| Thickness | Heating too fast | Cooling too fast | | :--- | :--- | :--- | | | Cracks from edge | Cracks from edge | | Deep (> 25 mm) | Explosive spalling (chunks fly off surface) | Internal cracking (hairline cracks deep inside, invisible until failure) |
Engineers use a standard formula to determine the amount of stress generated by temperature changes:
If you are working with a deep piece (e.g., kiln-casting, thick labware, or a glass block):
To make this feature stand out:
