Selecting the proper media can be as much an art as a science. A clear understanding of all the finishing requirements is necessary. Considering the needed edge rounding, surface finishing, cycle time, metal type and many other factors are critical.
Notice the very heavy flashing on this aluminum part (far left in picture) left over from the machining process. This ‘raw’ part also had some machining marks on the surface that needed to be removed. The easy solution to finishing this part is to throw it in a vibratory tumbler with some Ceramic Media (see part on right) to remove the flashing and surface marks. Alternatively, Plastic Media will take a little longer to deflash the part but will result in a smoother surface finish and less edge rounding (see middle part).
For this project, the objective was to get a smooth surface finish with slightly rounded edges in order prepare the part for a painting process. Ceramic Media was the best selection in this case due to the shorter cycle time, increased edge rounding and ‘rougher’ surface finish.