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Protecting and Repairing Plastic Headlights

Cloudy headlights are a common sight on modern cars, but they don’t have to be. By taking some precautions against wear and UV damage and removing damage when it appears, you can keep your car looking good and get the light you need to see.

Why Did Automakers Switch to Plastic?

Glass lenses required less care than modern plastic lenses, but they came with a lot of disadvantages:

– It’s more expensive than plastic.

– Its shape can’t be changed much without ruining optic clarity, making them impractical for sloped, aerodynamic front ends.

– It weighs more than plastic. That weight savings may seem small, but since the lights are ahead of the front axle, it has a pendulum effect on the car, which negatively effects handling.

– A damaged glass headlight leaves behind dangerous shards that can cause problems during and after an accident.

Why Do Headlights Get Cloudy?

Plastic is a polymer, which means it’s basically one big molecule with endless chemical bonds. Ultraviolet light can break these bonds, changing the structure of the surface plastic and making it opaque. The lens also gets hit with a number of things, including bird droppings, insects, and sand which can gradually wear down the surface.

Improper care can also cause yellowing: household glass cleaners contain ammonia which reacts with the plastic, turning it yellow.

How Can I Protect My Headlights?

Headlight protectant is like the protectants made for car interiors, but it’s formulated to be clear. Applying it after washing your car can shield your headlights from UV rays.

Protection films add a thin layer of plastic over the headlight, much like a clear bra. This both deflects UV light and takes on abrasion damage that would normally reach the headlight. When they wear out, these films can be peeled off and replaced. These films are also a popular way to temporarily tint lenses, but this can reduce the amount of light that can get out of the lens, making it harder to see and be seen at night.

If you regularly go off-roading, consider installing a set of headlight guards. These thin metal or plastic grilles deflect rocks and limbs. These attach directly over the headlight or can be integrated into a bumper bar.

Why Do I Have Water in my Headlight?

Your headlight is cracked. While this crack may be tiny, when driving along the highway, any water that gets onto the lens is being pushed in by the force of the air against your vehicle. Once it’s inside, it’s hard for the water to drip out, leading to a significant accumulation of water. This doesn’t just look bad, the thermal shock caused by contact between cold water and a hot bulb can burn out the filament or shatter the bulb’s outer glass. The only way to fix this is with a replacement headlight.

Is There Any Way I Can Fix Surface Damage?

There are all kinds of DIY methods from polishing off the top layer with toothpaste to dissolving it with nail polish remover, but the results can range from making no real difference to destroying the lens. If you want to get light scratches and oxidation removed the right way, visit a detailing professional or get an off-the-shelf headlight polishing kit. These kits include fine grit sandpaper, polish and wetting agents to safely remove the damaged layer of plastic. Before using one of these kits, be sure to mask off the area around the headlight so you can’t accidentally sand off the paint. Keep in mind that these kits are intended to remove a very thin layer of material from the top of the lens. Attempting to remove deep scratches can lead to low spots that can misdirect light and cause possible lens damage.

My Lights are Heavily Scratched and Oxidized. Do They Need to Be Replaced?

If your lights are fogged over and a light buffing isn’t going to bring them back, take your car to Merton Auto Body. Our technicians can safely remove the damaged layers from your headlights, saving you hundreds or even thousands of dollars on replacements. We can also replace damaged headlights, installing and aligning them so you’ll be able to drive safely. We proudly service the Waukesha County and surrounding Lake Country areas, including Oconomowoc, Delafield, Hartland, and Pewaukee.