To repair a scratch in the clear coat, first clean the car panel with warm soapy water. For scratches that have only penetrated the clear coat, the scratch can be carefully sanded out. After sanding the clear coating, the scratched area needs to be replaced.
Clear coating is a meticulous job that requires a precise environment, and the website paintworld offers advice on how to apply clear coat to a vehicle that was manufactured after 1997. Work in an environment with a temperature between 55 and 90 degrees Fahrenheit; Paintworld states that 75 degrees is optimal. When the weather is hot, work in the shade or early in the morning or late at night.
No matter what the temperature, never clear coat in the direct sunlight. When it is cold outside, work in a heated garage. Whenever possible, avoid high humidity. If the clear coating becomes cloudy, it is likely that the coating was applied in adverse conditions of temperature or humidity. Use straight, even strokes of the spray can with a 50 percent overlap, and wait 10 minutes between each application. After the final coat, it takes at least an hour before the surface is safe to touch.