Electrolytic Rust Removal Aka Magic

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Introduction: Electrolytic Rust Removal Aka Magic

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).

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

Step 2: Assemble Tank and Anodes

NOTE: Do not use stainless steel for the electrodes. As pointed out by a commenter on the intro page (thanks!) "The chrome in the stainless will leach out during the electrolysis and form hexavalent chromium compounds in your electrolyte. These are extremely bad for you." This is true - dont even think about using stainless steel for this project.

Assemble tank and electrodes

1) Space the rebar evenly around the bucket along the sides (running top to bottom). Mark the locations

2) Drill two small holes about 1/2 inch apart 2 down from rim for each rebar

3) Insert a 5" loop of tie wire through the holes around the rebar and out again . Lube the ends of the bar with anti oxidant compound and twist the wire tight and snip off so 1" of the wire is remaining. UPDATE: the tie wire eventually rusts out - mine in less than a year.  Consider using something more resistant to rust - suggestions welcome.  On the other hand, any time you are using electrodes, they are sacrificial - as is the wiring system that contacts the water, etc.

4) Once all rebar is in place, make 4 sections of copper wire with the ends skinned off to connect each rebar wire.

5) Wire nut each rebar to the next with a section of cooper wire (connecting the protruding tire wire (I also used Noalox on these connections). Do not connect the first and last rebar (ie: X---X---X---X---X---)

6) Add 5 tablespoons of washing soda to the bucket and fill within 2 of the rim with clean water (adding extra soda will not help&)

Step 3: Set Up Hanging Clips

Step 2:

1) Find a board (or any non-conductive object) to lay across the top of the bucket.

2) Attach a short lead of copper wire with an alligator clip attached to the water end. (I just stapled the wire to the board)

3) The clip should hang low enough to just enter the water. ( first photo below shows three clips - i was doing three parts at once..)

Step 4: Attach Charger

Don’t mess this step up – the polarity is important:

Make sure battery charger is OFF:

1) attach the positive (red +) end of the battery charger to the rebar wire

2) attach the negative (black -) end of the battery charger to the alligator clip over the water

3) I remember this by saying to myself “the rust flows off the tool towards the positive side”



Step 5: Attach Rusted Tool

1) clean a small piece of the tool where you will attach the clip - choose a place where it will also hang securely.

2) Attach alligator clip (which is attached to the negative end of the charger) and and hang the tool completely in the water. Its ok if the clip is in the water – it wont hurt it. Wiggle the clip to make sure you have a good connection.

3) Make sure the tool is attached firmly and is not touching the rebar or any part of the setup that is attached to the positive lead.

4) Areas of the tool that do not have a “line of sight” to the rebar will not be cleaned – if you have a complex part you might need to rotate it or add more rebar electrodes.



Step 6: Power It Up

1) set the battery charger to a low setting (6v – 1.5 amp works great for me)

2) Turn on the charger.

You should see tiny bubbles start to form all over the tool. As the process progresses, the rust will start to flake off and the water will become muddied with rust and goop and foam depending on how fast the bubbles are forming.





Step 7: Check Tool and Remove and Clean

Depending on the size of the tool, the amount of power used, the amount of rust, and your patience, the process will take from 1 hour to two days. The longer you leave it in the solution, the less work you will have to do to finish the clean up.

The tool will turn black and the rust changes form and flakes off.

If you leave it in long enough, you should be able to wipe the rust off with your finders and find a smooth (but pitted) surface. The nice part about this is that even after only 1/2 hour, the rust is much easier to remove with a wire brush.

NOTE: the tool will not come out of the tank ready to paint. it will still need wire brushing or final polishing with steel wool. the process leaves a gray/black layer of oxidant that you will probably want to remove prior to final rust-proofing or painting.

The photo of the saw below shows three stages: The left side was run for an hour and then brushed. The middle spot was steel brushed for the same amount of time but without the electrolysis (and rust remained) and the right side is the original rust.

Step 8: Samples

Here are a few samples:

The chisel was very rusted – normal rust removal would have required much original steel grinding to remove the deep pits that a wire brush would not have touched. Check out the stamp that was revealed after cleaning.

The entire project was started because I bought this sweet plane that was totally rusted. I only paid a few bucks, but knew that a used non-rusted one was worth quite a chunk of change. After the tank proces it took about an hour of going over it with the light wire brush wheel on the dremel to shine it up – but it would have been impossible without the electrolysis first.



Step 9: Final Rust Proofing

If you are not going to paint the tool then it will require immediate rust proofing.

I use this spray T-9 stuff that Highland Hardware sells

– but I think there are some less noxious easier to clean up products out there like Camellia oil

Step 10: FAQ


How big/small of an object can I do?

