What causes gel coat to cure too quickly, resulting in stress cracks?

Curing gel coat too quickly, leading to stress cracks, is primarily a result of over-catalyzed mixtures. When the amount of catalyst added to the gel coat exceeds the manufacturer's recommended levels, the chemical reaction that initiates curing occurs at an accelerated pace. This rapid curing can stress the material as it hardens, which may create tension that manifests as cracks or defects on the surface.

In contrast, low ambient temperatures can slow down the curing process, while high humidity may affect the curing characteristics but typically does not lead to rapid hardening. Thin application techniques usually result in slower curing times since less material is curing at once; however, they may pose other challenges unrelated to the immediate issue of stress cracking from rapid curing.