On a recent project I was asked to provide a consult for a client working on a tedious project. A New York jeweler was trying to polish a very intricate palladium casting and finding subsurface porosity in tight areas. There was considerable detail in this sculptural piece which required a smooth and clean surface and he had tried all sorts of polishing papers and compounds.
Bench jewelers who work with platinum and palladium on a regular basis will tell you that PGMs (Platinum Group Metals) need to be work hardened in order to get a good polished surface.
What I found for him was an excellent tool fit for the job from Gesswein. The ultrasonic hand tool available from Gesswein called Sonocraft can burnish metal harder and at the same time collapse any surface porosity that may be found in the casting. It comes with several tungston carbide tips and you can of course create your own special shapes. If you are trying to make quality platinum or palladium jewelry and perhaps working with less than perfect castings, this tool is your ticket to a happy-happy, joy-joy project.