With the casting quality and accuracy requirements increase, water glass or ethyl silicate binder system for the shell process caused by the "casting is not fine" and such problems as environmental pollution has seriously hindered the development of the domestic foundry industry. Therefore, to improve casting quality and reduce the gap with the international casting industry, replaced with a sodium silicate or ethyl silicate sol is imperative. At the same time improved water glass to sol transition period, without the need to increase more financial and material resources and alter the primary process, we recommend using water glass composite sol ---- Shell Technology to enhance the gloss of the casting . This method improved for those not able to complete the business process is particularly suitable.