Over time, the clear plastic headlight covers on all vehicles eventually become foggy, yellowed, and clouded. This gradual degradation of your headlights can significantly reduce visibility while driving at night, which is dangerous. It also makes your car look old before its time.
So how do you restore dull, weathered headlights to their former crystal clarity?
Luckily, there are several easy methods for how to clean headlights right at home using items you already have. The secret is to properly wet sand the headlight lenses down to remove the outer plastic layer. Then polish and seal the cleared surface.
In this step-by-step guide, you’ll learn how to clean headlights using toothpaste, bug spray, wet sanding, rubbing compound, and a sealant. Following these 5 simple steps can transform those unsightly foggy headlights and renew visibility and aesthetics.
Below you’ll find all the information and tips you need including:
- Why headlights turn yellow and become foggy over time
- Step-by-step instructions for wet sanding techniques
- Headlight polishing with toothpaste or bug spray
- How to apply protective sealant to protect from future damage
- Pro tips to get professionally clear results at home
So if your outdated headlights are making your car look old and reducing night visibility, restore them with this easy DIY process. Driving with renewed headlights will also help keep you safer on the road at night.
Table of Contents
Why Do Headlights Get Foggy and Turn Yellow?
The plastic polycarbonate lenses on the headlights of all vehicles will naturally degrade and yellow over time. Even if your car is relatively new, you may start to notice fogginess and discoloration forming on the headlight lenses.
There are a few primary culprits that cause the clouded, yellowing effect:
- UV Rays – Powerful ultraviolet radiation from the sun gradually damages and decomposes the plastic material that makes up headlight covers. This causes the lenses to appear frosted.
- Oxidation – Normal oxidation from the oxygen in the air also wears away at the plastic over years of exposure. Oxidation creates micro-cracks that refract light and make the headlights appear yellowed.
- Thermal Cycling – Repeated cycles of the plastic heating in the sun during the day and cooling at night leads to expansion and contraction. Over years of wear, this process clouds the headlights.
- Environmental Pollution – Air pollution like car exhaust, dirt, debris, and road salt can slowly stain the lenses yellow. Road tar also seeps into any cracks.
By understanding the science behind why your headlights deteriorate, it’s clear that no vehicle’s headlights are immune from the effects of sun exposure, heat, oxygen, and environmental pollutants. That’s why those clear lenses you had when your car was new end up discolored and foggy.
And when those plastic headlight lenses degrade to the point of reduced visibility, it’s not just an aesthetic issue. Cloudy headlights actually create a dangerous situation by decreasing your field of vision at night. Less light output means reduced road visibility that can easily lead to accidents.
So for both appearance and safety reasons, it’s important to clean and restore that clarity to your car’s foggy headlights and bring them back to their former glory.
How to Clean Headlights: Gather the Right Supplies
Before you start the process of how to clean headlights, you need to gather the correct supplies. Having all the proper tools and materials will make the job much smoother.
Here’s an overview of everything you’ll need:
- Wet Sandpaper – Start with a 600 grit sandpaper, and then move up to 800 and 1000 grits for polishing smoothness. The water lubricates the sanding process.
- Masking Tape – Tape off the area around the headlights to protect the car’s paint from getting scratched or sanded.
- Newspaper – Further protect paint by stuffing newspaper into gaps between headlights and body.
- Water Spray Bottle – Used to keep the sandpaper and headlights wet during sanding.
- Microfiber Towels – High quality cloths are perfect for drying, polishing, and buffing.
- Rubbing Compound – Removes sanding scratches and restores optical clarity to sanded headlights.
- Toothpaste – Whitening toothpaste acts as an abrasive polish to further clarify the lenses.
- Bug Spray – Spray-on bug remover also works to polish the plastic.
- Headlight Sealant – Prevents future UV damage and yellowing to keep headlights clear.
- Clay bar – Removes embedded contaminants from the lens surface before sanding.
While not all these materials are mandatory, having them all will give you better results. Don’t skip items like the clay bar, compound, sealant and quality microfiber towels if you really want your efforts to pay off.
Now let’s get to work on restoring those hazy, yellowed headlights!
Step 1: Thoroughly Clean the Headlight Covers
Before moving onto more aggressive sanding and polishing, start by giving the headlight lenses a deep clean. This preparatory step is important to remove all the dirt, debris, bugs, and contaminants that may be on the exterior.
Here’s how to clean headlights before wet sanding:
- Wash the headlights with soap and water just like you would clean the rest of the car. Dish soap works well to cut through grime.
