Thread: Electrolysis using an old computer power supply

Hi Rob

I have been using lead sheet for about 5 years (still on the same bits of lead) and no sign of plating
I use a 25v 50amp powersupply (gets the water nice and warm) but have used 12v battery chargers in the past
you need to keep an eye on the charger because as the process works you get better conductivity and may overload the charger
you can see my setup here
i have a bare wire running around the outside and then just lay the lead sheet over the sides so it contacts the wire i can then move them around as needed
you can see from the pic i have a rod inside the tank it has pvc around it with holes so it does not short out
hope this helps

Cheers
Harty

Originally Posted by harty69

Hi Rob

I have been using lead sheet for about 5 years (still on the same bits of lead) and no sign of plating
I use a 25v 50amp power-supply (gets the water nice and warm) but have used 12v battery chargers in the past
you need to keep an eye on the charger because as the process works you get better conductivity and may overload the charger
you can see my setup here
i have a bare wire running around the outside and then just lay the lead sheet over the sides so it contacts the wire i can then move them around as needed
you can see from the pic i have a rod inside the tank it has pvc around it with holes so it does not short out
hope this helps

Cheers
Harty

Thanks Harty,
If you get better conductivity as the process gets under way, that would be the opposite to the situation most get when using iron anodes, because as the iron corrodes the current decreases considerably till you stop and remove the rust with the rotary wire brush or similar. Unfortunately it doesn't take long for the corrosion to build again and you have to repeat the process. It is some time ago now, but when I did the bed of an old lathe I have, which is about 1.5 metres long, (using a stainless bin for both vessel and anode,so no corrosion), I didn't notice any current increase as things progressed, but that could easily be explained by the lack of guts in the power source. Your 25v x 50A is much, much stronger than an Arlec Charger-4, that I used. I had to introduce a variable resistance to keep the current below 4A, otherwise it would trip out, so it didn't have much chance to heat up LOL.
I had a look through your photos, - that's a fantastic restoration of your hydraulic teaspoon. The only thing wrong that I could see, was the paint job on the motor. Caterpillars are yellow, Listers are green! Have you completed her yet? I bet she would be great in the veggie garden Great work, keep it up, Regards,
Rob

hi Rob

with the lead you get very little build up at all maybe clean them after they have done 30hrs work this may be because of the increased surface area of the lead over steel bar but i definitely get an increase in conductivity as the part cleans even when i was using the battery charger (4 amp arlec as well) to keep the charger from tripping i would just lift the lead to reduce the amount in the liquid but you needed to keep an eye on it
with 50 amps it just makes it a whole lot faster

"hydraulic teaspoon" that made me laugh
the wife wanted me to weed the garden so i brought a garden weeder no weeds now even took out a couple of those 20ft high weeds that make a mess in autumn
it is running i just need to finish the canopy and she is all done much easier than a shovel

cheers
Harty

G'dat Harty,
The little digger looks great, and most impressive work on the various components.
On the de-rusting, in my situation, any increase was possibly masked by my 'variable resistor'. It consisted of a q/h headlight globe, dual filament (hi/lo beam) with either 1 or both filaments utilised, and if both used, they could be in either series or parallel, - I only used Parallel as I remember, so quite a bit of variation available. With a globe filament, the hot resistance is much higher than the cold, so it is ideal to make for a semi constant current p/s. What sort of deposits did you have to clean off your anodes when you eventually had to clean them. The stainless didn't seem to get anything on it to clean, but I worried that I might have been producing some heavy metal nasties, so tried the iron anodes to avoid that possibility. Cheers,
Rob.

Ropetangler

I have used stainless steel almost exclusively as the sacrificial anode since I was first aware of the electrolysis method of rust removal about eight years ago.

At that time I became aware that their might be a health issue regarding the use of stainless, although I was unable to find any further information about this.

More recently, since my post in this thread, I found a reference to chromium gas being a hazardous by product of using stainless for the anode. However, chromium gas is not exactly a gas and there is the extent of my knowledge of this issue.

Have you or any others more information on the extent of a hazardous byproduct from using stainless steel as the sacrificial anode?

Regards
Paul

Hi Rob

the stuff i cleaned off the lead was just a build up of gunk i just dropped them on the concrete when they where dry and it fell off
as for the stainless and chromium there is a lot of debate in what i have read but the lead works 10 times better for me so i only need to worry about lead poisoning now

cheers
harty

Hi Paul,
I don't have any specific information That I can quote, but I seriously doubt that Chromium gas is an issue, because chromium only melts at over 1600℃, so the vapour isn't likely to be a problem at normal ambient temperatures. There is the possibility though perhaps, of chromium salts being created in the electrolyte as a sort of by-product. At this point I am well out of my depth, so we need someone with Chemistry credentials to come to the rescue. I am aware that chromium compounds tend to be toxic, and commonly quoted chrome compounds said to be dangerous are the hexa-valent chromium compounds, but I have no idea if they are likely to be formed at all, or if there are ways to guard against producing them, or even if there are simple and cheap ways to detect them if they are formed. This is all stuff that I would like to know about too. No-one wants to turn their own back yards into toxic wasteland, that's for sure. Sorry I can't be of more help with this.
O.K. o the cleaning of the gunk, but what sort of stuff was it, in my case I had old paint and a sort of scum, maybe from old grease deposits not cleaned entirely prior to the de-rusting. Was this the sort of thing you had?
Regards,
Rob.

Don't worry about using stainless, the amount of hexavalent chromium you'll generate isn't worth worrying about. The dangers of backyard electrolysis are very low compared with using tools with sharp blades.

