Why do automotive headlights turn yellow and foggy?

So why do automotive headlights turn yellow and foggy?

• Oxidation: This happens due to the polycarbonate lens of modern automotive headlights are exposed to the air. Lenses develop microscopic cracks when exposed to UV radiation causing “cloudiness”.

• Road Damage: While driving on damaged roads, the small rocks and debris pit the polycarbonate lens of modern automotive headlights.  The gravel creates dents and pits on the lenses.

• Dirt and Chemicals: If a car is on the road for a period of time, it develops a thin layer of dirt and chemicals over the lenses of automotive headlights. This layer is opaque (cloudy) and the affect is to dim the lights or make the automotive headlights hard to see on the road.

• Water Vapor: Vapor is created inside the automotive headlight “box” due to high moisture content in the air which then gets trapped within the light box as the air outside the light box becomes drier.  This water vapor scatters the light coming through the polycarbonate lens and creates patterns and diffusion of light on the road making it hard to see clearly.

What are some fixes to clean your automotive headlights if they are not too far gone?

• Remove the top layer of the automotive headlight lens and clean it with specialty sand paper. (this seems easy with kits available in most auto supply stores, but be vary careful, if you do this procedure incorrectly, it can damage the headlights beyond repair)

• Polish the headlight lens using headlight polish with a microfiber towel. (this is often presented as a cure all easy fix, but results are varied and temporary)

Ways to avoid headlight problem

There are ways to prevent headlight problems, but you have to be cautious. Be careful about polishing the headlights because it can wear down that clear coat. There should be no grit at all in the polish and the soft polish medium can remove early signs of yellowing. If possible, the car should either be parked in a garage or having the headlights face away from the sun. This prevents the damage that can be caused by ultraviolet light.

If you wish to wash the headlights, it should be done with an automotive soap every quarter. This does have an advantage because the washing can prevent the buildup of acids and dirt that promote the yellowing. Should it appear that the yellowing is too advanced, the old clear coat is going to have to be removed with sandpaper or abrasive cleaner and a new coat of protective film applied.

Let a professional to do the work

That sanding work ought to be done by a professional. The work can be done by buying a kit from a retail store, but an amateur might make a mistake in sanding the very sensitive and soft polycarbonate surface of automotive headlights. That generates extra cost, which ought to be avoided. The professional can also recommend the right type of clear coat to produce the best results.  That professional is TouchStone Mobile Detailing here in Nashville Tennessee.

The very top of the automotive headlights turning yellow is not as serious an emergency as worn brake pads or pistons starting to malfunction. In fact, you can drive for weeks without noticing there may be a problem. Taking care of the automotive headlights is not something that should not be put off indefinitely.

Finally, when you look at a car in a parking lot, it is has yellow faded automotive headlights, does it look as valuable as the exact same car next to it with bright clear automotive headlights, think about it.