Cleaning and Restoring Yellowed Automobile Headlamp Lenses
Cleaning and Restoring Yellowed Automobile Headlamp Lenses
Are your vehicle's headlights yellowed, cloudy or scratched? You're not the only one. Unless you provide your vehicle's clear headlight lenses regular attention, in two years or less they can cloud to the point of being totally opaque, making it very unsafe to operate your car in the dark and in reduced visibility conditions. The solution is less complicated than you might believe. The good news is that you can restore this hazardous and unsightlyproblem in about 20 minutes. It's simple once you know the secret.
The Reason Headlamps Become Yellow and Dull?
The problem is not caused by abuse or neglect, as you might believe. It is an environmental problem. Without regular attention, UV rays from the sun, acid rain, salt and road debris degrade and discolor all clear plastics, including lens covers. If your automobile has halogen or another type of high-intensity discharge (HID) lighting, the problem can be worse. These sealed beam units function at increased temperatures, further contributing to degradation and yellowing.
What Is The Solution?
The cure is a simple fix-it process. Headlamp restoration is a plastic restoration process that takes away 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 thirty minutes.
You might be wondering why headlight restoration instead of buying new? Your headlights are a sealed unit, so you can't simply replace the lens cover. If you have a luxury car with high-performance lighting, replacement is very expensive. Restoration versus replacement can save you hundreds of dollars per lens, so it's well worth the effort. Plus, it's fast!
What kind of results can you expect? It may apear hopeless, but most likely the damage is not so bad. Even if your light covers are completely opaque, they can be restored. As long as the plastic has not yellowed completely, you stand a very good chance of total restoration.
Try A Gentle Plastic Polish First
If the damage is not severe, you may be able to resolve it with a simple plastic polish like Meguiar's PlastX. I recommend trying this step before any other. It will not be wasted time or money, either, because you need to use the product from time-to-time to maintain your headlights.
NOTE: Never use a household glass cleaning product like Windex on headlights. These cleaners are full of ammonia, which causes clear plastic to yellow.
If the plastic polish alone does not do the job, 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 seem 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 plastic polish may be all you require.
Sandpaper & Re-polishing Procedure
To clean away the damage with wet sanding and re-glazing, you need the following basics:
Polishing towels
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 pictorial guide, then have a look at my Guide to Detailing blog. Here are the steps:
STEP 1: Clean the headlamp lenses. A bucket of soapy water works best. Clean the surrounding area, too. Dry thoroughly.
STEP 2: Use painter's masking tape to mask around the headlamp. This will help protect your vehicle's paint finish. This only takes a couple minutes, so don't skip this important step.
STEP 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 remaining from the previous grit sandpaper.
As you sand, your sanding water will turn milky. This is the damaged layer being cleaned away. Use generous amounts 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 check progress.
STEP 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 several dabs of polish to the pad and start polishing the lens. As the polish starts to dissipate, add a bit more and resume polishing. Discontinue polishing once the lens is perfectly clear again. Finish with a final hand polish using a tiny bit of polish on a soft towel or applicator.
STEP 5: Wax to protect. Use a good car wax to reseal the plastic and protect from the elements.
STEP 6: Maintain monthly with a quality plastic cleaner/polish. The products I recommend most are Plexus and Meguiar's PlastX.
If regularly polished, your car's headlight lenses will never need restoring again!