Master Bond Polymer Adhesive EP21D is a two component epoxy adhesive for general purpose bonding formulated to cure at room temperature or more rapidly at elevated temperatures, with a one-to-one mix ratio, weight or volume. It readily develops a high bonding strength of more than 3000 psi at room temperature which unlike that of many other epoxy adhesives, is relatively insensitive to mixing ratio or substrate cleaning procedures. It produces durable high strength and tough, flexible bonds which are remarkably resistant to thermal cycling and chemicals including water, oil and most organic solvents, over the exceptionally wide temperature range of -60°F to 250°F. Adhesion to metals, glass, ceramics, wood, vulcanized rubbers and many plastics is excellent. The hardened adhesive is an electrical insulator. Color of part A gray, part B amber. Master Bond EP21D adhesive is widely used in the electronic, electrical, computer, construction, metalworking, appliance, automotive and chemical industries.

The cured adhesive fully meets the requirements of MIL-A-81236 (OS), MMM-A-134-TYPE 1.