How to Clean Headlights and Restore Them the Right Way

At some point you will take a step back to admire your detailing efforts and realize something is off. That showroom quality is almost there, but the headlights appear dull, maybe even slightly yellow. They need attention.

Signs of wear and aging should not be surprising, they sit on the front of the car, leading the way through all that road grime, bugs, tree sap, snow and ice, salt, pebbles, dirt, dust, and whatever else you encounter while on the road. And they are exposed to the sun, or more specifically to heat and ultraviolet light.

Why You Should Clean, Restore, and Protect Your Headlights

The demands on our headlights are great and they deserve some love.

Sure, we want to make those light enclosures look great, but we also want to ensure those headlights are operating properly. Yellowed, foggy, hazy lenses scatter light instead of casting a tight beam in front of the car as designed. Simply put, we see better with clean, clear lights.

Plus, a lens that spreads light, rather than focus it, is harsher to oncoming traffic. Keeping your headlights in tip top shape creates a safer ride for you and the other cars on the road.

The National Highway Traffic Safety Administration has even written a paper on the risks associated with degraded headlights and glare they produce.

So, with multiple reasons to keep our headlights clear and clean, let’s explore some methods and products used to tackle this unique task.

Cleaning Headlights vs Restoring vs Maintaining

To understand the means and methods we can use to keep our headlights clean and clear, we need to understand a little about the construction of the lens.

While some are still made of glass (if you have glass lenses, skip to the end of this article), most headlight enclosures today are made from polycarbonate (i.e. clear plastic).

Designers like the freedom they get with the plastic light enclosures. They can create eye catching lines and make a statement for a particular model using the headlights. This design freedom made polycarbonate housings attractive and they are now found on most modern cars.

Polycarbonate is light, impact resistant, and clear, so it does also offer some performance advantages over glass. But it is susceptible to scratching and UV degradation, so it must be sealed for use as an automobile headlight. Yes, your “plastic” headlights have a coating applied to them.

When this clear coating fails (e.g. breaks down from UV or is abraded off), UV light “attacks” the exposed plastic surface and forms a thin hazy layer, which may even appear yellow. So, the problem is not dirt that needs to be cleaned off, it is a thin layer “within” the lens surface and your protective coating is gone. This is a unique detailing problem that needs some specific restoration techniques.

First, it should be noted that routine maintenance will prolong the protective coating on your headlights. After cleaning, apply a coat of paste wax to your headlights to provide additional protection to the coated lens. I have seen some threads where people have claimed their poly-carbonate lenses lasted for over ten years with regular cleaning and waxing.

Second, when the polycarbonate  lenses do become cloudy and yellow, you have some options. It is easiest to divide them into DIY, commercially available kits and products, and wet sanding/clear coat.

How to Clean Headlights

For me, cleaning headlights is different from restoration of headlights. Cleaning is just washing them using the same method you would any other part of your car. You use a quality microfiber mit with a quality car shampoo and wipe them down. If you have bugs, tar, or any other substances stuck them use a quality bug, tar, and sap remover like Stoners Tarminator or McKee’s 37 Road Kill Bug Remover.

Related: [Review] McKee’s 37 Road Kill Bug Remover

If you’re trying to remove cloudiness you’re no longer cleaning your headlights but restoring them and you should be looking for the best headlight restoration method rather than how to clean oxidized headlights.

Car Headlight Restoration Home Remedy

While I prefer to clean and restore headlights in a more professional manner there are a few home remedies and homemade options that can be used to some affect.

There are do-it-yourself (“DIY”) techniques to remove the cloudy layer. But the results range from OK to barely effective. Then there are some methods that should be avoided at all costs.

Let’s review some of the popular remedies for how to clean headlights with household items to avoid and get them out of the way:

• How to Clean Headlights with Magic Erasers,
• How to Clean Headlights with WD-40
• How to Clean Headlights Bug Spray (DEET).

