PENNCOAT 401 MR Lining is a 40 – 50 mil mat reinforced room temperature cured silicon based polymeric lining for concrete substrates. PENNCOAT 401 is applied in two 10 – 12 mil WFT (wet film thickness) coats over mat reinforced PENNTROWEL™ Epoxy Primer. It offers the chemical and temperature resistance of inorganic silicon chemistry with the ease of application and cost effectiveness of conventional organic linings. PENNCOAT 401 is a unique thermosetting silicon polymer which cures with conventional epoxy chemistry yielding highly cross-linked polyether linkages. The absence of problematic hydroxyl and ester groups makes PENNCOAT 401 resistant to a broad range of corrosive chemicals, including 98% sulfuric acid, and chlorinated solvents. When the crack bridging advantages of a glass mat reinforcement are desired, PENNCOAT 401 MR (Mat Reinforced) utilizes a 1 oz chopped strand glass mat reinforcement in the primer layer.