GnatGoSplat Posted July 19, 2005 Report Share Posted July 19, 2005 I don't hear too much about people using electrolytic rust removal, but it's my favorite way to remove rust because it's the most thorough and also requires very little physical effort. Here is the bottom of my "new" junkyard fender... after scraping off the bubbled paint with a screwdriver, I found it was a LOT rustier than I thought. The really dark areas are deep pitting that came close to becoming a hole. I filled a bucket with water, then mixed in a couple tablespoons of baking soda. I've heard you're supposed to use "washing soda", but I don't know what that is and baking soda works and I have plenty of it. I think you only need 1TBSP per gallon of water. Then I immersed the rusty metal into the bucket and connected the negative (-) clamp from my power source to the fender, and the positive (+) clamp to a carbon rod which I'm using as the sacrificial anode. I didn't want the carbon rod to short against the fender, so I used a piece of scrap plastic to insulate the fender from the carbon rod. You can use anything conductive as the sacrificial anode... carbon, steel, copper, stainless steel, etc. Once power is applied, the rust and carbon rod immediately start bubbling. After a day or so, the water turns a disgusting thick black. It's a mixture of rust and spent carbon. If you use iron for the sacrificial anode, the water will turn a disgusting brown as the iron rod itself would rust. If you use copper, the water will turn a disgusting green. Basically the water will turn the color of the corrosion of the metal you used as your sacrificial anode. I've read that stainless itself won't corrode and won't make the water quite as nasty, but I've never tried that. I ended up changing from using my jump starter to using a battery charger as the power source - the battery charger actually worked better. Polarity is VERY IMPORTANT! Get the polarity mixed up, and a day later the rusted piece you wanted to de-rust will turn to brown sludge! The final de-rusted piece in its pitted glory. Unfortunately this process can't convert rust back into metal, it just removes rust from the steel on a molecular level. This process works great on small parts that can be immersed in water, I use it all the time. The best part is unlike mechanical rust removal, this doesn't remove ANY good metal. Quote Link to comment Share on other sites More sharing options...
slick Posted July 19, 2005 Report Share Posted July 19, 2005 Woah, thats pretty damn sweet! So, basically all I need is: Battery charger of sorts, bucket, water, baking soda, and a piece of iron? Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted July 19, 2005 Author Report Share Posted July 19, 2005 Yup... although most stuff I've seen on electrolytic rust removal recommends washing soda over baking soda. I just used what I have. Use only as much baking or washing soda as you need... it's only used to make the water conductive, and more won't make it more conductive. You only need to add more if there are no bubbles when you apply power. The process is also line-of-sight, so I've heard the larger surface area of your sacrificial anode, the better. You can use sheetmetal for this. Using a rod works, but takes longer. Also keep your positive charger clamp or clip out of the water or it will get eaten up too! It's okay for the negative one to be submerged. Depending on how pretty you want it to look afterwards, you might also want a wirebrush to clean it. The water solution doesn't need to be replaced no matter how nasty it gets. It can be reused over and over until you just can't stand how nasty it looks. Quote Link to comment Share on other sites More sharing options...
slick Posted July 19, 2005 Report Share Posted July 19, 2005 LOL, dumb question, but what do you do with your water once your done with it? Pour it on the ground in an unsuspection corner? Dumpster? Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted July 19, 2005 Author Report Share Posted July 19, 2005 I just poured it on the lawn! According to the FAQs I've found, they all say: How can I dispose of the solution? The bath will last until it gets so disgusting that you decide it is time for a fresh one. There is nothing especially nasty about it-it's mildly basic-so disposal is not a concern, except you may not want all the crud in your drains. Quote Link to comment Share on other sites More sharing options...
slick Posted July 19, 2005 Report Share Posted July 19, 2005 Works for me! Does it remove paint as well, or just rust? Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted July 19, 2005 Author Report Share Posted July 19, 2005 Just rust, but it CAN remove paint. If there's rust under paint, then the water will find its way in there. As the rust comes off, it'll take the paint with it. That's what happened to the rest of the bubbled paint that I couldn't get off with a screwdriver. Quote Link to comment Share on other sites More sharing options...
slick Posted July 19, 2005 Report Share Posted July 19, 2005 Hmm... good stuff. Thanks Shawn! Quote Link to comment Share on other sites More sharing options...
Jcrow Posted July 19, 2005 Report Share Posted July 19, 2005 I'm going to try it! It looks very similar to plating. You could put your whole car in a swimming pool and .... Quote Link to comment Share on other sites More sharing options...
slick Posted July 19, 2005 Report Share Posted July 19, 2005 I'm going to try it! It looks very similar to plating. You could put your whole car in a swimming pool and .... LOL, i was trying to think of a way to immerse big sections of my car. Quote Link to comment Share on other sites More sharing options...
