How To Restore Cloudy & Oxidized Headlights
February 10, 2023
In this months blog I’m going to share how we professionally restore cloudy and oxidized headlights enhancing your cars curb appeal and also providing the safety of properly functioning headlights.
At Dream Machine Detailing, I’m proud to offer our clients a well rounded menu of professional cosmetic car care services that cover most areas of your car, from the interior upholstery to the exterior paint and everything in between. Reconditioning the headlights is one of these specialty services and it is oh so satisfying.
Skip to the bottom of the article if you would rather watch a demo of this process, otherwise, read on.
Professional Reconditioning vs. D.I.Y. Hacks
You may have seen videos of folks using lemon juice, bug-spray or toothpaste to restore their headlights. These are entertaining D.I.Y. tricks and hacks that may provide a short term solution, but most likely will yield disappointing end results. No hacks for us. Our methods for restoring headlights come from years of experience using a professional headlight restoration system as well as training we received from industry icon and mentor Mike Phillips. Having your headlights restored the correct way either by a professional or a D.I.Y.er using the proper methods is the difference between the restoration lasting weeks or years.
Why do Modern Headlights Oxidize?
Your modern vehicles headlight lenses are typically made out of Polycarbonate, which is a fancy word for a transparent and durable plastic. Why oxidation prone plastic? Good question. Back in the “good old days”, circa pre-1990, most cars had glass headlight lenses. The old glass lenses do not oxidize like the modern plastic lenses do, so why the change to plastic? There are many factors, but it mostly boils down to crash safety regulations, fuel economy standards and vehicle aerodynamics. If you recall most glass lenses only came in round or square designs. Auto manufacturers made the change to plastic lenses primarily because plastic is easier to mold into the more complex shapes that their more aerodynamic designs required.
Why do Polycarbonate headlights need reconditioning?
One of the harshest elements that headlights see is UV rays from the sun. Auto manufacturers are aware of this so your new car leaves the factory with headlights that have a UV resistant coating on them. Over time the coating gets warn down and begins to deteriorate, especially if neglected. This degradation of the coating on the headlight will make the lights begin to look cloudy, yellow and sometimes even flaky. A headlight restoration usually is not needed on a newer vehicle, however if the vehicle is neglected it may need it sooner than a vehicle that is maintained and protected.
Oxidation Prevention
Cleaning your car regularly and removing potentially damaging road debris, chemicals and environmental fallout is a way to keep all areas of your vehicles finish lasting longer. Better yet, keeping a form of protection on your car year round, be it a traditional wax, a durable sealant or some sort of multi-year coating will act as a sacrificial layer and give your vehicles finish a fighting chance against our worlds harsh environment.
Restore or Replace?
Lighting technology on newer vehicles is more complex and more expensive than ever. Newer cars with the latest headlight technology have sealed headlight housings. The internals use HID (high-intensity discharge) or LED Projector lights (light-emitting diode) and some modern cars are now adopting adaptive headlights that will turn with the steering of the car to illuminate curves in the road. All are expensive technology to replace.
Typically a headlight restoration on a vehicle with the latest tech will cost half as much as replacement making it more cost effective. If it’s older technology then the cost of a restoration may be comparable to replacement. It also depends on how much work does it take to replace. Does the bumper cover or front fascia have to be removed? Sometimes the labor alone for replacement will make restoration more practical. Restoring in my opinion is always better since it keeps parts out of the land fill.
Why is headlight restoration important?
Beyond the obvious lack of curb appeal that cloudy and oxidized headlights create, the biggest factor when considering headlight restoration is vehicle safety. When the headlights become cloudy and oxidized it’s as if someone has put a light diffuser over the lens. It means that your lights aren’t going to illuminate the road as well. When driving down a dark country road at night and a potential hazard like Bambi the deer comes jumping out, that extra second of visibility can be critical for avoiding it. Bambi will be grateful as well. A headlight restoration will remove that diffused layer of oxidation restoring the light back to peak performance. It also is a small, but significant way to restore the overall look of the car making it more appealing for re-sale.