Magic erasers are actually abrasive and will scuff the lens. Chemicals like WD-40 and bug spray melt the lens, which brings back some clarity while making it soft and sticky so that dirt now sticks to the surface.

These are myths floating around on the internet that do more harm than good, with very short lived positive effects, so you should avoid them. Plus, they can cause damage to your car’s paint, another good reason to not even consider these options.

How to Clean Headlights with Toothpaste

To start, do not expect toothpaste to bring back headlights that look like a milk jug. This technique is best for lights just starting to show signs of UV degradation.

Make sure you use a paste, not a gel, and a toothpaste with baking soda is best. If your toothpaste does not have baking soda, you can simply add some baking soda to the paste. You will also need a microfiber or terry cloth.

As with many things, before we can get to the serious detailing, you need to clean the grime first. The lens must be clean and free of all dirt and debris that can scratch the lens. The last thing you want is to add more scratches to the headlight.

After making sure your headlight is clean, apply a generous coating of toothpaste. Then using your brush, aggressively scrub the lens in a circular motion. When complete, rinse the lens thoroughly with warm water and repeat as often as necessary. Multiple coats are almost always needed and it takes a little elbow grease to get the appearance you want.

Once you are pleased with the results, rinse the lens well and allow wipe it dry.

All the toothpaste is really doing is taking the place of commercial paint and plastic polish and acting like a abrasive. Really, you might as well be using a quality polish like Meguair’s Ultimate Compound.

Finally, apply a coat of paste wax or paint sealant, let it dry, and buff the lens to a finished appearance.

The wax will act as a degree of protection for the headlight, but this treatment is not long lasting. The wax layer must be maintained or the hazy, yellow look will soon return.

How to Clean Headlights with Vinegar and Baking Soda

This is another technique similar to using toothpaste, but with vinegar and baking soda. Some prefer the vinegar only, some use baking soda alone, and still others use the two in combination. You need to find what is best for your headlights through experimentation.

Once you fine tune your cleaning medium, apply to your lenses and scrub with a clean microfiber cloth. Rinse and repeat as often as necessary. (Note: This technique will not restore headlights that are anything other than very slightly hazy.)

After you achieve the desired results, apply a layer of paste wax or paint sealant then let it dry. Then buff to a finished appearance.

As already stated for the toothpaste technique, wax must be maintained and is not long lasting.

Best Commercially Available Headlight Restoration Kit

The headlight restoration kits and products you can purchase do vary, and so do the results.

With some research, you can find a decent kit like the Sylvania Headlight Restoration Kit and achieve good results.

The use of a kit that includes a protective coating should be considered a “temporary fix” and you will likely need to repeat the process once or twice a year, depending on where you live and whether your vehicle is garaged.

In general, most kits contain an abrasive, usually sandpaper or a sanding pad. Some include other things like an “activator” or buffing compounds to use in conjunction with wet sanding. The better kits also include a UV protective coating to apply at the end.

The kit process involves taping off the already cleaned headlight and wet sanding to remove the thin, hazy, yellow layer of plastic. These kits do vary on what chemicals to use and when, so follow the manufacturer’s instructions.

If your kit does not supply a UV protection coating, after you complete the sanding and buffing process, allow the headlight to dry and you can apply a coat of paste wax or paint sealant, let it dry, then buff to finished appearance.

Just like with the DIY methods, the wax is a temporary protective coating and it must be routinely maintained, or the lenses will quickly return to a milky appearance.

Some final thoughts on these restoration kits to consider:

• The kits with multiple grades of sandpaper that get to very fine (e.g. 2000 grit or higher) work best.
• Some kits require a drill to sand, some don’t. So, check to make sure the kit you buy will work for your situation.
• Finally, look for kits that include a wipe-on UV protection coating. The UV coatings they provide are not as good as a spray applied 2K clear coat or a ceramic coating (there is more on these coatings near the end of this article). However, the lights will stay clear longer than they would with just coat of wax. (And yes, you should routinely wax the “coated headlight” to prolong the life of the protective coating or you’ll find yourself restoring your headlights again.)