Originally Posted by Ropetangler

Hi Paul,
I don't have any specific information That I can quote, but I seriously doubt that Chromium gas is an issue, because chromium only melts at over 1600℃, so the vapour isn't likely to be a problem at normal ambient temperatures. There is the possibility though perhaps, of chromium salts being created in the electrolyte as a sort of by-product. At this point I am well out of my depth, so we need someone with Chemistry credentials to come to the rescue. I am aware that chromium compounds tend to be toxic, and commonly quoted chrome compounds said to be dangerous are the hexa-valent chromium compounds, but I have no idea if they are likely to be formed at all, or if there are ways to guard against producing them, or even if there are simple and cheap ways to detect them if they are formed.

There is a low probability of formation of volatile hexavalent Cr compounds in electrolysis but it does not need to be in a gas phase. As the bubbles of gas produced during electrolysis burst they inject aerosol of solution into the air which can be inhaled or ingested. Its the same way excrement is spread around by flushing the loo with the pan lid up. But unlike a loo or a worker that uses Cr 40 hours a week a back yarder is not going to stand over electrolysis baths for 40 hours a week. Electrolysis in a poorly ventilated area like a basement is probably more risky but an airy aussie garage is not likely to be a problem.

It is worth knowing what it does to you especially for blokes who want to have kids, there's heap of info out there - just do a search for Cr toxicity.

According to wikipedia the acute oral toxicity for chromium(VI) ranges between 50 to 150 micrograms per kg of body weight. For 100 kg person that is only 5 mg or about 1/6th of a drop of water. remember it's also sort of cumulative

Originally Posted by BobL

There is a low probability of formation of volatile hexavalent Cr compounds in electrolysis but it does not need to be in a gas phase. As the bubbles of gas produced during electrolysis burst they inject aerosol of solution into the air which can be inhaled or ingested. Its the same way excrement is spread around by flushing the loo with the pan lid up. But unlike a loo or a worker that uses Cr 40 hours a week a back yarder is not going to stand over electrolysis baths for 40 hours a week. Electrolysis in a poorly ventilated area like a basement is probably more risky but an airy aussie garage is not likely to be a problem.

It is worth knowing what it does to you especially for blokes who want to have kids, there's heap of info out there - just do a search for Cr toxicity.

According to wikipedia the acute oral toxicity for chromium(VI) ranges between 50 to 150 micrograms per kg of body weight. For 100 kg person that is only 5 mg or about 1/6th of a drop of water. remember it's also sort of cumulative

Still, I wouldn't worry too much if you're already using stainless in a backyard setup there is a low risk, not enough to stop using stainless. And it lasts much longer.

Originally Posted by mic-d

Still, I wouldn't worry too much if you're already using stainless in a backyard setup there is a low risk, not enough to stop using stainless. And it lasts much longer.

I agree, it won't stop me from using SS next time.

Hi, thanks for the info, but one unanswered bit - is it possible by choosing the right electrolyte, or current density or any other easily changed parameter, to avoid producing the toxic compounds altogether, because even if we don't breathe it in, eventually we have to dispose of the electrolyte, so it would be good to prevent its formation altogether if possible. Also is there a simple test for those of us without a photochromometer in the garage to test for the formation of these nasty compounds? Thanks in advance,
Rob

Originally Posted by Ropetangler

O.K. o the cleaning of the gunk, but what sort of stuff was it, in my case I had old paint and a sort of scum, maybe from old grease deposits not cleaned entirely prior to the de-rusting. Was this the sort of thing you had?
Regards,
Rob.

yep that would be it

cheers harty

Originally Posted by Ropetangler

Hi, thanks for the info, but one unanswered bit - is it possible by choosing the right electrolyte, or current density or any other easily changed parameter, to avoid producing the toxic compounds altogether, because even if we don't breathe it in, eventually we have to dispose of the electrolyte, so it would be good to prevent its formation altogether if possible. Also is there a simple test for those of us without a photochromometer in the garage to test for the formation of these nasty compounds? Thanks in advance,
Rob

From what I can gather once you go over a few V of electrolysis there is no stopping the formation but given the SS electrodes seem to last forever I wonder how much Cr ever reaches the solution.

A simple check for formation would be by checking the mass of the SS electrodes before and after use. You don't have to weigh the entire electrode, you could use a test piece of SS that is attached to the circuit. If the test piece weighs significantly less after electrolysis then seeing as 10% of SS is Cr it should be possible to determine the concentration of Cr ions is in the solution.

It would be interesting to see if a detectable difference in mass could even be detected. the detection limit is then determined by obtaining the greatest dynamic range balance you can afford.

Most ebay balances are 5000:1 or 10000:1 in range although I see several costing a whole $13 are 30000:1. (Contrast this with $1000 Laboratory balances that are 2,000,000:1 or more)

Using a 30000:1 balance (300 - 0.01g range) if you start out with a 300g piece of SS and it loses say 0.1 g of SS the give 10% of SS is Cr that means 0.01 g of total Cr are in the solution from that piece of Cr alone. If that is in say 40L (kg) of liquid that is by itself equivalent to 25 ppm which is well above the 0.10 ppm for total Chromium currently set by the United States Environmental Protection Agency for potable water.

Using a 2000000:1 balance I should be able to detect 0.5-0.1 ppm difference.
Maybe I will do this test next time as we have have these balances at work.

This is total Cr in solution and does not take into account if the Cr is in the hexavalent or trivalent state.