Two component, paste-like epoxy polysulfide for bonding, sealing and coating

Key Features

  • One to one mix ratio
  • Superior resistance to fuels and oils
  • Thixotropic paste
  • Room temperature curing compound
  • Resists thermal cycling
  • Withstands 1,000 hours 85°C/85% RH

Product Description

Master Bond EP21TPND is a two component epoxy polysulfide system with a paste consistency that cures at room temperature or more rapidly at elevated temperatures. It has a forgiving one to one mix ratio by weight or volume and can be used as an adhesive, coating and sealant. It’s very resistant to a number of chemicals including water, gasoline, fuels, oils, hydrocarbons, hydraulic fluids and many acids and bases. Significantly, unlike many chemical resistant epoxy based materials, this system has excellent toughness and flexibility. The combination of properties enables EP21TPND to withstand rigorous thermal cycling as well as mechanical and thermal shocks. It bonds well to a variety of substrates, including metals, glass, ceramics and many rubber and plastic materials. The cured system has excellent electrical insulation properties. Its service temperature range is -80°F to +250°F. One unusual feature of EP21TPND is the influence of adding heat to the curing cycle. When cured at room temperature the Shore D hardness is 60-65 and when cured at 200°F for 2-3 hours, its hardness is 15-20 Shore D. Therefore, to optimize properties, especially its chemical resistance profile, room temperature curing only is recommended. The color of Part A is black and Part B is amber, although, other colors are available. Polysulfide based systems, including EP21TPND, have been used as fuel tank sealants and as sealing compounds for electrical connectors exposed to fuels, oils and lubricants, for many years. EP21TPND is also widely used in the aerospace, OEM, electronic, electrical, chemical and related industries.

Product Advantages

  • Convenient mixing: forgiving one to one mix ratio by weight or volume
  • Easy to apply — adhesive spreads evenly and smoothly; non-drip viscosity
  • Ambient temperature curing imparts optimal chemical resistance and hardness
  • Forms tough bonds; resistant to thermal cycling
  • Bonds well to a variety of substrates
  • Superb resistance to oils, fuels and related chemicals

Industrial Certifications

1,000 Hours at 85°C/85% RH




EP21TPND is available is various sizes and units to accommodate customer's needs.

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