Headlight Cleaner

One more group of products should be mentioned. They are not really a restoration technique, they are designed to clean and protect in one application, like Turtle Wax Headlight Cleaner and Sealant. These are really more of a cleaner with a polishing compound that are intended for use on headlights.

Products like this will clean and maybe add some additional protection. But in plain speak, these are glorified cleaners. They will not remove the damaged layer of clear coat or plastic and restore your headlights.

Further, you must routinely re-clean your headlights when using a product like this. So, these are best for cleaning and maintaining headlights that are in good shape.

How to Restore Headlights with Wet Sanding and Clear Coating

The best technique to restore weathered headlights is also the most involved. Unfortunately, this is one of those times when there is no shortcut.

If you want to truly restore your headlights (and not just clean your headlights), it will take some know-how and elbow grease.

So, the first question should be, can I do this?

Headlight Restoration DIY

Prepare Headlight

The areas around your headlight must be protected. You can accomplish this using two different strategies:

1. Remove the headlight enclosures and do the restoration away from the car. (recommended)
2. Tape off and/or mask adjacent areas then work on the lenses on the car.

You will be using sandpaper and chemicals on the lens and you do not want to scratch or damage surrounding surfaces like chrome bezels, plastic surrounds, and painted surfaces.

Removing the light enclosures is a little more work, but it provides complete access to the lens and you do not have to worry about damaging surrounding surfaces.

If you choose to work with the lens in place, mask way more than you think you will need. I recommend buying a few cheap packs of plastic drop cloth and covering the entire car. Over spray from the clear coating is a real possibility. In other words, don’t skimp on this step.

The minutes spent protecting these adjacent surfaces is well worth the time and it will allow you to work as needed to get those headlights shiny and new in appearance.

If you choose to remove the lens, I recommend masking off the back of the headlamp assembly so you don’t clear coat the plastic in the back or get water inside the housing while sanding.

Wet Sand Headlight

Once you have protected all the surrounding surfaces, wet the lens thoroughly. Begin sanding in a horizontal manner, with a very light touch, using the coarse paper (i.e. the paper with the lowest number, usually something like 400). 400 Grit is a good starting grit.

Keep the lens wet and do not apply heavy pressure. Heavy pressure will leave heavy scratch marks. You’re done with the first grit when the lens has uniform milky white color rather than the yellow you started with.

Rinse off the milky solution that resulted from sanding with the warm water.

Repeat the wet sanding, but this time with a finer grade of paper (i.e. larger number than the previous paper). I recommend following up the 400 grit with 600 grit.

Use light to moderate pressure (just a little more pressure than used with the coarse paper) in a vertical manner, perpendicular to the strokes you made with the coarse paper. Changing directions makes it easier to see when you’ve removed the courser sanding marks.

Ensure the lens is wet with plenty of water the whole time while sanding. When you have done the entire surface, finish with some light vertical sanding.

Rinse the milky, dirty water off thoroughly with clean, warm water.

Stop sanding here if your intention is to clear coat the headlamp. Sanding to a finer surface texture than 600 grit will make it harder for the clear coat to stick and stay stuck for a long time (it will delaminate after a year or two if the surface is too smooth).

Optional – How to Polish Headlight Instead of Clear Coating:

If you don’t want to clear coat the lens after sanding, you can continue sanding through finer grits and polish out the lens. This will leave you with a clear lens but will require constant maintenance with wax or sealant to keep it from turning yellow right away, which it will still do very quickly.

I don’t recommend polishing instead of clear coating, but it is an option, a very time consuming and fruitless option. If you want to do this:

Wet sand progressively through finer paper (e.g. 800 to 1000 to 1500 to 2000 to 2500). Continue to alternate directions as you change grits (i.e. each successive sanding should be perpendicular to the previous sanding). Rinse well after you are done then using a clean cloth, dry the headlight.

After the wet sanding is complete, your lens will still appear slightly hazy. That is normal, so do not panic.

