Nambu Tekki Cores

The Core

The core is used to form the internal cavity of the tea kettle. The radius of the core is made 2mm smaller than that of the outer mold. The difference in the sizes of the mold and the core will become the thickness of the cast iron. Clay is melted in water and mixed well with sand to make the core. When the core is completely dry, it is covered with charcoal powder.