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Thread: Electrolysis- rust removal- basic method and tests (with photos)

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    Default Electrolysis- rust removal- basic method and tests (with photos)

    I use electrolysis for removing rust for a wide range of things and have been very happy with it.
    There was a thread a little while ago (which for anyone interested would form a good background reading for the purposes of this thread)
    http://www.woodenboat.com/forum/show...71#post2199271,
    where there became apparent (again) the differing and contradicting advice that can be given about this process.
    Since that thread I thought it would be interesting to do a few tests of the claims being made (to challenge/confirm my own and others beliefs), and just recently I have started a few.

    here is a decent write-up of the basics of electrolysis.
    http://www.htpaa.org.au/article-electro.php

    I have a few standard and cheap 12 volt battery chargers that I use for this purpose.
    My solution I make up of 'Lectric Soda' (or 'washing soda') (Sodium Carbonate) at approximately 1 teaspoon per pint of water.
    In contradiction to the article linked to above, I use regular mild steel for the electrode, rather than stainless steel. Though it works fantastically, there is a lot of talk around the net of some nasty's from stainless being released into solution. I would rather not deal with this.
    Mild steel works just fine, you just have to clean it up now and again.

    In the thread linked to above, there are a number of claims that were made about the hazards or downsides to electrolysis. Some of these I have tested, and gradually I might add some more, I would welcome anyone else adding any experiences and specific tests to this thread.

    after this first demo, I will try to deal with this claim
    Quote Originally Posted by Bob Smalser View Post
    I can tell you from experience electrolysis swallows copper, and that a little petroleum jelly on the exposed insulation ends isn't enough to protect it. All those electrical components should come out, and that means you'll be dismantling something, probably with lots of penetrating oil.
    and eventually try to do a few tests on various other metals and alloys.


    First here is a demo, also testing one of the issues raised in the above thread whether the slightly caustic solution and the bubbling process is able to get through oil, in this case baked on exhaust outlet oil. This deals with both the issues of whether oil/grease could be applied to protect certain things from the process, and also whether it is possible to try electrolysis as a means of de-rusting and or de-seizing something after one has applied penetrating and other oils in an attempt to free it up.
    To cut to chase before I show the photos- from my tests so far it would appear that this oil does block the process quite well and was not in any way dissolved off my metal with the solution and process.

    Normally I degrease my objects before putting them in, for this very purpose, but as I had no need to actually derust the oily bit on this piece it was a good opportunity to see what happended without. It confirmed my earlier suspicions.

    here is the exhaust outlet


    brass nut and copper washer left in place


    here is the baked on oil


    a scrap of steel for the electrode, cleaned up for the connection


    and a quick wire wheel on the exhuast outlet for a similar good connection. Positive to the sacrificial electrode (the red reminds me that this is the thing that is going to rust) and the negative to the thing to be de-rusted (the cathode).


    Pop in it, and away she goes. Obviously the positive clip needs to stay out of the solution, because it would rust away otherwise. The negative clip is fine to drop into the solution (and here is the hint as to how the copper test turns out)
    One path leads to despair and utter hopelessness. The other, to total extinction. Let us pray we have the wisdom to choose correctly.
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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    after a day in there, it is starting to get there. Because of the nature of this object, the process is greatly helped by pulling it out and using something to chip out the scale that is loosening up day by day.




    the oil, still very oily


    the electrode eventually rusts right up and the process slows right down,


    time to pull it out, scrape it off and give it a quick grind. Doesn't have to be perfect by any means, just needs to expose a bit of raw metal and process takes off again.


    after two days in the pot, it is getting a bit better. Note the brass (or is it bronze? I don't know) bolt has cleaned up but turned a little black. This is no problem and quickly cleans off.
    One path leads to despair and utter hopelessness. The other, to total extinction. Let us pray we have the wisdom to choose correctly.
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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    everything was pretty close except for the insides of the the water jacket part- it was loosening up but I was getting impatient so I rigged up another electrode to blast out the inside. Electrolysis works primarily in line of site between the electrode and the cathode, so manipulating the shape of your electrode can help sometimes.

    the rubber is to stop it shorting between the two




    anyway, a few hours later I had it out, gave it really good scrub and a wash, and then treated the whole thing with a rust converter. I don't usually do this, but I though it would be no harm and possibly some help for this part in my raw water cooled engine.

    normally the metal would look a bit cleaner than this, but the remains of my rust conversion have stained it blue/black. Here is the part ready for painting and installation.




