NASA Low Outgassing, Chemically Resistant Epoxy Features High Tg

Master Bond EP64 is a two-component, vacuum-compatible epoxy system engineered for bonding, sealing, and coating applications. It features a high glass transition temperature (T_g) of 210–215°C and meets NASA low outgassing specifications per ASTM E595 testing. This product is resistant to a variety of chemicals—including acids, bases, and many solvents—and serves as a dependable electrical insulator.

EP64 has a tensile strength of 3,000–5,000 psi and a tensile modulus ranging from 540,000–680,000 psi at room temperature. The system exhibits a Shore D hardness of 80–90. It is serviceable over a temperature range of -60°F to +450°F (-51°C to +232°C), making it suitable for aerospace and electronic applications requiring stable performance under vacuum conditions.

This system features a working life of 12–24 hours for a 100-gram batch at room temperature and has a moderate viscosity with good flow properties. The recommended cure schedule is 80–90°C for 4–6 hours, followed by a post cure at 120–130°C for 2–4 hours to reach its full performance profile. Achieving a T_g of 210–215°C with such a cure profile is the key distinguishing characteristic of this system. EP64 bonds to substrates including metals, plastics, rubbers, ceramics, and composites. It is available in standard packaging ranging from 1/2 pint to gallon kits, as well as in premixed and frozen syringes.