A variety of high quality surface finishes is another major advantage.
Zinc die castings offer excellent plating characteristics. Electro-plating is generally a multi-layered coating consisting of one or two copper layers, one or two layers of nickel, and a final layer of chromium, brass, gold, or any other palatable metal. Chromium plating is the most popular decorative finish when corrosion and high abrasion resistance are required./
Chrome plating adheres best to the ZAMAK alloys and ZA-8 followed by ZA-12. Chrome plating of ZA-27 is possible but more difficult due to the need to threat ZA-27 like an aluminum casting. Processes that provide a smooth, dense outer skin such as pressure die-casting and permanent mold casting are preferred when plating is being considered.
Chromating is a low-cost chemical treatment that provides additional corrosion protection against "white rust". This form of zinc corrosion is caused by prolonged exposure to damp conditions. Chromate finishes are produced by simple dip methods which deposit a thin chromate coating. Chromate coatings are often applied to instrument, military and automotive components where low cost resistance to moisture is require. These coatings normally have a bronze tone or metallic luster depending on the process used.
Phosphate coatings are primarily used to provide a good base for painting or powder coating.
Polishing and Brushing
Conventional high luster polishing or brush finishing techniques can produce appearances similar to chrome plating or stainless steel. When lacquered, these finishes are suitable for decorative, interior applications.
All zinc alloys form an excellent base for paints. To aid paint adhesion, phosphate or chromate pretreatments are often employed. Zinc alloys can also be electrostatically painted.
Powder coating involves electrostatic spraying of the zinc castings with an epoxy or polyester powder. The parts are then immediately oven cured for a hard durable finish. The result is an even, inexpensive, corrosion resistant plastic coating. Powder coatings are available in a wide range of colors.