Next, apply a headlight polishing compound and buff to a clean, clear appearance. Use a rotary polisher to speed and aid the process if necessary. Polish the lens until it is clear and defect free.

Rinse with warm water and dry with a clean cloth.

Apply a protectant such as past wax, paint sealant, or ceramic coating to protect the lens from yellowing again.

How to Clear Headlights to Protect Them

If you opted to skip the polishing so you could clear coat the lens, pat yourself on the back. You made the right decision.

This is normally done with a two-part (a.k.a. “2K”) clear coat. Two-part clears have an activator that cures the clearcoat to a hard finish. Cheaper one-part (1K) lacquer clear coat dry by solvent evaporation and are not as hard or durable once dry. A 2K clear will last years, whereas a 1K clear will most likely fail in less than a year.

Most 2K clear coatings are applied with a high-pressure, low volume (HPLV) or low-pressure, low volume (LVLP) sprayer. However, you can now find these coatings in a ready-to-use aerosol spray can such as SprayMax 2K Aerosol Clear which is my absolute recommendation.

The big caution when using a 2K clear is that they contain isocyanates which are hell on your lungs. You definitely want to wear at least a disposable respirator when spraying the clear. These can be picked up for as cheap as $15 online or at your local Harbor Freight.

Before applying the clear I recommend wiping the headlight lens down with a tack cloth to remove any dust and then spraying an adhesion promoter which will help the clear stick to the plastic. Both of these are an optional step but can help produce a higher quality outcome.

When applying a 2K clear coat, start the spray off the lens then move onto the surface in a slow, consistent horizontal motion. Keep moving all the way across and off the light enclosure. Always start and finish spraying off of the lens otherwise you’ll end up with spatter that will alter the texture of the finished clear.

Your first few coats should be very light and overlap a little on each pass. The light coats build up a tacky surface. Follow the instructions on the can for recoat times based on temperature and humidity.

Your final coat should be a heavier coat to help flow out or level the clear coat to the glass like finish you’re after. Be careful not to go too heavy or the clear will sag and run.

Allow the clear to cure for the time specified on the can. If you end up with an uneven “orange-peel” looking surface you can fix this with a light wet sanding with an ultra-fine (2000 grit) sandpaper and a good polish.

Protecting the Clear Coat on Headlights

To some it may seem silly to protect the clear coat since the purpose of clear coat is protection. If you want your headlights to look new for a long time you need to also protect the clear coat just like you would on your car’s body paint.

If you’ve recently clear coated your headlights allow them to cure fully before applying anything to the lens to further protect it. I recommend waiting 20-30 days before applying anything to allow the clear coat to finish outgassing.

My recommendation for new or newly restored headlights is to apply a coat of paste wax (lasts a couple months), sealant (lasts a few months), or a nano-glass ceramic coatings like McKee’s 37 Headlight Coating (lasts up to a couple years).

Another headlight protection option is a paint protection film (“PPF”). These are clear, peel and stick type films and do provide protection to headlights. There is no spraying a coating and that is an advantage for some. These products can be a little finicky to apply smooth, but once installed they do provide protection that lasts far longer than a simple layer of wax. You either DIY the headlight film using kits or have a shop that applies window tint apply the PPF for you.

Speaking of wax (or even an acrylic paint sealer for that matter), some prefer the simplicity of just using a wax or paint sealer on restored headlights. As already stated multiple times, wax will provide some protection, but you must be diligent and maintain the wax or sealer regularly. If you chose this option and do not maintain the protective wax or sealer, your headlights will become yellow and cloudy faster than you can say “headlights.”

How to Clean Cloudy Glass Headlights

We cannot forget those with glass headlights. It may be a surprise to some, but there are still some glass lenses out there and they do get water spots, abrasions, and scratches over time.

The good news is that the restoration has less steps. The bad news is it may take a whole lot of elbow grease depending on how bad the lenses have been weathered and worn. A rotary buffer can make the process easier if you are looking at a lot of polishing.

