The shell molding process employing synthetic thermosetting resin mixed with high grade silica sand and is a method of producing sand castings to very much closer tolerances. It is, of course, a machine molding process. The pattern plates used for this process must be of metal and capable of withstanding temperatures of 250-300°C. The amount of “draw” required for these patterns can be greatly reduced and rapping the pattern is not used for ejecting the mould from the pattern plate.

The shell molding process employing synthetic thermosetting resin mixed with high grade silica sand and is a method of producing sand castings to very much closer tolerances. It is, of course, a machine molding process. The pattern plates used for this process must be of metal and capable of withstanding temperatures of 250-300°C. The amount of “draw” required for these patterns can be greatly reduced and rapping the pattern is not used for ejecting the mould from the pattern plate.