Coatings for filling cracks within anodic films formed from, for example, a laser marking process are described. The cracks generally have widths of nanometers in scale and can extend from an external surface of an anodic film to an underlying metal substrate. The coatings fill the cracks to prevent liquid and contaminants from entering the cracks and reaching the metal substrate, thereby preventing corrosion of the underlying metal substrate. The coatings can be hydrophobic such that water is wicked away from the cracks. In some cases, the coatings are fluoropolymer coatings. Methods include spray-on techniques that provide a thin and uniform layer of the coating. The spray-on technique can be configured to spray on a fluoropolymer precursor onto the anodic film such that the fluoropolymer precursor diffuses into and polymerizes into the fluoropolymer coating within the cracks.