A great many sealer applications are not visible on the body of the vehicle. The primary function of sealants is to prevent air, dust or water from entering or exiting a section. However, many sealants perform other functions such as provide holding power, corrosion protection, and reduce vibration and noise. For example, body sealers are extruded over welded joints to keep moisture out and reduce corrosion.
Sealants generally have a high degree of elongation and environmental stability, but their tensile strength is less than structural adhesives so they are not used in structural applications.