US Patent 11833798 Panel with paint ready surface

In a preferred embodiment, a composite panel with a smooth outer surface, ready for painting with or without addition of primer, may be created by constructing a panel layup assembly upon a mold, the panel layup assembly including a composite panel having a core and a resin formulation, and a release film between the mold and the composite panel, where a smooth release surface of the release film is in contact with the composite panel upon construction; initiating curing of the composite panel at a first temperature within a lowermost ten percent of a curing temperature range of the resin formulation; continuing curing of the composite panel at a second temperature above the lowermost ten percent of the curing temperature range; and completing curing of the composite panel at a third temperature below the second temperature.