1. Preparation

For the best results it is essential that the equipment is clean and free from residue before mixing the gypsum. Any residue would have a negative effect on the setting time and expansion of the mixture. The gypsum should be mixed under vacuum, if possible, and to the exact water/powder ratio.

The gypsum should be sprinkled into the water. Follow the manufacturer’s instructions for mixing time and speed. Measuring the water/powder ratio by rule of thumb will automatically lead to considerable variations and poor results.