Pinholes or Gas

Technical Support

Struggling with a specific casting defect or just need general technical support?

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  • Bubble-shape cavities located on top side of parts when the tree is in casting position

  • Indicates that there was unburned wax pattern residue (soot or ash) in the shell; when molten metal was poured into the shell cavity and came into contact with the ash residue, gas was formed and trapped in the mold

Causes of this defect are evident in the other portion of the process; to cure, R&R recommends taking the following actions:


Burnout cycle is too short, burnout temperature is too low or there is a lack of oxygen in the burnout oven.

Any of these can cause incomplete pattern burnout. Improve the burnout conditions in the burnout oven to allow for complete pattern burnout prior to pouring.