What is sand casting, water glass casting, and silica sol casting?
SAND CASTING PROCESS
The Sand Casting Process is one of the cheapest casting processes because it uses wet clay sand as the main molding material.
Sand castings will have a very rough surface, with more surface and inside defects then other methods. Refer to the following photos for an example of surface quality on steel castings made by this process.
WATER GLASS INVESTMENT CASTING PROCESS
Water Glass Investment Casting Process uses water glass quartz sand as the molding material, which can stand temperature up to 1800 degrees, but it is more expensive than wet clay.
Water glass investment castings have much better surface smoothness, with less surface and inside casting defects. Refer to the following photos for an example of surface quality on steel castings made by this process.
SILICA SOL INVESTMENT CASTING PROCESS
Silica sol investment casting process uses silica sol zircon sand as the molding material, which can stand temperatures up to 2000 degrees. This molding material is very expensive.
Silica sol investment castings have a very good surface quality; the castings are very smooth with much less surface and inside defects. Refer to the following photos for an example of surface quality on steel castings made by this process.
Casting complexity, unit weight and wall thickness differences
Sand casting process can produce very heavy and very large steel castings, but it can not be used to produce too small, too complex or very thin wall thickness castings.
The following table could be referenced to tell the differences between the processes.
These photos demonstrate the complexity of the silica sol investment casting process.
Casting prices, big difference!
The mold material costs have caused a very big difference on their casting prices. The wet clay sand is very cheap, water glass quartz sand is expensive, and silica sol zircon sand is very expensive. For example, the sand casting is 1.45 USD/kg, water glass investment casting will be 2.50 USD/kg, and the silica sol investment casting will be 6.79 USD/kg.