[drkhrs925]

Ok, I know there is another thread in here about electrolytic rust removal, but the information in it is so far off base and dangerous that I am compelled to write up another one with some very strong warnings:banghead .

If a little is good a lot must be better :twak – this is absolutely positively not the case here. 2-10 amps at 12V is more than enough for this process to work. Any higher on the voltage and you are risking a bad electric shock. Any higher on the Amperage and you will just be heating / separating the water. The process will not work any faster by throwing 110 Volts into the mix:shocked . Your life however may go faster ( or end faster ) if you do.

It is not electroplating and should not be compared:twak . There is a “plating” affect but what you are plating is a very weakly bonded iron oxide that will wash off with soap and water. That is the black gunk that you have on your parts after you remove them.

DO NOT USE STAINLESS STEEL:twak :twak . This process tears apart the sacrificial anode and it ends up broken down in the water. Stainless steel contains chromium and this process will free that up into the environment. So you don’t have to change out your stainless anode but you will be exposing yourself and the environment to some very nasty and poisonous chemicals. I have also made the mistake of putting a galvanized pipe on the anode and ended up with light green plating on my parts (not desirable).

Highly Flammable :doh0715: – While the mix is bubbling the water is being separated into hydrogen and oxygen. This collects inside the rusty foam on the top of the water. I have read accounts of this popping / exploding on some people when the power supply was not shut off before removing the parts. It did not hurt anyone but it did make a very nasty mess. I have found that after turning off the power supply a good stir of the bucket will get rid of the foam and dissipate the hydrogen.

The last warning is that this process removed everything loose form the surface. The part will begin to rust again almost immediately if you don’t take steps to protect it. This is not an alteration to the part, it is just so clean of oil and oxidation that is completely unprotected.

Here is the best link to the process I have found so far.

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

http://www.davidbradley.net/ERR.html

The only exception I take to this information is the chemical used. Almost all the sites I found call for Arm and Hammer washing soda. I searched high and low around the bay area and did not find any. After so serious research I found that washing soda is Sodium Carbonate. Another name for this is Soda Ash – wait that sounded familiar – a quick look at my pool supply shed and I found Soda Ash "Ph up". That’s right it even spells out on the tub Sodium Carbonate 100%. I was so mad I could have strangled the horsepower hosts. So save yourself the trouble and make a quick trip to the pool supply store instead of every grocery store in town.

Ok, enough warning how about some pics of what an over night soak can do for you.

This is the axle tube and the Dana 60 BOM number before. It has been pressure washed with a 3500 PSI washer and is still very rusty. I had to get just the right angle to get a readable picture.

Here is a shot of my tanks. The one in the front has the knuckles and brake caliper mounts. The one in the back has the axles in it. Just a note, I used a set of jumper cables to connect across the u-joint. That way I made sure both pieces were electrically connected.

Here you can see the water line where it was hanging in the tank.

Here is the same BOM number and this is just a snapshot. It is clearly visible and the rust is even removed from inside the numbers. The best part of this is the inside of the axle tube has been cleaned as well.

This is a knuckle after being cleaned.

What I really like about this is the lack of effort. I used to spend hours with a wire wheel and still have rust down in the corners. I then use a sand blaster to get at those. Of course then it has to be washed out before painting. yikes – hours of rust up your nose. Now its a hit with the pressure washer, into the tank overnight, and another shot with the washer. Air gun dry and paint – done.

If you want a refund for the last 10 minutes of your life I will gladly return everything you paid meopc1: .

thanks for your time – hope you can use this

 

[Cobra Jet]

Awesome tech write up and great info too!

I guess if one had large enough containers or troughs of some sort (and of course the necessary room), larger parts could also be submerged (such as body panels).

Thx for that info!

 

[c-dub]

someone may find my whole truck in their pool with some wires and a car battery sticking out

 

[SigEpBlue]

Washing soda? Are they sure they don't mean baking soda, i.e. sodium BIcarbonate?

 

[Winder]

No it is not baking soda (sodium bicarbonate)....IT is washing soda (sodium cabonate)

 

[Bronco4Life]

someone may find my whole truck in their pool with some wires and a car battery sticking out

I wonder how pissed my parents would be if I parked the truck in the pool, and tried this...


Cool writeup, I may have to give this a little try with some stuff.

 

[El Kabong]

Wow. Bookmarked. What do you do with the soup when you're done?

 

[Winder]

you can dump it in the flower garden. I'm told it is good for roses and other flowers than need high iron content in the soil.

If you use stainless steel then the water is toxic......as in you need a haz-mat. Never use stainless or chrome.

 

[Bronco Rob]

you can dump it in the flower garden. I'm told it is good for roses and other flowers than need high iron content in the soil.

