Another option for creating a mold is routing plywood, medium
density fiberboard (MDF) or rigid insulation. Since the panels use a pressmolding technique, the material does not need to absorb water like in a slip cast. Slip casts require plaster molds so water can be absorbed into the plaster to create the thickness of the panel. Press-molding does not have as much water to be absorbed and the thickness is not determined by the absorption of the water. When using materials other than plaster, there is the possibility that they will not last as long. Plaster molds can be used approximately 100 times before they begin to lose their resolution. For the purposes of the final construction, these materials will be adequate in providing the necessary resolution since there will be a small number of casts made from each mold. The greatest benefit in using these materials is time. Plywood, MDF and rigid insulation can be cut down to the desired dimensions of the mold and laminated to create the needed depth. The following day, the molds can be cut on the CNC router and immediately used to cast the terra cotta using the press-molding method. The mold preparation of these other materials will take two days, compared to the seven required to prepare the plaster molds.
The terra cotta is rolled out on a flat surface to achieve a uniform
thickness throughout. Wooden dowels are used to limit the depth of the terra cotta. It is then lifted off of the surface and the smooth side of the terra cotta is hand pressed into the mold to create the front of the panel. The excess material is trimmed away and will be used for the next panel. The back of the panel is worked to remove the finger marks from pressing the clay into the mold. The panels dry in the molds for at least a day so they retain their
52