Electrolysis Rust-Removal

When Patty, Johnny Boy, Clynt and I went to Pick-A-Part last week, one of the topics discussed was using electrolysis for rust-removal. Having stripping off a few pieces of the Sierra (Which is from Quebec, although it spent many years in Ontario, which is notorious for it's excessive salting on it's roads) and decided to try it out. Despite Patty's and Clynt's assertations that the method work, I was skeptical of how well such a system could work. After all, we're not talking about a highly expensive set-up here. Still, scientifically, it was sound, and word-of-mouth said it was awesome. So, grabbing my reservoir housing (A metal cage that holds the plastic coolant reservoir), I went out and picked up all I needed. Parts and prices are as follows:

Battery charger, $19.99 from Canadian Tire. Provides the electrical current for the electrolysis effect.

Electrode Metal, $0-$2 from any available source. Provides the transfer of metal material to the object you're working on. As the electrode needs a direct path to your part, I suggest as wide an electrode as possible. I actually used a trimmed sheet of mild steel. Note: Do not use anondyzed or zinc-coated steel. Only use stainless steel, mild steel or iron. If you use stainless steel, ensure it does not hexavalent-chromium as a coating. This coating will break down and can cause skin caner if touched, and lung cancer if inhaled. Anondyzed metals will give off noxious fumes, and zinc-coated materials will weaken the target object.

A plastic tub, $13 from Home Depot. Holds the electrolyte mix. Note: Do not buy a conductive container. Ensure it is plastic, PVC or any other non-conductive material.

Washing Soda, $7 from London Drugs. Helps with the electrolyte process. Note: Some sites recommend using Lye. Using Lye will work just fine, however, it will make the mixture into a very potent base, which will damage your skin. Use gloves if you use Lye.

The only other things you need are water, which is free, electricity, which is cheap, and your part, which you should already possess. This mean your rust removal station will cost around $40 total.

Now, to start with, put your tub in to an area with some airflow. If you've followed by advice, the mixture shouldn't be volatile to breathe, but the process will give off quite a bit of hydrogen, which can be a danger if it combusts. Hydrogen goes up, so if you have a window cracked, or if you're outside, you'll be fine. Now, fill your tub up with water, and place the part you want to clean in the water.

Add a little bit of washing soda to the mix. I didn't measure, but more soda will not mean better or quicker results. All it will do is make the mixture increasingly harder on your hands, and make it more expensive. Just do it enough to "tint" the water slightly.

Now, clamp your positive electrode (Red, in almost all chargers) on to your sacrificial electrode (That steel or iron we talked about earlier). Make sure to keep the charger's electrode out of the mix, and make sure the steel/iron is far enough away from the part it wont short. Connect the negative to the part you're working on. Note: IF YOU GET THESE BACKWARDS YOU WILL DESTROY THE PART.

Now, assuming you've got that all working well, turn the charger on and walk away. Maybe watch a movie, or make an awesome sandwich. Or whatever grown-ups do.

Depending on how big, and how rusted the part was, will affect the amount of time required. If it's working, you'll see adorable little bubbles coming out of your part. Don't worry about leaving it too long, the process will only affect the rust. You wont accidentally destroy the part from leaving it too long.

After it is done, turn off the charger and retrieve the part. You may notice that some of it has turned black, or that there's still rust on the part. That's fine. Just grab a brush (I used an old one my mother used to use for the sink that was headed for the garbage) or a cloth, or really, anything non-abraisive. Use it to wipe off the rust. Note: You arn't trying to sand off the rust. If you're having to use a steel brush, or really having to work hard to see the clean metal underneath, the part isn't finished yet. Put it back in the mix and turn it on.

By this point, you should be looking at one very clean part, and one very dirty mixture. Online guides say you can keep this disgusting orange mix and just add a bit of water to keep using it indefinitely. I hadn't read that, and as a result, ended up tossing my mix down the drain. Don't worry, it is safe to do so. As I mentioned, the part should be perfectly clean. As in, flawless metal. It wont restore metal lost to rust, but unlike sanding, wont take off perfectly good metal in the process. I am actually blown away that a $40 D.I.Y. job took of rust as perfectly as was claimed. I strongly endorse others to pick up the supplies. Not only does it let you "re-shiny" parts, but you also nab yourself a good little battery charger, useful all on it's own.

As I lacked a camera when I did it, I haven't any pictures to post, but when I use it again, I will snap photos all along the way.

Dr.Fiero wrote: CFoss wrote: I also found that if I hooked up a battery in parallel with the process it worked WAY better. I didn`t figure out why. I thought at first it was current capability, but the battery wasn`t discharging. Now I think maybe it was the filtering ability of the battery. I'm thinking that it's a "cheap" rectifier in the charger (since it doesn't matter in it's intended application) with no choke, so it's letting a bit of A/C ripple through. You could also grab a transformer; push the power in one leg of the primary and out the other leg of the primary. That, along with a capacitor across the output (optional) should give a nice clean DC.  Probably safer than having yet another hydrogen gas bomb sitting there.  But on that note.... might want to have all this stuff outside, or with a brushless motor fan blowing across it all! As for the manifolds not cleaning on the inside....  I wonder if it's the exhaust soot simply being a really good insulator?  Could try scraping off a spot down to clean metal, then letting it flash rust.  Then see if you can clean it off! Another thing I'd like to see....  going backwards, and doing some electro plating with all this.  It'd be cool to clean off some headers (etc) and then doing a copper plate on them. Might have to nickel them first - been a while since I played with all this, so my metallurgy is a little rusty (hahahaha).

As for the part not cleaning, like I said, the sacrificial electrode needs a direct path to the part, meaning it wont clean inside the manifolds.

...And I must admit, that was actually a pretty good pun.