The skinny on skinning castings
This article identifies the three most common families of metal casting materials and discusses the reasons for powder coating them, the processes required to powder coat them, and some of the challenges that must be overcome to achieve a quality finished product. The article focuses on copper-, iron-, and aluminum-based alloys and problems that can occur with outgassing when powder coating.
Cast metals have been around for hundreds of years. Three families represent the most common metals used in castings today. They are copper-, iron-, and aluminum-based alloys. Methods of casting range from wet- to dry-sand die cast to lost wax, and batch run to continuous cast. The type of alloy used, casting method, foundry practices, and temperature control will all affect the properties of the final product. The one thing that all castings have in common is that they are all designed to become finished product at some point. In fact, "90 percent of manufactured goods contain one or more metal castings."1 In today's market, most cast products receive some type of finish. This article discusses powder coating finishes (Figure 1).