The next step is called burnout, and immediately precedes casting.  After dewaxing, the flasks are put into a burnout oven, and are heated to over 1400°F.  This not only ensures that no wax remains in the plaster, but it prepares the flasks to receive the liquid metal.  If the flask were cooler, the metal might cool before it reached the farthest cavities of the mold and the casting would be incomplete.  By heating the plaster, the metal has a better chance of completely filling the flask and producing the full number of pieces.

 

 

The flasks are removed from the oven with long tongs and placed in the centrifugal casting machine.  Metal is melted in a ceramic crucible, which feeds directly into a hole in the flask.  The carriage is then released and spins rapidly, flinging the liquid metal into the plaster, where it quickly hardens.  The flask is removed and set aside to cool slightly while the next crucible is set up and the next flask loaded into the caster.  It is then dipped in water to dissolve the hot plaster, allowing the metal to be removed.

 

 

 

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