This is a relatively simple, safe and cheap way to remove light or heavy rust from any ferrous object. I used this process to restore an old wood plane that I bought for $1 (it looked totally un-usable because of the rust). As opposed to grinding, heavy wire brushing and acid bath processes, this method removes none of the original steel and is not noisy or caustic.

How this works:

Several other sites do a better job of explaining the chemistry of this - but basically you set up a conductive solution and insert some sacrificial anodes. You hang your rusted tool in the solution and attach it to the negative end of the power supply. You attach the positive end to the anode and turn on the power. The current travels through the solution and in the process flakes off the rust - the flaking/softening occurs because of the reaction at the surface of the good steel that pushes the rust off.

See this site
for more info on the chemistry of it all. (now linked to a waybackmachine archive of the site - modern suggestions for this background are welcome).

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Step 1: Gather supplies

You will need:

This project cost me about $40 because I did not have access to a small battery charger. If you have a charger, then most folks with a decent shop full of crap can do it for almost nothing.

- Clean 5 gallon spackle bucket or other plastic container to meet your size needs
- 5 sections of 18” long 1/2” steel rebar ($5 at Home Depot –
buy in longer sections as needed) (DO NOT USE STAINLESS STEEL)
- 5 feet 12 awg (or so) insulated copper wire in two colors
- 5 yellow wire nuts
- several red wire nuts
- 5 feet pliable tie wire (non insulated) SEE UPDATE on Step 2 - the tie wire rusts out after about a year - you may want to use something more substantial or resistant to rusting.
- Box of washing soda NOT baking soda
- Anti-oxidant goo (IE Noalox – This is not necessary
but helps I think.
- Small battery charger or home made power supply ($20-$50 at AutoZone etc) - Its best if the charger
has a 6v option and an internal "trouble" switch that stops charging if something shorts out.
- Variety pack of alligator clips from RadioShack (unless charger comes with decent ones…)
- Outside outlet or extension cord
- GFCI protected outlet (this is a must in my opinion - working around power and water is stupid unless
you have GFCI protection
- 5 gal water
- misc clamps/small boards
- drill with 1/4 bit
- wire cutting and twisting pliars (linemans tools are best
- wire brush (better if on a grinder or dremel tool)
- anti rust spray or light oil
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I 1st came across this instructable:

And the suggestion box on the side led me to this one. While I dont know if there is a difference in quality in using salt vs baking soda, I liked yours better, being on a larger scale.

Although I wont be doing this project right away since I'm out of work, and get the the material for free, Some things I would different are:

- Instead of using rebar, I would use copper ground rods.

- 1/3 of the way down, and 2/3 of the way down, I would use #8 or #6 solid, bare copper, going from 1 rebar / ground rod to the other, kind of like a cage.

- At the top where you have them all tied together, I would also a use bigger gauge wire.

- Lastly, instead of using a 5 gallong bucket, I would a bucket a little taller (to be able to put long items in it.) I used to have that chlorine tablets came in.

-Optional - if you have 2 12volt car batteries, wire them in series (as seen here)

to give yourself 24volts DC

Just thinking about maximum conductivity, and to have it work faster.

Cant wait to get back to work to get the materials, so I can built and try it out!

Do not use copper rods. The copper will break down and produce some nasty chemicals.
Thanks for the tip. I was trying to think of maximum electrical conductivity. Also, I was looking for an alternative since I believe someone questioned using rebar since it itself rusts. What would you think about using galvanized ground rods?

I have read that you should NEVER use copper, stainless steel, or galvanized in this process due to the mess that copper makes and the noxious substances that come off of the stianless and galvanized.

Like that you showed samples and nice idea for a FAQ section

Well done

davidbarcomb2 months ago

Very nice. Thank you for sharing this

SIRJAMES092 months ago

COOL! I do not understand the science behind it, but I think I understand the mechanics of it.. .

In reference to the size of the object, when I saw the Titanic exhibit in Chicago a few years back, they had a piece of the ship & was doing the same basic process as you did. The piece was about 12 - 15 FEET long, about 24 inches thick & was bubbling like I would venture to say that with all safety measures in place, the size doesn't matter.

so the positive wire(in this case) connects all the rebar?