    I could get a bit more anal about cleaning up the little bits of surface rust that have appeared upon drying again, but as this is going to have raw sea water flowing through the water jacket part, have oily exhaust through the exhaust part, and be primed and painted on the rest, I am not too fussed about it. All the scale has been removed and it should be good to go for a while again.
    One path leads to despair and utter hopelessness. The other, to total extinction. Let us pray we have the wisdom to choose correctly.
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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Now the copper test.
    It has been my prior experience that brass, bronze and copper are not adversely affected by the process. If they are corroded, they will clean up and the dissolving of the corrosion will often leave pitting. The end result is that the metal has gone back to good metal and is slightly blackened. This blackness is very easy to polish off.

    So I was a bit surprised when Bob said that, speaking from experience, the process literally swallows copper.
    It was my belief, and I said as much in that thread, that the process worked quicker on copper, but did not by any means swallow it- at least not at any great speed.
    I have done copper in the brew before with no bad results. The worse the copper goes in, the more pitted it came out, but that is life.

    I was about to just stick a bit of copper plumbing pipe in the bucket and see how quickly it was 'swallowed', but then it struck me that I have been putting copper in the pot just about every time I do the process. Aside from the negative clip which is submersed during every application, on my main charger I use I have a series of alligator clips that are bolted to the main clip- this allows me to do many small things at once. These must have done a few thousand hours in the brew, and the exposed copper is just fine.
    So, instead of the copper plumbing pipe, I thought I should give Bobs claim a slightly better chance and at least try to establish a baseline of what is easily swallowed (I thought it would be!) - I tried to find the thinnest bit of copper I could and see if I could get the process to swallow it.
    Digging through old wires I got a thin one and pulled out one strand of copper, not much thicker that a hair.
    Popped it in, with a freshly ground electrode, and watched it literally steam away. The photo doesn't do it justice but this thing is really bubbling away.


    I left this thing going, checking it closely, waiting for signs of corrosion, for over three full days.
    Pulling it out, and looking at it, it is hard to say. It might be a tiny tiny bit thinner... maybe... I doubt it, but it could be. All that has obviously happened is that it is blackened.
    here is the wire end to end, the lower black bit that spent over three days steaming away, with nothing else in the pot to share the load, and the brighter bit the end out of the pot.

    Does it look much thinner? The black seems to give the illusion of it, but the shadow it drops, and the feel of the thing seems exactly the same.



    obviously there are better ways to clean copper, and brass and bronze, but from my experience so far, allbeit on a completely superficial level (I don't know what is happening on a molecular level) there appears to be absolutely no harm in putting some of it in if it is too hard or too annoying to remove from another object.
    In my experience electrolysis DOES NOT swallow copper, bronze or brass.

    That is it for the moment,
    gotta grab dinner.
    I will be testing some aluminium soon, which I suspect will be eaten a lot quicker and more succesfully than the copper.
    and I might also post up some of the interesting results that I have been playing with of deliberately creating a patina on brass/bronze by reversing the polarity of the process briefly.

    If anyone has and experiences, interesting results, wants to do their own tests- whatever, post it up and discuss away.

    Hans.
    One path leads to despair and utter hopelessness. The other, to total extinction. Let us pray we have the wisdom to choose correctly.
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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    And just a note-
    I don't mean to single you out Bob Smalser. This isn't designed to be a criticism or anything. Just some tests, where the copper result actually surprised me- I thought something that thin would dissolve quite quickly.

    I do hope you, and others, join in with some tests, results and opinions.
    Hans.
    One path leads to despair and utter hopelessness. The other, to total extinction. Let us pray we have the wisdom to choose correctly.
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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Being a bear of little brain I've only ever removed rust etc. by scraping and brushing. I'm even wary of rust converter! Your very helpful steps and photos will lead me to a whole new approach - thanks!!!! Rick

    PS I wonder where I can get a bucket big enough for my 3 tons of Twister ballast?

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Great post and pics. Thanks for posting up.

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Seriously Rick ? a big plastic bag would do the job .

    That's a very good tutorial Hans .....thanks for taking the time to do it .How big a battery charger do you use ? Mine is only 3500 milli amps ...the big one died .

    I still use the molasses method ,mainly cos I'm set up with a big tub of the stuff , but I might need to do this sometime !
    Try to work out what the marketing guy wants you to do then do precisely the opposite.

