The Difference Between One- and Two-Component Epoxies


It’s the question on everybody’s lips (well, at least those who work with adhesives in the manufacturing industries). What exactly is the difference between one- and two-component epoxies? Read on as we explore the differences and advantages of each type of epoxy.

One-Component Epoxies

An epoxy with one component can be applied straight from a container such as a stick, syringe or tube. One-component epoxies do not need to be degassed, metered or mixed before application. They do, however, require heat for correct curing. It will normally require the use of an oven or similar heating apparatus in order to fully cure. Some one-component epoxies can be cured via light with the use of ultraviolet. The advantage of one-component epoxies that they are less fiddly to use. They are also worth considering for assembly lines where a heating process naturally follows the application of an epoxy, or when only a small amount of adhesive is used.

Two-Component Epoxies

Two-component epoxies are far more common when it comes to large-scale manufacturing. In order to work they require users to mix together a resin and a hardener. Some containers eject both components at once from two adjoining cartridges, so they mix upon application. It’s the hardener that triggers the polymerization, which is essential to achieving full cure. The parts can also be combined mechanically or manually, during which time an exothermic reaction will occur and the molecules will link together. As the two-part epoxy is fully cured, it can be likened to a hard piece of plastic. Two-component epoxies result in stronger bonds than one part, thanks to the synergy concept – the whole is greater than the sum of its parts. Two-component epoxies also don’t require heat and can be cured at room temperature.

Many manufacturers, especially in the automotive or aerospace industries, will use both one- and two-part epoxy sealant options for different sealing jobs. Epoxy adhesives and sealants have a number of other uses. Those looking for other sealants or metal bonding adhesive options should look through the products available from retailers such as

In short, two-part epoxies are stronger and don’t require heat but are more complicated to use. Epoxies are just one option when it comes to sealants and adhesives, so do plenty of research before you choose an adhesive for your project.


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