electrolytic derusting

I'm writing this posting to report on my experiment with using lead sheet
as the cathode in electrolytic derusting.
Most if not all of the writeups on the Internet suggest just using steel
for the cathode. The cathode is the electrode in the electrolyte solution which
is connected to the positive lead from the battery charger. I have done quite a
bit of EDR using steel as the cathode, and I invariably had a problem. The
problem was that the steel would rust, and once it rusted, the current through
it would drop, so I'd have to keep pulling it out and scrubbing it off to get it
going again.
I don't like the idea of using stainless either, as the chromium is reported to
come out in the solution, making the solution very toxic indeed.
I know that car batteries use lead for electrodes, so I wanted to try it. I took
a rusty gate hinge and cut off a sheet of lead and set up the solution yesterday
and got it stabilized at about 5 amps current, which led to a nice foaming
action but without the clamps getting too hot.
This morning the current was still 5 amps, meaning the immediate problem of the
cathode's resistance growing is avoided by using lead. The part was clean.
I didn't use fresh solution, so I can't say if the solution got as nasty as it
does when you use a steel cathode.
My other concern was the cathode eroding, as it does when I used graphite
electrodes. Those wear away over time, and the solution turns black. The lead
did turn a dark brown color but it showed no signs whatever of wearing away.
My conclusion is that sheet lead makes an excellent cathode for electrolytic
derusting, surpassing steel, stainless steel or graphite.
Grant Erwin
Kirkland, Washington
Reply to
Grant Erwin
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I have been using lead cathodes for the past couple of years. One problem that you can get is if you use washing soda as the electrolyte (as I do at the moment), you will get some lead carbonate being formed. The lead carbonate is toxic, but isn't soluble in water. As you say, it certainly seems to work much better than steel or stainless as far as resisting polarization.
Regards Mark Rand RTFM
Reply to
Mark Rand
I've been using rebar in my tank. Works pretty swell......
I grabbed a chunk of stainless steel, but then learned that it creates a toxic mess in the washing soda solution.
What are the implications of using lead as the positive ..Cathode? Electrode? vis a vis putting toxic nasties into the solution?
Anyone?
Mark
Reply to
Mark Dunning
> >>I'm writing this posting to report on my experiment with using lead sheet >>as the cathode in electrolytic derusting. >> >>Most if not all of the writeups on the Internet suggest just using steel >>for the cathode. The cathode is the electrode in the electrolyte solution >>which is connected to the positive lead from the battery charger. I have >>done quite a bit of EDR using steel as the cathode, and I invariably had a >>problem. The problem was that the steel would rust, and once it rusted, >>the current through it would drop, so I'd have to keep pulling it out and >>scrubbing it off to get it going again. >> >>I don't like the idea of using stainless either, as the chromium is >>reported to come out in the solution, making the solution very toxic >>indeed. >> >>I know that car batteries use lead for electrodes, so I wanted to try it. >>I took a rusty gate hinge and cut off a sheet of lead and set up the >>solution yesterday and got it stabilized at about 5 amps current, which >>led to a nice foaming action but without the clamps getting too hot. >> >>This morning the current was still 5 amps, meaning the immediate problem >>of the cathode's resistance growing is avoided by using lead. The part was >>clean. >> >>I didn't use fresh solution, so I can't say if the solution got as nasty >>as it does when you use a steel cathode. >> >>My other concern was the cathode eroding, as it does when I used graphite >>electrodes. Those wear away over time, and the solution turns black. The >>lead did turn a dark brown color but it showed no signs whatever of >>wearing away. >> >>My conclusion is that sheet lead makes an excellent cathode for >>electrolytic derusting, surpassing steel, stainless steel or graphite. >> >>Grant Erwin >>Kirkland, Washington >> > > > I've been using rebar in my tank. Works pretty swell...... > > I grabbed a chunk of stainless steel, but then learned that it creates a > toxic mess in the washing soda solution. > > What are the implications of using lead as the positive ..Cathode? > Electrode? vis a vis putting toxic nasties into the solution? > > Anyone? > > Mark > > > >
Reply to
Ted Frater
15 years ago, I got some stainless steel expanded sheet metal at a scrap yard. It was very very fine stuff. the long dimension of the holes was about a 1/16". It looked like fine mesh until you got close. About 26ga thick
I used it to make a few lamps and, on a whim, I used some of the falloff in my derusting bucket.
I have been using the same piece ever since. It has not decayed in the least and surface is still bright. I do not know what alloy it is, but it is fairly magnetic.
Don't be so quick to dismiss stainless. Some alloys work great. I just don't know which alloys they are.
Paul K. Dickman
Reply to
Paul K. Dickman

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