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Serendipity! I was just about to ask about this process. I have been given a wood turning lathe (nothing fancy, a Ryobi) and a big set of gouges etc that are rusty. Thank you Hans.

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    I guess I'm shocked. It seems my sandblaster would have done that good in about an hour. 2 days? Oh my!
    excellent tutorial though.

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    I agree with Happ- while an interesting exercise in chemistry, sandblasting would be my choice, although for interior/nooks&crannys, perhaps a bit of phosphoric acid? (Sandblasting is also a "line-of-sight" process!)

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Bravo.

    I'll happily cede all your points on the details of electrolysis, as rarely use it. Just don't omit the context of my objections. You were supporting the idea of tossing an intact, fully-assembled engine in its entirely into an electrolysis bath. And a decades-old engine with crankcase seals that would leak, allowing your sodium solution to penetrate bearings, electrics, combustion chambers, valve seats, ring grooves, etc, et al. And the poster in question had no intention (or capability) of disassembling the motor down to its smallest parts to clean all that crud out afterwards. I was only speculating on the details of the damage.

    But even with your excellent explanations, that I still think the idea lacks merit is a gross understatement.
    Last edited by Bob Smalser; 07-05-2009 at 09:05 AM.

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Thanks guys, I am glad this is of some interest.

    Rick- A big enough container? Well, anything that will hold the water would do. For really big things, ie a car panel or a keel or something, you could use a cheap baby pool... anything really. One method I have not tried yet, for things that cannot be easily submerged is to wrap the object to be de-rusted in something like a towel- then place your electrode in, and wrap it in another towel... then wet the whole lot with the electrolytic solution (draining into a tub or something), turn the process on and just keep pouring water over the thing to keep it wet. Hardly ideal, but it would work.

    Peter,
    I should say, I really don't know too much about the precise way this works- I just jumped in and tried it, and worked with the results- trial and error with very little error. It is easy.
    My chargers- I can't quite figure out how many milliamps they are- they are just run of the mill small bottom end chargers, here are photos of two of them- maybe you can tell me.
    the current one these tests were done on

    the one I have multiple aligator clips connected to- that has done in the thousands of hours


    Jeff, it will make light work of those things. If there is any oil on them, or any lathe parts you need to do, just give them a good wash in hot soapy water before you chuck them in. When you are done, after pulling them out, and giving them a really good hot soapy scrub to get off the black (alternatively, if you want bright metal, give them touch with the wire wheel- but I like the black remnants), I like to put them in a warm oven until they are dry so you don't get surface rust- then give them a little oil.
    (EDIT- I should add, in case Bob is too polite to correct me, while this method will make light work of such things, for chisels and such, there are some good arguments as to why the methods Bob has written about so often (and well) might just be the better option. If they are really nice chisels, and deserve the full Bob treatment- phosphoric acid, ospho blue, etc etc, (IIRC) -then the greater rust resistance at the end might be worth the bit of extra work)

    D Happ, LOL, yeah, it takes a little time but the effort investment is really quite minimal. For simple surface rust, no doubt a quick sandblast would be way quicker. I don't have a sandblaster so that is not an option. Where this really comes into its own, IMO, is with rusted things that are hard to reach and really heavily scaled up. The photos of this exhuast outlet don't really show too much, but I had a good handfull of scale come out of this thing- that bulge leading to the threaded bit, as the water jacket goes all the way in there, was packed full of rust. I am not too sure how quickly or effectively sandblasting could have got it out.
    But this is just one method.

    Bob,
    I've been half way through replying, but come across an edit..
    If it came across that way, I am sorry, I did not mean to omit the context of your argument. That is why I referenced the thread in question, and recommended the reading of it.
    I did not simply want to just turn this into an argument about that issue, thus why I only posted the claims I was trying to test- but I guess a little discussion of it was inevitable.
    How you have represented my advise on that thread is not quite right. My main point of contention was that IF electrolysis was desired to be tried, on parts of the engine, not necessarily just tossing the whole thing in there- ie, seized bolts etc, submerging just one end or section of the engine, then it would need to be done BEFORE the oiling process. You said any oil could just be 'cooked off' which you still haven't clarified what exactly you mean by that, or how to achieve such once the oil has penetrated into a seized thread- nor whether you have actually done electrolysis after oiling failed, and you cooked off the oil. I was only speaking from my experience that once the thing is oily, electrolysis fails to work.
    My other points of contention were that, from my experience to that date, the process was not anywhere near close to as destructive to some metals as you asserted- I have tried to prove as much here and would welcome your comments on how this has differed to your first hand experience of it 'swallowing copper'.
    In my trials here, and there are more in the works, it seems that a well greased or oiled coating is a very good protector from the process. Copper is not overly affected, nor bronze and brass.
    I am not saying everything is unaffected- I am sure much is.

