Epoxy Resin® is the base material on which all West System 105 System epoxy compounds are built. The resin is a clear, pale yellow, low-viscosity liquid epoxy resin. Formulated for use with West System hardeners, it can be cured in a wide temperature range to form a high-strength solid with excellent moisture resistance. Fast hardener (205) is a low viscosity epoxy curing agent which is used when rapid cure is required. When combined with 105 resin in a five-cell ratio between resin and one partial curing material, the cured resin / hardener mixture forms a solid, high-strength, moisture-resistant solid with excellent properties. It is not intended for a clear coat.