Master Bond Polymer System EP21FL is a low to moderate viscosity, two component epoxy resin system for high performance casting, bonding, sealing and coating formulated to cure at room temperature or more rapidly at elevated temperatures, with a four (4) to one (1) mix ratio by weight. This compound is 100% reactive and does not contain any solvents or other volatiles. It is well suited for bonding dissimilar substrates with different coefficients of expansion . As a lower viscosity system it is also well suited for potting, coating, and sealing electronics. Master Bond Polymer System EP21FL produces high strength and tough castings, bonds and seals 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 more than 250°F. The hardened compound is an electrical insulator. Color of part A is clear, part B amber. Master Bond Polymer System EP21FL is widely used in the electronic, electrical, computer, construction, metalworking, appliance, automotive and chemical industries. As a flexibilized system, it is characterized by superior impact and shock resistance.