May
11
Learn about the basics of Casting Sand, Green Sand, and the
uses of Casting Sand.
Green Sand: Green sand is also called as foundry sand or molding sand.
This is utilized for sand casting. When this sand is oiled or moistened, it has
a tendency to pack well and retain the shape. Green sand is a mix of pulverized
coal, water, bentonite clay and sand. Out of these four components, the biggest
part is that of the sand. There are
several proportions of these four components. The different ratios are used to
adjust the surface finish, moldability and capacity of the hot molten metal to
degas. The prime use of this sand is in the metal casting. The coal is usually
called as sea coal in foundries. The amount of sea coal is less than 5 percent.
It undergoes partial combustion when there is molten metal present and this
causes offgassing of organic vapors.
