Master Bond Polymer System EP21AR is a two component epoxy resin compound for durable, high performance, coating liner and adhesive/sealants with outstanding acid as well as excellent overall chemical resistance. The EP21AR compound which is formulated to cure at room temperature or more rapidly at elevated temperatures, with a convenient two-to-one non-critical mix ratio by weight, offers a degree of acid resistance unmatched by any other currently available room temperature or heat curing resin composition. It can successfully withstand, for example, prolonged immersion in even 96-98% sulfuric acid and 36% hydrochloric acid for more than a year. A primary application would be as a coating and/or liner for chemical storage tanks, fuel storage tanks, chemical piping, scrubbers, chemical processing equipment, etc. Master Bond Polymer System EP21AR also features excellent resistance to fuels, oils, ethanol and many active organic solvents. In addition, it has superb bonding strength and is an excellent adhesive especially in acid environments. Master Bond Polymer System EP21AR is 100% reactive, does not contain any solvents or diluents and cures with minimal shrinkage. It readily develops a high bonding strength of more than 2500 psi at room temperature. Adhesion to metals, glass, ceramics, cements, wood, vulcanized rubbers, and many plastics is excellent. A non-drip version is also available. The EP21AR system has high physical strength properties and although rigid, it thermally cycles well over the temperature range -60 to 275°F. The Master Bond Polymer System EP21AR cures readily to produce a strong, thermoset plastic with superior electrical insulation characteristics and a desirably low coefficient of thermal expansion. Color of part A clear; part B amber. This epoxy compound is widely used in the construction, maintenance and repair, chemical process, metalworking appliance and electrical/electronic industries wherever durable, high performance, tough coatings, liners and/or adhesive sealants with outstanding acid, chemical and solvent resistance are required.