Electric rust remover

[adsm08 1,429]

So this is a topic that sparked a bit more interest than I expected when I first posted about it the other day.

 

These are great for rust removal, but can be used for other things like electro-plating. The idea is simple, take two pieces of metal, soak them in an electrolyte solution, run an electrical current through it in the right direction, and the electricity will force the oxygen out of your rust and forcibly remove it from whatever piece of metal you are trying to save/clean. If you want to plate, you just replace your sacrificial annode with the coating metal and reverse polarity.

 

The materials are things most of us probably have already. A battery charger, wire, jumper cables, a piece of scrap metal (preferably similar in surface area to the work piece, or larger), an old battery (optional) and a non-conductive container of appropriate size. I used a 55 gallon Rubbermaid tub.

 

 

Building it is fairly easy.

 

Step 1: Clean a spot on your work piece like you would if you were welding.

 

Step 2: Wrap bare wire around your cleaned spot on the work piece and a different piece of wire your scrap metal. Tight secure contact is more important that lots of contact area.

   2A: If scrap piece is rusty clean it up first.

 

Step 3: Place both pieces into the tub, not touching, and fill with water until they are submersed. Then add electrolyte. Washing soda (sodium carbonate) is the most preferred additive. I have been using Baking soda (sodium bicarbonate) which is also acceptable and somewhat easier/cheaper to get. Be liberal, most formulas say 1 tablespoon per gallon of water. Not enough makes it not work, too much doesn't hurt anything.

 

Step 4: Connect charger. You want your negative cable on the piece you are de-rusting and your positive on the sacrificial piece, then plug in/turn on charger to at least 6 amps. Most instructions I have read say you HAVE to have a dumb charger for this to work because a modern "smart" charger won't turn on. They are correct that a modern electronically controlled charger is going to detect that it isn't hooked to a real battery and not turn on. However, this feature can be bypassed by placing an old battery in the circuit. Clamp  your charger clamps to the battery, then connect your wires to the battery. If you use long wires from the pieces in the tank you can just clip them under the charger clamps, I used an old set of jumper cables from the batter to the tank wires and then clipped my charger clamps to them. Having the battery in there makes the charger turn on, and even after it is fully charged will provide current to the system after the charger shuts off. Should the battery drop too low the charger should kick on again.

 

Step 5: Using a voltmeter check voltage across the two pieces in the tank. If should read 12-14 volts. If it does not check all your connections. If it reads some voltage, but low, add more electrolyte. If you have a curtain of bubbles coming off the edge of the rusty piece that is closest to the scrap piece you can skip this step. Thee bubbles are a sign it is working.

 

Step 6: Go do something else. This process takes at least 12 hours to work well, on heavily rusted pieces it can take up to 48 hours.

 

Step 7: Retrieve parts, dry off, and brush clean.

 

 

I've post a few images of before and after around the forum, but here is a good one for comparing how effective this is:

 

 

This is after 3 days in the tank, and a very light pass with a wire wheel. The water line is clearly visible, showing how well this works.

 

Some other areas of this piece came away with bare metal just rubbing my fingers over them.

Edited October 23, 2021 by adsm08

[oliver2-44 8,832]

I love things like this that work while I play and sleep 

Edited October 24, 2021 by oliver2-44

[adsm08 1,429]

1 hour ago, oliver2-44 said:

I love thing like this that work while I play and sleep 

 

Me too. I get paid by what I get done, and that flat-rate mentality works it's way into the rest of your life, so for me anything I can set up and walk away from and have it keep working for me is awesome.

[ClassicTractorProfessor 5,255]

Funny this topic should come up tonight, as I am cooking some Maytag 92 parts in my electrolysis tank as we speak. I love being able to put the parts in and walk away to work on other projects

[Racinbob 10,256]

Nice write up. Manual chargers are still out there but unfortunately I believe all of them still requite a battery in the circuit. It's a safety thing so they don't spark when you connect them. The process is basically line of sight so I set my tank up so I can move the rods to accommodate various odd shapes.

 

 

Before:

 

 

After:

 

[adsm08 1,429]

3 hours ago, Racinbob said:

Nice write up. Manual chargers are still out there but unfortunately I believe all of them still requite a battery in the circuit. It's a safety thing so they don't spark when you connect them. The process is basically line of sight so I set my tank up so I can move the rods to accommodate various odd shapes.

 

 

 

 

 

I think one of my next big garage projects is going to be to build a dedicated tank with plates. Something I can just throw a part in, make sure it lands in the right spot, flip a switch, and leave.

[echris 1,425]

I've wanted to build one of these for years. Just never on the radar at the right time.

You know what's almost as much fun though? (OK, maybe like 25% as much fun), ultrasonic cleaners. I've experimented with all sorts of chemicals and dirty stuff of all sorts and giggle like a little kid when a cloud of contaminants explodes from the work piece almost a soon as you turn on the power switch. Not great for rust, but filthy stuff? Wheee!

Especially stuff like hard water. I have really hard water here and don't like water softeners so I clean my shower heads in the ultrasonic in white vinegar from time to time. 30 minutes later they're like new!

I'm going to save this thread so I can get back to it when it's time to do some home  de-rusting/plating!

Thanks!

[DennisThornton 4,769]

Electrolysis is a wonderful tool but right now I'm on a molasses kick.  Has some advantages but I use it, electrolysis and vinegar!  Not together!  Neither molasses nor vinegar will remove grease.  Molasses hasn't damaged anything so far including some wooden handles that I've kept a close eye on and won't damage good paint.  Handy sometimes!  Hard on rust with time but pretty gentle on everything else I've tried.  And I can stick my arm into it!  But due to the smell I prefer to use cord.