ZF-801B, a new kind of quick drying silica sol for precise casting, mainly made of silica sol and combined with several kinds of organic polymers and macromolecule materials, is specially used in fine casting for backup coats to fabricate shell. It is characterized by the following advantages ：
1.The drying time is apparently shortened. Generally, after about 2 hours the next layer can be done. The drying speed has gone up 50% in original condition and the production capacity is improved. When the wind speed is upwards 6~ 8 M /S, the drying time will be much shorter.
2.The silica sol, in which the organic polymers and fiber are added, improves the coating adhesion performance and phragmoid toughness. It is not easily broken especially in strong wind. The craze crack and flash of the cast are reduced. As a result the quality of the cast is improved.
3.The shell-mold that is easily broken has a high wet strength and low retained strength.
4.The silica sol has a longer service time as the polymers are alkaliproof and not moldy.

Technical index：
Appearance：Milky suspension fluid
Solid content(%)≥：30
SiO2 content%≥：25
Na2O content %：0.2～0.4
Viscosity（25℃）mPa.s：≤15
Density（25℃）g/cm3：1.18～1.22
PH Value（stock solution ）：9～10.5
Shelf period：(normal temperature)six months
Packing：30KG plastic barrel