BC Buck
Junior Member
My soils in STL must be tough on coppers. Everything comes out of ground looking red. Soap water, toothbrush and not able to see much. Take to work and run through ultrasonic tank (ph1 for food grade) and under high magnification look like red barnacles on surface. Tried scraping, polishing, and tumbling in reloading tumbler using cob with poor results. Not barnacle but eroded copper surface. What technique do you guys use to clean red Penney?