Caution for operation of plaster 1:
1. After mixing gypsum powder with water, if the proportion of water powder is found to be inappropriate, the amount of gypsum powder should be reconciled.
2. The stirring speed should not be too fast, in order to avoid the artificial introduction of bubbles, forming too many crystallization centers, resulting in gypsum expansion and strength reduction.
3. The filling model should be gradually from one side to the other, shaking filling, eliminating bubbles and filling the fine parts.
4. Volume expansion of gypsum during solidification
The factors affecting the solidification rate of ripe gypsum include the quality of ripe gypsum powder, improper mixing ratio of ripe gypsum powder to water, mixing time and speed, and water temperature.
5 can be modulated with building glue. On the other hand, it can also be made with glue-free gypsum powder, which can be directly mixed with water.
6. The mixing ratio of water and gypsum powder, the more water, the longer the solidification time of gypsum, the lower the density of gypsum; on the contrary, the more water, the shorter the solidification time, the higher the density and the higher the fastness. The mixing ratio of water and gypsum powder needs to be controlled according to the specific use requirements.
7. The longer the stirring time is, the faster the solidification time of gypsum is. Generally speaking, it can be cast by stirring until the gypsum powder is very uniform, and the stirring time is usually controlled within 5 minutes. The relationship between casting vessel and solidification time of gypsum powder. Whether the casting vessel absorbs water or not affects the solidification time. The solidification time of the non-absorbent casting mould of the casting vessel remains unchanged. On the contrary, the solidification time is shortened when the casting vessel is poured into the absorbent vessel.