The Basics
The way we do headlight restoration is by machine sanding the lens in order to remove the dead or damaged material. Once the damage is removed, the goal is to refine the sanding marks until they can be easily removed by using a liquid rubbing compound. Polish is used to get that extra 10% of clarity making the lenses glisten like new.
The Tools We Use
We use the 3M Professional Headlight Lens Restoration System. It’s on the pricey side and geared for the professional who does a high volume of cars. It comes with everything needed to achieve professional results. I often use our 3 inch Flex PXE 80 cordless mini polisher for this job when we’re mobile, but if you have access to shop air, the kit provides a 3 inch pneumatic rotary sander and a 3 inch pneumatic dual action polisher. The rotary sander is used for rapidly removing the UV damage and oxidation, while the dual action polisher is used for compounding and polishing the headlights lenses to restore gloss and clarity.
Sanding Disks
The kit comes stocked with all of the various sanding discs you’ll need from P500, P800, P1000 to P3000 (all in 3 inch diameter) in order to progressively refine the sanding marks so they’re easier to remove with the liquid rubbing compound and polish at the end. They are hook and loop and attach to the sander, via an interface pad. The interface pad gives the sanding disk some cushion and flex so it can contour to the working surface.
Foam Pads & Abrasive Liquids
For use with the dual action polisher the kit includes an assortment of 3 inch foam buffing pads. One firm density for compounding (cutting) and one soft density for polishing (finishing). These pads are paired up with their appropriate liquids, be it a liquid rubbing compound and a liquid polish, also included.
Consumer Kits
There is a simplified, stripped down consumer version of this kit offered by 3M at auto parts and big box retailers for the weekend warriors who’d like to do this process themselves. When starting out, back in the day, I used the consumer kit with good results. It took a little longer as some of the sanding was done by hand and instead of air tools or a battery polisher they made the kit work with a household electric drill. There are other kit’s available, but in my opinion the 3M kit is the way to go. I’m not sponsored by them, but I believe they have the best sanding disk technology.
Step One: Protect The Working Area
Before I begin sanding the first step is to use masking tape to protect the surrounding area around the headlight lens such as trim and painted surfaces. I use 3M Automotive masking tape you can pick up at most auto parts stores in the auto body section. Any automotive painting masking tape will work, however I find the 3M yellow tape has the most flexibility for making bends around curved shapes like headlights.
Pop The Hood
Depending on the design of the vehicle I may opt to pop the hood and lift it up to get it away from the headlight and save me time masking. I will layer the tape up a little to create a nice thick protective shield so there’s no chance the sandpaper will burn through the tape and accidentally hit the paint or trim. If I have popped the hood I might throw a towel over the adjacent engine bay areas as well in order to make clean up later a little easier.
Do The Messy Work First
I tend to do the headlight restoration process before washing a vehicle, because it is quite messy. I have yet to do a headlight restoration as a stand alone service, but in that case I would quickly cover the front of the car with some lightweight plastic to protect the area from mess.
Step Two: Heavy Oxidation Removal
Once the area around the headlight is protected the next step is to remove all of the damaged coating material and oxidation from the lenses. This is done by sanding the damaged lens. It can be done by hand, but I prefer using a machine because I find it more efficient and it leaves a nice uniform finish.
Wet Sanding
Have a bottle of soapy water on hand for lubrication as we are wet sanding the surface. I use a mix of water and dawn dish soap for slickness. I can say I have also used automotive glass cleaner for lubrication and it worked just as well. Before starting I’ll give the headlight a quick spritz and wipe down with a microfiber towel in order to start with a clean surface.
Determine Your Starting Grit
Start with the lowest number sandpaper, in my case P500 as it is the most aggressive grit in my kit to rapidly remove the heavy UV damage. If the oxidation isn’t super aggressive, maybe the headlights are just starting to show oxidation, you can probably get away with starting with P800 instead. The least aggressive you start the less time it will take to remove the sanding marks in the later stages.
Interface Pads
I attach the sanding disk to my 3 inch sander via the interface pad. This interface pad acts as a cushion to help the sanding disk contour to the surface. I keep the headlight lubricated with soapy water as I work. This helps flush away the dead material and keeps the surface cool. I also keep my sanding disks clean and free of build up by spraying them down with soapy water in between passes.
