended free in the solution; if its laying against the sides or bottom this will leave those spots unaffected by the rust removal. If your work piece is a complicated shape, you may need to rotate it in the solution once or twice during the process to get maximal rust removal.

Do not use stainless steel for your anode; there are toxic compounds that can be released- use plain steel by preference.

The gas that is released during the electrolysis is HYDROGEN. This is EXPLOSIVE; do not do this in any enclosed space.

The closer your work piece (the cathode) is to the anode (the sacrificial piece), the quicker the rust will be removed , but if they touch, you may ruin your battery charger.

A 10 amp or larger charger is best for this process; smaller amperages still work, but take much longer.

. The more surface area is exposed on the anode, the quicker the process will work, i.e. several pieces of rebar wired together will work faster than one big chunk. An optimal configuration would be small pieces of rebar or something similar wired together all around the perimeter of your solution vessel, with the workpiece suspended in the center.

WayneA13 (author)Cheese Queen2016-06-03

Hydrogen gas has an explosive range of 4% to 75% by volume of the air in the room, collectively known as "Lower Explosive or Flammable Limit" (LEL/LFL), and "Upper Explosive or Flammable Limit" (UEL/UFL). There has to be enough hydrogen to burn, thus the lower limit, but there also has to be enough oxygen, thus the upper limit. Below 4% there is not enough hydrogen, above 75% there is not enough oxygen.

By the way, the same is true for all flammable gases and liquids. In the case of liquids, there is a minimum temperature which the liquid must attain to produce enough flammable vapor to burn. It is called the "Flash Point" (not the TV series). It is the vapor produced by the liquid that burns, not the liquid itself. Liquids with flash points below 100 degrees Fahrenheit are designated flammable.

mtairymd (author)Cheese Queen2016-06-02

Very good points!

WayneA13 (author)2016-06-03

pH+ is nothing more than sodium carbonate, also known as soda ash. You can buy containers of it from any pool store, or online from Amazon.

mail2me (author)2016-06-02

how about making sure the box of white stuff's name is visble?????

mtairymd (author)mail2me2016-06-03

See Step 2

krieglers (author)2016-06-03

I made one of these many years back, I found the best thing to use is steel plate this increases the surface area there by speeding up the reaction.

Also buy a battery charger with a volt or Amp meter, if you see the needle or gauge starting to red line the is too much material in the bath and the fuse will blow on the charger or your charger will get damaged.

Datawolf (author)2016-06-03

When you connect the work piece you must avoid plunging the wire because the copper may move to the surface of the work piece !

astrong0 (author)2016-06-02

I use this for doing a sort of parkerizing (not sure how to spell it) for a couple of knife blades of mine. I remove the rust the same way to make sure it's gone, then purposefully re-rust it till it's all orange with rust. When placed in boiling water, the orange fe2O3 turns into black fe3O4 and it pretty resistant to the orange rust for quite some time.

IanL13 (author)2016-06-02

How many volts and amps do you think I could use ?

Could I use a 55 gallon plastic drum and a stick welder ?

How much Baking soda would I need if I used 55 gallons of water ?

Thx in advance Ian.

mtairymd (author)IanL132016-06-02

To be honest, I don't know the optimum power level. From research, the "more is better" has been stated in a few links. Others say to use the minimum to get the job done. As for ratios, the online range is pretty extreme. The minimum I found was 3.5 teaspoons per gallon. The max was 1.25 cups per gallon! My setup worked great but I assume there is an optimum point on power level and soda ratio where you would get the best results. Maybe an electrolysis expert (chemist) can chime in with a better answer.

IanL13 (author)mtairymd2016-06-02

Thanks for the information.

mtairymd (author)2016-06-02

Readily available at Walmart in Maryland or you can order it online.

LittlestWorkshop (author)2016-06-02

You should perforate your protector sheet. It will still work as required but there will be more current paths for quicker and more even results.

Good point.

andysuth (author)2016-06-02

Or reverse the polarity to start making rust "for whatever reason" you might want rust for.

kithmo (author)andysuth2016-06-02

Rat look.

andysuth (author)kithmo2016-06-02

Sorry Keith, not entirely sure I know what you mean.

Could you please elaborate?

Google rat bike and you will see.

HoneyB12 (author)2016-06-02

Speaking from a very non-electrical knowledge base - Is it safe (correct) to say that the Anode would be the "Away" or the rusty piece we are trying to clean up, and the Cathode would be the "Catch" piece or the sacrificial item? Electrical pixies have always give me the slip :-)

No, the workpiece (the piece being cleaned) is connected to the negative terminal so is the cathode.

HoneyB12 (author)2016-06-02

Speaking from a very non-electrical knowledge base - Is it safe (correct) to say that the Anode would be the "Away" or the rusty piece we are trying to clean up, and the Cathode would be the "Catch" piece or the sacrificial item? Electrical pixies have always give me the slip :-)

cjohnson148 (author)2016-05-21

how did you keep the electric from flowing back into the charger? doesnt this make a complete circuit the ground being attached while its running and water being conductive as well as your positive being in the equation?

goroberts56. (author)cjohnson1482016-06-02

If any circuit is open current will not flow (pretty much the definition of a switch). The objective to any [sound] design is to affect what is being used as the load and not the circuit providing the power. Ohms Law. Check it out.

gm280 (author)cjohnson1482016-05-21

cjohnson148., Yes, it is a complete circuit but an electrolysis circuit. That means the negative electrode is allowing electrons flow from the negative side to the positive electrode and taking the rust with it. It is a current flow issue and it works very well. It is similar to electro plating with things like copper, zinc, silver, gold and chrome most any type metal plating, but in reverse. In this circuit you are using the process to remove the rust and collect it on the positive electrode. Easy peasy!

Jax69 (author)2016-05-28

Great instructable and I've used this on a larger scale (motorcycle gas tank). One warning that I was given is make sure you aren't smoking or have any flame near this project as the bubbles given off are hydrogen gas that is extremely flammable. I didn't test this but took the warning to heart.

mtairymd (author)Jax692016-05-28

Thanks. I was thinking a gas tank would be the perfect application since you cannot get to the inside with typical mechanical methods. Yes, hydrogen buildup could be a problem. I did it outside on a covered porch.

andysuth (author)mtairymd2016-06-02

Fuel tanks are often made from tern, be aware of unexpected results with reverse electrolysis.

Mjtrinihobby (author)2016-05-23

very cool instructable! I love it.

mtairymd (author)Mjtrinihobby2016-05-23


cjohnson148 made it! (author)2016-05-23

made this and it works like a charm thanks man

About This Instructable




Bio: I like to design and build random things.
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