- My browsing around on the web found people doing anything from small parts in a 1/2 gallon tub to a trailer body in a swimming pool using a large welder for the power.

Does the solution "wear out"?

- No - it just gets nasty

How much power should I use?

- As little as possible to still get the job done. I think you will get better results with low power and two days of processing than high power and getting it done in an hour. The larger the object (surface area) the more power required to do it in a given amount of time. My charger is 1.5 amp 6 volt and works great for hand tools. the small stuff takes a few hours. The larger complex plane took a day and a half before i was happy with the amount of removal.

Is this dangerous?

- Only if you don’t have any common sense and don’t use a GFCI protected power source.

- Yes if you do it inside - the bubbles forming are evidently hydrogen which is flammable. Outside it does not cause any problems.

- The low voltage is pretty safe - especially if your charger has an automatic cut off "trouble" switch.

Are there any drawbacks to this system?

- Some people say that depending on the power and time involved, the steel can become brittle due to a temporary change in structure. This is cured by "baking" the tool for a few hours at 350 in the oven or letting it sit around for a few months before any hard use. see the links below for more info. I have not found this to be a problem.

These guys deserve the credit for teaching me how to do this and provide way more info on this system:

http://www3.telus.net/public/aschoepp/electrolyticrust.html

http://myweb.tiscali.co.uk/andyspatch/rust.htm#top

http://antique-engines.com/electrol.asp

5 People Made This Project!

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467 Discussions

i did everything that the instructions said to do but nothing happened. my charger read 100% charged and did not turn on. i connected it to my car"s battery and the charger tuned on immediately. can you tell me where i am going wrong?

Would I be able to use a 24 V battery charger from an electric scooter for this?

The charger plugs into a wall outlet with a grounded plug. Then it has a wire at one end with a small round plug that was pushed into a round port on the scooter. It's dead easy to snip off or remove the plug, leaving me bare ended wire for the electrolytic bath.

I don't have the charger handy, I'll have to dig it up, but as but as I recall, the charging plug is at the end of about two feet of reasonably rstandard small appliance or lamp wire. It's usually easy to split that kind of wire into it's two separate wires to attach to two electrodes.

BUT ( always a but ) how do I determine the + and - for these wires? Anybody know how I'd figure out which is which?

The rest of the stuff for this 'ible I already have. I have a number of rusted tools in need of major rehab to be useful again.

5 replies

i just saw this post, so you probably already have the answer. when you split the appliance/ lamp style cord, one side is smooth and one side has small ridges. the side with the ridges is the neutral side. the other is the hot side.

It will work just fine, probably better than the author's 6 volt charger or a typical 12 volt charger. I did some extensive reading on this a while back before I tried it and found a fellow that had experimented with it a lot. He found that, for whatever reason, 24 volts worked better than 12, but anything higher than 24 was no better.

You may find that a mobility scooter charger needs a 5/6v feed back before it will start to charge. This is a safeguard to protect from a short in the batteries on the scooter.

you could also get a cheap volt meter/ multimeter to find the polarity. plus, if you are on this site, reading this, it should probably be something you should have in your tool box anyways :)

Sure you can use scooter P.S. ... a few thing to keep in mind:

Search for the term "Scooter Pin Out" in images, and see if any pics look right.

24 volts is slightly hotter than the 14.6 in the demo... adjust time and expectations accordingly.

if you are not sure about polarity, run a quick test on scrap metal (or even a couple of pennies)

Not likely, but you might damage the charger... The process should work with about any DC supply you want to sacrifice.

Science moment: I believe the chemistry says you must exceed the voltage of the electronegativity of iron which is 1.83volts, so anything 2 volts and should work. High voltages make for some unwanted reactions though..

Tap and drill end of rebar to connect leads with ring crimps. Use plastic cable ties to secure rods at top or araldite to secure along the bucket sides. Use a fuse on positive lead in case item shorts directly to save charger.

Sodium carbonate is also used for swimming pools, to raise the ph. It is cheaply sold at Home Depot and other pool supply places as Soda ash.

Also, electricity flows from the negative to the positive, not as commonly thought. That is why the negative is connected to the work and positive to the sacrificial anode.

2 replies

That is electron flow, not electricity flow.

its always electron flow, “electric flow” is just a tradional way of describing circuit flow, and is not scientific.

