Silicon sol is handled by sodium silicate by ion exchange, after removal of Na + ions and other impurities of silica sol. It is the basic ingredient of amorphous silica, it is more silicate molecular weight polymer colloidal solution; White transparent liquid state, when high concentration colloidal shaped.
The stability of silica sol is very good, can be stored for a long time, does not need special curing agent, when making a shell and shell strength, to even higher than hydrolyzed ethyl silicate shell. Silicon sol and easy to use, with paint, just with alcohol or water to dilute, the SiO2 content of 20% ~ 24%, the viscosity of 8 cp.
The addition amount of alcohol should be lower than 30%-40% (volume fraction), and people should keep stirring and mixing time about 30 min. However, silicon sol wetting performance of casting is a bit poor, shell hardening process is a long dry process (hot air, etc.)