Hot bulging or creep present as a thickening, oversized or inflated casting. This defect could be similar to buckling, but typically without the sharp peak. This defect indicates that there was hot deformation of the ceramic mold under pressure of metal, forcing the shell to move or creep at a given temperature and pressure.

 

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