Dewaxing time: depending on the size and shape of a large module level, ordinary in 15 ~ 35min is appropriate. Die material complete condensation of simple determination method is above the water gate to see whether continuous presence of floating wax. Shell type erosion: in the dewaxing process, the shell cavity probably being residual wax and adhesion in type shell and form the unsaponifiable matter of, so after dewaxing shell should be used hot water repeated washing. If you add a little hydrochloric acid in hot water (0.5%), then the erosion results will be better. The shell should be placed upside down after scouring the boring, boring stops at the natural ventilation.