electrolytic rust removal

[T0rnado69]

to try to keep slim_boy_fat's - rotary table thread on topic ( sort of )

i thought it best to make a new topic on this subject.

now as i said in his thread i had near all the bits you needed to try it out.
so of course. you have to try it out... ? don't you.

i decided to nip into town to pick up a few new bucket's from wilko.

as i didn't want to use a bucket that had bits of cement or plaster in them.

or the one you use to wash the car.

so i rigged it up



plain black bucket, 4 anodes, wired together with copper wire.

after a min or two you could see it working.

then after a hour or so.




not sure if i should leave it running overnight ? due to the gas it gives off.
garage is fairly sealed...

 

[rikrobson]

I leave mine for a few days. There's no an awful lot of gas. The water will get yucky. And turn off the power before putting your hand in. It feels really weird.
Once the rust is gone it doesn't do anything more to the workpiece.

 

[Turbo]

I would suggest you use gloves for handling the items. One reason is the black oxide coating that forms on the steel gets grained into your skin and is hard to remove. Also my skin is sensitive to the soda solution and if I get it on my hands they are peeling next day!

A good way of cleaning the muck off the items is a pressure washer.

 

[ms08]

I would suggest you use gloves for handling the items. One reason is the black oxide coating that forms on the steel gets grained into your skin and is hard to remove. Also my skin is sensitive to the soda solution and if I get it on my hands they are peeling next day!

A good way of cleaning the muck off the items is a pressure washer.

Agree on gloves to keep hands clean......

 

[Maker]

It feels really weird.

To touch the solution you mean? Does it feel slimy? If so, what you're feeling is the saponification of the fatty acids in your skin, basically, it's your skin turning into soap.

 

[slim_boy_fat]

you have to try it out... ? don't you.

Good fun, isn't it?

If we'd lived 700 years ago, we'd all have been Wizards

 

[Gareth0123]

Good fun, isn't it?

If we'd lived 700 years ago, we'd all have been Wizards

More likely burnt at the stake!

 

[vw1]

What sort of voltage and current are you using and what's the surface area of the piece?

I used a car battery charger 12v .

 

[rtcosic]

not sure if i should leave it running overnight ? due to the gas it gives off.
garage is fairly sealed...

I was cleaning all the parts of a Jaguar rear suspension in a plastic dustbin. Power supply was an old Machine Mart buzz-box and rectifier knocked up by the boys. HUGE current, LOTS of evolved gases and contents raised to above blood heat. High concentration of washing soda so very stable foam several cms deep on top of the surface and extending above the rim of the bin.

This was in the shed - with the door closed - overnight.

Next morning one of the lads working on the project was relegated to the shed to do lots of cutting and grinding as it was too dirty a job to do in the garage.

We heard a dull thud followed by said lad stumbling out of the shed minus eyebrows and fringe and looking very bewildered.

He had inadvertently directed the shower of cutting or grinding sparks onto the foam layer in/on the bin. The foam of course is a stoichiometerically perfect mix of hydrogen and oxygen.

There is now a slight gap between the top of the shed wall and the roof.

This is now one of the shared stock of anecdotes regularly wheeled out when the group of lads get together....."Do you remember when....."

Good part was it ensured thereafter he always wore safety goggles when grinding - even when we weren't there to 'gently remind' him.

So - Yes - do ensure decent ventilation and don't direct a source of ignition onto the foam!

 

[rikrobson]

To touch the solution you mean? Does it feel slimy? If so, what you're feeling is the saponification of the fatty acids in your skin, basically, it's your skin turning into soap.

Ahh thats what that is. The same feeling when i'm forced into the bath once a year.

But seriously its like getting a mild electrocution all over your hand at the same time. If you realy want to know what it feels like, why not try it? but not with 240V of course.

I use a big shallowish plastic storage about 36'' x 12'' x 6'' (1000x300x150) and use an old battery charger. It draws about .5 Amps @ 14v.

At one end there is a 2mm steel plate for the anode. Its only been doing smallish items, but I need to experiment with additional anodes.

 

[rikrobson]

i turn the part after a while

 

[rikrobson]

The main problem is that i haven got enough scrap shhet for the anodes. I got plenty of fresh clean sheet, but that seems a bit of a waste

 

[anto]

Would a bit of sheet steel curved around the entire bucket/ container be a good electrode that would give a near perfect "line of sight"?
All sides except top and bottom would be covered then?

 

[PTvor]

There's allegedly a 'v/a per square centimetre' ideal rate...

Not that I took much notice when I did bits, I just whacked it in with the highest current I could get (extra sacrificial electrodes).

If you lower the current a bit, say by putting a bulb in series with one of the electrodes, you may have to wait a bit longer, but it's just as effective and you don't get so much scummy froth froth and gas. Also it's kinder to the power source if the electrodes touch, which can happen.

You can also limit the amount of washing soda and that will limit the current and the excessive gassing and scummy frothing and mess.

There seems to be something of a line of sight effect, but I've had no problems using two anodes in the bucket and turning the piece to be de-rusted occasionally.

Some people go in for anode holders with several equally spaced pieces of rebar which sit neatly on a bucket, but having experimented with this during the summer, I just couldn't see the point.

 

[PTvor]

Would a bit of sheet steel curved around the entire bucket/ container be a good electrode that would give a near perfect "line of sight"?
All sides except top and bottom would be covered then?

Yes, but as pdg said, it's not strictly line of sight and to me it seems like going to a lot of trouble for no great advantage. As anodes I used a couple of big old hinges clipped at opposite sides of a plastic bucket and it worked well, especially with turning the thing to be de-rusted every now and then.

 

[ronan]

I am sure you all subscribe to Keith Rucker on Youtube, he restores old machinery for a museum, he used a kids paddling pool in the video below to clean some big old castings. Clever idea and a good bit of info on electrolysis.

 

[fatfranky]

Dunno if this helps but I'm sure I once read of someone using a sheet of steel mesh rolled into a cylinder inside the bucket as electrodes to give 360 degree coverage! I suppose you could also cut a circle for the base and lid too!

 

[rikrobson]

Yuo dont want the anode too near the the cathcode piece. The anode is sacreficial and grows rusticles. these could touch the cathcode. Not sure what would be the result, but it could damage the item being treated.
Me thinks some experimentation is in order at the weekend exept when the rugby is on though (Saturday 20:00)

 

[PTvor]

^^
Yes, it's easy and cheap to experiment with this.

There are some things you don't do like use stainless steel or really anything but ordinary ferrous steel, and you need to have a care for the gas release.

 

[ms08]

I had heard - nt sure how true that in the US peeps have used swimming pools and dropped whole cars in (suitably stripped down of course).