The drying times associated with clearcoat, and the fact that most DIY painting projects take place outside of professional standard spray ovens, leaves paint finishes susceptible to contaminants floating in the air. Once a clearcoat has dried, pieces of dirt and grit are often visible in the final finish. These contaminants can be removed by wet sanding them out and buffing the clearcoat back to a shine.
Wipe the entire surface of the painted panel with a clean, damp sponge to remove dust and other airborne particles. Immerse a cut sheet of P1500-grit wet-and-dry sanding paper into a bucket of clean, warm water to dampen it, and wrap the paper around a rubber sanding block.
Place the largest, flattest area of the sanding block over each imperfection and make sure it remains flat at all times. Lightly move the sanding bock in small circles so the abrasive surface of the wet-and-dry paper begins to rub down contaminants in the clearcoat. Stop the process intermittently to see how far the painted surface has been rubbed down. Avoid reducing the clearcoat layer too far to eliminate the risk of burning through. Continue working in circles until contaminants are rendered invisible and the painted surface has a dull, flat appearance.
Dry the panel thoroughly with a clean piece of general-purpose workshop cloth and apply small beads of cutting compound over each rubbed-down area. Secure a foam textured applicator pad onto an handheld polishing tool (such as a rotary tool), and place the surface of the pad over the compound. Turn on the tool, making sure a manageable working speed has been selected, and buff the compound into the dulled clearcoat to restore shine. Take care to avoid fold lines in the panel with the edge of the pad to reduce the chances of burning through the clearcoat.
Once the shine of the clearcoat has been restored, wipe the surface of the panel clear of excess compound with a clean microfiber cloth. Check the surface for swirl marks caused by the abrasive particles in the compound. When swirl marks are evident, apply a small amount of glazing compound onto the surface of the panel. Exchange the foam textured applicator pad for a soft sponge alternative, and use the polishing tool to buff the glazing compound into the swirl marks to produce a perfect finish.
Protecting the Clearcoat
Wipe away excess glazing compound by hand with the microfiber cloth and carry out a final visual check to ensure all imperfections have been removed. Complete the process by applying a layer of protective wax polish over the surface of the clearcoat and leave it to create a film. Buff away the film with a new piece of microfiber cloth and the clearcoat will be fully resistant to moisture and ultraviolet sunlight.