MF 610 is a mildly acidic finishing product for high speed burnishing, tumbling and burnishing applications using magnetic needles. Great for use on gold, silver and platinum, as well as all non-ferrous metals like copper, aluminum, zinc and nickel silver. This is the best product we have found for use in magnetic tumblers for producing bright and shiny results will all precious metals. MF 610 will also keep your magnetic shot in great condition. MSDS.