When I heat sheets of sterling I notice a change in color of the
surface as I move the flame. The colors range from copper color to
blues and other colors. The colors come and go as the flame moves.
Is this the silver oxidizing? I notice the effect most strikingly
when I have no flux on the silver such as when I am in the first
steps of reticulation and want to oxidize the surface. I have also
noticed it, but not as intensely, when I did have Pripps on the
silver and was trying to minimize oxidation. I am using a propane -
oxygen torch and try to keep a slight flicker of yellow in the torch
flame (hoping that means I have a reducing flame).