If you use stainless steel then the water is toxic......as in you need a haz-mat. Never use stainless or chrome.

do not dump it in your garden. Rust is not just iron, it's iron oxide. It contains Iron (III) Oxide in it's raw form, that comes along with a NIOSH guide on what you should wear to protect yourself from it. Not to mention that most steel used in automotive applications isn't just steel, there are other fillers added to it in order to make it cheaper to produce. So any time you dig in your flower garden, wear your proper respiratory devices.

If a neighbor complained and the EPA showed up, you'd be charged with dumping toxic chemicals into the ground. No jail time, just a helluva fine and it requires remediation.

99% of electroplating machines reverse etch their product prior to plating. It's basically what you've done with your garbage cans. Stainless steel is a horrible conductor, that's why you rarely see it in electrical applications. There are too many additives for power to travel through it properly.

 

[Winder]

Everything below is stole from other websites. There are about 20 or so sites on the subject.


How can I dispose of the solution?
The bath will last until it gets so disgusting that you decide it is time for a fresh one. There is nothing especially nasty about it-it's mildly basic-so disposal is not a concern, except you may not want all the crud in your drains.

Why you should not use stainless steel electrodes for electrolysis
Many people using the electrolysis method for rust reduction swear by stainless steel, stating (incorrectly) that it's not consumed, stays clean and seems safe.
Stainless steel is indeed consumed when used in the electrolysis process, although slowly. The main problem with using it is the hazardous waste it produces. Stainless steel contains chromium. The electrodes, and thus the chromium is consumed, and you end up with poisonous chromates in your electrolyte. Dumping these on the ground or down the drain is illegal. The compounds can cause severe skin problems and ultimately, cancer. Hexavalent chromate is poisonous. These compounds are not excused from hazardous waste regulations where household wastes are.
These compounds are bad enough that government regulations mandate "elimination of hexavalent chromate by 2007 for corrosion protection."

Does your electrolyte turn yellow? That's a sign of chromates.

If you have been using stainless steel for the anodes (positive electrodes), wear rubber gloves when working with or near the liquids. If you need to dispose of it, allow it to evaporate into powders and dispose of the powders in sealed containers during your local "hazardous waste clean-up days".

Best bet - don't use stainless steel no matter how tempting it is.

*******************************
Advanced Chemistry
Rust is a complicated material. Typically, it is a combination of ferrous and ferric oxides, hydroxides, and hydrated oxides and some of these compounds may be present in several crystal forms.

There is much speculation in the chemical and archeological literature about the products that form when rust is reduced in sodium carbonate. In searching for an answer, people may find a lengthy publication on the DENIX web site ( https://www.denix.osd.mil/denix/Public/ES-Programs/Conservation/Underwater/4-IRON-2.html). Much of the electrochemistry described is not correct and the conclusions drawn about reduction products are not in agreement with most chemical literature. It was not until 1996 that some chemists from the Swiss Federal Institute and Brookhaven National Lab did definitive work on this subject (see papers by Virtanen in J. Electrochemical Soc. 1996 and 1999). Using a sophisticated X-ray technique they determined what was going on at the cathode when iron oxide is reduced. Normally reductions occur in solution. That is, something has to dissolve before it can be reduced. However, they found that iron oxide will conduct electrons and therefore can be reduced without going into solution. This process is referred to as solid state reduction. The ferric iron atoms in the rust begin to reduce to ferrous oxide, which initially results in a mixture of ferric and ferrous oxides. This combination is called magnetite and is often written as Fe3O4. Eventually, all the ferric oxide becomes ferrous iron. Under less powerful reducing conditions the product would be ferrous carbonate or ferrous hydroxide. However, under the extreme conditions of reduction powered by a 12 V battery charger, they found that ferrous iron can be reduced all the way to iron metal. All this chemistry can occur without any of the iron going into solution. So, based on this work, when we see the rust slowly turning black, we are seeing the formation of Fe3O4 which is black and eventually iron metal, which is also black. Finely divided iron is black, not shiny like a solid chunk of iron. All this work was done under laboratory conditions.

We wanted to find out what happened when a rusty plane iron was reduced in a bucket. We did reductions of heavily rusted iron object in sodium carbonate under conditions normally used from cleaning rusted objects. We used either a 1 or 5 % solution of sodium carbonate and a 12 volt battery charger and continued electrolysis for about 2 hours. The iron piece was dried under an oxygen free atmosphere (nitrogen). The loose black deposit on the iron surface was removed by sticking it to a piece of tape and it was analyzed by X-ray diffraction. We found that the deposit was magnetite. No iron was detected and no ferric oxides were detected in the black material that readily came off on the tape. Therefore, under our conditions, all the rust was reduced, but the reduction of what had been loose rust did not proceed all the way to iron metal. Perhaps it would have if we had continued electrolysis for a longer time. We had no way of determining whether the rust at the surface of the iron object reduced all the way to iron. We expect that at least some iron was formed at the surface, because after reduction the iron surface rapidly forms red rust (ferric oxide) if it is not quickly dried. Magnetite does not rapidly rust, but finely divided iron will form rust in just a few minutes if it is wet. We conclude, based on our work and that of Virtanen, that rust reduction under the conditions normally used for cleaning, results in the formation of magnetite and possibly some iron metal.

