After that, the crushed powder is poured into a container filled with water so that the liquid completely covers the clay and remained the top 15-20 cm of water. A day later the clay is thoroughly mixed with a wooden stick, spoon or paddle. To form a homogeneous liquid clay, resembling thick cream. From the mixture and remove the large mechanical inclusions, filtering it through a fine sieve. The number of cells per square centimeter must be at least 36, or even more. The filtered clay again leave for a day or three. Clay settle to the bottom, and excess water carefully removed with a pump. You will need to remove and other excess moisture from the clay.
A primitive filter for removal constructed of canvas bag. The semi-fluid mass rolled over it, and the bag is hung. If the cloth bag rare, lot of clay will flow away with the water, and if thick, the process is delayed for a few days. To speed up choose the rope tight and on the clay ground, put the yoke, getting the filter press at home. Freshly prepared, the clay was left for some time in the air, best to do it in winter, as less dust in the air. It is preferable to use for aging zinc tables. Zinc favors the development in the clay mass of bacteria that make it more plastic. Dried to the desired condition the clay is best stored in hermetically sealed zinc boxes. Stored clay at least a month, and the longer the term, the better.
Placed in a box the dough to prevent from drying out with wet rags. Not to worry about the frequent wetting and not to open this box too often, resort to some tricks. On the bottom of the box put a bowl with water and lower the ends of the covering clay fabric. The bowl of water covered with boards, which should be 7-10 cm from the surface of the water, on these boards and stacked the clay itself. Very soft clay is malleable and easily formed, but it sticks to the hands when working in the complex products under its own weight deforms. In the process of drying and firing the product of too soft of clay at best greatly reduced, shrinking in the worst — deformed into a marriage. The sign of the normal consistency of clay — easy to work with, but his hands remain clean.
The clay is the right consistency suitable for modeling large and complex forms, and easily takes the desired view from little effort. But when you add drops of water it turns back into a viscous, stick to hands mass. This criterion clay optimum degree of maturity and good drying, it is suitable for making molds of any size.