Operates vacuum casting machine to produce molten metal and pour castings of high density: Removes ceramic mold from preheat oven, using tongs, and places it on lift in lower air lock of machine.
Closes and clamps air-lock door. Inserts premeasured metal charge into upper air lock. Starts pumps to create specified vacuum in air locks. Pulls levers that cause ram to push charge into melting pot in vacuum chamber. Turns on current and adjusts temperature controls of furnace. Determines when molten metal is ready to pour by observing color through glass-covered opening, or by measuring temperature of molten metal with pyrometer. Moves controls that cause lift to raise mold from lower air lock to vacuum chamber. Pulls lever that causes furnace to invert and pour molten metal into mold.