    Here is what I finished saying in the other thread
    Personally, if attempting this engine, I would be trying to seal up (and yes, possibly fill with oil before hand) all the internals IF the whole thing was going to be dropped in there to do at once. I can't imagine that this would be very hard to do at all. The line of site reaction of electrolysis would mean that with electrolytic solution inside the engine, not much at all would be happening inside anyway- nonetheless, if possible it would only be prudent to attempt to keep the solution out of the internals until the thing can be dismantled and then parts dealt with individually (if electrolysis fails- then having the engine full of 'salty' water may not be the best thing)
    Fur the purposes of freeing up these exterior seized bolts, if electrolysis wants to be tried first, I would be keeping oil as far away as possible from them, to give it the best go at working. If it doesn't work, then no harm done, and you can try oil, heat, elbow grease, after.

    Dropping the whole thing in at once though is not the only option.
    It would be very easy to suspend bits of the engine that are seized into the solution and work on them one bit or side at a time.
    For example, if it is seized, one could suspend the flywheel in and work that off first, then next move onto the the crankcase and it's bolts, etc, etc.
    Last edited by hansp77; 07-05-2009 at 10:01 AM. Reason: Adding to reply to Skuthorp
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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    For interest here are a couple of other things I am experimenting with. If you thought I was crazy before, then this might seal the deal...
    the following IS a science experiment.

    Just a few spare boat bits from the shed.
    I love a good patina- but I have a few things where it is not so pretty and I would like to get a more even coat- and or the object in question would do well with a clean up of the casting and I don't want to leave it polished and wait for the patina

    Here is a fairlead,
    pretty rough in the casting and not so special in the patina- not helped by being found in a box of old rusting engine bits.


    I gave it a bit of elbow grease and got it to this point

    nice and shiny, temporarily... but what I want in the end is a nice patina on this now smooth surface.
    So why the hell did I do this to it


    well, this is the middle step. I trialed this first on a big chromed cleat below whose chrome was peeling off.
    Same process as with the one above, removed the chrome, cleaned the casting, polished it up, put it in the elctrolysis tub and used IT as the electrode (ie the opposite of what I would do if I was trying to remove corrosion from it). A few hours and it is caked up in this blue gunk, and then just left it to dry and weather outside for a while.
    A couple of days ago I gave this cleat it a buff on the cloth wheel, and I am not all too unhappy with the result. A nice start to a even patina.


    anyway, these last two are purely science experiments- I am not by any means selling the method, just playing around. Entirely different from the practicality of using the process to remove rust-

    I am going to mess with some of these things a bit more. Using the brass/copper/bronze as one should, as the cathode, does remove the corrosion quite well, and leaves it with a black finish. I will be doing polished piece like that also, and leaving it out to weather like these ones are doing, and seeing what comes up with the nicest, smoothest and quickest patina.
    One path leads to despair and utter hopelessness. The other, to total extinction. Let us pray we have the wisdom to choose correctly.
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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Quote Originally Posted by skuthorp View Post
    Serendipity! I was just about to ask about this process. I have been given a wood turning lathe (nothing fancy, a Ryobi) and a big set of gouges etc that are rusty. Thank you Hans.
    I would be reluctant to try this on hardened steel tools, as there is a risk of what is called 'Hydrogen embrittlement' which may cause your lathe chisels to be , well, brittle!

    The way I understand it, electrolysis causes tiny amounts of atomic Hydrogen to actually move through the steel upsetting the crystalline structure of the metal, and making it brittle.

    Cast iron can not be hardened (as lathe chisels can), so it is immune to this possibility.

    If anyone needs more than Hans's excellent tutorial,here's another good description of the process: http://wiki.owwm.com/RustRemovalByElectrolysis.ashx

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Cheers oznabrag, I forgot to mention hydrogen embrittlement in this thread- though I did in the other one.

