Simpson Strong-Tie Crack-Pac injection epoxy is designed to repair cracks in concrete ranging from 1/64-in. to 1/4-in. wide in concrete walls, floors, slabs, columns and beams. The mixed adhesive has the viscosity of a light oil and a low surface tension, allowing it to penetrate fine to medium-width cracks in dry, damp or wet conditions with excellent results. Resin is contained in the cartridge and hardener is contained in the nozzle.