Gurt electrolysis tank

[Maker]

It's not just on here. It's a common myth.

I believe @Maker ? gave a succinct description on the matter several months ago.

Sounds like something I might say.

It's line of sight-ish: The electrons (And therefore the de-rusting action) follow electrical field lines, something like this:



It's faster where there's line of sight, but the back-side of the part will get cleaned just fine, if a little more slowly. The problems come when you have deep holes or tubular/hollow parts. Electrolysis didn't touch the inside of these grinder tables until I stuck an extra anode down the middle.

 

[MattF]

Electrolysis didn't touch the inside of these grinder tables until I stuck an extra anode down the middle.

Been a few year since I last had a vat set up, but I can't recall having problems even with something like that, unless there were either air pockets else notable oil or grease coating the surface.

 

[finyuk2005]

You posh git.

my first thought too!! bloody jealous of that now!!

 

[Ross365]

It's faster where there's line of sight, but the back-side of the part will get cleaned just fine, if a little more slowly. The problems come when you have deep holes or tubular/hollow parts. Electrolysis didn't touch the inside of these grinder tables until I stuck an extra anode down the middle.

I'm looking at those words "a little more slowly" and think I might suggest "a good deal more slowly" based on the experience I had trying to de-rust a car wheel. Does the rate of de-rusting decrease directly with the separation of cathode and anode, or by the distance squared? Haven't used electrolysis here for several years.

 

[Maker]

Does the rate of de-rusting decrease directly with the separation of cathode and anode, or by the distance squared?

No idea, sounds like degree-level chemistry, I'll ask my brother.

 

[Turbo]

I've went through a few different anode designs on my electrolysis tank (a 200l plastic barrel). Out of all the designs the one that worked the best was lining the sides with sheets of steel cut into strips & welded together. It gave the most even derusting, it was the easiest to clean afterwards with a pressure washer & the anodes last for ages.

The worst anodes were made from some 25mm wrought iron bar linked with strips of cart wheel shoes welded on. They didn't work very well, were a pig to wash & they seemed to dissolve away even when not using the tank!

You will need to remove the anodes for washing, they get covered in crud quite quickly & become very inefficient ie you will waste a lot of electricity cleaning stuff.

It also really helps to connect the power directly to the item being cleaned using a crocodile clip & copper wire, grinding back a spot to clean metal to get a good contact.

I tried the method where you connect via the suspending wire & it rarely worked & gave poor results. You are only sending through 12v at 2A so not enough to overcome a poor connection. Given the rising cost of electricity every thing you do to increase the efficiency is important.

For really rusty stuff you may need to remove the item & power wash it a few times to get the best results.

 

[sako243]

Got a bit more done today, fitted the swinglift support tube/king post and braced it down to the stillage feet. Done it this way so the swing lift can rotate through 360 degrees.


View attachment 350492

And it can lift out when the hoist side of things are not needed.

View attachment 350493

Leccy hoist turned up today so thought I would try it. That machine rake is a lump.

View attachment 350491

View attachment 350490

View attachment 350489

View attachment 350488

I question why since you'll be bringing the thing over on the forklift anyway surely it's just easier to tip it in straight off the forklift?

 

[8ob]

I question why since you'll be bringing the thing over on the forklift anyway surely it's just easier to tip it in straight off the forklift?

Ed you know I hate that forklift with a vengeance the idea is to dump that tank in the corner of the yard and have a pallet of gear next to it that needs cleaning, far easier that it self loads.

Bob

 

[Screwdriver]

It isn't.

Nope. The line of sight thing is incorrect.

It's not just on here. It's a common myth.

I believe @Maker ? gave a succinct description on the matter several months ago.

Just because you keep saying it, doesn't make it so. The science is quite unequivocal and you have to rely on your precise definition of the line of sight "thing" being so cryptic.

The process involves the migration of charged atoms or ions within the electrolyte. The key point being "migration". They have to move in order for the process to occur and as much as you like to keep saying it is a myth, that is the science behind it. If a particle/atom/ion has to move then it stands to reason that there is a distinct difference between moving a short distance between the anode and cathode and having to travel a much further distance round a corner.

Ask yourself why a positively charged iron atom for example would bother going all around the houses to reach a shadow zone when it would have to first ignore a much stronger field emanating from a much closer area.

The effect is not digital, it is not a simple case of whether the process will or will not work, it is a matter of efficiency. Eventually a rusty part submerged in an electrolyte will become reduced and free ions will find some other area to react with. Having as much coverage as possible with anode material surrounding the part is way more efficient in both time and energy, plus the effect will be much more evenly distributed.

