Epoxy should not be applied directly to TotalBoat Polyester Structural Repair Putty unless the putty has been cured with an air-dry product, or is otherwise devoid of oxygen.
TotalBoat Polyester Structural Repair Putty does not come with any wax or air-dry product. When catalyzed with MEKP, it will cure to a hard material, but will have a slight tack to the surface, which will not allow for a proper bond to epoxy saturated fiberglass. TotalBoat Polyester Structural Repair Putty should have any wax, or air-dry removed and the surface should be abraded with a grinder or sander prior to applying epoxy saturated fiberglass, though it should be noted that the Polyester Structural Repair Putty will be extremely hard, and difficult to abrade.