Most modern vehicles use light and cheap plastic lenses and covers for their headlights. Unlike glass in vintage cars, plastic fades and oxidizes over time. That is why your car’s headlights will get foggy over time.
Foggy headlights are not only ugly but also a safety hazard. Your headlights won’t be as bright as they should be, which could drastically reduce night visibility.
Why Do Auto Headlights Turn Yellow and Foggy?
A couple of things will make your headlights lose their original gloss and shine. The most notable causes are:
Road Damage
Rocks and debris from the road can hit your headlights when driving down the road at speed. Over time, these small pieces of debris will create chips and pits on polycarbonate automotive headlight lenses that taint their clarity. When these chips build up, your car headlights will look foggy.
Oxidation
Exposure to sunlight and UV leads to degradation through the oxidation process. Just like oxidation damages tires and paint, it has a visible impact on your vehicle’s headlights and will make them foggy over time.
Dirt and Chemicals
Dirt and chemicals can make your headlights foggy, especially if you don’t clean them well. A thin layer of dirt and other chemicals on the lens will make them look blurred and aged. Luckily, a good cleaning will fix this form of fogginess.
Water Vapor
The last cause of fogginess comes from within. If the seam between your headlight box and the glass lens isn’t watertight, more water vapor than the headlight can vent will get into the structure.
As the headlights heat, the water evaporates, forming a film of vapor as it condenses on the inside of the lens. Your headlights will be foggy for as long as there is unvented moisture inside them.
What is the Best Way to Clean and Restore Foggy Headlights?
The cleaning procedure should vary depending on the severity of the fogging. Nonetheless, it would be wise to start with the least abrasive and involving cleaning procedures before going up the ladder.
Here are some suggestions to help you jump straight to the most appropriate cleaning procedure.
- Regular car soap and sponge wash: Ideal for a dirty car that’s not been washed well in a while
- Baking soda or toothpaste and a soft-bristle brush: Ideal for clean headlights that are still foggy on a relatively new (sub 40k miles) vehicle
- A headlight restoration kit: A suitable replacement for baking soda and toothpaste
- Wet sanding with fine sandpaper: Professional cleaning appropriate for very foggy old headlights with visible deep scratches here and there
- Complete opening and restoration: If the fogginess is from moisture within the headlight box
How to Clean Dirty Vehicle Headlights With Soap and Water
Sometimes, all your foggy headlights need is a deeply dedicated clean using soap and water. Dirty, grime, and chemicals can turn your headlights hazy, especially if:
- You left your car in storage for long
- You often use a pressure washer to ‘knock the dust off your car
- You take your vehicle to an automated carwash with no hand detailing
While basic cleaning might be enough to keep your vehicle presentable for years, detailing or hand-cleaning is the only way to clean specific spots (including headlights) to perfection.
You will need:
- Clean water
- Car cleaning soap
- Cleaning rags and towels
What to do
- Park your car in the shade to ensure the sun doesn’t dry up a headlight before you are done cleaning
- Mix some car cleaning soap and water in a bucket
- Dip a cleaning rag into the mix and use it to spot clean one headlight at a go
- Scrub the headlight in firm but gentle circles working from one side to another.
- Be keen to keep the rag wet and soapy throughout
- Ensure that you cover every spot of the headlight
- Rinse the headlight with clean running water until you get rid of all the soap suds
- Dip a clean rug in clean water, wring it dry and use it to wipe off excess water from the headlight
- Proceed to do the same to the next headlight
- If the fogginess were due to dirt and grime, you would now have gleaming clean headlights.
- If it wasn’t, this is the perfect preparation for other more aggressive headlight restoration techniques.
ProTip: Any of the procedures below abrade the headlight and get rid of the sock sealant layer. This is a clear coat that protects the lens from UV. You will have to reapply a sealant or a ceramic coat, or else your headlights will oxidize and fog up faster than before.
Using Baking Soda or Toothpaste to Clean Foggy Headlights
Baking soda and toothpaste are fine abrasives. Using them the right way could help you buff imperfections off the surface of the polycarbonate lens and restore your headlights to their former glory.
What you need:
All the products we used in the cleaning with soap and water section
- Baking soda or toothpaste
- A small mixing bowl
- A soft-bristled brush (a toothbrush will do just fine)
- More rags and towels
What to do
ProTip: If using baking soda, you will need one extra step. Mix half a cup of baking soda with some water to create a thick paste. The paste is easier to work with and more efficient than applying baking soda powder onto the headlights.
