Two component, low viscosity, room temperature curing epoxy for bonding, sealing, coating and casting

Key Features

  • Serviceable up to 300°F
  • Superior chemical resistance
  • Exceptional optical clarity
  • Withstands 1,000 hours 85°C/85% RH

Product Description

Master Bond EP39-2 is a fast curing, low viscosity, optically clear, two component epoxy system for high performance bonding, sealing, coating and casting. The mix ratio is a forgiving two to one by weight. Upon mixing, this very low viscosity system is relatively faster curing. As a coating, in sections as thin as 0.005-0.01 inches, it will become tack-free at ambient temperatures in 3-4 hours and will fully cure in a day or so. The optimum cure schedule is 3-4 hours at ambient temperatures followed by 2-3 hours at 140-170°F. An interesting property of EP39-2 is its ability to polymerize at lower temperatures, down to 40°F. Also, EP39-2 has very low shrinkage upon curing.

It is an excellent adhesive and bonds well to a wide variety of substrates including metals, composites, ceramics and glass as well as many rubber and plastic materials. Other desirable characteristics include resistance to blushing and exudation, reliable electrical insulation properties and good rigidity along with outstanding chemical resistance (see chart below). EP39-2 also can be used for smaller potting and encapsulation applications. The service temperature range is -60°F to +300°F. Also significant is its optical clarity and very good light transmission properties. This versatile system can be used in aerospace, electronic, optical, electro-optic and specialty OEM applications where the product properties mentioned above are beneficial.

Product Advantages

  • Convenient handling with a forgiving two to one mix ratio by weight
  • Easy application by roller, brush or spraying
  • Faster curing, shorter tack-free times and well suited for coating applications
  • Resistance to blushing and exudation
  • Good optical clarity and excellent light transmission
  • Cures rigid, well suited for machining or polishing
  • Outstanding chemical resistance

Industrial Certifications

1,000 Hours at 85°C/85% RH

Meets EU Directive 2015/863



Double Barrel Cartridge


Gun Applicator



EP39-2 is available is various sizes and units to accommodate customer's needs.

Case Studies

University of Hawaii researchers, under the sponsorship of the Department of Energy, were looking to develop photoelectrochemical (PEC) systems to produce hydrogen directly from water using sunlight as the energy source. These PEC systems need to be highly efficient (offering solar-to-chemical conversion rates of 10-15%), potentially low cost and long operating lifetimes.

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