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Picture of Electrolytic Rust Removal aka Magic
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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

Picture of Gather supplies
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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 had a old set of cast iron skillets that were all rusted. A simple soak in white vinegar overnight works well. Couldn't tell you about tool steel, I know vinegar and salt can be used to etch steel using a battery charger. (I etch designs in steel knife blades this way.) Point being, I think this a great method for steels. But for cast iron, just soak in vinegar. Great instructible, by the way!!!

great idea, you can also use water saturated with copper sulfate and your battery charger to etch copper and brass too

jamesb332 months ago

Hi,

I am cleaning up an old British Burmos brass blow torch / lamp made of brass and steel to use as a display piece. The problem is that the steel screws connecting the steel handle to the brass tank are rusted and will not come undone. If I was to place the steel handle submerged in my electrolytic conversion tank still attached to the partly submerged brass tank would there be any adverse effects to each of the two different metal parts?

Thank you in advance for any answers / advice.

WD-40 Blue torch Penetrating spray.

An impact screwdriver might be the answer there, the simple kind you kit with a hammer, they're actually quite good for corroded screws.

I would need to research this but my gut reaction is to avoid it. Brass is a copper-zinc alloy. I don't know about zinc, but copper does nasty stuff in an electrolysis bath.

If there's any acidity present, zinc is going to have a bad time. A good example of this, is when you make a lemon battery, wherein the 2 leads you insert into the lemon are 1x copper and 1x zinc. After a while, the zinc gets VERY nasty and unusable. The copper, not so much.

mciscato2 days ago
Hi,
How do you dispose of the electrolytic solution? Is it safe to flush it down the drain or should you better bring it to a collection point for dangerous chemicals?
Thanks!

Yes, mciscato, it is ecologically safe to dispose of through your toilet; I'm not sure what it might do to the china surface (I don't think it would harm it, but better safe than sorry) If you think about the contents, there is water, the soda product, and the oxidized material removed from the project; all inert chemicals. the Oxidized material would add iron to your garden spot, or flower beds, which is a good thing I believe.

Kialei2 days ago

Thank you brilliant and amazing person!! I now have hope to restore a few much loved items that need a little extra love. I cannot wait to try this and share the results. Thank you again!

When it rusts, can you just use this technique to also clean up the tie wire? Seems it would be worth at least looking into.

pitiolague9 days ago
What exactly is washing soda, i'm from Argentina and I think that doesn't exist here, so, if you give the components, i'll make it

Washing soda es bicarbonato de sodio en Argentina.

Do you have 20 Mule Team Borax in Argentina? It's the same thing. I use washing soda to make my own laundry detergent. Go to Wikipedia and type in Washing soda and it'll give you a better idea of what it is and some manufacturers. It is also known as soda ash or soda crystals.

It is so not the same thing. Washing soda is sodium carbonate. Borax is sodium tetraborate. The first is Na2CO3, the second is Na2B4O7.

Thank you for the correction. After reading your comment I did some further research and noticed the differences between the two. But... can't Borax still be used in this process if you can't get washing soda? Just a thought. I realize that Borax doesn't have the same sodium molecules as washing soda but does it have enough to aid the process of removing rust?

The problem is what the sodium is attached to, which in this case is the Borate ion. When you run a current through sodium carbonate, you split water in to hydrogen and oxygen, but the sodium carbonate is largely unaffected. This is because it is more difficult to pry (electrically) the carbon off the oxygen, than it is to pry the hydrogen off the oxygen. With Borax, that's not the case. You'll end up actually changing the borax into something else, most likely sodium hydroxide and boric acid. The sodium hydroxide probably won't have much effect on the process, but the boric acid might. It's commonly used as a flux in welding. I suspect it would end up covering the piece in a difficult-to-remove coating, but that's just a guess.

alba1009 days ago

How does this process compare, with the very simple process of immersing the object in a tub of 20% molasses and 80% water. Admittedly you may have to leave the object in the tub for a week or two, and it may smell a bit, but it seems to work ....any thoughts ????

