Questions about electrolysis

Flashpoint

Flashpoint

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I read in another thread here about using electrolysis to remove rust from metal parts. I believe I understand the process but I have a couple of questions.

How large a piece of sacrificial metal do I need? Does it need to be as big or have roughly as much surface area as the piece that I'm de-rusting? I assume it needs to conduct electricity and not be painted etc. Does it matter if it is already rusted? What exactly does happen to the sacrificial metal, is it pitted or corroded in some way?

I don't really want to use one of my computerized battery chargers for this purpose. I think this would freak it out. I'd rather buy a very simple old school 12-volt battery charger at Harbor Freight or something. Does anybody know what kind of current is required, would a little battery tender type thing work?
 
Button Pusher said:
It's science but it works like magic!

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Thanks but I mostly knew everything in that video already. She didn't really answer my questions.

It's hard to tell if that rust on the sacrificial metal could be wiped off or was it actually embedded.

I do think her 12 volt source setup is interesting. That battery charger is going to see the same load that the battery does so it's going to be providing the current for the process and for charging the battery if it's not already fully charged. I want to know how much current is usually drawn by that process so I'll know what kind and type of battery charger would be best. I think I'll just take a multimeter and measure the resistance of the sodium carbonate solution, that should give me an idea.
 
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Surface area does help so you don't want to skimp on it. Do you need a 1:1 as you mentioned? No. Not painted, rusty is fine but you want it to not be roached out metal. The more amps you have to put into the circuit the shorter it will take.

When I ran the tank for cleaning old cast iron I found, I used a grid of scrap 12 or 18" long 1/2" rebar that was suspended around the pots at 12, 3, 6, 9 and would brush them off every few hours (turn it off first lol) to remove the build up. The tank was a thick plastic chemical barrel cut down (not the flimsy black pickle barrels). Power supply was an old DC power supply that I could monitor and vary the amperage. Monitoring this told me how much the grid was coated in rust. The grid located all around the pot pulled the rust off from all around. If not, you have to keep turning the pot towards the grid. My friends know I have this setup and would drop off pieces and when I had a few, I'd put it all together and run them.
 
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I just recently made an electrolysis tank to clean up an old cast iron frying pan, not rusted just coated in crud. I used an old lawn mower blade as the sacrificial metal and it really rusted the blade. Took a wire brush in my drill and cleaned the rust off the blade to use again. I used my older manual battery charger without any issue.

I used a plastic trash can we had in a spare bedroom and when finished, just washed it out and put it back in place.
 
beamernc said:
I used a plastic trash can we had in a spare bedroom and when finished, just washed it out and put it back in place.
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"Honey, how did this brown ring get in the trashcan? "

"I have no idea.............................."
 
Button Pusher said:
Have you considered using Evaporust, it used the chelation process and is non toxic.
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Thanks for the suggestion. Evaporust looks great but you have to keep that pail of chemical around and it's certainly not cheap for enough of it to submerge an item like a large grill grate. I'd really like to get this electrolysis working, it's just water and sodium I can dump out anywhere. I have a lot of candidates for this. Mostly grill parts (cast iron grates and other parts) but also old tools and other stuff. I'm pretty sure this will remove any seasoning on cast iron cookware but that's fine.
 
My brother bought an Amazon controller and uses a plastic bucket. He swears by it. I need to get a setup for some of my rusty junk.
 
tod0987 said:
Surface area does help so you don't want to skimp on it. Do you need a 1:1 as you mentioned? No. Not painted, rusty is fine but you want it to not be roached out metal. The more amps you have to put into the circuit the shorter it will take.

When I ran the tank for cleaning old cast iron I found, I used a grid of scrap 12 or 18" long 1/2" rebar that was suspended around the pots at 12, 3, 6, 9 and would brush them off every few hours (turn it off first lol) to remove the build up. The tank was a thick plastic chemical barrel cut down (not the flimsy black pickle barrels). Power supply was an old DC power supply that I could monitor and vary the amperage. Monitoring this told me how much the grid was coated in rust. The grid located all around the pot pulled the rust off from all around. If not, you have to keep turning the pot towards the grid. My friends know I have this setup and would drop off pieces and when I had a few, I'd put it all together and run them.
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I went to HD today and bought a small sheet of aluminum and a steel pipe. I wasn't sure if aluminum would work cause it doesn't rust, but it does conduct electricity. The steel pipe will work I'm sure. So will the rust that forms on the sacrificial metal wipe off or is it actually eating into and embedded in that metal?

