'Adhesive' in National City is a material that binds together the surface of two materials. 'Sealant' is any material with adhesive properties that is applied as a rope or bead and that is formulated for use primarily to fill, seal, waterproof or weatherproof gaps or joints between two surfaces. A sealant is that fluid enough to be poured into horizontal joints. It forms a smooth, level surface without tooling. Sealant prevents excessive absorption of adhesive or penetration of liquid or gaseous substances. Adhesive and sealants can be both used as a replacement of each other in certain cases.
The primary function of an adhesive is to hold substrates together for the life of the product. However, adhesives are also useful for providing secondary functions that is in addition to performing a mechanical fastening operation; an adhesive may also be used as a sealant, vibration damper, insulator, and gap filler. Many designers feel that multi-functionality is one of the most valuable characteristics of adhesive bonding. Sealants on the other hand are generally used in National City as a barrier or a means of protection by excluding dust, dirt, moisture, and chemicals or to contain a liquid or gas. Even certain sealants, like adhesives, can be used to assemble parts, and many adhesives can be used to seal and also often used as a coating to protect a surface or an article. They can exclude noise and vibration, improve appearance, and perform a joining function. Sealants can also be used as electrical or thermal insulators, fire barriers, and as products for smoothing or filleting.