I acquired an antique brass bed that was painted brass-color by the previous owner. In some spots on the headboard, the paint has rubbed off and the brass underneath was tarnished. I polished these spots with Brasso and Nevrdull, and the tarnish easily came off the bare brass, BUT apparently some of the brown tarnished spots still have paint underneath, and I couldn't clean them.
How can painted brass tarnish? Is this stain something else? It's totally unscratchable whatever it is. Could it be the previous owner tried to polish the places where the paint had rubbed off, and the polish was stained?
