Versatile two part epoxy system for bonding, sealing, coating and potting that meets NASA low outgassing specifications

Key Features

  • Very fast curing; quick handling time
  • Excellent resistance to chemical sterilants
  • Outstanding electrical insulation properties
  • High physical strength properties

Product Description

Master Bond EP41S-LO is a two component epoxy system that combines rapid curing along with significant chemical resistance, which is an unusual blend of properties. EP41S-LO is certified to meet ASTM E595 for NASA low outgassing specifications. This lower viscosity system has a 100 to 20 non-critical mix ratio by weight. It sets up quickly after mixing and typically can be removed from a fixture in 40-50 minutes. It cures in 24 hours at 75°F, in 60-90 minutes at 200°F. To obtain optimum properties, curing overnight at 75°F followed by 1-2 hours at 150-200°F is recommended.

As noted above, EP41S-LO has superb chemical resistance. Typically, faster curing epoxies are somewhat less chemically resistant than other types of systems. However, EP41S excels at withstanding many chemicals, especially oils, fuels, acids, bases and many solvents. (Please refer to the chemical resistance chart for further details.)

EP41S-LO is 100% reactive and does not contain any diluents or solvents. It bonds well to a wide variety of substrates including metals, composites, ceramics and glass along with many plastic and rubber materials. EP41S-LO is a highly reliable electrical insulator and is particularly well suited for use in small sized potting applications. Most importantly, it has minimal shrinkage upon curing.

The color of Part A is clear and Part B is amber. The service temperature range is -60°F to +250°F. EP41S-LO is highly desirable in aerospace, optical, electro-optic and similiar types of applications where fast curing and vacuum compatibility are important requirements.

Product Advantages

  • Non-critical mix ratio of 100 to 20 mix ratio by weight
  • Easy to apply, especially by brushing or rolling
  • Very fast curing at ambient temperatures; relatively short fixture times
  • First rate chemical resistance, particularly to most liquid sterilization materials
  • Very good adhesion to many different substrates
  • Complies with NASA low outgassing standards

Industrial Certifications

ASTM E595 Compliant




EP41S-LO is available is various sizes and units to accommodate customer's needs.

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