Speed & Technique
I use my sander set to a low-medium speed and apply a moderate pressure to the surface to keep the disk flat and the heat down. I don’t want to burn the plastic by using the tool at a high speed or by using too much pressure thus creating too much heat. I keep the tool moving at an even moderate pace, never hovering over one spot for too long and work back and fourth over the entire headlight.
Section Passes
I do what’s called “section passes” by working across the entire lens area in one direction (side to side) and then working the other direction (up and down). Some headlights may be a strange shape. In that case I’ll work back and fourth over the whole surface allowing the shape of the headlight to dictate my section pass. Sometimes some headlight designs may require some hand sanding if a tool can’t get into a tight area. The goal is to remove all of the oxidized or “dead material” and create a uniform surface. If the surface looks uneven then it needs to be sanded more.
Sanding Slurry
The wet sanding process will create a sanding slurry as the dead material is removed. I use a microfiber towel to wipe excess slurry residue away in between section passes. Once the slurry turns from yellow to white that is an indication that the dead, oxidized and damaged layer has been successfully removed. The headlight should now have a dull, uniform, white and opaque finish. This initial sanding step with the P500 or P800 will take the most time as it’s removing all of the dead and damaged coating material from the lens surface.
Step Three: Refining The Sanding Marks
Next, begins the process of progressively refining the sanding marks from most aggressive to least aggressive. The next lowest grit in the kit is P800. If you started with P800 then move to P1000. I repeat the same technique as before working over the entire area in back and forth motions using lubrication as I go. Once again I’m looking for a uniform finish. I want to replace the more aggressive sanding marks with progressively finer sanding marks.
P1000 & P3000 Trizact Blending Disks
Continuing the progression I move on to P1000 and finally P3000 which are called Trizact Blending disks. These are very fine and the disks have a little padding to them. With each progression more and more clarity of the lens is restored. Jumping ahead from one sanding step to the next too quickly can leave some deeper or random sanding marks behind that the finishing steps (compounding and polishing) will have difficulty removing. It’s important to take the time to achieve a uniformed finish with each step by removing any deeper scratches that can be seen. Shining a light into the lens or turning it on can help reveal any deeper sanding marks that might be hiding. The P3000 will restore a high degree of clarity to the lens with only a very slight haze from micro-scratching (micro-marring) left behind.
Step Four: Final Compounding & Polishing
Once we’ve finished with the P3000 Trizact disk now we’re ready to machine compound. This step will remove any haze or micro-scratches left from the sanding steps.
Machine Compounding
I use a firm density foam cutting pad and a liquid rubbing compound paired with a 3 inch free spinning, dual action, random orbital polisher. I use the pneumatic polisher that comes with the 3M kit or my cordless Flex PXE 80 mini polisher to do the job.
Dual Action, Random Orbital, Machine Polisher
The beauty of using a dual action, random orbital polisher is that it mimics the “random” motion of a human hand at high speed. The dual action means that the pad rotates in a free spinning orbit and also oscillates back and fourth randomly. This makes the machine very easy and forgiving to use. It is also incredibly safe to use as it’s free spinning action will slow or stall on edge which means it is very hard to generate a level of heat that would do any damage to plastic or paint. This process can be done with a rotary tool such as a drill. You just have to be a little more careful with the speed.
A Little Liquid Goes a Long Way
I apply several pea size drops of liquid rubbing compound to the buffing pad and then dab it around on the lens. Next I’ll turn the polisher on to it’s lowest speed and quickly spread the product around creating a uniform film of liquid product on the working surface.
Next, I’ll ramp up the speed to medium/high and work the polisher back and forth doing section passes as before. I apply a moderate pressure to the pad and move the polisher at a slow to moderate pace over the headlight until the compound liquid is almost transparent.
If there is still micro-scratches or sanding haze I will re-apply more compound and continue until there are no sanding marks remaining. In between section passes I will wipe away compound residue with a microfiber towel to see my work.
