Rusty Junk to Useful Stuff EASY With Chemistry!

Intro: Rusty Junk to Useful Stuff EASY With Chemistry!

Backyard DIY Electrolysis for Rust Removal on Cast Iron and Tools

I'll bet everyone reading this has a secret stash of rusty something-or-other; Granny's Dutch oven, tools left in the rain, a cool garage sale find. If only there was some quick and easy way to return the metal to bright and shiny...

There is. Here's a sweat-free, pain-free method of removing every particle of rust from your rusty junk- using the miracle of electrolysis and some random stuff you probably already have laying around.

STEP 1: Equipment for Your Miracle

Here's what you need:

An automotive battery charger, 10 amps or bigger. A smaller trickle charger will work, but it might take weeks instead of hours to remove all the rust. One with a built-in ammeter is best, so you can tell when you have a good connection.

A plastic tub, bucket or container, big enough to suspend the rusty article completely free of the sides and bottom; you want the solution to circulate freely. You can also line a cardboard box or basket with plastic to hold the solution- anything will work if its sturdy enough and can be lined in plastic

Arm & Hammer WASHING Soda (not baking soda). You'll find this in the laundry detergent aisle.

Steel for the anode- rod, sheet, bar, whatever you have handy or can buy cheap. Old metal junction boxes, pieces of rebar, literally whatever you have. The more surface area the better.

A non-conductive rod to suspend the rusty article from. I used a piece of CPVC pipe, but wood is good too.

Some wire, any kind

STEP 2: Safety First

Do this outside, please.

You will be generating some hydrogen gas and you don't want any explosions in the garage.

Step 1) Fill the plastic container with a measured amount of water- when filled, you will add 1 Tablespoon of washing soda per gallon of water; stir to dissolve. Tip- make the last gallon you put into the tub HOT water, you can dissolve ALL the washing soda in the hot water and you'll get a fast, thorough dissolve.

Step 2) Place the non-conductive rod across the top of the solution container, and wire your rusty article to is so your article hangs completely submerged, but not touching the sides or bottom.

Step 3) Place your anode steel in the solution (the anode can touch the sides and bottom, and it can stick out of the solution too) but make sure it is AT LEAST 2” from your rusty article. Any closer and you will pull too much current on your battery charger and might damage it.

You can use more than one anode, such as multiple pieces of rebar on different sides of the rusty article, as long as all the anodes are electrically connected, i.e. wired together. Using more than one anode speeds up the electrolysis, and you won't have to move and turn your rusty piece during the process, but use whatever is easiest for you. You can also do more than one rusty article at a time, as long as- you guessed it- they are electrically connected to one another and nothing touches.

Step 4) Connect the BLACK clamp of the battery charger to the rusty article, and the RED clamp to the steel anode, and turn on the charger. You can use an extra alligator clip jumper if that makes a better connection to the piece than your regular clamp.

Turn the battery charger on and check the ammeter to see whether or not its “charging”- if not, you may have to scrape a clean spot in the rust so you make a good electrical connection.

Let 'er rip!

STEP 3: Making the Magic

You will see bubbles start to form almost immediately, and an ugly rusty sludge will collect on the surface- all normal.

Every so often, turn off the charger and lift out your rusty piece to inspect how the rust removal is going; take this opportunity to turn or invert the piece if you are using a single anode, to make sure all parts are getting blasted.

The length of time you will have to leave your rusty article will depend on how rusty it was and the amperage of your charger. It will probably take a few hours, maybe overnight to totally remove the rust. It won't hurt anything if the charger continues to run, but it won't help either.

You can dump your rusty, sludgy water on the garden, or save it for your next rust-removal project. * note; if you used a stainless steel anode, you may have generated some semi-toxic byproducts; better to not dump this down the storm drain or into your vegetable garden.*

STEP 4: Yes, You ARE a Genius;

When you remove your work piece the final time from the solution, you will have noticed that instead of rust, your piece is now covered in a sooty black oxidation layer. The easiest way I've discovered to remove this is with 3M Brand GRAY Finishing Pads, available at Lowe's in the sandpaper aisle, but if you need a more polished surface, you may have to work with the softer white scrubbies. It only takes a few minutes to remove the black stuff.

And voila, you have resurrected Granny's Dutch oven with the expenditure of just a little bit of money and the time it took your cauldron to do it's bubbly electrolysis magic.

Take a bow!

STEP 5:

STEP 6:

Comments

[dec123]

does the size anode make a difference? also i imagine that carbon steel would be better than SS (even ignoring the price difference). finally, i imagine that the anode has to be rust-free too?

[Texas_Mike]

This is a wonderful process. I have a very rusty but structurally strong late 1960s early 1970s Sears Mini Bike that I've started to restore. Now, all of the metal parts are completely rust free. Instead of a 5 gallon bucket I had to use a 60 Gallon plastic trash can to submerge the frame. I simply added a proportionately larger amount of Super Soda. Totally excellent Instructable. Thank you for posting it.

[I MP]

Have never gone the process of using electrolyis, I simply use a solution of cosmetic grade citric acid which is a totally biodegradeable plant product for my salvaged hand tools. Sometimes a wire brush is needed to completely remove the rust. For the cast iron cookware I salvage at flea markets , garage sales and thrift stores I use oven cleaner from the dollar store.

