I live in Florida and my A/C unit is about 15 years old. It still works fine but the outside condenser unit has become a real eyesore. The grille over it is covered with rust. It originally had a plastic coating around/over all of the wires that apparently didn't last in the Florida sun. The plastic coating dried, cracked and peeled away leaving exposed metal underneath to rust. Can I remove the wire grille, brush it down with a wire brush to remove the remaining plastic coating bits and paint it with Rustoleum Cold Galvanizing Compound Spray? Is there a better solution? Even though this old girl looks as rusty as can be, all of the rust is on the grille. Thanks!