The annular plaster mold cracked. Self-made annular gypsum mold was naturally air-dried for two days, and numerous cracks appeared as soon as the fire was baked. Is it not dry enough or the proportion is wrong? How to choose gypsum line in domestic industry? Look at the surface first. Second, look at fluency. Third, look at the thickness. Many inferior plaster lines on the market are made of asbestos, which is easy to prick hands and inhale into the lungs. Black, yellow and white, it will be broken when you pinch it. Shanghai Tongfa gypsum line guidance: Choose absorbent Baiyi when choosing gypsum line. Clear lines on the back; フッズョゴヌ