Hi y’all. An interesting thing happened to a fellow smith. She put gold filled (over brass) finished pieces into the tumbler and they came out silver. Anyone wanna hazard a guess as to why this would happen? It’s the first I’ve heard of it.
Brass pieces are usually plated in nickel before then being plated in gold. This would definitely be the case if the gold plating was a flash (very thin) plating (which would easily come off with polishing).
Janet in Jerusalem
Gold-plating must be at least 4 microns thick to enable a long lasting and durable wear. Gold-plated watches use this thickness! Yes Janetb, you are so very correct, a base metal such as brass must be nickel plated first!!
Gerry, on my iPhone
She had some 14k gold in the tumbler too. Not plated, the real thing.