Enamelled Copper Bowls

I make bowls from sheet copper on a lathe and then enamel over the top. The enamel is in powdered form (it is basically powdered glass) and gets seived over various parts of the form and fired for a few minutes in a small kiln at around 800-950°C. I am attempting to get an interesting reaction between the various enamels, the copper and the heat of the kiln.