1, the rough surface wax models, because the pressure is too low, or the firing rate is lower Wax material contact with the inner surface of molding density is not enough, serious still can appear fold.

2, wax models exist bubble, a is the surface bubbles visible with the naked eye, and the other is a wax mould inside the bubbles, usually is bigger, also can't see with the naked eye, but can pass the wax models of local summon up found that it was caused by wax mould gas expansion.