Disclosed are methods for applying and curing a multilayer coating on a substrate. The methods include applying to an aluminum substrate a primer composition, coalescing the composition to form a substantially continuous film over the substrate, exposing the film to radiation to cure the film, applying a second composition to the cured film, coalescing the second composition to form a substantially continuous second film, and curing the second film. The primer composition includes a polyene and a polythiol.