And the negative wire get connected to the rusty piece you want cleaned?

And the 2 wires/leads/??? are never to make contact with each other?

Is that correct?

planca402 months ago
Could this process be used to remove finishes as well as rust? Such as a nickel or copper?

Yes, but with a but. I'm not exactly a chemist, but I know as much as that when you work with electrolysis and galvanism, how noble the metal is galvanically plays a huge part in how it will perform. It should be pointed out, though, that electrolysis is used to put on said coats on your metal parts, so in theory, doing the reverse should be just as easy.

bahi2 months ago

I've heard of hydrogen embrittlement with this method. Does this happen?

Anyway, superb instructable, thanks.

woodswolf12 months ago

Thank you for mentioning that a by product is hydrogen, highly flammable. :) Hydrogen is lighter than air (think Hindenburg dirigible), so do not do this under any kind of awning or overhang that could trap the hydrogen. I have all the stuff I need to do this, need the time now! The pictures are a great help! It really shows the difference in before and after, just what I needed to convince me to try this! I had an old central power oil well system on my property (1906). I have found dozens of old parts that I want to clean up. Thanks for the great instructions!

profpat2 months ago

i did this to de-rust and old airgun, but i used baking soda for the electrolyte. gave me good result too!

cstaton12 years ago
Hello, I'm currently doing this in the back yard, loosely based on your instructable. What I'm noticing is, with tools with uneven rust coverage, that the areas with the least rust seem to attract most of the electrolysis, leaving the most heavily rusted areas untouched. Have you noticed this? Is there a way to counteract it?

While this method is pretty amazing, you will always be best served to take a wire brush to your rusted tools to get the heaviest rust off before you try this for exactly the reason you state here. The solution has to penetrate to iron to work effectively, and thick rust will hamper that.

TheFrankTurk2 months ago

You had me at "shop full of C---".

pet14152 years ago
I need the name for my science fair please. Great article
Electrolytic Rust Removal is the process.
Washing Soda is also known as ("aka") sodium Carbonate (not bicarbonate, that is baking soda, won't work)
Anode is the POSITIVE (red clip) power type, it goes to the sacrificial part.
Cathode is the NEGATIVE (black clip) or GROUND power type, it goes to the part to be cleaned. The electricity flows from the POSITIVE to the NEGATIVE, so it takes the iron with it and cleans off the junk by the new iron trying to reach the old iron.

Hope these terms help....

it would help more if any of it was correct. Electricity flows neg to pos. and the process works because rust is already damaged metal, the ions in the rust flow easier than good metal, it comes apart 1 ion at a time and travels to the anode where it re-forms.

Ferrite2 months ago
Works great! I user an old CPU power supply instead of the battery charger and still chugging along fine.
les.parker.352 months ago

I knew it could be done but no clue as to how . I have a Cotton fuel tank that needs this treatment many thanks to you all .Regards Les.

lord.bagel4 months ago

If someone would be so kind as to help me out here... I followed all the steps, connected the black negative clip from the stanley 2-amp (BC209) battery Charger (for 6 Volt and 12 Volt Batteries) to my item and the positive red clip to a sheet of steel. As soon as I plug in the charger, the "reverse polarity" warning light turns on. I'm only reading about 0.3 volts between the item and the steel anode... nothing's happening.

You need a Manual charger, not an automatic

That is your issue. Your charger has a circuit to detect a valid battery and doesn't apply current unless it sees what it wants. Harbor Freight chargers do this too. You need to find an older or non-automatic charger, or a fair sized 12VDC wall wort transformer. I've used an old laptop charger for this purpose before and have "modified" HF chargers to be non-automatic for use as a 20A 12V power supply.

