What is a common characteristic of a good sealant?

A good sealant must remain flexible after curing because this characteristic allows it to accommodate joint movement without cracking or breaking. In aerospace applications, the structures are often subjected to thermal expansion, vibration, and other dynamic forces. If a sealant were to harden completely, it could become brittle and potentially fail, leading to leaks or structural integrity issues.

Flexibility after curing ensures that the sealant can maintain a tight seal under varying conditions, thereby providing reliability in protecting against moisture, air, and other environmental factors that could compromise the integrity of the assembly. This is especially important in aerospace environments where safety and durability are critical.

While rapid drying, clarity, and cost are notable characteristics in some contexts, they do not universally define the effectiveness of a sealant in critical applications like aerospace. Flexibility post-curing stands out as essential for performance and longevity in challenging operating environments.