China can also be repaired by using a cold cement, which should not be fired. Apply the cement with a stick, on the edges of both pieces, and put them together very carefully. Set the china aside, so that it will remain undisturbed until dry. If there are many pieces, join two or three, and let them dry, and gradually add on the others until the article is complete. Allow two days for an ordinary good drying, without artificial means, before handling.
A strong cold cement is made by mixing two parts of cheese to one part of powdered lime, adding water until the mixture is of a semi-liquid consistency. Mix and grind it with a knife until it has become tacky. Apply this to the edge of the china, and join the pieces carefully, allowing one day for it to dry.
Many large crockery houses use this cement exclusively, and find it very satisfactory.
FIRING CHINA
If the kiln is raised upon a box or platform from 10 to 20 inches high, it is more convenient to stack, and also to regulate the burner. Have the box covered with a piece of zinc or sheet iron. Connect with the chimney in the most direct way, using 7 in. pipe which must not taper. If the chimney hole should be smaller, have it enlarged to this size. Set the brackets in the support upon the side of the kiln. Fill the can with kerosene oil and place upon the bracket adjusting the funnel so that the oil will drop into it. Place a small piece of asbestos fibre as large as a thimble in the iron tray in the bottom of the burner, and keep the slide in the burner well open.
Kilns are shipped with the clay in a green state in order to insure safe transportation, and must be fired in order to dry out any moisture before firing china.
Turn on the oil in a fast drop and apply a lighted match or taper to the asbestos fibre, which has become saturated with oil and will light. Allow the oil to flow in a broken stream for about 15 minutes. By this time the burner has become hot and will consume more oil. At first, the bottom of the pan need not be more than one-half covered, always exercising care not to feed it too fast in the beginning. As the kiln becomes hotter, the oil may be increased gradually and a red glow will be seen through the mica window in the door. This will gradually increase until the whole interior is red, also the flames may be seen through the mica window at the top. From this time the oil may be turned on as fast as the burner will consume it without overflowing. Usually the first time it is fired it is best to allow the kiln to run slowly for four or five hours or longer if necessary, and until it shows a good red throughout the inside, and hotter than for firing China.