How are the castings made?
The Bowmanville Foundry employs the green sand casting process. Green sand is by far the most diversified molding method used in present casting practices. The process utilizes a mold made of compressed or compacted moist sand. The term “green” denotes the presence of moisture in the molding sand, and indicates that the mold is not baked or dried. The mold material consists of silica sand mixed with a suitable bonding agent (clay) and moisture. To produce the mold a flask, a metal frame, is placed over production tooling in the form of a pattern or matchplate of the desired part shape. Molding sand is compacted in the flask and takes on the shape of the pattern to produce a cavity representing one half of the casting. Compaction is achieved by squeezing the mold. The other half of the mold is produced in like manner, the pattern and flask is removed and the two mold halves are positioned together to form the complete mold. Molten iron is poured into the cavity in the sand mold through
