The pattern is placed in the flask which rests on the molding machine. A bench will do, but the "jolt-squeeze" molder makes the day go by more easily. This machine has a large air cylinder which will compact the sand against the pattern creating a hard mold. Some patterns do not lend themselves to this squeeze operation and must still be rammed by hand with a bench rammer. Sand is shoveled into the flask, covering the pattern and rammed or squeezed until the mold is full and packed hard.

Molding sand has just enough clay and water mixed in to enable it to bond together with sufficient strength to retain the impression from the pattern even after the pattern is removed. Here the mold has been opened. The molder will remove the pattern, cut the spru hole through the top half (cope side), blow away any loose sand from the mold faces, and then close the mold and clamp it or weight it for pouring.

Ramming the mold