Earlier I showed how to remove rust using kitchen utensils. This works great for relatively flat areas, but it can be a pain for things with intricate corners and crevices, like nuts and bolts. Today, I’m going to show you how to use stuff from your garage(*).

(*) If you don’t know where that is, it’s where people tend to store all the stuff they don’t have room for in the rest of the house.

To remove rust, we’ll need

  1. A large 12V battery (expensive option) or much better, a car battery charger capable of supplying 2 amps. I have a nice manual Schumacher with big copper windings—none of that digital stuff.
  2. Sodium carbonate also known as washing soda. You can find the Arm and Hammer variety in a yellow box in the laundry detergent section. If not, go to the gardening/pool section and look for pH booster or pH up, which is what I got.
  3. A piece of iron or carbon steel. Do not use stainless steel as that contains amounts of metals that are toxic. I use a door hinge, but rebar is perfect. The important thing is that it has a large surface area.
  4. A plastic container (not metal!!!!).

I’m not going to describe the setup, but just give you some links.

Things that are good to know

  • The solution is reusable. You can keep it forever.
  • Unless you used stainless steel, the solution is also non-toxic. It is essentially soap water with rust in it—and it looks pretty gross.
  • You can use sodium bicarbonate (found in baking soda) which is only about half as effective, but it’s better just to get the sodium carbonate.
  • The larger the surface area of your sacrificial anode, the faster the process.
  • If you like your clamps, do not let the positive/red one touch the solution but keep it dry. The negative can be submerged no problem.
  • The higher the amp, the hotter the process. This is not good. Just stick with 2 amp.

Stupid things you should not do!

  • Do not use sodium chloride (kitchen salt) it produces chlorine gas which is not only not very good for you. It is also highly combustible.
  • Do not smoke or do anything that causes sparks. Keep the charger as far as possible from the solution. The reaction releases hydrogen (as well as chlorine gas if you’re being stupid). Think Hindenburg. So keep it outside in a well-ventilated area.
  • Do NOT use a metal bucket. Consider where the ions like to go, right? To the rusty bolt on the ground clamp, not the bucket.
  • Do not stick your hands in the water. Do not stick anything else in the water.
  • Make absolutely sure the clamps AND whatever is attached to the clamps do not touch each other and short circuit. Your charger won’t like that!
  • 12V is not going to kill you unless your resistance is low, which incidentally is the case if your hands are wet and covered in electrolyte, or you’re wearing a metal bracelet or rings in which case, … well, just don’t.

I’m sure there are other stupid things you shouldn’t do, so if you feel like you do not understand the physical and the chemical process, maybe it’s better to leave it alone.

Other than that I have had great success with it. Unlike the aluminum foil, it really gets every nook and cranny, although you have to wait a couple of ours for it.

So if you didn’t know it before, you now know two methods which together can remove most rust and make things look much newer. I don’t know about you, but I get a kick out of it. I use it to restore bikes, something which I will tell you more about tomorrow.

Interesting fact: You can MacGyver this by connecting a 12V car alternator to your bicycle or treadmill and get the sodium carbonate by burning sea kelp and dripping water through the ashes.

Originally posted 2009-08-27 00:19:14.