Lots of places to find instructions using a torch for silver clay-but you
do need a kiln for the copper/bronze version of metal clay. Check out Rio
Grande jewelry supply, links to youtube , Cool Tools, Pam East enamelist,
PMC Guild, metalclayacademy.com Many of these have areas that have short
instructions on aspects of metal clay or links to places that will give you
lots of information. The clay is tiny particles of metal mixed with a
binder and water. When you heat your design you are 'sintering' the piece,
driving off the water and binders, making the piece into mostly all metal
again. This is why there is some shrinkage to contend with after heating.
Kiln firing is just more certain in terms of temperature and time. But to
begin to see if this is what you want to do, there is a learning curve to
working with something that is like clay, a torch may be the better option.
The clay generally comes with a heating guide-time and temperature. But
there are tables available on line if not. Good luck and have fun!