Not too far of a drive from our campsite was a bell foundry located in Brockscheid. We took a tour of how they made bells and saw some that they were currently working on.
Here is how you make a bell (short version): Using a piece of wood, the shape of the bell is cut out. A clay model of the inside of the bell (core) is made from the wood form. The core is covered with grease and a clay “false bell” is placed over this. More grease is covered over the false bell and then more clay. The entire thing is baked & cooled (melting the grease). The top layer of clay is removed as well as the “false bell.” The top layer of clay is placed back over the core. There is now space between the core and the top layer of clay, where the bronze is poured in. Once dried the top layer and core is removed to reveal the bell.