    I have never witnessed it personally, though I am not too sure how I would exactly notice unless it was extreme. I do hardened tool steel all the time, chisels, plane blades, drill bits, etc. I have yet to notice any increase in their brittleness, and have not found much certain evidence online of this actually being a problem- just more of a theoretical issue that can be gotten around if there is a concern about it.
    As with any of this stuff I am more than happy to be proven wrong- I just haven't found any actual testimony of this being a real problem.

    from the write-up I linked to at the top
    http://www.htpaa.org.au/article-electro.php
    Atoms of hydrogen absorbed by steel are known to enter the lattice of iron atoms and prevent the layers from sliding past each other easily. This causes the steel to become more brittle and liable to crack. The absorption of hydrogen by steel is a familiar problem in industry which arises during steel refining, heat treatment, acid pickling or electro-plating. It can also happen as a result of simple corrosion. The standard remedy is to bake the objects in ovens to drive out the absorbed hydrogen (200°C for four hours would be a typical regime in industry). The simple passage of time is also known to cause loss of hydrogen from steel. Hydrogen embrittlement may occur to some extent during electrolytic de-rusting. This may be a cause for concern with saws or other edge tools. It might be wise to wait a while before setting saw teeth after prolonged, electrolytic de-rusting. Alternatively, baking the tool in the oven for hour or so at about 150°C (300° F) should remove absorbed hydrogen. Note that this baking temperatures is low enough to leave the temper of most steels unaffected. Since hydrogen embrittlement is reversible, it should not cause too much anxiety. I believe that the advantages offered by electrolytic de-rusting justify wider experimentation by tool collectors. As more experience is gained clearer knowledge of its advantages and disadvantages will emerge.
    and another forum with a bit of discussion about embrittlement.
    http://www.practicalmachinist.com/vb....html?t=156015

    anyway,
    gnight.
    One path leads to despair and utter hopelessness. The other, to total extinction. Let us pray we have the wisdom to choose correctly.
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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    I'm wondering whether you could "cook through" oil and grease and thus kill two birds with one stone by substituting NaOH (sodium hydroxide, lye) as your electrolyte solution (though I'm surprised Na2CO3 didn't do the same thing)...

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    How are you removing the chrome?


    Love the info!!!!!
    Ric in Richmond

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Thanks, Hans, for that clarification/demystification on the Hydrogen embrittlement issue.

    I have heard of one instance where HE was definitely the culprit in the loss of a fine hand saw.

    On the Old Tools list many years ago, one of the members was using electrolysis to clean an old Disston, and found that his usual container was just a little short. He decided to bend the saw a little so it would be submerged and went ahead and zapped it for a day or two.

    IIRC, when he removed the saw from the bath, the end simply went 'pop' and came right off in his hand. The theory was that Hydrgen had worked it's way into the structure of the bent steel and, when it sprung back to shape, it broke itself off at the former bend.

    Pretty crazy stuff.

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    WHY go through all that stuff?

    Just get some Phosphoric acid. It turns the iron oxide to iron phosphate.
    Otherwise it stops the rusting.

    OR grit blast THEN put on the phosphoric acid rinse with water, and after it is dry paint with epoxy paint. Paint within 4 hours.

    Thats all you have to do.
    I love the smell of fresh cut plywood in the morning.

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Quote Originally Posted by donald branscom View Post
    WHY go through all that stuff?

    Just get some Phosphoric acid. It turns the iron oxide to iron phosphate.
    Otherwise it stops the rusting.

    OR grit blast THEN put on the phosphoric acid rinse with water, and after it is dry paint with epoxy paint. Paint within 4 hours.

    Thats all you have to do.
    True enough, Donald.

    On the other hand, electrolysis will not only remove rust, it will actually repatriate some of the iron, the black rust, back into the piece. It simply removes the red rust.

    Further, on old saws (not the subject here) it will clean the steel and reveal the etched maker's mark like new. Very delicate touch, if you need it.

    Edited to add:
    a) FeO = ferrous oxide
    b) Fe2O3 = ferric oxide, hematite, and red iron oxide
    c) Fe3O4 = ferrous ferric oxide, magnetite, and black iron oxide
    Last edited by oznabrag; 07-05-2009 at 12:31 PM.

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    The advantage of a phosphoric acid treatment is that it fills the rust pits with iron phosphate and seals them off from the after rust that's common with electrolysis when the item can't be quickly primed and painted.

    But the down side is the iron phosphate residue is dark, and is difficult to polish off completely when used on steels sensitive to heat.





