When I smelting copper, I noticed that, the melting point is about 2000 degrees f. and a propane torch gives out 3000 degrees f., why isn't the copper melting?
Copper is one of the better thermal conductors, if you are heating a small piece of copper (such as a wire), it should melt. However, if you are heating a large object, expect the process to take a while (if it melts at all). Due to the high thermal conductivity, you are actually heating the entire thing using a small torch. Also, with the small difference in temperature between the flame temperature and the metal melting point, the speed of heat dissipation may exceed the heating. You could try using a hotter welding torch with acetylene fuel.
either your flame is not hot enough, too much yellow in the flame instead of blue, or you're losing heat somewhere
your losing heat perhaps you need some kiln bricks to contain the heat
