One of epoxy's advantages is that it forms a very strong secondary bond to cured polyester resin, vinyl ester resin, as well as other epoxy products used in Fiberglass Reinforced Plastics, also known as FRP. If the previous resin has cured, the epoxy will rely on a mechanical bond, so it is very important to abrade the surface, giving the epoxy the best mechanical bond possible. Always remove any wax or amine blush from the previous FRP surface prior to applying epoxy.