Introduction to mould making & casting with Carsten Theumer

In order to get to know the material bronze and the technology of casting, we produced a classic bell form using the bronze casting method with the help of Carsten Theumer, the head of the BURG’s metal casting workshop. The original form was turned from solid wood in preparation according to the classical method. In addition, we used a finished bronze bell as a second original mould for the casting. For the construction of a casting mould, open mould boxes made of wood or steel are first required, which are equipped with guides for better handling. The original form is placed in the upper moulding box and then filled up and compacted step by step with special oil sand for bronze casting. Then the box is turned, the counterpart is put on and the inside is powdered with a separating layer of talcum powder. The second half is filled with oil sand in the same way and compacted by beating. The talcum powder allows the crates to be opened and the original mould to be removed. Sprue channels and vent holes are modelled into the sand and the two boxes are closed again. When pouring in the melt, some melt or at least smoke should rise from the vent channels, which can be seen as an indication of a successful casting. However, it is only when the casting is removed from the mould and exposed that it becomes clear whether the casting was successful or, as in our first attempt, the melt has not reached all the way through.