Electrolysis for rust removal

[dkop1]

So I'm sure some folks on here use electrolysis to remove rust from old steel objects. I've got a question, does using a higher voltage or higher current power supply make any significant impact on the speed of the reaction? I'm currently using a 15volt, 435 milliamp power supply and wondered if something different would work better. My setup now does work, it's just rather slow.

 

[Fretters]

You don't want to go any higher on voltage, and sinking more current doesn't speed things up massively. What do you class as slow?

 

[EdT]

IIR,The rate of progress relates to the amperage per square inch of surface you are trying to clean very much like plating. So, yes a higher amperage source would work better. I use an old 10 amp battery charger and it works OK, but a big part still can take a while. You also need to turn the part since its a "line of sight" process between the two poles unless you've rigged up several electrodes around the container I think some of the newer "smart" battery chargers may not work because the load does not look like a battery and they're "smart" enough to shut down. Not positive, but I think that's the case.

 

[dkop1]

Fretters: by slow, I mean it took 7-8 hours to clean up 3 open ended wrenches (approx 4" long) only one of which had rust on it's entire surface. the other two were perhaps 30% covered in rust?

If this is as fast as it can go, I have no problem with that. However if say a higher current charger would do the job quicker, I'll gladly rig up something to do so.

 

[dkop1]

EdT: Thank you! I did notice that the wrench closest to the anode cleaned up quickest... perhaps I'll put anodes on 3 sides of my rectangular container. and see if I can dig up one of my 12v 850 milliamp chargers I have numerous of. Now to find what box they wound up in during the move....

 

[Dagny]

Just be careful you will be separating the components of water hydrogen and oxygen make no sparks after its been hooked up for a while.

 

[pendragon1998]

I've stuck a lit match into the bucket while my electrolysis was running...nothing. The hydrogen and oxygen produced dissipate much to quickly to become explosive, at least in my setup.

 

[slip knot]

I use lawn mower blades in my E-vat setup. they give a pretty large surface area and are free. As posted already this is a line of sight method so you may need to turn your array of electrodes regularly.
I've been using this setup for a while and have found that the amps dont matter as much as the number and placement of electrodes. I've got 3 blades in the barrel right now with a 10 amp charger. I pull the blades every day and scrub the **** off with soap and a brush. same with the working object. Most jobs get a couple of hours in the tank. heavier rust obviously gets more time.

 

[bluebolt]

I use lawn mower blades in my E-vat setup. they give a pretty large surface area and are free. As posted already this is a line of sight method so you may need to turn your array of electrodes regularly.
I've been using this setup for a while and have found that the amps dont matter as much as the number and placement of electrodes. I've got 3 blades in the barrel right now with a 10 amp charger. I pull the blades every day and scrub the **** off with soap and a brush. same with the working object. Most jobs get a couple of hours in the tank. heavier rust obviously gets more time.

Lawn mower blades sounds like a great cheap idea!

 

[Fretters]

As posted already this is a line of sight method....

Seeing as this misnomer has cropped up again, a slight clarification. It's not a line of sight process. A single anode would be effective on all surface area of the cathode, (the piece being derusted). However, the simple fact is that current flow will take the path of least resistance. In a process like this, however, there's no such thing as a direct path, so all of the surface area of the part being cleaned is affected, to some degree. The process will merely be quicker on the part closest to the anode, nothing more. Multiple sacrificial pieces dispersed around the piece merely balances the reaction out, but a surface which is "blind" to the anode will still be affected regardless. It's merely an overall speed & consistency issue, not a will/won't situation.

 

[Fretters]

Fretters: by slow, I mean it took 7-8 hours to clean up 3 open ended wrenches (approx 4" long) only one of which had rust on it's entire surface. the other two were perhaps 30% covered in rust?

If this is as fast as it can go, I have no problem with that. However if say a higher current charger would do the job quicker, I'll gladly rig up something to do so.

You could get some improvement most likely with slightly higher current, more anodes etc., but a few hours or overnight isn't unusually long time. I tend to stick to around 1.5A or less most of the time regardless.

 

[dkop1]

Thanks everyone! I'm going to try more anodes spaced on three sides of my container first, and maybe higher current later. I've got a lot more wrenches and sockets to go so if I can finish sooner, I'll be happier

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[404]

A higher current will make the reaction go faster. I have used a DC welding power supply in the past. The extra current put cracks around the threaded holes in my graphite electrodes where the power terminal is attached.

I went back to an old battery charger for charging forklifts.
Less frenzy this way.

 

[BuddyC01]

I read an article last night that described using thin gauge sheet steel so you basically have huge surface area and 360 degrees coverage. Hadn't heard that suggestion before.

 

[Fretters]

I read an article last night that described using thin gauge sheet steel so you basically have huge surface area and 360 degrees coverage. Hadn't heard that suggestion before.

The problem with using thin sheet is that it doesn't last long. Fine for occasional use, but if you have the vat in frequent use, you'd be replacing it quite often.

 

[larry4406]

I used a piece of expanded metal mesh that I bent to follow the interior of a 5 gallon bucket. Similar to Fretter's basket idea but no floor.

 

[notlob]

I've been using worn out circular saw blades. 3 or 4 spaced around the perimeter of a large plastic muck bucket. Cheap, easy to scrape the **** off, long lasting, and lots of surface area for max amp flow


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[8man]

4 graphite plates wired around the inside of a mineral bucket (the large one from Tractor Supply - after the cows emptied it) and a 8 amp Craftsman 40 year old battery charger. Works very well. I'm looking at upgrading the power supply, because I don't want to ruin my old Cman.

 

[dkop1]

I've since grabbed some oddball pieced of flat steel stock out of the scrap bin at work that have been used to make shims, keys, etc. And now have three anodes in my setup, and things go significantly quicker! Still using the same low power charger

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[pendragon1998]

4 graphite plates wired around the inside of a mineral bucket (the large one from Tractor Supply - after the cows emptied it) and a 8 amp Craftsman 40 year old battery charger. Works very well. I'm looking at upgrading the power supply, because I don't want to ruin my old Cman.

I was looking into some graphite plates since I believe they are 'wipe-clean' and would let me avoid wire brushing rust off the iron anodes, but graphite plates are a bit spendy for me. Any cheap sources?

 

[404]

I lucked out and got a bunch of cut offs on ebay. The graphite does not collect any crud at all, just leave it alone.
It does dissolve very very slowly as far as I can tell. Water turns black at any rate.

 

[dkop1]

Let my alligator clips from the charger fall into the bath overnight, they're shot now [emoji14] but it did give me more anode surface area! I'll be replacing those later, and using lock wire to attach my anodes to my clips which will no longer hover precariously over the vat

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