Stopping off is a manual molding technique used to cast a shorter or modified version of an existing pattern without physically cutting the pattern itself. The molder packs green sand into the unwanted section of the mold cavity after the pattern is drawn, creating a new boundary for the molten metal. This saves the cost of building a custom pattern for a one-off variation.
Heard on the job
Stop off the last six inches of that pipe pattern so we can pour a custom length for the repair job.
Insider tip
Stopping off requires a highly skilled molder, as the hand-packed sand must match the density of the rammed mold to prevent a blowout.