What is the importance of elongation and adhesion?
Silicone sealants have good elongation properties which allows for movement within the joint. The silicone must adhere to the substrate otherwise the sealant can be forced out of the joint under pressure. The amount of joint movement that can be withstood and still maintain the seal on a joint is determined by the diameter of the cured silicone bead, the amount of elongation (typically measured as a % – Hylomar silicones typically have approximately 400% elongation when they initially cure, and then degrade over time when exposed to heat, oil, and atmosphere) and by the adhesion – if the silicone won’t adhere to the substrate – the metal flange – then the seal will fail.