Jcrow Posted July 19, 2005 Report Share Posted July 19, 2005 I found this: Washing soda--sodium carbonate--is in the same family as baking soda. It has just been processed differently. It is much more caustic/alkaline, with a pH of 11, and while it doesn't give off harmful fumes, you do need to wear gloves. It is found in the laundry section of most supermarkets. Arm & Hammer is one brand; Shop and Save has a generic house brand. Quote Link to comment Share on other sites More sharing options...
Brian P Posted July 19, 2005 Report Share Posted July 19, 2005 cool beans Quote Link to comment Share on other sites More sharing options...
jeremy Posted July 19, 2005 Report Share Posted July 19, 2005 I'm going to try it! It looks very similar to plating. You could put your whole car in a swimming pool and .... LOL, i was trying to think of a way to immerse big sections of my car. .....My house has a pool.... Quote Link to comment Share on other sites More sharing options...
Jcrow Posted July 19, 2005 Report Share Posted July 19, 2005 Did you strip the paint off first? If so, how? Quote Link to comment Share on other sites More sharing options...
Intlcutlass Posted July 19, 2005 Report Share Posted July 19, 2005 I'm reading this, and I'm think'n to myself "Wile E Coyote.....Supergenius" Another way to do this if you don't have a battery charger, is to go to Home Depot, and buy the Behr driveway cleaner.($13.?? for a gallon) It's Phosphoric acid, it will eat the rust and leave the good metal after a day or two. HOWEVER!!! , it's NOT as friendly to the environment. I like Shawns suggestion and will try that out for sure..... :worship: Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted July 19, 2005 Report Share Posted July 19, 2005 nice post! Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted July 19, 2005 Author Report Share Posted July 19, 2005 Did you strip the paint off first? If so, how? Not really... The paint was all bubbled because the metal underneath it was rusted, so I just scraped it off with a flathead screwdriver. The first pic is what it looked like under the bubbled paint. The rest of the paint came off as the rust came off. A little wire brushing helped the paint come off the very few areas that weren't badly rusted. Quote Link to comment Share on other sites More sharing options...
THe_DeTAiL3R Posted July 19, 2005 Report Share Posted July 19, 2005 That's amazing! I'll definatly have to try that sometime Maybe I'll go to walmart and buy one of those kiddie pools! Quote Link to comment Share on other sites More sharing options...
GP1138 Posted July 19, 2005 Report Share Posted July 19, 2005 Holy shit, that's fucking awesome! Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted July 19, 2005 Author Report Share Posted July 19, 2005 I'm going to try it! It looks very similar to plating. Yeah, that's what I've heard. Next step will be to see if I can find a really cheap way to zinc electroplate it since obviously the original zinc coating is long gone. I know Eastwood has a $70 kit, but I've heard you can zinc and copper plate at home using household chemicals. Anyone remember how this was done in those high school chem class demos? Another way to do this if you don't have a battery charger, is to go to Home Depot, and buy the Behr driveway cleaner.($13.?? for a gallon) It's Phosphoric acid, it will eat the rust and leave the good metal after a day or two. HOWEVER!!! , it's NOT as friendly to the environment. Good tip! I use phosphoric acid on parts that don't fit into a bucket. It works pretty good, but DO NOT use it on any kind of spring steel! Phosphoric acid can cause hydrogen embrittlement so it shouldn't be used on any kind of spring steel or hardened steel. Quote Link to comment Share on other sites More sharing options...
Jcrow Posted July 19, 2005 Report Share Posted July 19, 2005 I have done zinc plating, cant remember the polarity off-hand, but its muriatic acid from the pool store you dip it in. This causes hydrogen embrittlement too I believe. I think you have to bake in an oven for so long to get rid of the H2 Quote Link to comment Share on other sites More sharing options...
Supreme Cutlass Posted July 19, 2005 Report Share Posted July 19, 2005 :worship: :worship: :worship: :worship: :worship: I've done that in chemistry a while back, but I totally forgot about it. Quote Link to comment Share on other sites More sharing options...
DiscoStudd Posted July 19, 2005 Report Share Posted July 19, 2005 Very cool! Shawn is definitely the mad scientist of this forum . Hmmm, if I could only find a tray wide enough to contain my swaybar that needs refinishing . Anybody have a spare aquarium they're not using? I do have one question, though. What amperage setting do you set the battery charger to? My charger has the 2 amp "trickle charge" and the 10 amp "fast charge" settings... Quote Link to comment Share on other sites More sharing options...
GnatGoSplat Posted July 19, 2005 Author Report Share Posted July 19, 2005 I used the 2 amp trickle charge setting, but I'm sure either would have worked... I originally used a jump starter which is capable of supplying way more than 10 amps! Quote Link to comment Share on other sites More sharing options...
99RegalGS Posted July 20, 2005 Report Share Posted July 20, 2005 WOW!! Very cool post Shawn!!! Will keep this in mind. Quote Link to comment Share on other sites More sharing options...
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