When copper is exposed to air, it begins to age and change color. This is both normal and useful, since the patina coating serves as a protectant for the raw copper underneath. Some people, however, prefer the shiny, “new penny” appearance of raw copper, or wish to restore their copper to a new appearance. To do this requires nothing more than polishing the roof to the desired appearance, cleaning off all traces of the polish, and then applying a specially formulated clear coating to keep the copper looking new. Of these three steps, cleaning & polishing accounts for 95% of the successful results, and most failures are due to skimping during this necessary step.

Hi there!
First off, I'm a newbee and don't work much with metal at all, but when I came across a blog entry here dealing with the patination of brass I knew that I'm at the right place!
I am in the process of building a reproduction of an old guitar and I need to age the metal parts so they look convincing.