Pewter is a soft, malleable metal consisting primarily of tin. Decorative plates, jewelry, figurines and even keys (see picture below) can be made with pewter. Since pewter is so soft, it is difficult to maintain a polished finish on the surface. It is common to treat the pewter design with a black coating that is then polished away from the high spots to produce an exaggerated 3-dimensional effect.
The black oxide coated parts are vibratory tumbled with Precision Ceramic Spheres and a mild acid cleaner such as Kramco 1030 to ‘clean’ the high spots. The spheres provide an excellent bright and clean finish without removing the oxide from the interior relief areas of the part. Cycle times can be as short as 10-15 minutes depending on the desired results.
If a matte finish is more desirable, a cutting/abrasive version of the Precision Ceramic Spheres can be used. To remove more of the oxide, a triangle media is ideal.