Master Bond EP21LSCL-1 is a two component, low viscosity epoxy resin system featuring superb optical clarity as well as outstanding non-yellowing properties. This system has a forgiving mix ratio of 100 to 60 by weight. It will cure readily at 75°F in 3-5 days or 3-4 hours at 150-200°F. The optimum cure is overnight at room temperature followed by 3 hours at 150°F. EP21LSCL-1 has very low viscosity. It is also low exotherm, meaning it has a long working life and fits nicely when used for larger potting and encapsulation applications.