Master Bond Polymer System EP39MHT is a low viscosity, two component, epoxy resin system for high performance potting, encapsulation, sealing and bonding. It cures readily at ambient temperatures to an exceptionally tough and thermally stable thermosetting polymer featuring outstanding electrical insulation properties, remarkably high resistance to thermal shocks and mechanical vibration, inertness upon exposure to water and a wide range of chemical plus capability for sustained service at temperatures up to as high as 450°F. The Master Bond Polymer System EP39MHT is 100% reactive and does not contain any solvents or other volatiles. As it develops very little heat during curing it is particularly desirable for casting thick sections with complicated geometrical configurations up to several inches as well as thin sections with minimal shrinkage and stress development. Master Bond Polymer System EP39MHT is especially recommended for use of application and where cured assemblies must retain excellent electrical insulation and mechanical strength properties even upon exposure to adverse environmental conditions at both ambient and elevated temperatures in the presence of water, many organic solvents and other chemicals. Master Bond Polymer System EP39MHT is based on a novel polyfunctional epoxy resin and a uniquely formulated hardener which makes feasible both the attainment of ambient temperature cures and development of outstanding thermal stability for prolonged service at temperatures up to the 400-450°F range. Additionally the cured epoxy polymer exhibits remarkably high resistance to thermal cycling and many chemicals including water, acids, bases and solvents such as ethyl alcohol, toluene, xylem etc. Adhesion to both similar and dissimilar substrates such as metals, glass, ceramics, woods, vulcanized rubbers and many plastics is excellent. The hardened epoxy resin maintains its electrical insulation properties even at elevated temperatures in the presence of moisture. The EP39MHT epoxy resin system can be color-coded to facilitate mixing. The color for part "A" is clear and "B" is amber. Master Bond Polymer System EP39MHT is widely used in the electronics, electrical, computer, construction, metalworking, appliance, automotive and chemical industries. It has proven particularly successful for potting and encapsulation electronic assemblies with complicated geometrical configuration which are subject to thermal cycling and/or mechanical vibrations in adverse environments.