    There are some tricks to bring out an etch I describe in the saw article below.



    Rustproofing Tools

    Advanced Handsaw Filing and Restoration

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Hans , did you say above that the reversed process worked to remove chrome ? I have a variety of old fittings , quite nice stuff but marred by being neither chromed nor polished bronze ...just a bit of both !

    A simple way to remove the chrome would be great ! It's
    a long drive to a chrome plate works and the guy charges for his service ...not unreasonably !
    Try to work out what the marketing guy wants you to do then do precisely the opposite.

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Back in your box Gary .I don't mind paying but prefer to do it myself if I can .

    The 1 1/2 hr drive each way is a factor too .
    Try to work out what the marketing guy wants you to do then do precisely the opposite.

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Seriously Rick ? a big plastic bag would do the job .
    Actually, yes! I have to take the ballast off the Twister and it's about 3 tons. The problem is that I'll probably have to grind off the rust to find out how the blasted thing is fastened anyway. But, once off, a plastic container of some sort could be a good alternative for cleaning it up nicely using electrolysis. Some have suggested sandblasting but I don't think this would be feasible for me at home - although if anyone thinks it could be done without transporting the Sahara home, I'd be glad to hear the advice. I do have spraying gear. My plan until yesterday was to take all the rust off with a coarse disc on the angle grinder. Rick

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Removing the excess mechanically is a good idea anyway Rick .Here's the method I use , much slower than Hans' but it works very well too .
    http://www.woodenboat.com/forum/show...light=molasses
    Try to work out what the marketing guy wants you to do then do precisely the opposite.

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Thanks Bob, thanks Hans, seriously good information here. When we move in to the new place we will be about 1.7k from the sea though not in direct line of sight. I expect that salt residue in the air will be a constant problem for my tools even though I intend to provide proper closed storage. Bob's invaluable information on rust proofing was in my mind already.

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    This is a great demonstration of electrolysis, IMHO. Thanks for posting it. Not to criticize the method, it seems to be a great tool for rust removal.

    However something I've used is a solution called Evaporust http://www.evaporust.com/. A while back I put some engine parts in it for a week and it completely removed surface rust. The evaporust starts out yellow and gradually turns black. I can safely pour it down the drain. I was then able to paint the parts and had no problems with recurrence of rust. Also there is no line of sight characteristics as with electrolysis.

    I don't have any stock in the product; it is just something that I found that works.
    Will

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    If you have a large item you can make a tank with sand and plastic sheeting.
    Carpe the living sh!t out of the Diem

    I'd rather look back at my life and say "I can't believe I did that" instead of being there saying "I wish I'd done that"

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Quote Originally Posted by skuthorp View Post
    Thanks Bob, thanks Hans, seriously good information here. When we move in to the new place we will be about 1.7k from the sea though not in direct line of sight. I expect that salt residue in the air will be a constant problem for my tools even though I intend to provide proper closed storage. Bob's invaluable information on rust proofing was in my mind already.
    Don't forget Lanocoat or Enox spray .Very good on tools .
    Try to work out what the marketing guy wants you to do then do precisely the opposite.

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Regarding removing chrome-
    running the process with a chromed piece on the cathode (where it should be) at times has some success in bubbling off the chrome, and at others does not touch it- similar to paint- it all depends on the piece, the quality and condition of the plating. I usually find that if I want the chrome to stay on, it will flake off, and If I would like it off, it remains
    Reversing the process, as Peter raised, is something that I will be experimenting more with. Obviously one can't do this for very long as it will just eat the piece.
    (The way I see it is trying to introduce small faults in the chrome first, scratches with low grit sand paper, etc, and then put the piece in as the electrode briefly to try to get some corrosion under the chrome, then switch it back to normal, with the piece as the cathode again, and blast away the chrome that has now been undermined by corrosion- and possibly repeat- this would be trying to force the conditions where chrome does nautrally seem to completly bubble off- when it has been damaged, scratched, etc, and undermined) (Honestly though, I doubt I will be making any discoveries here to put the chrome platers and de-platers out of business)

    just for reference though, the above cleat was de-chromed the hard yakka way, angle grindle and flap disc, and then lots of hand sanding to finish it off, before polishing with rouges.

