Silica sol is mainly used as binder for investment casting coating and can be used as surface coating and reinforcement coating for shell. It can not only reduce the cost but also improve the working condition to apply the small particle silica sol to precision casting instead of ethyl silicate.

Used for thin shell precision casting, it can make shell high strength, high dimensional accuracy, good casting finish, better quality than sodium silicate molding, and cheaper than ethyl silicate. It is especially suitable for large castings, castings requiring high surface finish and castings requiring no or little allowance. Using silica sol as high temperature resistant coating for mold casting can make the coating have good heat resistance and abrasion resistance, reduce the loss of molten metal to mold under high temperature, and contribute to mold release.