When the kiln position of the bone china water cup is too close to the burner or the electric furnace wire, the degree of vitrification on one side of the green body will be much higher than that on the other side. The following problems may also occur: due to the difference in firing shrinkage on both sides of the green body, there will be differences in the absorption of the glaze, which in turn will cause differences in the colors on both sides of the green body.
When an excessive amount of suspending agent is added to the grouting slurry, the color of the surface of the plaster mold will fade and become brownish. As the number of grouting increases, the function of the mold will become worse and worse, and even mold removal is a problem. At the same time, the grouting body also began to fade, and the discolored parts were mostly the contact points between the mud and the plaster mold and the edge of the vessel. The drying speed and hardening degree of these parts were higher than other parts on the body. After the green body is fired, the degree of vitrification of the faded part is relatively high (sometimes it even appears glossy). The discoloration is caused by the deposition of soluble mixture in water on the outer surface of the green body. Discoloration marks can be removed by rubbing the body well with a damp sponge before firing in the kiln, although some spots will reappear at a later drying stage. In addition, there is a more effective solution: slow down the drying speed of the green body, so that the salt can be evenly deposited on various parts of the green body, instead of all concentrated on the edge of the vessel place.
Post time: Jan-11-2023