Electrolysis testing

Rob Edwards posted a link about using electrolysis to clean up parts. Thanks Rob. Looks like a real timesaver.
<http://www.stovebolt.com/techtips/rust/electrolytic_derusting.htm>
I've been out in the garage fooling around with it and it seems to work just fine. It saves lots of wire-brushing, sandblasting, etc. Also the process is a lot cleaner than wire-brush or sandblast.
I had some expanded metal laying around from an old trailer part. I cut it up and bent/formed it around the target part and to act as the electrode. Seems to speed up the action.

Fascinating. I'll have to use my neighbors swimming pool and drive the GT6 into it. Then plug in the charger. Problem is the whole car might dissolve before I get back.

Seriously, that is really interesting. Never heard of that as a gear-head garage technique.

I have heard of that process before in another use. They run continuous low level current through metal bulkhead in salt water to prevent corrosion.

i also recall a little device jc whitney had once (way back when i was much younger reading the old "warshovski" (sp) catalog that turned into whitney. anyway, it would send a current through the vehicles frame to "deter" rust. wonder what happened to that idea.....last i saw of it, was on some B movie where the cat (insert neighborhood animal) pee'd on it and got the "shock" of it's life.

Warshawsky and Whitney were sister companies in the same building in Chicago. The entrance to one was on one side of a corner of the building and the other was just around the corner. Warshawsly was the "wholesale" store, Whitney the retail. The wholesale end was kind of phoney, but the prices were lower than the Whitney ones, I remember it well, bought a lot of stuff from Warshawsky.

A while back, someone with more chemistry knowledge than I, posted that the Whitney stuff was bogus and that the sacrificial anodes of the Navy required different chemistry and therefore weren't of any use in preventing rust.

There's something about zinc anodes swimming around in my gourd. I don't know what good they would do anywhere, zinc is a self sacraficing metal. It corrodes and flakes away faster than most unless alloyed with tin, then it corrodes and that forms a protective barrier like on a tin roof.

many water heaters use a sacrificial anode to prevent the tank from rusting out and the water tower we just tore down at work had an electrically charged anode to prevent rust that worked for 50 years

Well....I must confess, however, they were pa's old catalogs...he's more of a pack-rat than I. As a kid, they were the neatest things. Today, well, just crap.

That's right, what was I thinking of? The water heater in my Scamp travel trailer has a zinc anode that's gone bad or something, makes the water stink like hell. We just shut off the water and gas to it. We've never used the tiny shower, just bathouses at campgrounds, and can heat dishwashing water on the stove. Doris would like to take it out and gain more cabinet space.

I thought that the last JC Whitney catalog I looked at still had that gimmick.

It's all about nobility! The less noble metal will erode by electrolysis before the more noble one. The "zincs" used on many boats, especially in salt water, will erode before the steel, thus protecting the steel. Once they have gone - beware! They will work with fresh water as well but salt water is more conductive. They don't work on cars because the corrosion is selective - not all the vehicle is exposed at the same time! However, I like the swimming pool idea!

We used zinc on the hulls of our fishing boats to protect the exposed metal parts, ie prop and shaft.

What attracts me to this method is that I can set up the bath/charger/etc. in the morning and go off to do other things. In the evening, brush off the part, rinse well, prime, then stick another part in the bath to cook till in the morning. Repeat as required. Major time saver.

It sure sounds neat David. I think it would be fun to try myself. Do you just use a trickle charger? Do you have it set to 6V or 12V? Can you just dump both leads into the water like that without flipping a circuit breaker?

I haven't tried different voltages or different charge rates mainly because the old charger I am using only worked on the 12V-2A range. I didn't want to burn up the good charger on an experiment.
I'm just guessing but I don't think that higher amp rates would make any difference. Seems to me the charge rate (amps) is going to be controlled by the metal and the electrolyte solution. I kind of like it slow and easy like anyway, especially since I'm not around to constantly monitor the thing.

Anybody with any chemistry background jump in here and let us know.

HI david,
No chemistry background, but my observation has been thus: The larger the surface area, the higher the current. The closer the proximity between the anode and the part, the higher the current. The stronger the solution, the higher the current. The higher the current, the faster the reaction. I think the article says to try to keep the current in the 2-4 amp range....

HTH!