Foggy headlights don’t just take away from the aesthetic appeal of your ride — they’re also a safety hazard. By reducing light output at night, yellowing headlights impair your seeing ability, putting you and everyone else in your car in danger.
Thankfully, foggy headlights are pretty easy to fix. What’s more, you don’t have to spend a hefty amount at the mechanic since headlight restoration is something you can do yourself.
Here’s our comprehensive guide on how to restore headlights permanently, plus a few quick temporary fixes to try if you're in a rush.
What Causes Foggy Headlights?
When you first buy a car, all its parts, including the headlights, are usually pleasantly shiny. A few months down the line, the once shiny headlights are replaced by foggy headlights due to:
- Oxidation: A majority of modern cars feature polycarbonate plastic headlights. Unlike glass, polycarbonate plastic develops microscopic cracks that turn yellow when exposed to sunlight, eventually causing a cloudy or foggy headlight appearance
- Time and Weather Conditions: Although polycarbonate plastic headlights are typically covered using a coating film, exposure to harsh weather conditions over a long time makes the coat peel off
- Water vapor: Condensation trapped in your car’s lightbox is also a common culprit behind dulling headlights
- Dirt and chemicals: If you’re always on the road, your car may develop a thin chemical and dirt layer, causing yellow headlights
How to Restore Auto Headlights
Sanding is the best, most efficient way to restore auto headlights permanently. Sanding headlights strips away the foggy layer, revealing the once shiny light lenses you loved. Here’s what you’ll need:
- Warm, soapy water
- Plain water
- Soft, dry cloth
- Masking/painter’s tape
- Sandpaper sheets - 600, 1,000, and 2,000 grit
- Plastic Polishing Compound
- Flannel polishing cloth
- UV resistant sealant
Clean Your Headlights
Sanding headlights without proper cleaning grinds contaminants deep into their surface, resulting in a rough, uneven surface with poor adhesion.
Use warm, soapy water to clean the headlight lenses’ surface, rinse, and then wipe dry using a soft, dry cloth. You may want to wash the surrounding areas too to help with the next step.
Tape Off the Area
You don’t want to accidentally sand off your car’s paint which would just turn into another new and expensive auto problem on your list.
Before you start sanding away to restore your headlights, apply masking or painter's tape around the headlight area. Two strips of tape are usually enough. If you feel insecure even after using tape, you can always remove your headlights, but this will be a lot of work.
Once you clean foggy headlights and tape away the area, it’s time for the real work to begin. You will need elbow grease and different grits of sandpaper to get the job done. Note, the higher the grit, the finer the sandpaper. Start with the coarsest option and gradually work your way to the finest.
That said, here are the sanding steps for this DIY headlight restoration project:
- Dry sand with 600 grit sandpaper: Since it’s the coarsest, sand down your headlights using the 600 grit sandpaper, sand in straight horizontal lines until the whole surface is covered, and ensure you maintain a consistent pattern until you’re satisfied the foggy layer is gone. If your headlights are heavily oxidized and cloudy, you may use 400-grit sandpaper.
- Wet sand with 1,000 grit sandpaper: Using your water spray bottle, apply water (serves as a lubricant) on the surface of your headlights, and lightly wet sand using the 1,000 grit wet or wet-dry sandpaper. As advised, follow consistent sanding motions for an easier headlight restoration process. Also, keep on lubricating the surface using water.
- Wet sand with 2,000 grit sandpaper: At this point, your headlights should be clearer, and this last round of sanding is to get that extra oomph and smoothen out the headlight lens surface. As we did in the previous step, lubricate the surface using water and lightly use a 2,000 grit wet-dry sandpaper to smooth out the surface using consistent motions.
Clean and Polish
With the cloudy layer gone, your headlights will now be clearer and looking almost new again. If you want to get that showroom sparkle back, you'll need to clean and polish them. Wipe the surface using alcohol and paper towels to removing sanding debris, and then rub in your polishing compound with a flannel polishing cloth using consistent motions for an extra shine.
Alternatively, if you want to use your power tools, you can also buff and polish your headlights using a cotton buffing wheel on an angle grinder or a felt polishing wheel with an angle grinder or die grinder. Instead of a polishing compound, you would use a blue rouge buffing compound bar with these kinds of buffing wheels. Just make sure you run it on a low setting that won't heat the plastic surface too much which could cause damage to the headlamp.
Apply UV Sealant
Although sanding your headlights is a somewhat easy and efficient way to restore headlights, it's not something you want to have to do all the time. If you want to remove the cloudy look for a long time, you'll need to finish off this project with a UV sealant.
Applying a UV sealant keeps headlights from oxidizing again. You’ll want to use at least three coats to preserve that amazing headlight shine you achieved through sanding.
Quick (Temporary) Fixes to Restore Headlights
Sanding is efficient, but it calls for elbow grease and is time-intensive. Here are some easy, temporary fixes you can use to clean foggy headlights when time is an issue:
Besides brushing your teeth, toothpaste has 101 other uses, including restoring your headlights. It contains slightly abrasive ingredients that break down oxidative contaminants on the lens surface.
Mix toothpaste with baking soda and evenly rub it onto the headlight’s surface. Let it dry, and then wipe off using a soft wet cloth. Your headlights will be clearer than before, and you’ll be set for the next few night errands.
Use Baking Soda and Distilled Vinegar
Similar to toothpaste, baking soda and vinegar are incredibly versatile products. While cleaning auto headlights, baking soda breaks down the contaminants, while vinegar efficiently removes the grime.
Mix one part baking soda with one part vinegar to create a fizzy paste. Rub the paste on your headlights, let it sit for a few minutes, and then use a soft cloth to wipe it away. You will have shinier headlights in no time.
Use Coca Cola
Yeah, you read it right — your favorite drink can also restore auto headlights. It contains phosphoric acid, which is quite efficient in removing rust and stains.
Transfer a can of diet coke (it’s easier to clean since it has no sugar residues) into a spray bottle and spray a reasonable amount on your headlights. Let it sit for a minute, and then dry it using a microfiber cloth. If your headlights are heavily oxidized, you may have to repeat the process several times.
Restore Auto Headlights with Dish Soap
For this method, first, wipe off your headlights to remove dust and other debris. Apply some hot water and dish soap, and leave it to sit for a few minutes. Wipe in circular, consistent motions, and rinse. Repeat the steps as needed.
Preventing Headlights from Oxidizing
While foggy headlights aren’t completely unavoidable, check steps you can take to keep headlights from oxidizing fast:
- Park smartly: the main reason why headlights yellow out is UV radiation — parking your car under a shade whenever you can is the easiest way to slow down headlight oxidation.
- Wash your car: As noted, car headlights sometimes get cloudy due to dirt and chemical layer. Washing your vehicle regularly using the right cleaners helps prevent fogging.
- Sand your car headlights periodically: You don’t have to wait until your headlights are completely yellowed out to sand them out. Sanding headlights once every few months will keep them looking as shiny as they were when you first bought your car.
Restoring Headlights Permanently
Headlight restoration is a project you can handle yourself on a slow Sunday afternoon by following the tips above. However, keep in mind some of the DIY headlight restoration techniques are only effective for a short while. Sanding is the best option to restore headlights permanently.