Polishing Ground Glass
Glass parts (think: marbles or lab equipment) are not the most common but when made often need to be polished after being ground to the correct shape and size. The grinding process leaves the surface with an etched, scratched, matte finish.
Barrel tumbling these types of parts is ideal as it is a less aggressive process than vibratory tumbling and can be used wet or dry depending on the process requirements. Dry tumbling is a longer cycle time but will usually provide a better finish on glass.
These soda lime glass balls were tumbled for 36 hours with Hardwood Media and the Hi-Glos Final Finishing Cream. This resulted in the clear finish seen.
A multi-step process using Hardwood Media and succession of finer and finer Finishing Creams may have reduced the overall cycle time; however, this would have required more labor to change out the media with each step. A single step process is the easiest and most economical method to get the desired results.