I have been electrolyzing found objects, Civil War artifacts, cannonballs and shells(properly disarmed), for over 40 years. I certainly recommend paying attention to the science and chemistry in this 'ible and the information sources the author cites. And, I apologize if I appear to be a know it all. Having said that, my experience has been different. I use ONLY salt. It does a great job, no problems I ever saw. You only need ONE sacrificial cathode, not several. I never heard of or experienced shadowing. I recommend using an old (American made) file. This way you can control the current going through the cathode. Just pull the file up a little if you want to slow down the process. Also, lasts MUCH longer than rebar. Salt solution takes perhaps 2-3 hours to get funky and efficient. On wrought iron the process takes off all bad metal, no wire brushing, etc. needed. Example, I cleaned a complete dug Enfield Rifle lock this way and every stamping was clearly readable. Just rinse item off and dry with a hair dryer. This article was sold perhaps 15 years later, great condition, no rerusting, no oil, wire brushing, etc. Be careful with cast iron, go slow. If you overdo it, it will get soft, almost soft enough to carve with a knife. A trickle charger with overload protection operating at low amperage is what you want. If you want less than 2 amps, just pull the file up a little. The funkier the salt solution, the better it works. But I always changed it when it got really nasty. If cleaning a two- or three-piece iron or steel item, it's sometimes better to have two or three leads going to the object. As I understand it, this is not reduction. Perhaps the author can explain if soda accomplishes reduction(conversion of corrosion back to good metal). I once read an article where immersing a non-ferrous artifact wrapped in a woven metallic blanket in an acid(I believe) visibly converted corrosion to good metal and preserved detail. I would sure like to read some comments on this. Again, please allow this intrusion into an excellent 'ible.

I made this and cleaned up a railroad trust plate, unearthed in my neighbor's garden. It worked so well, I brought an old flat iron to a shiny gray lustre in the same manner. Now I'm going out to fine other artifacts. The process is as much fun as it is useful.

Does one have to change the 'sacrificial' rod from time to time ?. I am finding that the process is becoming less effective each time I de-rust a fresh item. The advice here is that the solution does not wear out - so is the rod attached to the positive terminal the issue ?

1 reply

The sacrificial anodes eventually erode away, though that will take quite a while. That said, you need to clean them periodically or they will become covered with a layer of the rust and gunk cleaned from the tools...and this means they won't conduct electricity properly for the process to work.

I use graphite plates and rods for my sacrificial anodes. They deteriorate less and the "gunk" just wipes off. Pretty cheap to buy.

Oxiclean contains wash soda. I saw a demo using it and other than some suds it preformed the same as plane wash soda. Every store in my area has Oxiclean. Hope this helps out

I just did this recently and here are two issues I ran into and how I solved them:

1. Washing Soda: In Northern California it must be banned or something however it is easy to make. Take Baking Soda and spread it out on a cookie sheet or put it into a bowl. Pop it into a 400 degree oven for 40 or so minutes until you have the juiciest pot roast ever seen. If a pot roast has not appeared then you will have Washing Soda. Store in lightproof container.

2. Battery Charger (IMPORTANT): Automatic battery chargers will NOT work. The electrical flow is not a battery load as it expects and will fault. It will be as if it was broken. I tried two and both behaved the same. Beware of Sears. Online they show a manual charger however it is the SKU of an automatic. This may be another Northern California Space Time issue. Also ordering from Amazon, for all addresses I had it threw an unshippable addresses error. I can buy explosives just fine. I found that eBay has variable power supplies for about the same price as a automobile battery charger and the one I got works great. It is a 0-30V, 0-5A and it costs about $45. There are models with lower voltage/amperage that are in the $20s. Obviously no problem shipping to my address.

Hope this was helpful.

2 replies

I know I'm replying to pretty old material here, but I just wanted to give your comment a "thumbs up" and thank you for your input. Having read through many different tutorials and watched videos by reputable creators, very few address the fact that some chargers will default to an error message. After seeing what you wrote, I tried a universal power source and got a chemical reaction right away. FWIW, I used baking soda and it works. Thanks!

You can use some automatic (smart) chargers, as you said, they might not start because they have a battery/charge detection, but you can kick start them by connecting a 1.5v battery to its leads for 1-2 seconds with some wire. After that charger kicks in and remains on. You can also reconnect without battery later on, I am guessing that solution/metal ions hold a residual charge if it ran for a little while. Just in case someone runs into the same problem.

0
user
KwonP1

1 year ago

I dont know why this instructable says baking soda isnt acceptable. I've removed rust off several parts using baking soda no problems. I used 2 tbsp per gallon of purified water, and repurposed a laptop charger to provide 19 volts dc at 3.42 amps. Electrodes were 0.090" steel sheets placed around the part. Exposed copper in the solution didnt cause problems, and took about 17 hours to complete. The part was covered with orange gunk that washed right off. The part needed immediate oil as the solution completely degreased it.