What phenomenon is indicated by lines or cracks appearing in the coating surface?

The presence of lines or cracks appearing in the coating surface is indicative of alligatoring. This phenomenon typically occurs when a coating is subjected to stress, such as temperature fluctuations or movement of the substrate, leading to a characteristic pattern reminiscent of alligator skin.

Alligatoring happens when the coating begins to shrink and crack, which can be caused by factors like improper application techniques or the use of incompatible coatings. It is often a sign of underlying issues with adhesion or flexibility of the coating material and can result from environmental exposure that affects the integrity of the coating film over time.

Understanding alligatoring is crucial for coatings inspectors, as recognizing this pattern allows for proper assessment of the coating's health and the potential need for repairs or recoating to prevent further deterioration.

On the other hand, blistering entails the formation of bubbles in the coating due to trapped moisture or solvent, while peeling refers to the lifting away of the coating from the substrate, usually caused by poor adhesion. Layer delamination is essentially the separation between layers of a coating system, often due to improper application or curing processes. Each of these conditions has its own distinct visual indicators and causes, which differentiate them from alligatoring.