The Differences Between Adhesives & Sealants

Adhesives and sealants are both substances used to bond or fill materials, but they serve different purposes and have distinct properties. Here's a breakdown of the key differences between the two.

Adhesives are used to bond materials together. They are used to create strong, lasting attachments between surfaces by holding them in place and are designed to resist stress and shear forces, making them ideal for applications where strength and durability are required.

Sealants, on the other hand, are used primarily to fill gaps and prevent the passage of fluids, air, or contaminants between surfaces. They provide a flexible barrier that blocks leaks but generally don’t have the same bonding strength as adhesives. Sealants are often used in joints, seams, or spaces where slight movement might occur.

Adhesives have high bonding strength and are formulated to provide strong, permanent bonds. They are designed to withstand various mechanical stresses, including tension, shear, and compression. Examples include epoxy, superglue, and construction adhesives.

Sealants typically have lower bonding strength than adhesives. They are meant to form a protective layer rather than hold two surfaces together with high strength. They are more focused on sealing gaps or joints rather than withstanding mechanical loads. In terms of your car, you might use a gasket sealant to improve the seal and stop oil or fuel leaks or a windscreen sealant to keep the outdoors from seeping into your interior.

Basically, if you’re trying to keep two materials together, such as wood, metal, plastic, and glass, then you’re going to want an adhesive. Use sealant if you have areas where sealing or filling is required rather than bonding, such as when you need waterproofing, air-tight sealing around windows and doors, or filling gaps between tiles or pipes.

Adhesives & Sealants at Repco

Whether you need a water-glycol resistant sealant for your thermostat, silicone adhesives for powerful bonding, or even tapes and specialist repair kits for windscreens and radiators, we’ve something for your needs.