Water and electricity don’t mix, except in the case of electrolysis. People who collect and restore old cast-iron cookware use electrolysis tanks (E-tanks) to remove rust and even seasoning. Creating and using a homemade E-tank is relatively safe if done properly. But before we dive into the details, let’s take a look at what electrolysis is and how it works.
Explaining Electrolysis
Electrolysis has many uses. In the case of rust removal, it involves an electrical charge that travels from one piece of metal to another through an electrolyte solution (a liquid containing charged ions that make it capable of conducting an electrical current). This effects a chemical change in the metal pieces, damaging a sacrificial piece (called the “sacrificial anode”) while repairing the other item in the tank (your grandmother’s cast-iron skillet).
In electrochemical terms, electrolysis decomposes chemical compounds. Some resultant atoms are liberated as hydrogen and oxygen, while others are deposited as a solid on the electrodes (black sodium carbonate and rust). As for the rust on your pan, it either detaches from the surface of the cast iron or is converted into a deposit that can be easily removed. Electrolysis is, method, not rust , because it reduces hard, red rust to soft, black rust that you can then remove. Because electrolysis doesn’t cause scarring or pitting on the pan, it’s the preferred method of nearly all collectors and restorers of cast iron.
