Originally Posted by Robo410
aluminum needed electricity to refine economically so it became a 20th century metal. It also has to be heavy cast and polished( like magnalite) or hard anodysed (acid electro dipped) to make it non reactive, and all that made it more expensive than cast iron.
Anodised is a process that confuses me. Most references to the process involve a type of electrical deposition of material to the surface strata of the base metal. And anodise certainly could come from anode, the electricall positive portion of the circuit. Gold plating uses a similar technique, using a chemical to disolve the gold, which is used as the cathode, or emmiter, and the base metal used as the cathode. As electrons flow from the cathode to the anode, the gold molecules are deposited on the base metal and become molecularly joined to that metal.
What confuses me about the process is personal experience. I worked for Lockheed Missiles & Space, on a contract to overhaul one of the U.S. Navy's Deep Submersible Rescue Vehicle (D.S.R.V). When the electronics portion of the project was completed, I was sent to perform corrosion control on various hull and structural componants. Part of that control was the anodization of aluminum parts, followed by painting with epoxy primers and paints. The anodizing was accomplished by disolving a powder in ordinary fresh water, and then painting the aluminum with the resultant solution. It changed the aluminum color and created a hard-anodized finish that resisted salt water corrosion. The paint was applied to add further protection from the elements. No electricity was used in the process, except to power the compressor for the paint guns, grinders, etc.
Now I know this has nothing to do with cooking, but is merely the ramblings of a curious engineering type. I would hypothesize that there is both an electro-chemical technique, and simply a chemical technique. After all, it is by electrical eddy currents that base metals corrode in the first place, supplied by hte electrical properties of dissimilar metals, oxygen and the prescence of either an acidic or alkaline electrolyte (think battery).
Seeeeeya; Goodweed of the North