EP39-2 is a fast-curing optical adhesive for bonding to a variety of substrates such as glass, metals and plastics. Master Bond Inc. designed the transparent adhesive, sealant and coating to resist abrasion and chemicals, including a variety of acids, bases and solvents. It has an index of refraction of 1.56, optical transmission from 350 to 1000 nm, and a service temperature range from -60 to +300 °F. The low-viscosity EP39-2 can produce films as thin as 0.005 in. that become tack-free in 3 h at room temperature.