• by vinux

Today a friend of the pot asked me a question about the number of purple sand clay. Because this friend of the pot always feels that the lower the number of purple sand pots, the rougher the clay, so the permeability of this pot is worse. When answering this question, I also combined many opinions from pot friends including pot makers. Now let’s share it with them together.

First of all, the number of air pores in the original clay determines the air permeability of the purple clay, and the air pores of the fired purple clay pot can only be seen under a very high magnification microscope. The number of air pores in purple clay pot is determined by its own inherent physical and chemical properties, rather than by the appearance of the clay particles. Therefore, it cannot be said that if the purple clay is milled finer, the air pores of the clay will decrease or disappear; if it is milled coarser, the air pores will increase.

The coarseness of the mud particles cannot determine the permeability of this purple sand pot. Even if the number of coarser pots has some changes in permeability, it is almost negligible, and even the most precise and advanced scientific instruments may not be able to detect this difference.

If the statement that the coarser the particle size of clay is, the better its breathability is true, then we can fine grind porcelain clay as much as possible, or add coarse sand to coarsely grind the particles. If this is done artificially, will the pot made with this porcelain clay also have the same breathability as a purple sand pot? If it is true, it means that not only purple sand has unique breathability. Do you think it’s possible?

Screen sieve for filtering the coarseness of Purple Clay Mud.

The same piece of ore, after grinding, will definitely have both fine and coarse particles. Through the sieving of different meshes of mud for sieving, different meshes of mud can be classified. The same craftsman uses this coarse material and fine material respectively to make two pots of the same style. We cannot say that the purple sand pot made with coarse particles must be more high-grade and beautiful than the purple sand pot made with fine particles. It depends on individual aesthetic judgment to choose which pot, after all, people’s preference for mud fineness is different. Some people think that the purple sand pot made with coarse particles is rough and simple, while some people think that the purple sand pot made with fine particles is delicate and full of flavor. These can be chosen according to individual preferences, but there is no relationship between the air permeability of the purple sand pot and the fineness of the mud.