The sand casting process can be of two types. It all depends on the type of sand used. While the first one uses green sand, the second one of the air set method.
In this process, casting iron is made using moulds of ‘wet’ sand. The sand literally contains water and organic bonding compounds or clay. Thus the mould is still green or uncured as the metal is poured into it. The green sand casting process doesn’t mean the sand is ‘green’. Rather it means the sand is used while it’s still wet. Coal is used in this process to ensure the off-gassing of organic vapours.
In this method dry sand is bonded with fast curing adhesives. This sand casting process is also known as no bake mould casting. Typically if bank sand is not used, then lake sand is more preferred. Air set moulds are created with the help of a casting flask. The sand is spread around a pattern to create the mould cavity. It’s in this cavity that the molten iron is poured to complete the casting iron process.
At Newby Foundries, we will help you choose a process that best works for you.