Abstract: The subject invention discloses a composite structure and a resin component for use in the composite structure. The composite structure includes a first layer, comprising a styrenated unsaturated polyester, and a second layer. The first layer is a show surface of the composite structure. The second layer includes the reaction product of the resin component and an isocyanate component. The resin component includes an isocyanate-reactive component, an amine-based catalyst, and a temperature-activated catalyst that is different from the amine-based catalyst. The amine-based catalyst is active at ambient temperature for initiating an exothermic reaction between the isocyanate component and the resin component thereby establishing a reaction temperature greater than the ambient temperature. The temperature-activated catalyst is active at the reaction temperature for completing a cure of the isocyanate component with the resin component.