Question: What is the difference between a hardener, a primer, an accelerator, and an activator for adhesives and sealants?
Answer: This terminology can be confusing because the terms are often used interchangeably between technologies and differently by various manufacturers of the same technology. The term hardener is most often used in two-part epoxy adhesives; most manufacturers call the part that actually contains the epoxy molecule the “adhesive,” and the part that contains the curing agent the “hardener.” Some of these epoxy systems also contain additives in the hardener component to speed up the cure; these are usually called “accelerators” or “catalysts.”