Awesome Anodizing

Anyone who has peered into the engine compartment of a racecar has seen anodized parts gleaming in a variety of colors. Unlike chrome or gold plating, which are used on ferrous metals like steel, anodizing is a plating process for non-ferrous metals such as aluminum and magnesium. Commonly used on hydraulic fittings on racecars and airplanes, it can even be applied to entire aluminum bodies or interior panels. Some of the many aluminum or magnesium parts that can be anodized are wheels, fuel injection stacks, intake manifolds, interior panels, hydraulic fittings, hoods and grilles.

No Dull
Bare aluminum oxidizes if left exposed to air, turning from bright silver to a dull gray. Anodizing will prevent the dulling process, and can provide a splash of color as well. Custom and show cars benefit from the dazzle of anodized parts, and racecar crews appreciate not having to polish parts to keep them looking good for sponsors and fans.


In a commercial anodizing shop, the process begins with parts being hung from a rack to be moved from one vat of chemicals to the next. First stop is an acid bath where the parts are etched and cleaned. Then it's time for a bath to remove the acid (using desmut chemicals) before being dipped in sulphuric acid to open up the pores of the metal. Then an electric charge plates a clear finish onto the metal. For an even shinier finish, some platers offer "bright dip," an acid dip that brightens up the aluminum prior to plating.


Although a clear anodizing will give the metal a shiny look and prevent corrosion, for a show car look the parts can be dyed a variety of great colors as well. This involves dipping the parts in a vat of colored dye and then sealing with a clear coat. The longer the part is left in the vat, the darker the color will be.


Unfortunately, the color will fade if left in direct sunlight (some colors are better than others; black is the most durable). The color coating is also very thin and prone to scratching. Be aware that anodizing will add a tiny amount to the size of the part, so be sure this will not cause clearance problems before you get started. If you have a tight fit, you can use steel wool to remove the anodizing.