Most headlight lenses for cars are made of polycarbonate plastic. Age, exposure to sun and the environment causes the lenses to turn yellow and hazy, cutting down on the amount of light they project, especially at night. Drivers can replace their headlight lenses with new ones, but this is an expensive fix. With headlight lens cleaning kits on the market, as well as polishing compounds for plastic, cleaning the fog away is a cheaper option. With a little elbow grease and less than an hour’s time, your headlight lenses will look brand new again.
Wash the car to remove any dirt or particles of sand, as they will scratch the lenses when you polish them. Waxing the car before cleaning your headlight lenses will help in keeping the polishing compound from sticking to the painted surface. Leave approximately 1 foot around the lenses unwaxed.
Apply masking tape around the area of the headlights you will be polishing. This will protect the paint and chromed areas from unwanted scratches when applying the polishing compound.
Dip a piece of terrycloth towel or flannel cloth into the polishing compound. Begin rubbing the compound onto a small area of the lens, rubbing it in a circular motion. When the polishing compound dries, the haze should lift from the lens if it is not severely scratched or dinged. Continue applying the polishing compound until both lenses are polished and the haze is gone.
Use a piece of wet, 1000-grit sandpaper to remove scratches the polishing compound will not remove. Soak the paper in cool water for 10 minutes and begin rubbing lightly with straight strokes over the scratched area. Dry the area off with a towel to check the evenness of your sanding. Wipe the area clean and dry when you are satisfied.
Sand the area again by using a piece of 1500-grit wet/dry sandpaper. Sand the area this time at a right angle, being sure to keep the paper wet. Clean and dry the area before continuing with the next step in sanding.
Sand the area again graduating with each sanding to higher grit sandpaper and sanding at a right angle until done. Start with a wet 2000-grit, then move to a wet 2500-grit sandpaper, finishing with a wet 3000-grit sandpaper. Clean and dry the area each time before moving onto the next grade of sandpaper. Clean and dry the lens when the sanding is finished.
Polish the entire lens again with the polishing compound. Apply some to your terrycloth towel or flannel cloth and apply in a circular motion. When you have finished polishing each lens, the haze should be gone from the headlight lenses.
You can also polish the lenses using an orbital car polisher with a terrycloth polishing pad.