Thread: Removing Rust with Electrolysis

Originally Posted by Twisted Tenon

I don't know if this belongs on this site so if it is moved, fair enough
I have this theory and I don't know how silly it is so here goes.

I have about 5 old Nokia phone rechargers that put put about 3V each. If I was to strip the wires back and connect 5 to the tool and 5 to the sacrificial piece, would this work? Or am I missing something really obvious?

TT

It depends on the size of the object but in general you need about 50 watts (ie something like 4 Amperes x 12 V) to perform successful electrolysis in a reasonable period of time. The current is determined by the concentration of the electrolyte but despite what it sprayed around on the web going to much higher currents does not help much.

3V mobile battery chargers typically put out a max of 100mA so the most Wattage available is 3 x 0.1 x 5 = 1.5W so on that basis alone there is a problem if you want things done in a reasonable time.

If you put the chargers in series you can add their voltages together but they then have the same max current going through them - any more and they overheat and trip out so you will get ~15 V but only a max of 100mA - this will will work but it will be very slow.

If you put them in parallel you can now add the cuurents but not the V's so won't get more than 500 mA at 3 V which will also be ssssllllooooooww.

Get you self a computer supply (available at almost every kerbside rubbish pick up) the can output 12V up to 20A+, but this high a current is not necessary - adjust the concentration of the electrolyte so that the tank draws 4 - 5A and it will work nearly as fast and not crud up the electrodes as quickly.

Have a look at this thread.

What Bob said.

I guess it depends on what length of time you consider reasonable.

I reckon the distance between the work and the anode is more important than the concentration of the solution and I have very successfully used way less than 4 amps but I don't mind waiting - sometimes for days.

Car battery chargers are cheap and would be much less of a hassle than multiple phone chargers.

Originally Posted by Avery

What Bob said.

I guess it depends on what length of time you consider reasonable.

I reckon the distance between the work and the anode is more important than the concentration of the solution and I have very successfully used way less than 4 amps but I don't mind waiting - sometimes for days.

I agree that even 4 A is not necessary, 4A seem to work overnight if the electrodes don't crud up, but otherwise 1 - 1.5A seems to work in proportionately less less time.

Car battery chargers are cheap and would be much less of a hassle than multiple phone chargers.

The problem with most new 12V vehicle battery chargers is they won't supply any juice unless there is something like a 12V battery in parallel.

Originally Posted by Avery

Car battery chargers are cheap and would be much less of a hassle than multiple phone chargers.

I guess so Avery, I believe that's where I'll end up. Was worth the thought though

Thanks for the link Bob.

TT

I use a 12 Volt car battery charger on its lowest setting, and it works very well

Originally Posted by JillB

I use a 12 Volt car battery charger on its lowest setting, and it works very well

I use a battery charger too. I have a 4 amp and a 10 amp. I "regulate" the process by varying the distance between the object being derusted and the sacrificial anode. Just trial and error.

There was a very extensive thread a little while back on this subject. BobL was a major contributor.

Regards
Paul