There are glass polishes on the market with cerium oxide that work well on polishing glass headlights, like Carpro Ceriglass Glass Polish, and they even sell kits that include the applicator and microfiber towel.

To polish your glass headlamp, apply the compound and buff the surface to remove the embedded dirt, debris, water spots, and light scratches to restore the clean, smooth, clear lens.

But you may need to keep at it, depending on how bad your lights are. An orbital polisher is your best friend if the lights are in rough shape to start, or if you have some defects like small scratches to get out. And deep scratches may be beyond what can be reasonably removed. New lights might be needed if defects like scratching and abrasion are severe.

Be warned, cerium oxide-based polishes are messy, so you might want to cover up the surrounding paint and lay down a tarp.

As an alternative to polishing, some people like to use clay bars on glass lenses, and while they help remove dirt and debris, they are not as effect as a polish that contains cerium oxide. But for removing road film and water spots, clay bars are effective, and it may be all you need.

One last item worth mentioning, some like to protect glass with a sealer, like Griot’s Garage 11033 Glass Sealant. No, glass does not turn yellow and cloudy on exposure to UV like plastic, but it does get dirty and water spots (which can etch glass) can be a problem. A sealer helps to prevents issues like water spots and makes it hard for bugs and road grime to cling to the glass and etch them.

Headlight Lens Replacement

As I mentioned earlier, sometimes you’re better off replacing headlight lenses. If they become so UV damaged that you can see horizontal lines within the plastic they are too far gone to restore to like new condition. The plastic itself has begun to fail.

Even if the lights aren’t too far gone you need to carefully weight out the value of your time. Properly restoring your headlights takes hours and a fair bit of materials. It’s also not a guarantee of a perfect outcome or lasting solution.

You can buy reproduction headlight assemblies for between $70 and $150 for most vehicles from companies like Depo that are CAPA certified and fit and look like new. These are the lights I buy for my personal vehicles because I feel they are the best headlights for the money.

For that low of price, I cannot justify for myself to spend a dozen hours and $50 on materials to restore the lights. I’d much rather just replace the headlight assembly and be done with it. On top of that, I can usually still sell the old headlights for a few bucks to someone on eBay or Craigslist, even further closing that cost/benefit gap.

Wrapping it Up

We covered a lot of ground on a unique detailing task: how to clean headlights. But for good reason, we all want those clean, clear headlights that are like jewelry on our cars. The shine and twinkle of those light enclosures are essential for that showroom appearance. Not to mention the safety improvement for you and other cars on the road.

Unfortunately, to achieve the desired results, there is no substitute for wet sanding, followed by application of a quality protective coating. The problem with polycarbonate enclosures is unique. The surface layer degraded by UV light must be removed by wet sanding. Then a good protective coating, not just wax, needs to be applied to prevent the hazy, yellow look from reappearing before your next mortgage payment is due. It is a bit of work, but the end result is a headlight restored to an almost new condition.

We presented some less effective options, like commercially available kits and DIY techniques. These may work for you if the headlights are not too far gone. But do not expect miracles from these alternate methods; the approaches will not work on a headlight that is severely weathered.  Plus, you must maintain the lesser quality protective coating used with these techniques.

For those who have glass headlights, there are polishes on the market that will help to restore that clear, sharp look you want. But keep in mind, if you have deep scratches or abrasions, these may not come out, even with aggressive buffing. After the polishing is done, using a sealer on the glass lens will provide resistance to water spotting and dirt build up.

Finally, for those who have severely worn, weathered headlights, your best option may be to replace the lens. You can find Certified Automotive Parts Association (“CAPA”) approved headlight enclosures at a reasonable price. They will have an OEM appearance and fit like factory new. Sometimes, the best restoration technique is to simply replace that worn out component.

So, armed with the information, it is time for you get out there and get those headlights to showroom quality. Plus, your lamps will light the dark road the way they were intended. Happy Detailing!