The distribution of the effect on rusted parts becomes really obvious with a large surface area where it is not uncommon to be able to see the pattern of the anode being virtually printed onto the workpiece. A good example would be to have a small anode right next to a large flat workpiece like a plate. The area closest to the anode will become "cleaned" (lit. reduced) so as to leave a bright patch which gradually tails off towards the edge. On the reverse (in "shadow" from the anode), the opposite will be seen where ions which make it around the back of the plate will first react with the edges leaving a largely untouched spot in the middle.

On the other hand, if you would like to argue the science, I will be delighted to discuss the matter at a much deeper level. You will of course need to explain precisely what you mean by "nope" and "the line of sight thing"

 

[Maker]

I'm looking at those words "a little more slowly" and think I might suggest "a good deal more slowly" based on the experience I had trying to de-rust a car wheel. Does the rate of de-rusting decrease directly with the separation of cathode and anode, or by the distance squared? Haven't used electrolysis here for several years.

No idea, sounds like degree-level chemistry, I'll ask my brother.

He didn't know either. It stands to reason that a bigger anode area, smaller separation and higher voltage will all increase the current and speed things up, quite how much it speeds it up I'm not sure, I always just left it overnight, if it wasn't clean by the morning I'd reposition things and try again. I tend not to bother any more, citric acid is good enough for me, and any wetted surface gets clean.

 

[MattF]

On the other hand, if you would like to argue the science, I will be delighted to discuss the matter at a much deeper level. You will of course need to explain precisely what you mean by "nope" and "the line of sight thing"

Aye, like I've nowt better to do with my time than enter one of your endless, pointless "discussions".

Theorise all you will, & have your opinion 'til the cows come home. It won't change a thing though.

I'm quite sure 8ob will draw his own conclusions from the simple realities, as he experiments with his setup.

 

[Screwdriver]

Aye, like I've nowt better to do with my time than enter one of your endless, pointless "discussions".

Theorise all you will, & have your opinion 'til the cows come home. It won't change a thing though.

I'm quite sure 8ob will draw his own conclusions from the simple realities, as he experiments with his setup.

Yeah I didn't think so and I don't blame you. There is no argument which supports your statement.

Be nice if you would stop spreading your opinion as if it were fact though. It is an interesting subject with plenty of science behind it.

 

[sako243]

Ed you know I hate that forklift with a vengeance the idea is to dump that tank in the corner of the yard and have a pallet of gear next to it that needs cleaning, far easier that it self loads.

Bob

Make it a drive-in tank and solve both your problems

 

[MattF]

Yeah I didn't think so and I don't blame you. There is no argument which supports your statement.

Be nice if you would stop spreading your opinion as if it were fact though. It is an interesting subject with plenty of science behind it.

I'm not going to post the response which comes to mind. Let 8ob come to his own conclusion, & stop cluttering & derailing yet another thread with your "wisdom & knowledge".

 

[Onoff]

This thread is getting far too charged, I'm migrating the short distance to the pub.

 

[roofman]

great job just about big enough to lower a ford transit into it

 

[MattF]

This thread is getting far too charged, I'm migrating the short distance to the pub.

Like you needed an excuse.

 

[Screwdriver]

This thread is getting far too charged, I'm migrating the short distance to the pub.

You should go the long way round, it's just as quick...

 

[knighty]

will galvanised cathodes work? not hot dip, just the thin zinc coating?

I'm assuming the zinc will block it... but maybe it'll just float away?

 

[Screwdriver]

will galvanised cathodes work? not hot dip, just the thin zinc coating?

I'm assuming the zinc will block it... but maybe it'll just float away?

My Google-fu is weak this evening, can't make head or tails of it but I would be wary of introducing an exotic metal into the mix. You never know what you're going to end up with and what do you mean by "work" anyway? The cathode is your workpiece where you would hope to reduce a previously oxidised metal. Is that what you mean by "float away" hoping the process will attack the substrate?

If so then my guess is no. The zinc will have protected the steel part and there won't be any rust underneath it to dislodge the coating. I find the same problem with paint. If the part isn't rusted then whatever is coating the part will not be displaced.

Either way, if I was going to experiment with electrolysis (or electroplating!) I'd do it outside in case of excess hydrogen and have a plan in place to dispose of whatever toxic solution you end up creating.