Over time, the plastic that makes up your headlights will degrade and cloud over.
If yours aren’t shining quite like they used to, here’s how to clean your headlights.
Most headlights are made of polycarbonate plastic, which is durable and scratch-resistant. But over time polycarbonate clouds over, mostly due to UV rays that degrade the outer layer of plastic.
Fortunately, there’s a simple and inexpensive solution. Unlike glass, the polycarbonate plastic can be polished back to a surface as smooth as new, in a procedure that won’t take more than a half-hour. Check out our list of the best headlight restoration kits.
Wash your car
Wash your car to remove any surface dirt. Waxing it, at least within a foot or two of the headlamps, is a good idea, because drips and droplets of the abrasive polishing compound are less likely to adhere to a freshly waxed surface.
Mask Off
Head out to the store and buy some blue, low-tack painter’s masking tape, the handy stuff that peels off easily. Mask the area around the headlamp that needs to be polished. You may want to remove nearby trim, especially chromed metal or chrome-finish plastic, because we’ll be polishing and sanding with materials that can destroy the chrome.
Sand
All of these products use an abrasive such as sandpaper to scuff away the outer layer of haze. This is the most important step, so be thorough. When you’re done, the entire headlight should be clear of any yellowing and have a rough, dull surface. Soak a piece of 1000-grit wet/dry sandpaper in cold water for 10 minutes. Lightly sand the lens in straight strokes. Methodically cover the entire lens surface, always sanding back and forth in one direction. Keep the surface wet while you work. Again, be careful not to damage nearby paint or trim. Use the palm of your hand to conform to the curved surface of the lens.
Sand until the pits, discoloration and scratches you’re trying to eliminate are gone. Don’t rush this part. And don’t be afraid to dry the surface with a towel and check the uniformity of your sanding. When you’re done, clean and dry the area.
Polish
A fine polish cleans up the sandpaper scratches and makes the headlight lenses clear again.
Start the repair with polishing compound and a flannel or microfiber cloth. Smear some compound on the lens and polish in a circular motion. As the polish gets ground into the cloth and dries out, it lifts the haziness right off the lens. Most of the compound eventually winds up on the cloth, but it probably takes about 10 minutes of rubbing per lens, so don’t be in a rush. If you have an orbital polisher, you can use that with a lamb’s wool or terry-cloth pad. Don’t polish the paint off nearby surfaces. Simply proceed with compound until the lens is shiny.
Apply UV Sealant
There’s a reason we tested only headlight lens restorers with a UV protectant. The sanding step removes any protective layer that was originally applied to the headlight, and if you don’t reapply that shield your lights will haze over again in as little as a few weeks. Some products, such as the ones from Sylvania and Lenz Solution, promise extended protection.
Adjusting Your Headlights
If you’ve removed your lights to clean them, you need to line them up properly after you put them back on.
Here’s a quick way to eyeball the aiming.
* On a level surface, park the car a few inches from your garage door or the wall of a large building.
* Use chalk to mark the locations of the headlight beams.
* Back up 25 feet (about two car lengths); the low beams should still be level and pointing straight ahead to within a few inches of the chalk marks.
* If not, adjust the beams by turning the headlight’s two setscrews-one for up/down, one for left/right.