Machine Polishing
The final step is to polish. I use a soft density polishing pad and a liquid finish polish and repeat the same steps as compounding only now I’m just looking to restore clarity and remove any slight haze that the compound may have left. I buff the polish residue off with a microfiber towel and the end result should be a crystal clear headlight lens.
Step Five: Apply UV Protection
Finally, since we have removed the damaged factory coating we need to properly protect the lens from it’s main nemesis, the sun. This is the step that often gets overlooked and when not done, the raw Polycarbonate lens will oxidize faster than before.
Ceramic Coating
In order to prevent pre-mature oxidation we apply our own UV coating in the form of a ceramic coating. I prefer applying a multi-year ceramic coating for it’s ease of install and long term durability.
Surface Preparation
Before applying the coating it’s important to prepare the surface for proper bonding. I will wipe the lens down with an oil and wax remover in order to remove any oils or polish residue. This will make sure the coating will bond properly to the lens giving it it’s best chance for long term durability.
Coating Application
Next, I apply the coating to a sued or microfiber applicator pad and apply uniformly to the lens area in a crisscross pattern. Once I see the coating flash (rainbow appearance) I will buff off with a clean microfiber towel.
Cure Time
On average a ceramic coating will need 15-24 hours to properly cure and typically should not see any harsh weather or a car wash for about 6-7 days after application. If allowed to cure correctly a good ceramic coating will last years.
Durability
The coating we apply will typically last up to three years if the vehicle is properly maintained. If the lights begin to fade again it’s time to sand or compound off the coating and re-apply a fresh coating once again.
Limitations of Headlight Restoration?
There are some limitations to headlight restoration, for example it will not fix internal or external cracking from experiencing years of hot and cold temperature cycles. It also won’t fix pitting, gouges or cracks from impact damage. There is also the possible case where the oxidation is so bad that the integrity of the plastic itself is beyond repair. In those cases it’s time to replace the lights.
Dream Machine Detailing Headlight Restoration Demo
Follow along as I demo our headlight restoration process from start to finish in this video from December of 2020.
Recap
Step One: Prep
Mask off around the headlight with masking tape (Recommend 3M Automotive masking tape).
Step Two: Oxidation Removal
Use soapy water or automotive glass cleaner to liberally lubricate the surface and the sanding pad. By hand or with a 3 inch machine buffer make overlapping section passes starting with P500 or P800 grit sanding disc. Work until the sanding slurry turns from yellow to white and you have an opaque uniform looking finish. This step will take the most time.
Step Three: Refinement
Depending on your starting grit using the same technique as above use P800 or P1000 grit sanding disk to remove all P500 or P800 grit sanding marks creating a uniform surface. When using P1000 grit you should notice some clarity begin to come back to the lens.
Using P3000 Trizact Blending disk remove all 1000 grit sanding marks creating a uniform surface. Should notice clarity of the lens looking better than before you began sanding.
Step Four: Final Compound & Polish
Using a firm density polishing pad and a liquid rubbing compound with a 3 inch Dual Action, Random Orbital buffer remove the P3000 sanding haze restoring nearly perfect clarity.
Remove any left over compounding haze using a soft density foam polishing pad and a liquid finishing polish to restore perfect clarity to the lens.
Step Five: Apply UV Protection
Protect the lens by applying an aerosol applied clear coat or a hand applied ceramic coating to protect the headlights from pre-mature oxidation.
Summary
So there you have it. That is how we do professional headlight restorations using the 3M Professional Headlight Lens Restoration System. Just like the other services we offer there is an incredible satisfaction of watching the headlights transform from cloudy and oxidized to sparkling and new in front of our eyes. If you’re looking to learn this skill I encourage you to go buy a consumer kit and try it out. If you’re worried about messing up your own car, borrow your friends beater or find some junkyard headlights to practice on. Better yet do what I did and take a comprehensive detailing class. I took hands on training with industry icon Mike Phillips in Stuart Florida and he covers headlight restoration and so much more.
Lastly, If you’d like us to restore your headlights we would be grateful to have your business! Just shoot me a message through our contact page. Thank you for reading and happy detailing!
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