A professional who controls equipment to weigh and mix gypsum with specified proportions of fiber, retarder, perlite, and other additives to make plaster. Respnsibilities include:

• Starts mixing machine and sets weigh hopper.
• Engages screw feeder that feeds specified amount of gypsum from storage bin into weigh hopper.
• Weighs additives according to specifications and dumps them into hopper.
• Opens gate of hopper to drop ingredients into mixer.
• Opens mixer gate after specified time to discharge mixed plaster product into packer hopper.
• May fill bags with mixed plaster.