Everyone has some rusty tools/junk/etc. laying around right? Some rust removal methods are destructive to the good metal underneath the rust, and/or require a lot of elbow grease. Some of the chemical means of rust removal are expensive and pretty toxic. I'm lazy, I don't like buying toxic chemicals, and I have tons of rusty junks laying around. Museums use electrolysis, why shouldn't I? It doesn't require toxic chemicals and it's
cheap. You can even dump the used solution on your lawn, or reuse it indefinitely.
Equipment required:
1. A DC power source. Most people seem to use a "dumb" battery charger. The new "smart" chargers won't work for this.
2. An ammeter. Most of the old "dumb" battery chargers have an ammeter built in. If it doesn't, you can buy a cheap one to wire in series.
3. A non conductive container large enough to hold the part to be de-rusted. I've seen everything from tupperware dishes to kids swimming pools used. I've also seen wooden boxes constructed and then lined with plastic sheeting or tarps.
4. Water. From the tap, well, distilled, whatever.
5. Sacrificial anodes. These can be junk pieces of scrap steel or graphite rods/plates. I've used both and greatly prefer the graphite. Much cleaner. Graphite isn't expensive and is easily found on ebay/amazon or at places like mcmaster carr.
6. Some way to suspend the parts in the solution. Plastic/metal/wood doesn't matter as long as it will hold the weight of the part.
7. Steel wire. I use bailing wire because it's cheap and easily available.
8. Copper wire.
9. Sandpaper or other abrasive
10. Scotchbrite pads. Gray seem to work the best, but any will work fine.
11.
Stainless steel wire brushes. Get whatever size is appropriate for the size of the part you're cleaning
12. New paint or other finish of your choice.
13. Optional: soldering iron or torch, solder
***IMPORTANT***
DO NOT use stainless steel as a sacrificial anode. You will create hexavalent chrome by doing so.
Here's mine. Pretty simple. Rubbermaid tub with four pieces of rebar tied together with copper wire. These are sacrificial anodes, but I have tied additional graphite anodes to the rebar with bailing wire. The bar across the center is a scrap piece of copper pipe I had laying around. I used rebar for this last time, but it was nowhere to be found.
Washing soda. It's less than $5 for a little over three pounds. That's more than enough to drain and refill this particular tub many times, though doing so is unnecessary. The solution can be reused. Just skim the nasty stuff off the top and add water to replenish what's lost to the process and evaporation.
Here's the power source I used, an old "dumb" battery charger. I got this for free, installed a new power cord, and it works. Beyond that, I can't tell you anything about it. I have no idea of it's current output capacity, though I would guess it at 8-10 amps. The ammeter works, and is pretty accurate as a bonus.
Here's what I'm going to clean, scrapyard fresh. Pretty rusty, with a lot of caked on dirt. No oil or grease, which means less cleaning.
Any dirt, grease, oil, loose rust, etc. needs to be removed. Again, I'm lazy so I used a wire brush on a 4.5" angle grinder.
I've cleaned it up and disassembled it as much as was possible at present. The bolts are rusted solid and the cross pins that hold the climbing pins are also rusted in place. It needs de-rusting before further disassembly and any more rust removal. This process will require good electrical connection at the point it is connected to power. I sanded the points where my wire would touch to bare metal. The process works in a "line of sight" manner, so the more area that's exposed to the sacrificial anodes the better.
Here's the tub with 10 gallons or so of water in it and a cup or so of washing soda mixed in. The concentration of washing soda isn't all that critical. I've also "suspended" the jack body via bailing wire from the copper pipe running down the middle. Sorry it's blurry, I didn't realize until it was computer screen size.
I just stated that the washing soda concentration wasn't critical, and it really isn't. That said, higher concentrations will allow for more electrical conductivity. This isn't a problem as long as the power source can handle it. Start with a tablespoon per gallon and go from there. You can also adjust current consumption by the surface area of your sacrificial anodes. Larger anodes equal more current consumption. Mine are pretty big, so I changed the concentration.
Connect the positive from the power source to the sacrificial anodes. I soldered copper wire to the top of the rebar, so all of them are connected together.
Connect the negative from the power source to the part, or in my case, the bar my part is suspended on.
Now I plug the charger into 120v and turn it on. Unfortunately the picture I took didn't show the bubbles that immediately formed due to the light and murkiness of the solution.
Even so, the ammeter shows that there is good electrical connection and work is being done.
A little while later I added a bit more washing soda to help speed things up.
Here's what the solution looked like after about an hour.
And again after about another hour.
Here's a vid showing what it looks like while running.
I just went out and checked it again. The layer of gunk on the top is getting pretty thick and it's still showing about 5 amps. That's good since it means I haven't lost electrical connection due to gunk buildup on the anodes or a fouled wire. All in all, it took me longer to set the tank back up and refill it than it took to run the brush over the entire jack and sand a spot to get good electrical connection. Other than occasionally checking to see that it's still running, there's no more work until the part comes out. I'm guessing it will need to run at least a few more hours before it's done all it can. It's likely that it will still have some rust in areas that aren't "line of sight" to the anodes. So, this will continue later.