The other chemistry that occurs is the electrolysis of water. At the anode water is oxidized according to this equation

2 H2O = O2 + 4H+ + 4e-


The H+ formed is quickly neutralized by the carbonate to make carbon dioxide. So, some of the bubbles at the anode may be carbon dioxide as well as oxygen. At the cathode water is reduced

H2O + 2e- = H2 + 2OH-

It is important that any copper connector to the anode 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 rerusting.


I have not heard of anyone claiming that the washing soda and iron will form a toxic by product. Solutions made from something other than Sodium Carbonate would cause a problem. Do you have a link or a resource you can post?

 

[drkhrs925]

very nice addition winder, thanks

Bronco Rob - your right its iron oxide but that is how you find most natural iron since it oxidizes naturally. It is very common to ad rusty iron shavings to rose beds to help with their color.

I personally like the evaporate and dispose, but since I am using strait iron I will simply drain off the clear water after it settles and send the rest to the landfill with the trash.

Oh yeah, did I mention that it settles quite nicely. The day after you remove the parts, all the rust and junk settles to the bottom. That being said you can simply set up a siphon just above the gunk and get rid of most of the water right down the drain. Again this is only if you degreased all your parts first. I would prefer to send it to the water treatment plant then the storm drain so consider the environment. If you consider what you put in carefully you make no hazardous waste.

 

[89MustangGX]

Amazing that you can do that at home. Thanks for the info.

Adam

 

[96broncoman]

thats awesome. might have to give it a try....

 

[DcSkater602]

ok i need a new project so that i can do this...

so wait can u describe how to hook up ur negative side to something submerged under water...chain to it or what???

positive just goes on rebar or something and then dipped in

dc

 

[4Wheelin Rust bucket]

i saw this done in my monthly issue of Ol' Skool Rodz magazine..... looks cool!

 

[Winder]

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

http://www.htpaa.org.au/article-electro.php

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

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

Check out these links. Several good pictures and different setups.

You need more electrodes the larger the project. I kind of works on the "line of sight" principle, so you want to surround the rusty piece with as many electrodes as you can. You can use a chain or piece of wire to suspend the rusty piece in the solution.

 

[Bronco Rob]

very nice addition winder, thanks

Bronco Rob - your right its iron oxide but that is how you find most natural iron since it oxidizes naturally. It is very common to ad rusty iron shavings to rose beds to help with their color.

I personally like the evaporate and dispose, but since I am using strait iron I will simply drain off the clear water after it settles and send the rest to the landfill with the trash.

Oh yeah, did I mention that it settles quite nicely. The day after you remove the parts, all the rust and junk settles to the bottom. That being said you can simply set up a siphon just above the gunk and get rid of most of the water right down the drain. Again this is only if you degreased all your parts first. I would prefer to send it to the water treatment plant then the storm drain so consider the environment. If you consider what you put in carefully you make no hazardous waste.

Yea and the correct way to get the iron oxide you add to your gardens is from a Garden Center, it's mixed properly. Adding straight iron oxide to your soil will more than likely cause the plants to die.

And unless your doing a Chemical Analysis of the solution you used, which also contains sodium carbonate at this point, so now your basically adding salt to the mixture, while used in moderation softens water, which in turn makes your process work more efficiently, acidic soil isn't good for all plants.

So now you have Salt, Iron Oxide and whatever other chemicals come off the pieces of steel your stripping. You're process of drying and scraping and sending it the landfill is better than pouring it in your roses. Gardens are expensive and hard to grow, there is no reason to do potential damage to them.

 

[Stock83]

So I have a set of rusty headers that I can get hot tanked for $15. Would this process be better/remove more rust, or should I just hot tank em?

 

[Winder]

Hot tank will eat away rust and some of the good metal as well. The electrolytic process will only remove rust and paint. it is better for thin/small parts.

 

[drkhrs925]

Rob, did you take chemisty at all. Sodium carbonate is not salt and further than that the solution is base not acidic. You are raising the Ph of the soil a bit but I do agree on one thing, unless you are cleaning something that was pure steal with no paint or oil you don't want it in your garden. This process will pull off oil, loose paint, and other finishes. So the best place for it is the landfil where it will decompose over time.