A professional who tends equipment that mixes ingredients to produce slurry (plaster mix) and feeds slurry into rollers for pressing into wallboard or lath. Respnsibilities include:

• Regulates flow of stucco (dry plaster mix), water, and soap solution into mixing machine in specified proportions.
• Adjusts glue feed for sealing board edges, using handtools.
• Observes flow of mix onto wallboard paper and removes lumps from mix, using putty knife.
• Observes scoring and folding of paper for defects and notifies knife operator of defects found.
• Tests slurry samples for density, using measuring cup and scale.
• Inserts weighted needle into slurry and times needle with stopwatch as it settles into slurry to determine setting time of slurry.