Electrolysis Tank

[8pack]

5 to 20 amps should be sufficient from what i have read any more amperage won't gain you anything. as to the anodes be sure to put one on each side of the part. I have found that i would get better results doing so.

Ok. I am going to add 2 more anodes so I have better coverage in the tank. The 2 pieces of rebar were 5ft long so it covered the full length of the tank on both sides. These are only 17” and they are not fully submerged to avoid corroding the terminal connection.

I will find out more today when I swap in the front leaf springs.

 

[scudzuki]

I could…..but one of the big appeals of the graphite rods over the steel anodes was not having to worry about the anode being line of sight to be effective.

At least for this part, I am trying to avoid moving it. It is a nine leaf 3/4ton spring pack and is ridiculously heavy. My tank is just simply 2 layers of 20mil plastic and every time I move that spring I run the risk of ripping the plastic. I have already managed to put some pinholes in it just getting the first spring in and out. I lose about 3 gallons/day of solution which I can manage. Anymore and I have to do a small rebuild which I want to avoid.

The next round are the smaller front leaf springs and a series of other much smaller parts so I think it will be less of an issue.

Just trying to learn more about this mysterious thing called electricity and basic chemistry. My garage definitely looks like a high school science project right now!

The process is not line of sight regardless of the anode material.
Read this article I just found to see some of the benefits of using carbon anode (in addition to the elimination of the rapid re-rusting when using a steel electrode)
https://www.robotroom.com/Rust-Removal.html

 

[Bandit723]

Line of Sight
In the first electrolysis session, I used a single anode and occasionally rotated the part. In the second set of electrolysis sessions, I used two anodes (on opposite corner of the container) and did not rotate the part.

In both cases, it was obvious that the areas where the anode and cathode were nearest each other produced the greatest quantity of bubbles. However, my experience in electronics suggests that the more resistant paths will still receive current, just less. (Consider current through parallel resistors.) Indeed, all areas of the piece to be cleaned showed bubbling and cleaning action, even if they were not nearest or “line of sight” with the anode.

Nevertheless, I am convinced that complete de-rusting of the object will occur more quickly, evenly, and efficiently by surrounding the cathode by the anode or by regularly rotating the part. Otherwise, the cleanest portions of the object will waste electricity splitting water until the still-rusted portion receiving the least amount of current is finished. Also, because the cleanest portions will likely conduct electricity better than the rusted areas, and since the anode will become less conductive as it is corroded or coated, the process will become increasingly inefficient.

 

[8pack]

UPDATE:

Put my 2 front springs in the tank and they ran about 12hrs using the graphite anodes.

I actually found the rebar anodes worked better….here are the picks of my springs. The one on the left was after I cleaned it up with a hand held wire brush. On the right it just came out of the tank. The right hand spring had quite a bit of scale still and I am not happy with how it came out. Needs to go back in.

I did not find that line of sight was not important. The anode definitely needed to be line of sight to work effectively.

In terms of the lack of flash rust, I think it is a little better but it still flash rusts.

The big question for me is do different types of steels react differently. These are obviously spring steel. Maybe cast iron behaves differently or stamped steel has a different outcome.

I will keep trying and check back in. I put my cast iron exhaust manifold in tonight which is heavily rusted and pitted but ran out of washing soda so will have to wait until the AM to restart it.

This time I am running both rebar and graphite rod in the tanks to see how it goes.

 

[Bandit723]

@8pack I have always used a deep container to do this. I am just wonder if the shallow depth of your tank and the fact you are not fully submerging the anode is a factor here.

 

[8pack]

Might be. I have a rusty cast iron intake in there now and reduced the amps to 10 from 20. The water was really black on the last cycle and the anodes were visibly worn more than I expected. Maybe the higher amperage.

if I fully submerge the anode the screw and ring will corrode. That is why I put multiple in to be sure there was enough surface area.

I am curious to see if the cast iron reacts differently from the spring steel.

This is a good learning process!

 

[8pack]

The verdict:

I put my Rusty exhaust manifold in with the carbon anodes to see if cast iron would behave any differently than spring steel….no. It ran for 24hrs and the result was disappointing. The picture belo is after it was scrubbed with a steel brush.

I emptied the tanks as it was full of black carbon and put my pick up bed crossmember in with fresh water and washing soda. I ground off the rust on the ends of the rebar to expose bare metal and reinstalled them in the tank.

The reaction appears stronger and you can see the rust lifting off. I rubbed a small section with my finger and the rust came right off. This was after running 6 hrs. I think another 6 and it will be done.

Short story, for me 5/8” rebar seems to be the better anode.

 

[TommyRS70]

I could…..but one of the big appeals of the graphite rods over the steel anodes was not having to worry about the anode being line of sight to be effective.

At least for this part, I am trying to avoid moving it. It is a nine leaf 3/4ton spring pack and is ridiculously heavy. My tank is just simply 2 layers of 20mil plastic and every time I move that spring I run the risk of ripping the plastic. I have already managed to put some pinholes in it just getting the first spring in and out. I lose about 3 gallons/day of solution which I can manage. Anymore and I have to do a small rebuild which I want to avoid.

The next round are the smaller front leaf springs and a series of other much smaller parts so I think it will be less of an issue.

Just trying to learn more about this mysterious thing called electricity and basic chemistry. My garage definitely looks like a high school science project right now!

Breaking Bad Rust Removal System!!! Ha!

 

[tom3]

Best thing I've found for an exhaust manifold is a good degreasing, then a light go over with a sand blaster. Knocks the rust right off.

 

[8pack]

FINAL VERDICT:

Rebar no graphite. This is the before and after of one of the bed cross members after 8hrs at 12v 20amps with 5/8” rebar.