Epoxy

Plain-English definition

Epoxy is a high-strength adhesive that comes in two parts: a resin and a hardener. When equal amounts of both are mixed together, a chemical reaction occurs that causes the liquid to cure (harden) into a solid, durable plastic.

Why it matters

Unlike wood glue or super glue, epoxy does not rely on air to dry or moisture to activate. It cures purely through its internal chemical reaction, which means it is excellent for filling large gaps or bonding completely non-porous materials like metal, glass, and rigid plastics. Once cured, it is incredibly strong and often waterproof.

Common mistake

A common mistake is failing to mix the two parts thoroughly. If the resin and hardener are not mixed completely, the chemical reaction will be incomplete, and the adhesive will remain sticky and never reach its full strength. Always mix for at least a full minute before applying.