Part III: Casting and refinement
When the plaster molds are done, I can proceed to porcelain casting.
Molds and porcelain must be prepared to this step. Before every single cast molds are washed, dried and cleaned from plaster dust.
Porcelain preparing is more complicated. The doll is casted in porcelain slip, which is liquid ceramic mixture diluted to the consistency of solid cream. This liquid is required to have absolutely no bubbles in it, as they cause the most defects. At high temperature the surface of the porcelain melts (you can compare with glass production out of the sand by melting), and the bubbles blow up causing an unattractive spot. To get rid of the bubbles, the porcelain slip is prepared carefully: it’s filtered and settled for few days.
Now, the mold is clean, the slip is ready, and the casting may be started. Parts of the mold are fixed with a rubberband and the slip is poured gently into the molding channel. As the slip gets into the mold, the porous plaster start to absorb water. On the inner surface of the mold forms a layer of more dense porcelain, and in the center it remains liquid. When the layer of dense porcelain is thick enough, the form is turned over and the liquid slip is poured out.
The detail dries inside the mold for a while. Later, the mold can be opened carefully: a raw part of a future doll appears.
As plaster can’t exactly repeat all details of the model, every part of every doll is refined by hand. Little facial features, nails, wrinkles on hands and feet – all is done individually.
Raw porcelain is very fragile, even a little bit of pressure breaks it. To make this work a little easier, an intermediate firing can be preformed. It is done at temperature 900°C. It makes porcelain a little solider and it doesn’t dissolve in water anymore, so I can smooth it to perfection with wet sanding. I remove the seams and polish the details with abrasive sponge until they become silky.
Now the smooth and detailed parts need to dry.