Clear coat is the protective barrier used to cover paint on cars and boats, providing an extra guarding layer against stains or damage. Applying the clear coat helps protect your paint for the future, but improper preparation or application of the coat itself leads to mars in the final appearance of the object. One common problem is fish eyes in the clear, which look exactly as they sound: swirling, circular spots that ruin the appearance of the clear coat. Properly cleaning the surface before you begin and careful application will help you avoid these unsightly marks.
Things You'll Need
Lint free cloth
Fish eye eliminator
Wipe down the painted surface with a dry tack cloth to remove dirt and dust. Dampen a clean rag in mineral spirits and wipe the surface again; the solvent cleaner will remove any grease, oil (including skin oil) or wax buildup. Any contaminants on the surface at all will result in fish eyes in the clear coat, so make sure you thoroughly clean the surface.
Dry the cleaned surface with a lint free cloth to make sure you don't leave any dust or particles behind. Inspect the entire surface you intend to clear coat to ensure that there are no more contaminants; spot clean any areas as necessary.
Mix fish eye eliminator, a specially designed paint additive, into your clear coat material before you begin painting. Find this material at automotive supply shops and some paint specialty retailers. Follow specific product instructions regarding application rates, as the amount of eliminator needed will vary by product and by the amount of clear coat you use.
Add any additional additives, such as thinner, to your clear coat as required by specific product instructions. Read carefully, as these requirements may change depending on the spray gun you use and other factors.
Spray the clear coat onto the surface in smooth, even, thin layers, overlapping passes by about ½ inch to avoid lines in your final product. Apply the necessary number of coats, allowing each coat to dry in between as recommended.
Future fish eye problems may be related to the equipment you use. You must constantly clean or replace the air filter on your spray gun, or you will contaminate the surface or the clear coat itself while you spray.
If you do find fish eyes in your final product, your best bet is to completely strip away the clear coat and start over. Simply spraying over the spot or trying to sand away a single section of clear coat will only make the problem worse.
Make sure the coat of paint below the clear coat is completely dry before you begin your coating. Otherwise you will mar the paint and the clear coat will not bond correctly.