Fired pottery is not the same color?

Ceramic firing. The firing process of unglazed green ceramic billet is called plain firing, and the re-firing after glazing is called glaze firing.

The main function of plain firing is to volatilize the water in the green body, volatilize and burn organic matter, decompose carbonate, preliminarily form the mineral composition and structure, improve the strength of the green body to facilitate the processing process such as decoration, and reduce the loss.

In ancient times, many famous ceramics such as Tang Sancai, Yaozhou porcelain, Lang kiln red, Jun red, and some celadon porcelain tires were glazed after plain firing.

When using glaze with a lower melting point, such as fine pottery, in order to make the green body achieve a better degree of sintering, the green billet is first fired at a higher temperature (1200-1500), and then fired with a lower temperature (950-1050) glaze after glazing. Although the temperature of the glaze is lower than that of the plain firing, there is an extra layer of glaze on its surface, and when the surface of this layer of glaze does not match the expansion coefficient of the body, it will be deformed, so when the novice makes it for the first time, some will produce glaze cracks, some will peel off in layers, or the deformation is serious. If it is pottery, it only needs a temperature of 800 degrees Celsius to be plain fired.

The coloring of pottery works should be divided into two situations, one is to use the method of glazing before firing, because it has to go through the barbecue of fire, and all are mineral pigments with high-temperature oxide as colorant.

Second, after firing, some potters feel that the color is not satisfied, or they will repair the glaze and re-burn, or they will not use some resin pigments with good adhesion to repair.

Clay can be glazed if it is not fired plainly.

Soft pottery is colored first, and then burned, but because some colors will change color after firing, so determine the color first when making, if it will not change color, you can color it first, and when it will change color, it is recommended to burn it first and then color. When making soft pottery, the first thing is to knead the soil, and the unprocessed soft pottery material needs to be kneaded evenly, and the density inside the material can be reduced after the density increases.

There are four main methods of clay glazing:

1.The dipping glaze method is a method of glazing, which is to apply the glaze to the surface of the body very evenly, even if the shape is complex. It has the benefits of saving time and being easy to operate. However, when using this method, the whole body can be immersed in the glaze slurry.

2.If the glaze is large, the volume of the container is not large enough, or the difficulty of the operation procedure will inevitably be encountered when the glaze dipping method is used for glazing.

3.Brush glaze is a glazing method that is best used for coating small areas or painting with glaze.

4.Glaze spraying method This method places the clay blank to be glazed on the turntable, and the glazer sprays the glaze while rotating the turntable regularly.