- Use a clay bar kit to remove embedded contaminants from the surface of the lenses. Spray clay lube on the surface and gently rub the clay bar over the headlight. The clay will pull out debris from the pores.
- Apply isopropyl alcohol to the lenses and wipe clean with a microfiber towel. The alcohol will remove any remaining residue and prep the plastic for sanding.
- Thoroughly dry the headlight covers with a clean, dry microfiber towel to prevent water spots.
This initial deep cleaning stage is quick and prevents you from grinding dirt into the headlights later on. It also allows the sandpaper to scuff away the top layer of plastic evenly.
So don’t neglect prepping with a thorough cleaning before moving onto sanding and polishing steps. The small time investment is worth it!
Step 2: Wet Sand the Headlights with Progressive Grit Sandpaper
Now onto the real restoration process – wet sanding the headlights! This abrasive process will physically remove the top few layers of degraded, oxidized plastic to reveal the clear base material underneath.
Here is the complete wet sanding process:
- Tape off the area – Protect the car’s paint by applying masking tape around the perimeter of the headlights. Stuff more newspaper between gaps in the body panels for extra precaution.
- Start with a 600 grit sandpaper – This coarse grit will aggressively scuff away the top oxidized layer. Always wet the sandpaper before sanding to provide lubrication.
- Use light pressure and keep the surface wet – Rub the sandpaper over the lenses in a back-and-forth or circular motion. Spray more water as needed to keep the plastic wet. Let the sandpaper do the work, no need to apply heavy pressure.
- Sand until the yellow film is gone – Be patient and sand with the 600 grit until you sand away the oxidation and reach a clear layer. Apply moderate pressure if needed on stubborn areas.
- Move up to 800 grit – As you get closer to a smooth, transparent surface, step up to 800 grit sandpaper. This finer paper smooths out 600 grit scratches.
- Finish with 1000 grit – The 1000 grit gives the final polish to the surface for maximum clarity. Don’t skip this step! The fine grit removes any remaining hairline scratches.
- Spray off residue – Hose off the headlights to remove all the sandy residue. Be thorough here so the compound can bond directly to the plastic.
- Dry the surface – Wipe dry the newly exposed clear lenses with a fresh microfiber towel before moving onto the polishing step.
When wet sanding, take your time and pay attention to get the oxidation fully removed and achieve a uniformly smooth finish. Remaining sandy residue or scratches will drastically reduce the final clarity.
Patience is well rewarded, as you’ll soon see those dull, yellowed lenses look crystal clear again!
Step 3: Polish the Headlights With Rubbing Compound
At this point after wet sanding, the foggy plastic outer layer is removed to reveal the clarified inner material. But likely there are still some slight sanding scratches and imperfections on the lenses.
That’s where headlight compound comes in – to polish out any remaining marks and restore that optical clarity.
Here’s how to polish headlights after sanding:
- Use a mild rubbing compound, preferably one designed specifically for headlights. Regular car polish is too abrasive. An excellent choice is Meguiar’s Headlight Restoration Compound.
- Apply a small amount to a microfiber cloth. Rub the compound into the cloth to prepare it for polishing.
- Spread the compound on the headlight and rub in using firm, circular motions. Applying pressure generates heat to help the compound work into the surface.
- Remove residue and reapply compound as needed. Wipe away any dried polish with a clean microfiber towel. Reapply fresh compound to maximize gloss.
- Work until scratches disappear and clarity returns. It may take several rounds of compounding to achieve that glass-like finish. Don’t quit too soon!
- Remove all residue with a dry microfiber towel once finished polishing. Spray surface with water and dry again if any compound remains.
Take the time with this polishing step for best results. When done thoroughly, the headlights will look as good as new.
Step 4: Use Toothpaste or Bug Spray as Extra Polish
For an optional extra step after compounding, you can use ingredients like whitening toothpaste or bug spray as an additional polish. These abrasives work to further enhance the clarity and remove any leftover haze.
Here’s how to use toothpaste and bug spray:
- Select a whitening toothpaste with higher grit abrasives like baking soda. Avoid gel types.
- Apply a small amount directly onto the headlight lens.
- Gently rub the toothpaste into the plastic with a microfiber cloth using small circular motions.
- Wipe away dried paste with a clean towel and rinse any residue.
- Reapply more toothpaste and polish again if needed.
- Dry thoroughly with a microfiber towel when clear of scratches.
