The process used in wet sanding is very similar to standard sanding except water is used as a lubricant to protect the surface being sanded. This method is often used on delicate or easily damaged materials like the plastic of fogged up or scratched headlights. If you want to restore the headlight lenses on your car, using the wet sand method is a good idea because it will diminish the chances of ruining your headlights.
Arrange masking tape around the headlights to protect the finish of the car. Don't put any of the tape on the headlight lens or you will not be able to sand it.
Dip a piece of 800 grit wet sandpaper into a container of water until the sandpaper is soaking wet. Spray the headlights with a spray bottle filled with water.
Sand the entire lens of the headlight with the paper by making smooth, even strokes with the wet sandpaper. Use light pressure to remove a very thin layer off the surface of the lens.
Switch to 1,200 grit sandpaper and wet it in the container of water. Spray the headlight with water again if it is sandy or dry. Sand the lens in the same way you did with the rougher paper.
Sand the lens one more time with wet 1,400 grit sandpaper. Make sure the lens of the headlight is very wet before you touch it with the paper.
Apply a coin size amount of plastic polishing compound to a 5-inch foam buffing head on a power buffer. Buff the compound into the sanded lens.
Stop buffing every minute to wipe down the lens. Clean it with water and dry it with a cloth to see if the headlight requires further buffing. Keep doing this until the headlight is crystal clear.
