I setup a small electrolysis bucket. The negative is attached to an old cast iron tractor carb and the positive is hooked up to an old rusty cast iron busted shear. Nothing seems to be happening to the carb, but there is definitely a ton of stuff on the shear. I've cleaned the shear off a few times just to make sure it's not hampering anything. It's been sitting for about 8 hours now. I was hoping to pull the carb out and it'd be looking nice after a rinse and brushing, but it's as if nothing has changed. Thoughts?
Electricity runs positive to negative. If you're trying to clean the carb, it should have the positive.
This was my initial thinking. Searching google for these setups always says that the part you're cleaning is hooked up to the negative. I am using one of these (wise or not) to do this with. http://www.amazon.com/Clore-JNC660-...14&sr=8-3&keywords=jump+start+battery+charger
I use a small trickle charger but I hook the neg clamp to a graphite rod.All immersed in water/soda ash mixture.
If you connect a positive charge to a graphite rod of other soft metal it will make it a sacrificial anode then your negative charge will be connected to the piece you are wanting to protect or clean like a piece of corroded iron for instance. The sacrificial anode should in theory absorb the corrosion. Ay least that is my understanding of it for all it is worth. This is how we used to protect our chill water systems when I was working as an operating engineer. You can use graphite, magnesium, aluminum zinc and metal that is soft and conducts.
This is how my anode looked after cleaning it off lightly with a wire-brush. Are you thinking I should replace this with a softer metal? There is pitting on this but I'm uncertain if it's from the oxidization or if it's coming off and going onto the carb.
If the shear is cleaner than the carb switch the electrodes. The hell with theory. Maybe your charger is wired backwards.
Hehehe. I'd be surprised if it's wired backwards. It's a fancy jump start charger... but I can't 100% rule out its not doing some sort of switching. I ordered a carbon rod too.
Just checked on it again, and yeah, after light brushing the scissors/shear (anode) is starting to look nice. Again, however, I cannot tell if material is being removed beyond the rust.
LOL the wife bought a cheapo charger when we needed one and had no cash once. She went to hook it up and blablam. She came in blinking her eyes and saying that her car must have a short or something so I went out and took a look and they had the red clamp on the ground wire. Luckily she didn't go to hook the ground directly to the battery and all it did was squelch a little paint and scare the hell out of her.
First-- Never put positive lead on your work product. Always negative lead. Second-- This process works in line-of-sight between the sacrificial anode and your cathode (work product). The best way is to surround your work product with anode(s), like a piece of sheetmetal curved into a drum shape, or multiple anodes connected to each other. I use a 5 gallon pail with four pieces of rebar. Third-- Be patient. The slower the better. The process is self-limiting so you can leave it overnight or for a whole week and it won't matter.
It's been going for about 18 hours now, there's no no real change (that I can notice) on the outside of the carb. Shear is almost completely free of rust. I can read USA and 48 on it now.
Well, my background is plating and when we want to electro clean a part we would generally run reverse current. That is the work piece +. Although some substrates work better cathodic. I guess rust removal is different than plating... I understand you generate hydrogen at the anode and oxygen at the cathode and it the conversion of the rust back to oxygen that cleans the part. So in the end I don't understand why the s****er blade is derusting & not the carb.
Follow these instructions. They should work well: http://antique-engines.com/electrol.asp What is the solution you are using? I used washing soda with success. Google "washing soda".
Washing soda, same process as linked there. I'm going to leave it on over night, see what happens. So the shear is completely free of any rust, just bare metal. The carb's outside is fine, always was. The inside of the bowl is terrible. In places there's 1/8" build up of rust. I thought maybe it was casting marks but I hit it with a dremel and it instantly powered into rust.
The stovebolt guys have it down! read down to connecting the battery charger. http://www.stovebolt.com/techtips/rust/electrolytic_derusting.htm
I'm sure you already know this but in case you don't, it only works line of site. I've had a lot of success using this technique for rust removal but I haven't done it in a while. It will probably corrode the hell out of the shear. I use pieces of rebar around the piece that are all wired together in series. Easy and cheap to replace. It sounds like your carb just has a lot of corrosion. It may take a while to get it clean. When it's clean it will turn it black. That will come off with water and a good wire brushing.
The part to be cleaned should be connected to the Negative. Also, heed the advice about not using a stainless anode. Hexavalent Chromium is not something you want to be exposed to.
If you want to clean the INSIDE of the carb, you are going to have to install an anode (positive) of mild steel inside the carb, ensuring it doesn't touch the carb itself (= short circuit). Like others have said, it works line-of sight. If you use a steel 20litre (5 gallon?) drum as your anode and container, it will work quickly (overnight) as your anode is surrounding the workpiece. Negative to workpiece. Positive to mild steel s****. Anyone who tells you different must live in a parallel u niverse where the simple laws of chemistry and electrickery don't apply.
This is an awesome idea. I have some drums laying around... Also, I placed the upper portion of the carb in for 16 hours straight without messing with it... came out looking pretty good and the shear is a bit lighter... so everything is properly working.