This is some tool casted using this green sand casting technique. Basically, you use sand and clay and water to make the mold for what you want to cast. It's an older technique to traditional bronze casting. The instructor for the class was giving a demo trying to make a cast of these bells that he was working on. The sand and clay are reuseable but it has to be remilled before it can be reused. I would really love to take this class but it's during the week and it would be hard for me to make it there because of work. The instructor told me that he's a guitar maker by trade and he also teaches the musical instrument making class.