Electrolysis Tank-Cleaning Rusty Cast Iron

What is an electrolysis tank anyway? This is a method using a manual battery charger, sacrificial stainless steel, and an electrolyte solution that will clean rusty cast iron and steel items. An Electrolysis Tank uses the following materials:

  • A Manual Battery Charger, typically a 2/10/40/200 model. Make sure it’s Manual, and does not have the “-CA” designation after the model number, as that is not a true manual charger. You may have to order online. Do not bother with cheaper models or other power supplies, you want a battery charger with an internal cooling fan and enough power to run with stainless plates. DO NOT RUN YOUR TANK ON THE 200 SETTING. The 200 setting is only for starting a car.
  • A Rubbermaid or other plastic tub. More advanced users may find some kind of stainless tub and use that as the sacrificial anode. Plan carefully for what size you intend to use. Some simple math will calculate how many gallons of water you will be using . Also plan for what size anodes you will need for the tub.
  • Sacrificial stainless steel for anodes. Get some non-magnetic stainless steel sheets to fit your tub at a scrapyard, or purchase pre-cut online. 304 and 316 are recommended. Magnetic stainless will also work. Note that 316 is perfect for a corrosive environment. Note: I do not recommend regular steel. It wears out too quickly, requires frequent cleaning, and is not as effective as stainless. DO NOT USE GALVANIZED or COATED.
  • Arm & Hammer Washing Soda or other Sodium Carbonate product such as Ph+ for pools. Note this is not the same as baking soda. You can find this on the laundry aisle in most grocery stores.
  • Jumper Cables, or other means of connecting the plates. I simply purchased four sets of 4-gauge cables (try to get shorter lengths) and connected each plate that way. I’m not an expert in electrolysis, so I suggest you join this group on Facebook for other setups and more expertise: ElectrolysisTanks. Special thanks to Dru Humphrey and Wayne Boughan for answering all my questions.
  • And finally, some means of hanging and suspending the pieces, typically a 2×2 piece of wood for example from which to hang the piece; and coat hangers, stainless wire, etc., along with some C-clamps with no coating to hold the piece.
  1. Put together your tub and set your anodes in place, and fill with water and keep track of how many gallons you are using. You need to add 1/2 Cup washing soda per 5 Gallons of water. Warm water helps the washing soda dissolve. Add water periodically to your tank as it evaporates, you don’t need to add any more washing soda.
  2. Hook up your jumper cables, first connect your master positive red jumper on the battery charger to the first plate (red goes to sacrificial anodes). Next take another red positive jumper cable and put on the first plate, and then onto the second plate. Repeat procedure all around. Or connect plates in a more advanced manner.

    Take the master negative black cable from the charger and attach it to the black negative end of one of the jumper cables, you’ll use the other black end to attach to the piece. This protects your battery charger cables from wearing out. Make sure when you connect the piece, you are using the other end of the black negative cable that is jumped to the main battery cable.

  4. Connecting the Piece

    Ensure your piece is not touching any of the anodes. Connect the correct black negative jumper to the piece, I use a DIRECT CONNECTION ONLY. Some people will connect the jumper to a wire, but I do not recommend it. It’s okay if the jumper goes in the water a little. Ensure everything is secure, then put the battery charger on 10 or 40, whatever your charger has, and use the Hold setting. If there are no noises, sparks, etc., you’re good! (If anything suspicious happens, turn off charger immediately.) You should see some bubbles and swirling nearly right away. Monitor it for a bit, and you should be able to let it go on its own once set up properly. A good setup is only going to take a few hours to clean most pans that have say, light rust. I usually start any gunky pans off in the Lye bath. See https://castironcookingandrestoration.com//clean-cast-iron-lye/.

FAQ and tips:

  • Is the tank going to attract mosquitoes? No, the larvae cannot grow in the electrolyte solution (washing soda).
  • How often should I change the water? Once the water gets goopy and doesn’t swirl easily, time to change out the solution. Otherwise, just add water as it evaporates. Might want to mark your original water line. No need to add more soda. It stays in concentration.
  • Could I electrocute myself? Not likely, and I haven’t tried the following, but many experts have put their hand in the water while the tank is running and only feel a slight tingle.
  • Why can’t I use an automatic battery charger? This would require that you put a dead battery between the battery and the tank so that the charger does not cycle off. The experts do not recommend it, please buy a manual charger.
  • What about computer power supplies? Due to the nature of the best tank build using stainless plates, you need a more powerful charger with a cooling fan. The experts don’t bother with these smaller power supplies and instead buy a nice manual battery charger with an internal cooling fan, plus it will last longer.
  • Strain out your tank with a pool skimmer or kitchen strainer to keep the water cleaner.
  • Do not use more washing soda than recommended. This can cause your charger to have too heavy of a load and short out.
  • Do not e-tank Aluminum, Brass, Copper, anything plated or coated including tin cans, galvanized sheet metal etc…The things mentioned here should not be in an E-Tank AT ALL in the form of anode or cathode!
  • DO NOT run your tank on the 200 setting, this is only for starting a car!
  • Use a well-ventilated area, preferably outside for your tank, and no smoking around the tank.
  • Once you take your pan out of the tank, be prepared to at least clean it with Dawn soap and get it oiled and ready to season. See https://castironcookingandrestoration.com//seasoning-cast-iron/.


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