- Start by following the regular soap and water clean procedure we outlined to prepare your headlights for this restoration technique.
- From now on, you will work on one headlight at a go
- Once the headlights are dry, apply and distribute a thick amount of the toothpaste or baking soda paste onto the headlight
- Let the mix sit on the lens for around 3 minutes so that it dries a bit
- Use a soft brush and circular motions to rub the toothpaste or baking soda paste into the plastic
- Remember that these are abrasives. Use gentle, deliberate action to avoid scratching and making the lens worse.
- You should see the yellowing and fogginess diminish as you scrub
- Be ready to do repeated passes and rub for a while to get results. Resist the urge to apply more pressure. Its the gentle and repeated passes that will polish the lens to a pristine look without damaging it
- Once you are happy with the results or can see no further gains, use a clean damp towel to wipe off the excess residue before rinsing and cleaning everything off with clean water
That should clean most of the fogginess and scratches off your headlights. If you still see any gauges or your headlights are still foggy, you could try another pass using baking soda or a commercial headlight restoration kit.
Using a Headlight Restoration Kit
There are tons of headlight restoration kits in the market, and most of them promise lasting and fast results.
While most work, some promise to overdeliver, leaving you disappointed. A practical kit has three main components.
- An activator that makes the headlights easier to sand
- A specialty fine-grit sandpaper or sanding compound
- A finish and sealing coat applicator
Some restoration kits are gentle and a step higher than baking soda, while others are abrasive enough to get rid of even the toughest yellowing and scratches.
- The mild kit is an excellent DIY project kit.
- The more aggressive needs more skill. Only use it if you are confident.
The Mild Kit (Example: Cerakote Ceramic Headlight Restoration Kit)
The Cerakote ceramic headlight restoration kit is an example of a mild headlight restoration kit that uses a chemical oxidation remover, some hand abrasive pads, and a sealer to fix your foggy headlights.
- Since it isn’t that abrasive, it is hard to go wrong when using it as your first DIY project.
- Just ensure that you use masking tape and waterproof paper to seal off adjacent painted panes to avoid abrading or applying the product onto them by mistake.
- Apply the oxidation remover to the headlights and let it sit for around 10 minutes
- Use the provided rubbing pads and discs to remove deep oxidation and light scratches.
- Clean and dry the headlights before applying the provided ceramic coating to protect your newly restore headlights
The Aggressive Kit ( 3M Headlight Restoration Kit)
The 3M Headlight Lens Restoration System is a comprehensive professional-grade kit that goes beyond mere cleaning to buffing all the imperfections of your headlights.
It comes with a buffing compound, disc pad holder, and progressive sanding discs. You will need some practice wet sanding and video tips if this is your first time doing such a job.
You’ll also need a drill attachment to use the pad on your electric drill.
While this product can produce professional-grade results, you can damage your headlights and surrounding panels if you use too much pressure or skip steps when wet sanding progressively with the different grit sandpaper.
If you are not comfortable with the sanding even after watching video tutorials, use the other cleaning procedures. If they don’t restore your headlights, consider getting someone more handy or a professional to sand the imperfections down for you.
ProTip: A professional bodywork shop might not need the 3M restoration kit. They can sand down and buff imperfections off headlights using their bodywork sandpaper and buffing compound.
Can You Clean Oxidized Headlights With WD40?
While WD40 might make your foggy lights better for a couple of days, the dirty look will come back after a while.
This is because WD40 won’t eliminate the oxidation as it is not an abrasive compound that will rub away the damaged top layer of your headlight’s polycarbonate lens. WD40 polishes the lens hence the temporary sheen.
Does Toothpaste and Baking Soda Clean Headlights?
Yes. These two products have mild abrasive capabilities and can effectively restore foggy headlights. Just remember to apply a sealer or ceramic coat to make the effect last longer.
Check this too: What Are The Best Headlights For Night Driving?
Will Magic Eraser Clean Headlights?
Technically, Magic Eraser is an abrasive tool. It could get rid of oxidation and yellowing on your headlights. Be sure to use it wet and rub in gentle circular steps just as we described in the baking soda or toothpaste section.
Test on a small corner of the headlight first to ascertain that it isn’t too abrasive for your car headlight’s lens finish.