Following some of the information here, and the fond memories I have of my sixth grade science fair project, “What effect does electricity have on different water solutions?” I took a few minutes this morning to throw together the ultimate ‘geek’ rust remover. Well, it’s not the ultimate version yet — I’ll get to that later. But for now, it’s working perfectly.

Essentially, I took a old ATX computer power supply with a blown 3.3v circuit. I shorted out the power-on line to ground with a paper clip, so that flipping the hardware switch on the back of the supply box turns the unit on. Then I broke out the multi-meter and had some fun.

Thanks to the wonder of Direct Current, a computer power supply that creates +12vdc and -12vdc outputs (all of them do) gives you the capacity to power 24v circuits. The + and – are measured in comparison to ground. If you don’t use ground, but connect the + and – lines directly, the full differential is 24v. Likewise, if you wanted 7 volts you can use the +12 and +5 volt lines, or the -12 and -5 volt lines. The difference is 7. If you wanted 17, you could use the +12, and -5. See how this works?

For the scroll saw restoration, I’ve got some pretty heavily oxidized (rusted) parts. One of the worst, is a very long non-galvanized iron bolt and two nuts. I found a plastic tub, some spare wire, and a hunk of aluminum that I used as a test piece for brazing when I built my wire closet rack. These along with the aforementioned computer power supply make up everything you need for a geek rust remover.

I used some spare 14gauge wire to connect from the power supply to the anode and cathode. The hunk of aluminum (which is an excellent conductor, I might add) is the sacrificial cathode. It’s sacrificial, as the cathode will be consumed over time with this process. I wrapped the anode wire directly (and tightly) around the bolt to be cleaned. I also screwed the nuts onto the bolt, so they would all get cleaned at once.

I mixed some baking soda and water — I totally eyeballed how much to use, put some in the tub, and fired up the power supply for a test run.

Insta-fizz! Entire chunks of rust came loose in the first few minutes.

So from that, I filled the tub on up, re-oriented the cathode and anode, and fired it back up. Here’s photos of the final solution (pun! pun!) and the whole setup.

I should note, that I’ve turned off the power and removed the part a few times. I can scrape the back, chunky rust off with my fingernail.

Progress

Results

Cathode

This is the cathode, post rust removal. You can clearly see where I had wire-brushed the lacquer off the aluminum when I brazed the angled joint a few years ago. The parts that still had lacquer didn’t corrode as badly. There were huge flakes of sodium & other metallic substances built up on the cathode. Pretty cool stuff.

This entry was posted on Saturday, February 9th, 2008 at 4:20 pm and is filed under Constructive Things, Core Dump. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.