Ceramic inclusions present as missing areas of metal in the casting; appearing as small, round, irregular or angular craters, depressions or cavities of various sizes; typically superficial with traces of ceramic and refractory material. This defect indicates that something is present in the mold cavity that prevents the casting from fully filling to the shell; typically ceramic shell debris, bits of the pour cup, or the inner mold surface broke off into the molten metal during pouring and were left behind on the casting surface. 

The causes of this defect are evident in the wax, shell and other portions of the process. To cure these causes, R&R recommends taking the following actions.