Causes and countermeasures of spherical protrusions on the mold surface

It is mainly caused by the residual air (bubbles) remaining on the surface of the wax after the embedding material is blended.

1) The effect of vacuum embedding is better for real air conditioners and embedding materials.

2) Spray a surfactant on the surface of the wax before embedding (e.g. Castmate from Nissin)

3) First coat the embedding material on the wax mold.

4) Use pressure embedding method to squeeze out bubbles.

5) Pay attention to the direction of the wax mold when embedding, and don't have a depression under the joint between the wax mold and the sprue.

6) Prevent air bubbles from being mixed during embedding. Casting ring and casting seat. The buffer paper must be tightly closed; the embedding material must be poured along the inner wall of the casting ring (using an oscillator).

7) Do not shake after filling the casting ring.