Abstract: A casting apparatus, comprising: a heating chamber having an open lower end defined by a periphery; a chill plate having a peripheral region for supporting one or more casting molds thereon and being in movable to move the molds from within the heating chamber to below the lower end of the heating chamber to withdraw the casting molds from the heating chamber; a cooling spool disposed at the periphery of the open lower end of the heating chamber and including a surface area for receiving heat energy radiated from at least one of the heating chamber and the casting molds; and a spool shield disposed at the cooling spool and movable to control an amount of the surface area of the cooling spool available for receiving the heat energy. In another embodiment there is an additional inner cooling spool movable inside the area surrounded by the casting molds for receiving radiant energy. A second spool shield at the inner spool controls its available surface area.