Electrolysis

[ddoan]

Over the past month, I've gotten an electrolysis set up going for rust removal. The last tractor I got (a Ford 2N) had hardly any paint on it to remove, but LOTS of rust. My Dexta was the same way. So, I knew I had to get something going that would effectively address this tedious process. Some friends on my other tractor forum strongly encouraged me to take the time to put together an electrolysis tank. Here is one photo of my pot a cookin:



I also created a "How To" based on what I've learned so far, for those who might be interested:

https://picasaweb.google.com/tractorNstuff/Electrolysis#

Don

[dexta roadless]

wow. this is very interesting. however what kind of solution do you use.

[Bensdexta]

Don,
Thanks for your useful write up. I have used electrolysis quite a bit too and find it cheap and convenient. I tend to use a fairly low current < 0.2A on small parts as I've read this preserves more of the original part. Another point - don't use stainless steel for the anode, as this produces toxic products (Don: I see you're not using stainless).

There's a good website here: http://myweb.tiscali.co.uk/andyspatch/rust.htm

One other point is that electrolysis embrittles springs, so if you do derust springs this way, it is best not to exercise them for say 6 months to allow the embrittlement to be reversed as the absorbed hydrogen gradually diffuses back out of the iron.

All the best,

[ddoan]

I use a solution of 1 tblspoon of Arm & Hammer Super Washing Soda per gallon of water. You can add more Washing Soda, but at a certain point it doesn't do any better.

Ben, I do not use stainless steel. However, I am glad to know about the springs. Quite often, for small parts, I just let them soak overnight in a 1:4 solution of phosphoric acid and water. Next morning, the scrub right up.

Don

[EddieJ]

I also created a "How To" based on what I've learned so far, for those who might be interested:

https://picasaweb.google.com/tractorNstuff/Electrolysis#

Don

Hi Don,
I'm sure that this information would make a great addition to this websites 'Wiki' pages and could be a great help to all.
As you may know the wiki is accessable here http://www.fordsontractorpages.nl/wiki/ ... ePage.html using the details fordsontractorpages and dotty. Any one can add to the information.
I look forward to reading it along with your great photos.

[commander]

One common technique to fight hydrogen embrittlement is to bake the parts at 400F (205c) for 3-4 hours. Do this shortly, within a couple of hours, after you have removed them from the electrolysis tank...smaller parts - clean them up first, then pop 'em in the wife's oven. ...Let them cool off slowly ,in the oven is safest.......

In case anyone is wondering, embrittlement doesn't seem to be an issue with the steels used in your tractor's tinwork.....no need to worry about it on your sheetmetal items.......it primarily affects high tensile or hardened steels....springs, lift arms, hardened and highly stressed fasteners, some cutter and implement parts might be affected.

[ddoan]

it primarily affects high tensile or hardened steels....springs, lift arms, hardened and highly stressed fasteners, some cutter and implement parts might be affected.

Jack,

How significant is the embrittlement? I've cooked a number of hardened steel items - the cylinder head, for example - and am curious as to how likely it is that there would ever be a problem.

I think I could sneak a few pieces into our oven, while the wife's not looking, but some parts - like lift arms - would be tough to get into an oven. Although, I could pop them onto our BBQ grille with the steaks. Even at that, how long is long enough to heat them?

Don

[commander]

That seems to be an open question?

Most of the literature on the subject, and presumably the research and experience behind it, relates to either welding or electroplating.....according to the literature I've seen, it happens when hydrogen is present along with either (high)heat or 'some other medium' to force the hydrogen into the metal.....acids used in plating are often given as an example....

I don't honestly know if much research has been done on this as relates to using electrolysis to remove rust. It's certainly a more limited field. Conservationists restoring old cannons or whatever for the museum probably aren't too concerned about it anyway . It is often mentioned as a possible concern by hobbyists like us who are trying to restore (and use) old cars and tractors.
Certainly the hydrogen is present in electrolysis . Electric current breaks water down to hydrogen and oxygen., the bubbling you see at the electrodes. Alkaline solutions (ie washing soda) aren't considered harmful to ferrous metals, so I'm not certain they can drive hydrogen into the metal. Unlike arc welding, the currents and temps are low....so to me, more uncertainty on the subject.


If you're concerned about it..bake the items ....400 f for 3-4 hours... or just let them set for a few months...the hydrogen will slowly migrate out on it's own, as mentioned up in earlier post.

Sorry, no definitive answer from me......perhaps someone else?