Which coating defect refers to the formation of small holes in a paint layer?

The formation of small holes in a paint layer is known as pinholes. This defect occurs when bubbles of air are trapped in the film during the application or drying of the coating, leading to tiny holes that can expose the underlying substrate to moisture and other environmental factors. Pinholes can compromise the integrity of the coating, allowing for corrosion and degradation over time.

Pitting, while also involving small depressions, specifically refers to localized corrosion or surface imperfections that cause damage through the substrate rather than through the paint film itself. Cracking involves visible fractures in the coating, while blistering pertains to the formation of raised areas due to trapped moisture or solvents beneath the coating layer rather than small holes. Understanding these distinctions is crucial for proper identification and remediation of coating defects during inspection processes.