In doing both, this is cleaner and yes faster, but the molasses works GREAT too! It depends on what you have, and if this is something you can do. If you have a very thin item, or one with lots of lettering this is better, but I have gotten frozen channel locks and pipe wrenches clean and working with Molasses, but it takes time and wire brushing (a lot).

cdunmire made it!5 days ago
works great that was after only being in for a few minutes and then wiping with a sponge
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sberrier8 days ago

if you switch the wires to make the work piece positive and the anode negative you can actually build up the metal, just wondering if this would work on pitted metal for smaller car parts to build them back up

Quester-599 days ago

Great Idea, Never thought of Removing Rust, Will give it a try. Thanks

thegreat589 days ago

In order for the steel to become brittle, it would have to be in the solution for months or even years. A low voltage will not change the structure at all. I speak after 40 odd years of welding, machining, and HD mechanics. Nice Inst.

ghaom9 days ago

I have referred to this instructable many time over the years and I use it on my swamp cooler each spring. I have a large tub made out of PVC pipe and 6mil plastic sheeting. I have a large rebar pattern of a Z for the bottom and one 12 in piece sticking up because the door is 40 in by 40 in. I will do the four doors and pad holders over the course of a couple of days and then brush the stubborn rust spots, reprime and paint and then with new aspen pads I am ready to go. Thank you.

Great idea. But try using TSP ( trisodium phosphate Na3PO4 ) as an electrolyte since Iron(III) Phosphate is incredibly LESS soluble than Iron(III) oxide. [ Ksp = ~1 E -34. çompared to ~ 1 E -20 ]. TSP sold as a commercial wall cleaner in hardware stores.
rseufzer1 year ago
I used conductive aluminum wire so it wouldn't rust away. Works great.

It seems to me that Lowes (and maybe other Big Boxes) have aluminum in expanded metal available (think screen door guards, lathe panels [4' X8']) that will work for this project. Aluminum makes a perfect "Sacrificial Anode" for hot water heaters in campers, and home water heaters.

krstecd1210 days ago

can i use NaHco3 please answer me

ALTERNATIVES I've used:

Baking soda when I couldn't find washing soda at big city stores

Brass (soft, cheap) wire brushes for cleaning (keep one for before and a cleaner one for after)

Laptop power supply (more amps is better)

Small power supplies for small stuff in a plastic coffee can

Any scrap iron/steel metal instead of rebar - old lawnmower blade is awesome

Rebar is often on the side of the road near construction sites

I am lazy...usually my rebar just sticks out of the bucket and I wrap wire around it instead of your fancy holes with tie wires and wire caps

GREAT Instructable! (other than the red clips on the negative in the photos) I was looking for some reminders...I hadn't done this in about 8 years. Works great for hand tools (even neat old scissors or pliers), all kinds of blades (as you've shown), engine parts. Very easy to re-paint the handles afterwards.

I keep mine in the garage because of all the rain Houston gets, but I do keep the garage door open since you are making space shuttle fuel (hydrogen and oxygen) and really don't want that blowing up on you. Thanks for this Instructable!

filtercages10 days ago

Although not caustic, the solution is nevertheless a skin irritant.

filtercages10 days ago

Writing as someone who electroplates, cleaning/prepping steel requires two processes.

First the item is alkaline cleaned (preferably hot) to remove grease and other debris with or without electrolytic action (although it does enhance the result), then after rinsing being immersed in a weak solution of usually hydrochloric acid.

It is the latter that removes the oxide/rust - not the alkali. Admittedly a very prolonged immersion will attack the steel.

Budweiser1435 months ago

I 1st came across this instructable: http://www.instructables.com/id/Electrolysis-Rust...

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? http://m.homedepot.com/p/ERITECH-5-8-in-x-8-ft-Galvanized-Ground-Rod-815880UPC/202195736/

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.

From my scant bit of research, I've also seen warnings that using copper and/or galvanized steel anodes will result in copper and zinc being electroplated to the item you're attempting to remove rust from.

okeasy42353 months ago
would a laptop power supply rated at 19 volts, 6 amps work? or would a 12 volt 5 amp power supply be better

Either supply should work okeasy4235. I use a 12 volt 10 amp automotive battery charger to clean some cast iron pans and I know of people that actually use 12 volt 50 amp battery chargers for this but most people don't need anything above 10 amps.

Wow! This is really amazing! All this while I have always thought that rust could only be prevented but can never be removed after it has happened. Nevertheless, you have really opened up my eyes and it is really necessary to try something new to be able to accomplish something we have never imagined to be possible. Now, removal of rusts is no longer a problem.

rose_adamaj2 months ago
My brother is a gunsmith. When I was telling him about this & showing off a couple things I've de -rusted, he told me two things I thought I'd pass along. Apparently this is well known and done a lot in the gun smithing world.
1. There is a 'tipping point' between rust removal, and eating into the metal. If an item isn't already pitted, leaving it in too long will pit it. The solution is to keep checking it.
2. As stated in the ible, put oil on immediately after item is dry. He actually puts oil on three days in a row. If you don't oil it, rust will start very quickly & it will rust even worse than before.
I use half beeswax mixed w/ mineral oil. So far I have applied it only once on the couple things that I have done, and that has been enough.
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