Where the
world gathers for metal finishing
Q&As since 1989


-----

Help design steel shot to polish quarters

2000

Hi,

I have 500 pounds of quarters than I need to polish and gold plate. To get a mirror finish we were going to nickel plate them but right now it is cost prohibitive and takes more time than we have.

I saw a quarter that had been in a vibratory finisher with steel shot and it was more brilliant and shiny than the quarters we had nickel plated as samples. What I want to do is polish them first when I get them from the mint and then gold plate directly onto them with no nickel plating. I figure this should work since they are nickel already.

I don't know much about polishing so I was looking for recommendations on shot size and shape and if any liquid compounds were needed. I have a huge 5 gallon vibratory finisher already. Thanks for your help, post here or email me directly.

Rob Henry
Gold Touch Inc - Cleveland OH

---

Quarters have quite a lot of copper in them, even in the cladding, which has the potential to diffuse into gold; but since this is a non-critical application at ambient temperature, I tend to agree with you that you probably should be able to dispense with the nickel plating.

Any polishing should probably be done wet because wet polishing is less aggressive than dry. I think that you might want to look at plastic media as well as your steel shot.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2000