Devcon 230-15800 1lbs Flexane 80 Liquid, Medium-Hard, Black Color Product features Medium-viscosity urethane fills voids completely Faithfully reproduces mold detail and cures to semi-rigid rubber Mixes and pours easily Ten-hour demolding time Product description Testing and approvals are Dielectric strength tested according to ASTM D149. Tensile strength tested according to ASTM D412. Applicable materials are concrete, fiberglass, most metals, rubber, wood. Ideal for semi-rigid casting. Polyurethane chemical compound. 350.0 volts per mil dielectric strength. 87.0 Shore A hardness. 2100 psi tensile strength. 10000.0 cP viscosity. 26.5 lb/in3 volume. 350 volts per mil Dielectric strength.