This article compares water glass casting vs silica sol casting in terms of surface finish, cost, and dimensional accuracy.
Precision investment casting is widely used for producing complex metal parts with high precision. Among the different investment casting methods, water glass casting and silica sol casting are the two most common processes used in industrial manufacturing.
Although both belong to the lost wax casting process, they differ significantly in surface finish, dimensional accuracy, cost, and suitable applications. Understanding these differences helps buyers choose the right casting process for their projects.
Firstly, from Chemical Composition:
- The water glass casting process mainly uses water glass as the main raw material. The silica sol casting process uses silicate hydrated glass as the main raw material.
- Water glass is a combination of oxide and silica, while silica sol is a high molecular polymer formed by the condensation of silicate solution.
Secondly, the Production Methods are also different.
- The water glass casting process usually adopts the traditional sand casting method. That is, water glass and sand are mixed to form a sand mould, and then the metal solution is injected.
- The silica sol casting process uses precision casting, which uses the characteristics of silica sol to mix it with modelling materials to make a high-precision silica sol core, and then inject the metal solution.
Third, Casting Effects are different.
The surface of the casting produced by the water glass casting process is rough, the precision is low. And it is easy to produce pores, sand holes and other process problems.
The silica sol process has the advantages of high precision, high smoothness, and high strength, and can produce finer and more complex castings.
Fourth, the Prices are different.
Water glass castings are less expensive.
Silica sol castings are more expensive.
Comparison Between Water Glass Casting and Silica Sol Casting
| Item | Water Glass Casting | Silica Sol Casting |
|---|---|---|
| Surface Finish | Rougher | Very smooth |
| Dimensional Accuracy | Medium | High |
| Tolerance | CT7–CT8 | CT5–CT6 |
| Cost | Lower | Higher |
| Typical Materials | Carbon steel, alloy steel | Stainless steel, high precision parts |
| Application | Industrial machinery parts | Precision components |
There are obvious differences between the water glass casting process and the silica sol casting process in many aspects. The specific casting process to be applied needs to be determined based on the specific requirements and production conditions of the casting.
For a complete overview of casting technologies, read our Metal Casting Process Guide.
Real Manufacturing Example
We recently completed a custom stainless steel silica sol investment casting project for an overseas client.
Need Help Choosing the Right Casting Process?
If you are unsure whether water glass casting or silica sol casting is the better option for your project, our engineering team can help evaluate your drawings and recommend the most suitable manufacturing process.
Feel free to send us your drawings or specifications for a quick quotation.
