casting is metal casting process
that employs reusable molds or
permanent molds, usually made from
metal. The most common process uses
gravity to fill the mold. The
gravity process begins by preheating
the mold to 150-200 C (300-400 F).
The mold cavity is then coated with
a refractory material or a mold
wash, which prevents the casting
from sticking to the mold and
prolongs the mold life. Any sand or
metal cores are then installed and
the mold is clamped shut. Molten
metal is then poured into the mold.
Soon after solidification the mold
is opended and the casting removed
to reduce chances of hot tears.