We hereby present a coarse-grained model of a typical polyester resin for coil coating applications. We validate the model via comparison with experimental data. The interactions between coarse-grained particles are described by the MARTINI force-field [Marrink et al. et al. J. Phys. Chem. B 2007, 11, 7812]. Our model and molecular dynamics simulation protocols indude the description of a hardener and the formation of cross-links between the hardener and the polyester resin. We perform experimental tests; on the thermodynamic and mechanical properties of the system, and compare them with molecular dynamics simulations. The model estimates the glass transition temperature of the coating within 30 K of the experimental measurement. The model captures correctly the broadening effect of cross-linking on the glass transition, and on the temperature dependence of the elastic response of the polyester resin.