What is G ypsum plaster formula ? Before determining the amount of gypsum retarder, it is necessary to test the raw gypsum powder purchased. For example, test the initial and final setting time of gypsum powder, standard water consumption (that is, standard consistency), and flexural compressive strength. If possible, it is best to test the content of II water, semi-water and anhydrous gypsum in gypsum powder. First measure the indicators of gypsum powder accurately, and then determine the amount of gypsum retarder according to the length of initial setting time of gypsum powder, the proportion of gypsum powder in the required gypsum mortar and the operation time required for gypsum mortar . The amount of gypsum retarder has a lot to do with gypsum powder: if the initial setting time of gypsum powder is short, the amount of retarder should be larger; if the initial setting time of gypsum powder is long, the amount of retarder should be less. If the proportion of gyp...