Two component epoxy adhesive, sealant, coating and encapsulating system

Key Features

  • Exceptional chemical resistance to acids
  • Serviceable from -60°F to +400°F
  • High bond strength
  • Low viscosity
  • 100% reactive
  • Withstands 1,000 hours 85°C/85% RH

Product Description

Master Bond EP21ARHT is a two component epoxy resin system for high performance bonding, sealing, coating and encapsulating. It has a convenient 100 to 50 mix ratio by weight and is formulated to cure at ambient temperatures or more quickly at elevated temperatures. It has exceptional resistance to a wide array of chemicals, particularly to acids (a more detailed list appears below). It is especially noteworthy for its resistance to sulfuric and hydrochloric acids. Realistically, one should adhere to the optimum cure schedule referenced below (the longer the post cure, the better the chemical resistance).

EP21ARHT is 100% reactive and contains no solvents or diluents. It has very low linear shrinkage upon cure. Also, it has outstanding physical properties and electrical insulation values. EP21ARHT can be used as an adhesive, sealant, coating, potting or encapsulating material. EP21ARHT is especially useful for coating tanks and other vessels that may contain acids. It is serviceable over the wide temperature range of -60°F to +400°F. It adheres well to a wide variety of substrates including metals, glass, ceramics and many rubbers and plastics. The standard version of this system has a lower viscosity with good flow. A non-drip version called EP21ARHTND is also available. Part A is clear and Part B is amber clear. This epoxy compound is widely used in aerospace, electronic, electrical, chemical processing applications and in other applications where chemical resistance to acids is needed.

Product Advantages

  • 100% reactive compound does not contain any solvents or diluents
  • Versatile cure schedules; ambient temperature cures or fast elevated temperature cures
  • High bonding strength to both similar and dissimilar substrates
  • Wide temperature service capability from -60°F to +400°F
  • Good electrical insulator. Low viscosity. Ideal for potting and encapsulation
  • Outstanding chemical resistance, particularly to acids

Industrial Certifications

1,000 Hours at 85°C/85% RH

Meets EU Directive 2015/863



Double Barrel Cartridge


Gun Applicator

Premixed & Frozen Syringe


EP21ARHT is available is various sizes and units to accommodate customer's needs.

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