I also looked for a simple 12V source at Harbor Freight and they just don't make them anymore, everything has a microprocessor in it. I'm going to buy a bench type 12V power supply instead.
 
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Well I just dropped $82 $58 (found a cheaper one) on a 0-30V bench power supply, lol. It's pretty cool, you can set it to maintain a voltage and let the current vary or maintain a stable current by varying the voltage in response to the load. I used to be an electronic tech so I'll enjoy having this around. For squirrels and such. 😁
 
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Flashpoint said:
I went to HD today and bought a small sheet of aluminum and a steel pipe. I wasn't sure if aluminum would work cause it doesn't rust, but it does conduct electricity. The steel pipe will work I'm sure. So will the rust that forms on the sacrificial metal wipe off or is it actually eating into and embedded in that metal?

I also looked for a simple 12V source at Harbor Freight and they just don't make them anymore, everything has a microprocessor in it. I'm going to buy a bench type 12V power supply instead.
Click to expand...

The grid is sacrificial. That aluminum will not work. The rust on your item will be transferred through the solution to the grid. This will eventually build up to the point the reaction slows considerably. Turning it off and brushing down the grid with a wire brush will reexpose the grid to the solution. Then turn it back on.

castironevan.com

DIYs | Cast Iron Evan

How to build a lye bath and electrolysis tank for stripping and restoring cast iron
castironevan.com
 
JohnFreeman said:
"Honey, how did this brown ring get in the trashcan? "

"I have no idea.............................."
Click to expand...
The entire process didn't leave a ring, washed right out. Only a small "rust stain" where the lawn mower blade was clamped to the side, smaller than a little finger nail. My wife actually suggested that I use the trash can. :)
 
JohnFreeman said:
This is kind of overkill but: (amazon $44)

View attachment 697500
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I went ahead and ordered this, I like the adjustability and it will put out 10A. Flexible enough so that I can use it for other stuff


DC Power Supply Variable,Eventek Bench Adjustable Power Supply 30V 10A,Switching Regulated DC Power Supply with LED Display，Coarse and Fine Adjustments with Alligator Leads https://a.co/d/3B90i9x
 
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That should work fine. I remember paying for some of those for a NC State Engineering contest team we sponsored and they seemed to work fine for the purpose.

Having a regulated supply around is quite handy! The electrolysis process works well.
 
Up and going! I'm using 24v to speed things up a bit. It's pulling about 5 amps.

20231113_191956.jpg
Yes I'm letting the negative clamp slip into the solution but it doesn't seem to hurt it, however I just read that it could contaminate the solution with heavy metals that you don't want to pour onto your lawn so I will find a way to suspend it.

Battery is not doing anything, it was used earlier for testing the setup.
 
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Flashpoint said:
Up and going! I'm using 24v to speed things up a bit. It's pulling about 5 amps.

View attachment 698577
Yes I'm letting the negative clamp slip into the solution but it doesn't seem to hurt it, however I just read that it could contaminate the solution with heavy metals that you don't want to pour onto your lawn so I will find a way to suspend it.

Battery is not doing anything, it was used earlier for testing the setup.
Click to expand...


How did it work out?
 
Flashpoint said:
Up and going! I'm using 24v to speed things up a bit. It's pulling about 5 amps.

View attachment 698577
Yes I'm letting the negative clamp slip into the solution but it doesn't seem to hurt it, however I just read that it could contaminate the solution with heavy metals that you don't want to pour onto your lawn so I will find a way to suspend it.

Battery is not doing anything, it was used earlier for testing the setup.
Click to expand...



Actually it will erode the clamp. Ask me how I know.
 
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