- Use a spray-on bug remover product, not the wash type.
- Mist a light, even coat of bug spray onto the headlight lens.
- Let it soak for 2-3 minutes. This allows the chemicals to break down contaminants.
- Wipe off with a dry microfiber towel using gentle circular motions.
- Repeat process until achieving desired level of clarity.
- Wash off all residue. Dry lens completely.
Toothpaste and bug spray add that extra abrasive polishing power to remove the last bits of haze and imperfections. Try one or both to take the clarity to the next level.
Step 5: Seal the Headlights With Protective Coating
Now that you’ve uncovered perfectly clear, transparent headlights, it’s crucial to seal and protect the plastic lenses. This clear coat acts like sunscreen to defend against UV rays and oxidation.
Here’s how to seal headlights:
- Only apply sealant to fully dried lenses – Ensure all water and cleaning products are dried first. Sealant won’t adhere well to wet plastic.
- Tape off the area around headlights. Protect the car’s paint finish from potential sealant drips.
- Apply a thin, even coat of sealant like Meguiar’s Keep Clear Headlight Coating. Follow product instructions. Less is more here – you want a light coat without drips.
- Allow sealant to cure before driving according to product directions. Curing time is usually 20 minutes to an hour.
- Wipe away any excess fluid and re-apply to missed spots if needed after curing. Remove all tape.
- Reapply sealant every 6 months. Regular coats prevent the improved clarity from regressing back to a yellowed, cloudy state.
Sealing the headlights is a crucial final step to lock in the clarity gains. Don’t skip the protective coating or else all the sanding and polishing work will be for naught!
Professional Tips and Tricks for Best Results
Follow these pro tips and tricks during the restoration process for smoother sailing and professional-grade results:
- Work in a shaded area – Sunlight causes plastic and compound to dry out too fast. Work under a patio or tent for easier application.
- Ask someone to help – It’s difficult to evenly sand and polish both headlights alone. An extra set of hands makes the process much easier.
- Take your time sanding – Slow, deliberate sanding creates a smoother finish. Rushing causes uneven scratches and swirl marks. Let the sandpaper do the work.
- Keep the lenses wet when sanding – Remember to frequently spray water when sanding to lubricate the plastic. The wetness captures debris too.
- Clean frequently – Wipe away built-up residue often for clearer visibility. Spray lenses with water to remove compound.
- Work in sections – Divide each headlight into sections to systematically sand and polish the entire surface.
- Use a power buffer – Optionally use an orbital buffer with headlight compound for faster, more effective polishing.
- Cure sealant properly before driving – Don’t rush the curing process or drive too soon or sealant may stain paint or rub off.
With these handy tips in mind throughout the restoration, you’ll achieve longer-lasting results that look professionally done.
Frequently Asked Questions
Still have some lingering questions about restoring your cloudy headlights? Here are answers to the most common questions about the process:
How long does the restoration process take?
Plan for 2-3 hours for the full restoration process on both headlights. Rushing through steps leads to mistakes, so allocate ample time.
Do you need power tools?
No – hand sanding and polishing works fine. Optionally, a power drill with polishing attachment speeds up compounding.
Will toothpaste or bug spray damage the plastic?
When used properly, these shouldn’t cause damage. Avoid applying forceful pressure and immediately wash off any residue.
Can I just apply sealant without sanding/polishing?
No – sealant adheres best to freshly clarified plastic. It bonds poorly and peels on UV-damaged, oxidized lenses.
How long does the clarity last?
Frequent sealant reapplication keeps headlights clear for years. Plan to re-sand and polish every 2-3 years for a deep clean.
Is it safe to clean xenon headlights?
Yes, just avoid sanding the glass lens itself. Only sand/polish the outer protective plastic cover.
Can I use water instead of compound?
No – water doesn’t have the abrasives to remove sanding marks and enhance optical clarity. Stick with polishing compound.
Hopefully you now feel empowered to restore those unsightly, faded headlights on your own car or a loved one’s. While it takes time and elbow grease, the dramatic results are well worth it.
The moral of the story? Don’t hesitate to dive into the simple 5-step headlight restoration process. Gather the supplies, clean thoroughly, sand with care, polish to perfection, and seal for longevity.
Your car will light up the road ahead with newfound luminosity, and also look years younger. No longer will you dread night driving with dim yellow beams.
So what are you waiting for? Make today the day you finally see clearly and bid farewell to those foggy headlights for good. Just imagine how great your car will look when it’s all done.