I'm slowly restoring a 1996 Jeep Grand Cherokee. It was abused for most of its life in mid-Atlantic USA, so there's more rust than intact metal it seems. I don't like replacing things that can be repaired, so I spend way too much time restoring parts and hardware.Rust removal is a frequent task, and I thought I'd share my technique. The pictures are of nothing special, just some levers that are part of the parking brake mechanism. Just what I'm currently working on. Here's a before picture, after a little washing and scrubbing.http://bit.ly/2t8telo step is electrolytic rust removal. Takes the rust, leaves the intact metal untouched. Process is easy and forgiving. Just avoid stainless steel in all of this, since it can create some nasty byproducts. Fill a container with water and washing soda (not baking soda). Use about a tablespoon of washing soda per gallon of water.Find some sacrificial metal, some sort of iron or steel, preferably with a large surface area. This will be your anode and will be damaged by this process. You can also use carbon rods, and I have had some thoughts of trying to use zinc sheets with the hope that the zinc would coat the piece being restored. No idea if that would work though.Find a DC power supply, or just make a diode bridge (super cheap). I don't think the specifics are extremely important, I've used everything from 6v @ 2 amps to 30v @ 5 amps. I'm sure there are benefits to finding an ideal here, but I have no idea what they are and these aren't exactly precision parts we are working with. I use a variable DC power supply that I accidentally dropped a 2x6 on. Speed of the process will depend on many factors, but I'd say start with a couple hours or so. There shouldn't be any damage from longer periods, but don't take my word for it. I've left larger pieces in for about a week and didn't have any issues.Stick your sacrificial anode in the water along with your piece to be restored (cathode). Make sure they aren't touching. It is good for them to be close, but you also want as much line of sight between the two as possible. I use 4 pieces of rebar in a 5 gallon paint bucket. Wire everything up - negative lead on piece to be restored, positive on the sacrificial piece. Don't swap those, or you will damage your part. Electrons flow from negative to positive, so just imagine the rust flowing in the same manner. Remember not to use stainless steel. I use some copper wire I had lying around.Something something electricity and water, don't die. Oh, and the bubbles you see being released are hydrogen gas. You can capture and burn it if you're bored. I doubt it's much of a fire hazard unless for some reason you are doing this in an extremely well-sealed room.Anyway, here's a picture of the setup and a post-electrolysis picture of the parts. You might have a little rust clinging to the pieces, but it should wipe right off. That may or may not be a light bulb in the water to keep it from freezing. Again. Will probably get a lot of complaints about how dangerous it is, but honestly just don't touch the sparky bits and everything will be fine. Or, maybe just turn it off before splashing around.http://bit.ly/2UI35Wi black residue on the parts, as I understand it, is some other form of iron oxide. Something about ferric, ferrous, oxygen atoms per iron atom. I don't remember. Removing it is pretty easy by soaking in white vinegar (acetic acid). Citric acid would probably work faster, but is more expensive. Adding salt will apparently speed up the process, but I haven't tried that. This part of the process has the potential to damage the underlying metal (not quickly, probably need a few days at minimum for that to happen noticeably), so I just stick with the mild acid. I don't know the details of the reaction, but the vinegar has served me fine.The process can be hugely sped up by doing the soak in an ultrasonic cleaner. I used a jewelry cleaner I bought my wife a while back. Fun side note - apparently these aren't resistant to acetone or mineral spirits. This is now my garage ultrasonic cleaner and I owe my wife a new one.http://bit.ly/2tdKnKi result. The dark areas aren't staining or corrosion; they are caused by the surface pitting from 23 years of rusting. That would need some sort of sanding or filing to polish up, but in this case there's no point since these are destined to be coated, and the rough surface will probably just give me better adhesion.Parts will rust fairly quickly after doing this, so dry them fast and paint or coat them somehow before leaving them in a warm/humid environment, or getting them wet. I highly recommend Fluid Film for a wide range of automotive applications.Anyone have advice for how to improve the process, or able to fill in the sciencey details of the processes? Especially curious to see if it is possible to remove rust and coat with zinc at the same time with electrolysis. via /r/DIY http://bit.ly/2GfIV2D
