Molding sand

[1] There are many recipes for the proportion of clay, but they all strike different balances between moldability, surface finish, and ability of the hot molten metal to degas.

The coal, typically referred to in as sea-coal, which is present at a ratio of less than 5%, partially combusts in the surface of the molten metal, leading to the offgassing of organic vapors.

There is no clear record in history to attribute the first metal casting and use of molding sand, but ancient artifacts and writings allude to a period around 3200 B.C.

The history of molding sand is difficult to study, as much of the origins of the practice predate writing.

Molding sand was used exclusively for bronze casts, which was pioneered by the ancient Chinese.

A crucible containing bronze is poured into the Green Sand, which contains a hollow shape below, that will become the finished cast.