Hardeners are used to cure epoxy resins. However, simply adding a hardener to an epoxy resin may not cause the epoxy mixture to cure quickly enough. If this is the case a different hardener may be required. Also, hardeners with certain additives can be used.
Reaction of curing agents with epoxy resins results in hard, thermoset materials. These thermoset materials are often used as coatings and as components in finished goods, like adhesives or composites.