Why is silica sol used in investment casting?Silica sol is a kind of emulsion colloid. Because the colloidal particles are tiny (10-20 microns) and have a large surface area, it does not affect the true color of the coating material. Silica sol is miscible with water and immiscible with organic solvents. Soluble in alcohol or water mixed in any proportion. The salient feature of silica sol is...