A two-part epoxy adhesive having a resin component containing a mixture of an epoxy resin and an internally flexibilized epoxy resin and a hardener component containing a mixture of a flexibilizer and an unmodified or modified aliphatic amine, an unmodified or modified polyamide, or combinations thereof. The resin component and hardener component are mixed and applied to substrates, or applied to substrates and mixed, and then allowed to cure yielding a cured epoxy resin having a tensile elongation at room temperature of greater than 30%. The initial curing time is less than 3 hours.