QUESTION: I need to assemble some sheet metal parts and must choose between a tough acrylic adhesive and an epoxy. Which would you recommend?
ANSWER: Both types of adhesives are very versatile; the choice depends on your operating environments and manufacturing situation. Invented in the 1940s, epoxies are the oldest and most tested adhesive for this application. A wide range of epoxy adhesives is available, from heat-cured, one-component systems (normally requiring several hours to fully cure) to two-component, ambient-cured systems. The general rule of thumb is that if your adhesive must resist very high temperatures and aggressive environments, then you need to use a heat-cured system. Higher temperatures give better molecular mobility to a curing adhesive system and promote more chemical crosslinking.