When is cracking of a coat considered severe?

Cracking of a coat is considered severe when the crack extends to the substrate because it indicates a significant failure in the coating system. This type of damage can allow moisture, contaminants, and other environmental factors to penetrate the coating, leading to corrosion or deterioration of the underlying material. Substrate exposure can compromise the integrity of the entire coating system, making it critical to address such issues promptly to prevent further degradation and ensure the longevity of the surface being protected.

Other scenarios, such as cracks affecting only the top layer, superficial cracks, or those occurring in corners, do not necessarily reach the same level of seriousness since they may not compromise the coating's ability to protect the material underneath. Addressing these lesser forms of cracking may be necessary, but they do not represent an immediate threat to the substrate itself.