Lost Wax Casting (silica sol)

 The coasting bond brushed on the pattern surface is silica sol in this process.

 Parts made with lost wax casting(silica sol) have the tolerances are 0.1 mm for the first 25 mm (0.005 in for
   the first inch) and 0.02 mm for the each additional centimeter (0.002 in for each additional inch).

  A standard surface finish is 1.3–4 microns (50–125 μin). Compared with the water glass process, Parts made    with lost wax casting(silica sol) have betterexcellent surface finish and higher dimensional accuracy.