    Regarding the questions along the grain of, why go thru all this?
    Well, because it works, and it can make very very light work of things that used to not be such, it is easy and safe, and it is very very cheap. For some applications I believe it to be possibly the best alternative (or one of), of course not the only, and not by any means the best or only in all applications.
    If I could have a little shed gnome working away for me when I was asleep, restoring hand tools, etc, then I would honestly prefer he was using Bob Smalsers techniques and chemicals...
    But I don't have the gnome, the only thing that keeps working for me when I go to bed is the battery charger, and the chemicals for Bob's method cost significantly more here than a bag of laundry additive every couple of years (especially for the amount of stuff that I have de-rusted).

    So once again, this is just one of many methods of removing rust. Not the only, not the best by virtue. I don't have a sandblaster, I don't want one or need one. But, being just one technique to remove rust, it is not necessary to treat this as an either or issue- it can be used for some applications, and not for others, or as I sometimes do, in combination with other methods.
    Personally, I use electrolysis on hand tools and many things which might be better done by the methods Bob has explained so well, because the results are great, or good enough for me (and many others out there who are happy with the process). I try to keep the tools oiled, as one should, and/or deal with surface rust as it arises, maintaining the tool as one would as if it was new, and gaining that aged patina slowly along the way.
    For some things, often I will use electrolysis in combination with phosphoric acid. If the piece is really bad- I blast off the rust, easily and cheaply done, then I clean it up, and let a bit of suface and pitting rust re-form again- and then treat it with some phosphoric acid to get that fine layer of iron phosphate.

    Mostly I like leaving a good amount of the black iron oxide (or is it ferrous oxide, or magnatite?) on rather than brushing it back to bright metal. After a bit of oiling and use, this black layer becomes quite a good protection itself.
    One path leads to despair and utter hopelessness. The other, to total extinction. Let us pray we have the wisdom to choose correctly.
    Woody Allen

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    this was an interesting read
    from here

    Forgive the repeats, but I am going to quote it in full, because it adds some well explained technical details of the whole process- that I am still trying to get my head around.

    Background

    I wanted to clean some badly rusted plane irons. I used the electrolysis procedure employing a battery charger and a solution of washing soda (sodium carbonate) (see http://Rusty2L.com [obsolete link]). I was astounded by the favorable results. I am an electrochemist, yet I didn’t know what was happening to the rust. Neither did any of my colleagues. This was too much for my curiosity, so I went to the chemistry literature to see what was happening. Much of what I found was incorrect electrochemistry and a lot was speculation. In fact, it was not until 1996 that the chemistry was figured out. I thought others might also want to know what was happening in this process so I wrote up the results.
    The Chemistry of Cleaning Rusted Iron by Electrolysis

    by Spencer Hochstetler and Bill Tindall

    The cleaning process has 4 components- a battery charger, the water with sodium carbonate (washing soda) dissolved in it, an anode (stainless steel object such as a spoon) and the cathode (the rusty iron).
    The solution

    The solution of sodium carbonate has two purposes. First, sodium carbonate is basic. The electrochemical reactions that occur at the rusted iron work best in a basic solution. Lye (sodium hydroxide) would work as well but it is less safe to use. Sodium bicarbonate, baking soda, may not work as well as sodium carbonate because it is less basic. The other purpose for the sodium carbonate is to make the water conduct electricity. When the salt, sodium carbonate, is dissolved in water it becomes sodium ions, Na+, and carbonate ions CO3-2 . These positive and negative charged ions carry the current in solution. Carbonate moves to the positive wire from the battery charger and sodium moves to the negative wire. This movement of ions through the solution results in a current, just like electrons moving in a wire results in a current. Pure water has a high resistance, about 20 million ohms per centimeter, and negligible current would pass without the sodium carbonate ions.
    The battery charger

    is a source of electrical current and voltage. Current is the flow of electrons in a wire. Voltage is a measure of the electron energy. So, the battery charger provides electrons with an energy of 12 volts at its negative lead and accepts electrons at its positive lead. The current indicated by the meter provides a measure of how many electrons are flowing. Current can also flow through water, if the water has ions dissolved in it, as provided by the sodium carbonate. When the battery charger is connected to the solution with a metal anode and cathode, the negatively charged carbonate will migrate to the positively charged anode and sodium will migrate to the cathode. The solution completes the circuit so a current of electrons can flow from the negative wire of the battery charger to the positive wire.
    continued next
    One path leads to despair and utter hopelessness. The other, to total extinction. Let us pray we have the wisdom to choose correctly.
    Woody Allen

