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).
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).
Remove these ads by
Signing UpStep 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
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
Visit Our Store »
Go Pro Today »
1. stainless steel does not conduct amps well don't use it.
2. Copper for your anode is better used and a copper pipe flatting ¾ of it with a hammer
3. the further your anode is away from your work peace is bad it takes more amps and time to work on cleaning.
4. Power 1 to 12 volts they don't matter at all amps is what matters 10 amps works the best no closer than 4 inches from what you are cleaning the farther your anode is from what you are cleaning the more amps it takes to do the job.
5. Cleaning soap phosphates use TSP you will find it in a store that sales paint it is a mild soap use
for cleaning walls in the house to paint. It will not harm you. Plus add two cups of white vinegar to 4 gallons of water in your 5 gallon buck of water mix with soap it will help to conduct the amps better. O and what I mean that TSP won't harm you I mean your hands please people don't drink it is a small joke:)
and one more thing please people stop telling people that stainless steel is toxic if they use it because its not it just wont carrier the amps. The only way to make it toxic is to weld with it over a long time or by passing volts throw it at high amps in a acid bath and I mean amps 150 amps and up.
Thank you for your time hope this helps
When S.S. undergoes electrolysis hexavalent chromium (remember Erin Brockovich?) an industrial byproduct and toxin is produced due to chrome in the SS being released into the electrolyte. The result is a disposal problem. If you doubt any of this, research HHO fuel cells and you will see Stainless is used as anode and cathode to create Browns Gas A.K.A. HHO(hydrogen, hydrogen, oxygen). Having a disposal problem is not on my list of must haves, so I'm forced to look at titanium which is very expensive, and only moderately conductive.
http://www.rickswoodshopcreations.com/Miscellaneous/Rust_Removal.htm
"It is important that any copper connected to the anode does not touch the solution. If it does, copper will oxidize to cupric ion, Cu++. The connector will be destroyed. Most of the copper ions formed should precipitate as copper carbonate or copper hydroxide, but if any of this dissolved copper reaches the cathode it will be reduced to copper metal on the iron object. Its presence will promote rapid re-rusting."
Re the stainless steel advice - there is simply too much other advice out there warning of the potential hazards of this, so I am going to maintain my statement that stainless should not be used. for example, here is one of the original electrolytic rust removal sites that was inspiration for this instructable:
http://antique-engines.com/stainless-steel-electrodes.htm
So anyway, I'm going to stick to err on the side of caution on this one and continue to caution against stainless, but am interested if there is something definitive on this. Lastly, I don't see a real benefit to stainless, its more expensive, and we are talking about a disposable anode by definition, no matter what kind of conductive material it is...
1. I only used washing soda in a 1tbsp /gal ratio. My largest tank was 7ft W X 3ft L X 3ft D. This was for the lathe bed and the Mill body.
2. My anodes are always steel plate. Plain old 1/8" mild steel. Pieces about 10inx 12 in. In the large tank I had 8 of them. In a 35gal plastic garbage can where I did most everything I used 2. I drilled a hole and bolted bailing wire (now called tie wire) to them and hung them in the bath.
3. I clean my pieces using a plastic bristle brush and some orange gojo degreasing hand cleaning stuff. Just get the grease off your part so it will conduct. This process has removed everything from unseen grease and dirt & paint, but especially rust!
4. Leave overnight.
5. remove the anodes and simply wire brush the crud off and set them aside to be used again. The anodes will corrode completely away eventually. I think it kinda looks cool the pitting and corrosion that occurs on the anode. the way I see it, the more surface area of the anode the more electrons can flow onto it and the more rust it removes.
Sorry I don't have pics of the tank ( I may somewhere) but I do have before and after pics of the machines, however in the after they are completely repainted. I've done parts hanging half in the bath then rotated over after the first part is done. Screws bolts and nuts are easy when you simply cut a long piece of wire then tie them all together with a couple wraps around them and space them about 1" apart. the results are nothing short of amazing. There is no damage to the original part.
Warning!! Get the polarity right! If not you will corrode whatever you are cleaning into something unusable really quickly.
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: http://www.amazon.com/Battery-Tender-021-0128-Plus-Charger/dp/B00068XCQU/ref=sr_1_1?s=automotive&ie=UTF8&qid=1336404217&sr=1-1 (12V 1.25A).. Will it work OK?
I plan on dunking my rotor(s) and hopefully my calipers as well..
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
jim
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
jim
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
jim
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.
Cheers,
jexter
I set up the tank with the work piece inserted and fill with water from the garden hose. The carbonate does not dissolve easily in cold water. I get a half gallon of hot water and dissolve a handful in that. Then add slowly to the main tank until the charger current comes up to what I want. I have an old 6 amp 6/12 volt charger. I don't know the chemistry either, but believe the lower voltage works better, and it is really amps per square inch of tool surface that controls the process.
I pull the tools out about every half hour and give them a light scrub with a brass bristle brush. The brass won't scratch cast iron. You can find good brass brushes at stores selling barbeque grills. Watch that they are not just brass plated steel though. If you scrub the piece while it is wet with carbonate, some of the brass will plate over onto the iron, giving it a slight yellow cast. I think it looks antiquey. If you don't like that idea, rinse the piece well before brushing.
I wrote an article featuring this instructable, check it out here at http://www.squidoo.com/electrolytic-rust-removal. I will be adding more content as I go along so stay tuned!
A suggestion for those of you who might be using this method to remove rust from an older steel-frame bicycle. Electrolysis is the only method that I know of which can completely de-rust the inside of a bicycle's frame. It can be accomplished by putting a metal anode in the tubes, surrounded by a perforated insulator to prevent direct contact with the cathode (bike frame).
For the seat-post tube you can use something like a piece of rebar inside a piece of PVC pipe with a lot of holes drilled in the pipe. For tubes that are harder to get something into (e.g. the top tube & down tube), you'll need something more flexible. An old chunk of steel cable or the jacketing from metal coated electrical cable can work, provided you can find something that's not stainless or galvanized. Then you just need to put your flexible anode inside some old hose with a whole lot of holes cut in it and feed it into the hard-to-reach spots.
I'd also suggest not de-rusting the inside of a frame at the same time as the outside. With the anodes inside the tubes, they're very close to the cathode, and so will slow down the rust-removal from parts that are farther away from their corresponding anodes, like the outside of the frame.
I hope that this helps someone to keep a classic bike back on the road!
Turns out all that is needed is something to make the water conductive. The action of electrons leaving the (negative)workpiece on their way to the (positive)anode knocks the non-conductive rust off the workpiece. So don't fret over TSP/baking/washing-soda issue. Use any of them. In fact, plain old salt works fine: table salt, rock salt, ice-melter salt, water-softener salt. I used a cup of salt per gallon of water.
Using salt, I know for sure that hydrogen and oxygen are produced during operation. So long you don't trap these gases somehow, they will dissipate far to rapidly to be an explosion hazard, but I wouldn't tempt fate by making a spark over or in the bucket during operation. Unplug your DC power supply first, THEN disconnect your electrodes.
Bare 12 gauge copper wire is excellent to secure the rebar for this project.