Master Bond Inc.'s Polymer Adhesive EP21AR was designed for high-performance bonding in applications where high chemical resistance is required. This epoxy is resistant to strong acids, alkalis, water, salts and organic solvents, and it cools at room temperature with a 2:1 mix ratio by weight. It has a 2000-psi bonding strength and is relatively insensitive to mixing ratio or to substrate cleaning procedures. The EP21AR operates over temperatures from 260 to +250 °F. When hardened, it acts as an electrical insulator.