Make a physical mold used for mass-production from plaster and wax.
Tends tanks that impregnate asbestos lining stock with asphalt solution: Loads vacuum tank with rolls of asbestos lining, using hoist. Turns valves to admit specified quantities of asphalt solution into tank. Turns steam valves to heat tanks, observes temperature control chart, and adjusts coolant valves to maintain temperature within specified limits. Transfers impregnated rolls of asbestos from tank to oven, using hoist. Allows material to heat for specified time to complete impregnating process. Starts blower to dry and exhaust fumes from asbestos. May standardize width and thickness of asbestos lining [CALENDER-MACHINE OPERATOR]. May test impregnated stock to ensure conformance to specifications, using brake-testing machine. May deliver samples to control laboratory. May tend mixing machine to prepare impregnating solution.