The parts are assembled using slip (a water suspension of porcelain) in colors ranging from white to very dark red-brown. The colorant is iron oxide. The parts come mostly from material removed from other work during the Sculpting Stage or from palettes (blocks or cylinders of clay specially prepared from slip and/or clay scraps).
The parts are assembled in one of two ways. The first method is to use two hemisphere plaster molds of unequal size (the larger for the work's body and the smaller for its lid) whose inner concave surfaces have spherical curvature. Once the hemisphere molds have been filled with material, the fabrication is complete. As the water evaporates, the porcelain centers in each mold are compressed with special spherical tools to form concave cavities. When most of the water has evaporated, the porcelain pieces will be firm enough to remove from the molds. The second method is to embed the parts on the surface of a solid white porcelain sphere. The example illustrated below is for piece #845 in process:
Twenty buttons (left) with diameters of 3.8 cm and height of 1.5 cm are reshaped with diameters is 3.3 cm (inner) and 4.3 cm (outer). This will allow them to correctly fit the surface of the white sphere with circumference of 29 cm. They will then acquire the correct configuration of the hexapent, i.e., five hexagons around one pentagon (right).
The 12 negative pentagon star-like spaces are then filled with white porcelain (far left). To complete the embedding of material, a small cone-shaped scrap is embedded in the center of each of the 12 pentagons (center). On the following day, the protruding cone pieces are cut away and the surface is smoothed and compressed. The sphere is finally water sanded (right).
After final adjustments (smoothing and compressing the edges) are made to the spherical surface, the work moves to Stage 3: Equilibridization.
|EIGHT STAGES OF THE OCTAHEDRAL PORCELAIN PROCESS|