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    The Anode

    The most simple anode to consider is an anode made of stainless steel. In this case, the anode is inert, that is, the stainless steel does not undergo any chemical reactions. Its only function is to provide electrical contact between the positive lead of the charger and the solution. The copper connector of the battery charger must make good contact with the stainless steel but it must not touch the solution. If it does touch, it will dissolve. The copper that dissolves will wind up depositing on the iron object being cleaned and cause it to rapidly rust (see advanced chemistry section for details). When 12 volts is applied to the anode some chemistry does occurs in the solution touching the anode, which will be explained below.
    There are two chemistry terms, oxidation and reduction that must be explained in order to understand the chemistry that occurs at the anode and cathode. Oxidation is a chemical reaction where something gives up electrons. When a chemical species gives up electrons we say it oxidizes. For example when iron metal oxidizes it looses two electrons to become ferrous iron, Fe++. If iron loses three electrons it oxidizes to become ferric iron, Fe+++. Reduction is when something accepts electrons. For example, if Fe++ accepted two electrons it would become iron metal, Fe. We would say, ferrous iron was reduced to iron metal.
    Oxygen likes to be reduced. When oxygen is reduced, accepts electrons, it makes oxide, O--. If we put oxygen together with iron metal, the iron is oxidized (gives electrons to the oxygen) and the oxygen is reduced (accepts the electrons lost from iron). The product is one form of rust, ferric oxide, Fe2O3. It is always true that whenever something is oxidized, something else must be reduced. Electrons must come from somewhere (oxidation), to go somewhere (reduction).
    Getting back to the anode..... The anode is hooked to the positive wire of the charger. The positive wire accepts electrons. If the positive wire is accepting electrons something is losing electrons (oxidizing). When 12 volts is applied to the anode, water is oxidized at the anode surface and gives electrons up to the anode. The product is oxygen. The bubbles you see coming from the stainless steel anode are oxygen that resulted from the oxidation of water.
    The Cathode

    The cathode is connected to the negative wire of the battery charger. The negative wire supplies electrons. Therefore, something must gain electrons at the cathode (reduction). Two things are reduced at the cathode, water and the rusty iron. The reduction of water produces hydrogen. The bubbles coming from the cathode are hydrogen gas. (A safety note: The fuel for the space shuttle is hydrogen and oxygen. Rust electrolysis should be done in a well ventilated area so that explosive concentrations of hydrogen and oxygen are not reached.)
    The evolution of hydrogen plays a beneficial role in the cleaning process. All these tiny bubbles forming at the surface blast things off the surface that aren’t stuck tightly. Loose rust, grease and even paint are removed by the action of the hydrogen bubbles. This process is sometimes called cathodic cleaning. I suppose the anode is scrubbed too, but who cares.
    The reduction of interest is the reduction of the rust. Rust is typically a mixture of many iron compounds. Which iron compounds are present in rust depend on how much oxygen and water was present when it formed and many other factors. The electrochemical reduction of rust is very complicated.
    During electrolysis the rust turns from orange to black. It is natural to wonder what the black stuff is. In most cases, the rust next to the iron is reduced to iron metal. This reduced iron will form a somewhat porous layer of new iron on the object cleaned. After electrolysis the iron object will rust very quickly unless it is protected because this porous layer of new iron has a high surface area and it is particularly susceptible to oxidation (rusting). The rest of the rust may reduce to a variety of compounds depending on the compounds in the original rust and the details of the electrolysis. Typically the black stuff that can be rubbed off after electrolysis is a mixture of iron metal and magnetite, Fe3O4 , an oxide of iron. Magnetite is an intermediate product in the reduction of rust to iron metal. It is the black stuff in magnetic recording tapes.
    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.
    Spencer Hochstetler and Bill Tindall
    some of this last stuff, is interesting. After some of my more adventurous science experiments, I have noticed some weird things happen, requiring a change of the solution. I suspect now that this is because playing with copper, brass and bronze on the electrode (or annode) end, is releasing stuff into solution which then does stuff.
    I have never noticed this rapid re-rusting, but after playing with a lot of copper last year, have had the solution simply stop working on steel, and even once seem to put some sort of coating on the steel.
    Anyway, interesting stuff.
    One path leads to despair and utter hopelessness. The other, to total extinction. Let us pray we have the wisdom to choose correctly.
    Woody Allen

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    Default Re: Electrolysis- rust removal- basic method and tests (with photos)

    Thanks for the posts, I haven't found time to try mine yet.

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