Two component epoxy system featuring exceptional bonding strength properties

Key Features

  • Convenient handling
  • Excellent structural adhesive
  • Combines low viscosity and optical clarity
  • Provides superior electrical insulation values

Product Description

Master Bond EP31 is a two part epoxy system used primarily for bonding, but is also serviceable as a coating, sealing and encapsulation agent. The processing is relatively easy and straightforward with a forgiving mix ratio of 100 to 30 by weight. It cures readily at room temperature or more rapidly at elevated temperatures. At ambient temperatures, it cures in about 1-2 days, and at 200°F, in about 2-3 hours. To optimize properties, an overnight cure at room temperature followed by 2-3 hours at 150-200°F is desirable. Upon cross linking, EP31 has toughness and resiliency allowing it to withstand aggressive thermal cycling. Most prominent is its remarkable tensile lap shear and peel strength (summarized below). It bonds well to a wide variety of substrates, including metals, composites, glass, rubber, ceramics and many plastics. Some other desirable attributes include chemical resistance to water, oils and fuels; very good optical clarity and low shrinkage upon curing. It is a first class electrical insulator, which, when combined with its good flow properties, enables it to be used for smaller potting applications. The service temperature range is -60°F to +250°F. It is also available in a non-drip version called EP31ND. This robust product profile allows EP31 to be considered for use in aerospace, electronic, optical, opto-electronic, specialty OEM and related industries.

Product Advantages

  • User friendly handling and processing
  • Versatile cure schedules
  • Stellar lap shear and peel strength properties
  • Top notch electrical insulation properties
  • Impressive optical clarity
  • Product Citation

    EP31 was cited an article titled “Piezoelectric Microfiber Composite Actuators for Morphing Wings” by Timothy D. Usher, Kenneth R. Ulibarri Jr., and Gilberto S. Camargo at the Department of Physics, California State University at San Bernardino, California. Click here.

Industrial Certifications

Meets EU Directive 2015/863





Premixed & Frozen Syringe


EP31 is available is various sizes and units to accommodate customer's needs.

Case Studies

In a report published in the US National Library of Medicine, National Institute of Health, regarding the use of a novel non-instrumental platform to enable a Loop Mediated isothermal Amplification (LAMP) based assay for Salmonella enterica, Master Bond EP31 is cited as follows. "All aluminum and acrylic parts of the cartridges were fit together with a two-component epoxy (EP31, Master Bond, Hackensack, NJ, USA) and cured overnight."1

Request Information