Master Bond Polymer System EP21TPFL-1 is a two component, low viscosity, highly flexible epoxy polysulfide elastomer compound for high performance bonding, sealing and casting offering outstanding resistance to fuels, water, oils and many other aggressive chemicals. It has been formulated to cure readily at ambient and more quickly at elevated temperatures with a user friendly noncritical ½ mix ratio, by weight or volume. The low viscosity facilitates easy mixing of the two components. This compound is 100% reactive and does not emit any volatiles during curing. Master Bond Polymer System EP21TPFL-1 represents a major technical advance over previously produced products without containing any potentially hazardous ingredients such as heavy metal curatives. The color of part A is clear while part B is dark brown .

The Master Bond Polymer System EP21TPFL-1 has excellent physical strength, high impact resistance and remarkably superior electrical insulation properties. These desirable properties are maintained even upon prolonged exposure to hostile environmental conditions including high and low service temperatures, immersion in fuels, water and many other chemicals. Dimensional stability is retained after extended aging in various environments. Adhesion to both metallic and nonmetallic substrates including aluminum, steel, copper, glass, ceramics, wood and most plastics is excellent. Although highly flexible, it's chemical resistance profile is vastly superior to urethanes and silicones It's a wide service temperature range extends from -65°F to +250°F. EP21TPFL-1 is widely employed in aerospace, avionics, marine, construction, and in applications where corrosion resistance is required. A flowable high viscosity version as well as a "non-drip" version called EP21TPFL-1ND are also available. EP21TPFL-1 is a superior nonhazardous alternative to traditional Mil Spec type polysulfide adhesives, sealants and coatings, which have long been specified in applications as demanding as fuel tank sealants and potting and sealing compounds for electrical connectors exposed to fuels, lubricants, and oils. The shelf life is 1 year in unopened containers.