[Namron] lost wax Casting?

[Jacq Ball]

Here's my 2 cents:

Kiln is the right word I think, though there are all kinds of kilns.
Ceramic kilns don't seem to work so well for working with metal, but
there are lots of kilns made specifically for metal. This article on
the Lapidary Journal has some info for the curious.

http://www.lapidaryjournal.com/feature/kilns.cfm

As the previous poster mentioned, you might be able to get by without
such specialized hardware for simple stuff, though 3" sounds a bit
large to me.

Another thing that might work is metal spinning. I don't know if they
make bells that way, but I know that's how they make Zildjian cymbals.
Seems like that would have the advantage of allowing you to use a
sheet of a given gauge and end up with something that has no weird
irregularities in thickness that might reduce the bell's acoustic
quality.