Many small-run, decorative pewter manufacturers either hand polish or have smaller equipment for polishing cast pewter parts. While we have detailed pewter polishing in a previous post using steel tumbling media, small vibe tumblers generally are not able to handle the weight of steel media.
Before (first) – Polished (second)
These lead-free pewter parts showed rough and dull surface finishes. While the objective was not to completely remove the flashing and produce a mirror-like surface finish, these parts did need to be cleaned and polished.
A two step process was used in a small (4 gallon capacity) vibratory bowl. The first step used a general purpose Ceramic Media and a mild acid compound to remove oxidation on the surface and soften/remove the flashing. This resulted in a smooth, matte finish. Instead of using steel tumbling media in the second, polishing step, a Precision Ceramic polishing media was able to bring up a nice shine on the parts in a relatively short cycle time of 2 hours. A neutral pH compound was used to keep the parts clean and bright.