Go to Cast Iron Cooking facebook page, or google Electrolysis tank; it will help answer your questions.

lord.bagel4 months ago

If someone would be so kind as to help me out here... I followed all the steps, connected the black negative clip from the stanley 2-amp (BC209) battery Charger (for 6 Volt and 12 Volt Batteries) to my item and the positive red clip to a sheet of steel. As soon as I plug in the charger, the "reverse polarity" warning light turns on. I'm only reading about 0.3 volts between the item and the steel anode... nothing's happening.

rseufzer8 months ago
I used conductive aluminum wire so it wouldn't rust away. Works great.
TheReusery8 months ago
I found the best thing to use as an electrode instead of rebar is expanded metal that is cut and bent to form a perfect circumference inside the bucket and attach with bolts that can also be used as your conductors . This eliminates "line of site" issues .
sochart1 year ago
I'd like to setup an electrolysis station in my garage. Can I add some antifreeze in the system for the next cold months ?
ToolNut and everybody else on this site.
I'm new to the site and retirement. This tutorial is just what I need to salvage stuff I've accumulated over the years. I know I'm anal and maybe my concern has been addressed in an earlier post, and if it has I hope the administer will delete this comment. But if anybody's concerned about safety, NEVER NEVER use the wrong colored clips for connections. RED is always positive and an uninformed person with the best intentions could mix things up and trash a good charger. I'm sorry, what I was referring to were the pictures in Steps 2,5&6. Please correct me if I'm wrong and I appolagize if I am.. But isn't there a red clip connected to the blade? and shouldn't it be a negative connection (black) I hope I didn't offend anyone.
Be Safe
ToolNut (author)  allniterunner2 years ago
It is a red clamp, but not related to polarity. I had to use a spring clamp to hold the wire onto the tool, and the clamp I happened to have was red. I can see how that would be confusing. If I ever re-do the pictures, I'll buy black clamps for the tool. the wiring is negative to the rusty tool, positive to the rebar/anodes. Step 4 outlines this.

No offense - and good clarification! I will make a note on the picture.
My most humble apologies. Considering all the great contributions you've made to Instructables I had no right to question your method and should have understood better what you meant by initial set-up. The operation worked better than I could've asked for and did a great job on my parts. I'm sorry that my initial post had to be one as a snob. You did great portraying the concept of how it should be set-up, and I failed to be more comprehensive in my reading. As I sit at your bench of wisdom I hope to absorb many more ideas and tricks of the trade that I missed the first time around.
Thank you for not torching me

I don't think you need to apologize, and he can correct me if I'm wrong, but I think ToolNut didn't expect an apology either. The fact that you might not have commented if you had been "more comprehensive" in your reading actually highlights one of the risks of Instructables: a picture is worth a thousand words. That red-handled spring clamp DOES look an awful lot like the positive clamp of a battery charger, and you may have saved someone from using their favorite old tool as a sacrificial anode to brighten up some cheap rebar!

Instructables has no shortage of "concern trolls" (NEVER do ANYTHING with electricity EVER!!!!1!), but the good authors seem to welcome comments that point to photos or text that might be misinterpreted by reasonably intelligent people.



(just kidding!!! thanks for the laugh!)
ToolNut (author)  ToolNut2 years ago
Also, note that I state on the photo that uses this clamp that its a hokey set up as my first run, and the alligator clips were a good upgrade.
tbird23402 years ago
Great article.. So what is the consensus for the metal to use if not the rebar?

Also, I don't have any of that tire wire and not sure HD or Lowes even sells that.. Can you just use electrical wire for that?

Anyone know what store(s) have washing soda readily available?

I have this charger here: (12V 1.25A).. Will it work OK?

I plan on dunking my rotor(s) and hopefully my calipers as well..
Wal-Mart. Go to the cleaning products - laundry detergent, dish soap.

I found Washing Soda at Fred Meyer and assume it can be had at other Kroger stores like QFC, but sodium carbonate is also sold as a PH up product for pools and spas and as a water softener. I found some at Home Depot, but had to ask where their very well hidden pool chemicals were.

This is my first post here and I don't wish to offend, but this isn't an instructable for the perfect electrolysis tank, just ToolNut's design of "an" electrolysis tank. That's not meant to criticize, but to point out that every single thing can be replaced with something else(except water and electricity) that you probably already have and that might actually work better. Don't get hung up on the details.

Ideally you'd want the surface area of your anode to be equal to or greater than that of the cathode(the part you're trying to clean).

The battery tender should work just fine, but might switch to "float" as the part gets cleaner.
It's been a while but SCUBA shops used to have all plastic wire ties, to prevent various attached items from disappearing due to corrosion.
Good Luck
mr fat1 year ago
jew991 year ago
hi it's great work even many years past. THANK
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