Abstract: A thermosetting, organic solvent-based, primer coating composition for protecting metal surfaces which includes a solvent solution of: (a) a hydroxy-functional polyester resin; (b) a thermosetting acrylic resin; (c) a hydroxy-terminal polybutadiene resin, a hydroxy-terminal epoxidized polybutadiene resin, or mixtures thereof; (d) a blocked isocyanate crosslinker including at least one dimethyl pyrazole blocked isocyanate; (e) an aminoplast crosslinker including at least one melamine-formaldehyde condensate; (f) a catalyst; and, (g) a pigment. The primer exhibits excellent flexibility after curing to allow the primer to be coil coated onto metals as a thicker film and to have the metal subsequently formed without film fracture or loss of adhesion.