[christochandy]

Thanks for the post. This site and writer in it gives a lot of useful and helpful informations. Thank you all and God bless you.

[cardinalZin]

I used this process yesterday on a handful of long-rusted tools. The Washing Soda was tough to find locally but a web search showed that Walmart had some, and they did. Next, my "smart" car charger wouldn't push voltage through what it determined was clearly not a battery. Instead I used a desktop variable DC power supply that I had used to drive an old ham radio--it worked great even at its max of about 16V and 5 amps. I coated all the fresh steel with ACF-50. Great Instructable!

[Udon]

Seeing as we're on the subject of chemistry......

You can make washing soda out of baking soda.
Sodium bicarbonate (baking soda) decomposes into sodium carbonate (washing soda) at temperatures above 50deg Celsius. So as long as you have pure-ish baking soda (baking powder will go badly...), stick it in any pan, turn on the heat, and wait. You will see the baking soda powder will start bubbling in a weird way, especially as you shake it around the pan. The boiling effect is the powder giving off carbon dioxide. You can't burn it, and just keep going until there doesn't seem to be any more gas coming out, and you're done.

Voila.
Homemade washing soda.

Interestingly, this is the reason why we must be very careful when making cookies or anything that use baking soda as a raising agent. The ingredients need some acidity to react with the alkaline baking soda (and so baking powder has a mix that will neutralize when combined with liquid and exposed to heat). If not, the product will still rise, but a terrible soapy flavor will remain from the now heat-converted washing soda, and hence, we only use baking soda if we are really accurate and follow a tested recipe.

[mulapretaz]

I already did this with Sodium Carbonate.

[Braindead63]

I'm not an expert, but I think that the anode should be any steel except stainless.

My apologies if I am in error. I make mistakes when it is time for it.

[PaulD279]

That's my understanding too. The chromium is toxic, I believe.

[KristinC35]

I use old cell phone chargers for the power source. Only use DC (direct current) never use AC ( Alternating current)

[lgroger]

I find this really interesting but can I ask a stupid question? Water and electricity are generally a dangerous combination - what happens if you touch the water during this process?

[KristinC35]

when the positive and negative end are in the water it is a complete circuit. If you touch the water nothing with happen. If only one end is in the water you may feel a very slight tingle.

[marcel-demoulin]

Power supply or battery charger is about 12Volt: No danger

[DanC66]

The charge is so low that it probably won't do you any harm, though you should be wearing rubber gloves if you're putting your hands into water with soda in it anyway. The bigger danger is getting your hands wet and then touching something connected to the mains supply.

Safety first!

[KristinC35]

A very very important note: DO NOT USE STAINLESS STEEL for the anode! Many steel plates come with a zinc coating. Be sure to sand it off before use.

[osterac]

Hi, I noticed that you said to use at least a 10 amp battery charger, but never mentioned the voltage. Then in your picture, your charger appears to be putting out less than 2 amps. 2 amps at 5v would be a cell phone charger. 2 amps at 36v is a whole other story - the first is 10 watts and the second is 72 watts. I have a bench power supply that can provide a steady current anywhere from 0-30v at 0-5amps. Where would I set it?

[papa-ralph]

I generally run 12v @ 4 amp. My power supply is not adjustable but is capable of putting out 36 amp. So I adjust the current flow by the amount of soda that I use.

[sreeci]

OsterAC,

A battery charger is always 12Volt., with 2Amp and 10Amp output respectively. There are smaller Battery Charges also. But we are speaking about Battery Charger related to the procedure, described by this Auther.

So, coming back to your curiosity, please assume, that the Author i.e.: Cheese Queen was using a 12 Volt battery Charger @ 10Amps.

Please thank the Author as most people have already done.

Thank you, OsterAC

[clothier_bruce]

A car battery is referred to as '12V', but that figure isn't meant to be taken literally: it depends. When you charge it up the voltage needed is 14 to 15V. Modern chargers are sophisticated electronic devices and who knows what they get up to, but for electrolysis you'd want an old-fashioned el cheapo charger. The maximum current would depend on how expensive and heavy it was: a big one might do around 10A, but I think most bog-standard chargers opted for around 4A. But cheap chargers ( all you need for this ) were just a transformer and rectifier bridge. which gave dirty DC as there was no capacitor. For crude charging this was perfectly OK and also perfectly OK for electrolysis. The disadvantage for a battery was that the voltage output was about 18V open-circuit. This figure also has to be understood: the transformer was 'loose-coupled' so the current became self-limiting - a safety trick. Nevertheless, if the battery was left permanently attached, it boiled dry as these cheap chargers didn't go into trickle-mode. For that you need some electronics. Bottom line: an old cheap battery charger is a lousy battery charger - buy a nice electronic one. But it would be a terrific choice for basic electrolysis.

[J DeweyJ]

Maybe you should say, or have said, a "car" battery charger. Battery chargers are NOT always 12 volts. I have plenty of batteries, even some SLA ones that are less than 12 volts.

Your method of removing rust certainly is interesting, but I prefer a soft wire wheel on a bench grinder or drill. A lot faster, less trouble and less mess.