Are your car's light covers yellowed, cloudy or scratched? You're not alone. Unless you give your automobile's plastic headlight lenses regular attention, in 24 months or less they can deteriorate to the point of being totally opaque, making it very dangerous to operate your car in the dark and in reduced visibility conditions. The solution is easier than you might think. The good thing is that you can restore this dangerous and ugly issue in thirty minutes or less. It's a piece of cake once you learn how.
Why Do Headlights Turn Yellow and Dull?
The issue is not caused by abuse or neglect, as you might have heard. It is an environmental problem. Without regular attention, UV light from the sun, acid rain, salt and road debris degrade and discolor all clear plastics, including lens covers. If your car has halogen or another type of high-intensity discharge (HID) headlights, the problem can be worse. These sealed beam units function at increased temperatures, further adding to degradation and yellowing.
What Is The Solution?
The cure is an easy fix-it job. Headlight restoration is a plastic repair process that does away with visible damage and restores a like-new finish to the lenses. Even bad cases of yellowing, hazing, and scratches can be fixed in less than a half hour.
You might be asking yourself why restore instead of replace? Your headlamps are a single module, so you can't just replace the plastic cover. If you have a luxury car with performance lighting, replacement is expensive. Fixing versus replacement can save you hundreds of dollars per lens, so it's well worth the effort. Plus, it's fast!
What sort of results can you expect? It may appear hopeless, but chances are the damage is superficial. Even if your lenses are totally opaque, they can be restored. As long as the plastic has not yellowed completely, you have a very good chance of total restoration.
Experiment With A Mild Plastic Polish First
If the damage is slight, you should be able to solve it with a basic plastic polish from the auto parts store. I suggest trying this solution before any other. It won't be wasted time or expense, either, because you must use the product from time-to-time to maintain your lighting.
NOTE: Never use a household glass cleaning product like Windex on clear plastic. Household glass cleaners are full of ammonia, which causes clear plastic to yellow.
If the plastic polish by it self does not work, then you need to repair the damage with a very fine sand paper (2000 grit is very safe) and re-polish to restore a clear finish. While it may sound difficult or complicated, it's not. Wet sanding is fast and simple.
TIP: You can test to see if your lenses will respond to hand polishing with a small dab of tartar control toothpaste. Toothpaste is mildly abrasive. If the small test area vastly improves, then you know polish alone may be all you need.
Wet Sanding & Re-polishing Procedure
To clean away the damage with wet sanding and re-glazing, you require the following basics:
- Polishing towels
- Bucket of soapy water
- Latex gloves (if you have sensitive skin)
- Painter's masking tape (1" to 1.5" width is best)
- Plastic polish
- Wet/dry sand paper (600, 1200, 2000 grit)
- Sanding block (1" x 2" erasure works great)
- 2.5" Velcro backing plate for use with 3/8" drill or cordless drill
- 3" foam or wool polishing pad with Velcro backing
If you need a more in-depth guide, then visit my Guide to Detailing blog. Here's the procedure:
TASK 1: Clean the headlamp lenses. A bucket of soapy water works well. Clean the surrounding area, too. Dry thoroughly.
TASK 2: Use painter's masking tape to mask around the headlight. This will help protect your vehicle's paint finish. This only takes a few minutes, so don't skip this important step.
TASK 3: Wet sand each lens. First determine the amount of damage to each lens. If your headlight lenses are scratched or if they are completely opaque, you will need to start with 600 grit sandpaper. Sand thoroughly, and then progress to1200, then 2000 grit.
If your lenses are not scratched and are only slightly hazy, you can probably get away with using 2000 grit paper only. The first sanding step is where you will actually remove the scratched and cloudy layer of plastic. The finer grades of sandpaper are to remove the scratches left from the previous grit sandpaper.
As you work, your sanding water will turn milky. This is the damaged layer being removed. Use plenty of water for lubrication and to keep the sandpaper clean. Keep sanding until the surface feels perfectly smooth. The drippings will become clearer as the damage is taken away. Dry thoroughly between sanding steps to inspect progress.
TASK 4: Re-glaze headlight lenses using plastic polish on a 3" polishing pad (foam or wool). First connect the Velcro backing plate adapter to your drill.
Apply a small amount of polish to the pad and begin polishing the lens. As the polish starts to dissipate, add a bit more and continue polishing. Stop polishing once the lens is perfectly clear again. Finish with a final hand rub using a small amount of polish on a clean towel or applicator.
TASK 5: Seal to protect. Use a good car wax to reseal the plastic and protect from the elements.
Maintain monthly with a quality plastic cleaner/polish. The products I recommend most are Plexus and Meguiar's PlastX. If maintained regularly, you won't need to do the
headlight restoration procedure again!
