Introduction: How to Restore Faded Hazy or Yellowing Headlights by Wet Sanding and Polishing
Tutorial on how to restore faded, hazy, foggy, or yellowing headlights using the wet sanding and polishing method. I’m redoing an old video, this was the 10th video I uploaded to YouTube back in March 2011. Here I wanted to improve the quality of the video and go over some commonly asked questions too. I have the materials at home already, so no off the shelf kit is needed. Faded headlight doesn’t look good on a vehicle and can cause poor light output at night.
- 1000, 1500, & 2000 grit wet/dry sandpaper
- sanding backing pad
- bucket of water with soap
- polishing compound
- microfiber cloth
- clean polishing clothes
Step 1: Method Number 1 - Preparation
For this, I am using my 2006 Dodge Ram as an example. This can be done with the lights left in the vehicle or they can be removed. I will provide both examples along with two different polishing methods too. I prefer removing them as they’re only held in with three bolts.
This applies to the plastic style lens, it’s made of a polycarbonate type plastic which can withstand the abuse from road debris, however over time the UV coating does tend to deteriorate and you’re left with this yellowish, hazy, and rough finish. As you can see with these lenses, the deterioration is mainly on the top of the lens, this is the area most exposed to weathering, UV light, etc.
Step 2: Washing
I would highly recommend washing them to remove any dirt or debris, which may potentially cause damage. The last thing you want is a small stone or sand being caught between the sandpaper and lens or polishing cloth and lens. I’m using the same multi-purpose cleaner which is used on interiors. Leave the bulbs installed or tape off the holes, do not get water inside as this can damage the reflector or cause staining inside.
No need to dry the lens, next we will be wet sanding the plastic.
I would recommend pre-soaking the sandpaper in a bucket of water, you’ll need 1000 grit, 1500 grit, and 2000 grit. This must be a wet/dry compatible sandpaper, otherwise, it will fall apart when exposed to water. A small amount of soap is added to the water to help with lubrication. A backing pad can be used and I’ll show you that in a moment.
Step 3: 1000 Grit Wet Sanding
Starting with 1000 grit, make sure the lens is wet, then sand the surface working evenly across the lens. With sandpaper, the smaller the number, the coarser the grit, therefore it will remove material faster and leave larger scratches. Some people do start with 800 grit on severe lights, however, that will remove material quicker and it’s not something I’d recommend for beginners. More work is also involved in removing those 800 grit scratches.
Keep the area well lubricated, rinse the as needed when there’s excessive sanding residue build-up, and keep inspecting the lens for clarity. You may notice an outline or ghosting in the lens, this is normal. That is the old UV layer being removed. With 1000 grit, this is used to remove a majority of the imperfections. When wet, the lens will appear somewhat clear, but if dry, it will be hazy and this is perfectly normal.
Step 4: 1500 Grit Wet Sanding
Next is using 1500 grit, again make sure the lens is well lubricated with water, then continue the same process. Being that this lens is fairly flat, it’s easy to use the rubber back. A backing pad can be used to prevent any distortion and allows you to provide even pressure across the surface. On smaller lenses, you may consider using the palm of your hand. Light to medium pressure is all that’s needed. Rinse the lens and sandpaper as needed to remove any sanding residue and continue to work the surface. Less time is needed here as we’ve already removed a majority of the imperfections. In this stage, we’re only really removing any slight imperfections and the 1000 grit sanding marks. If the lights were on the vehicle, you’ll need to rinse the area around the headlight as the residue will stay on the paint and can be hard to clean once dried.
Step 5: 2000 Grit Wet Sanding
Finally, is using 2000 grit sandpaper. This will be the last of the sanding stage, some people do prefer going up to 3000 grit which does make it a little easier on the polishing stage, however, I have found it isn’t needed. Using the same process as previously, ensure the lens is well lubricated along with the sandpaper, then work the surface. Work evenly across the lens, light to medium pressure, this stage is used to remove the 1500 grit sanding marks. Rinse the lens and sandpaper as needed. Despite wet sanding the surface, some UV coating is still left on the front of the headlight, but due to its deterioration, the UV coating has been removed on the top and you may be able to see that transition line.
Step 6: Polishing by Hand
When dried, it will still appear hazy and this is normal. The plastic should be white with the yellowing removed, there shouldn’t be any outlines of the old UV coating as this can be sometimes visible after the polishing stage.
Make sure the light is dry, next is onto the polishing stage. There are various polishes available on the market, one of the easier to use polishes is Meguiars Ultimate Polish. Polishing can be done by hand, it is a bit more work-intensive but safer for beginners. A machine polish can be used such as an orbital, rotary, or even a drill attachment With this being plastic, the surface can be easily burned, so extreme caution is needed.
Polishing by hand, always make sure your polish is mixed so shake the bottle. Then apply a small amount to a soft clean cloth and work it into the surface. Linear or circular patterns can be used, whichever is easiest for you. Light to medium pressure is only needed, do not allow any dirt to come in contact with this stage. This is the type of project, if you invest more time, you’ll end up with a better finish.
After a couple of minutes, wiping away the polish, you can see the light coming up. I will give an example of using a machine polisher in a moment.
Continue polishing the light and after a little longer, here is the final finish. The UV coating has been removed in some spots, therefore the light does not have that full protection again and I’ll show you how to protect the light in a moment.
Step 7: Method Number 2 - Preparation & Washing
Moving onto the opposite light, this time using a different method. Wash the light and surrounding area so no containments cause any issues.
Dry the light and area, then apply tape on the surrounding area such as the paint, plastic trim, rubber gaskets, etc. The only for drying is so the tape can stick to the surface. Being that the lightly sits slightly below the fender edge, this is a high-risk area where you can damage the paint with either wet sanding or machine polishing.
Step 8: 1000 Grit Wet Sanding
Wet the surface and we’re starting out with 1000 grit again. Depending on the model, some vehicles do have replaceable lenses, some vehicles even have glass lenses depending on the market and that can be a retrofit option too depending on your budget. Always make sure the surface is well lubricated and rinse the sandpaper and surface as needed. Make sure you do rinse the vehicle’s surrounding surface, the residue left behind from the lenses when dry can be hard to remove.
Step 9: 1500 Grit Wet Sanding
When done, moving up to 1500 grit sandpaper. This process can be used on fog lights, tail lights, and any other form of plastic style lenses on vehicles. I have even had viewers in the past who used this method for cleaning up faded snowmobile or motorcycle windshields and gauges. This method isn’t intended for glass style lights.
Step 10: 2000 Grit Wet Sanding
Next is moving up to 2000 grit sandpaper. Clear coating lights are also another option, however, it would be a different process and the finish grit would be 1000. I do have an older video of this, however, I’ll do an updated version in the future. Using a clear coat after 2000 grit may cause adhesion issues, resulting in peeling.
Step 11: Polishing
Rinse the light, removing any residue, and then dry. Now onto polishing, this time using a machine polisher. This is a rotary polisher that will have the most risk of damaging the surface. I prefer using a finishing pad, each company will have different color ratings for their pads. Apply the polish to the pad in dabs, then smear it on the surface to reduce the chance of sling. The headlight can be installed back into the vehicle making this a little easier, but you do have the risk of damaging the paint just like wet sanding. Apply light pressure, only use the weight of the polisher across the surface. A slow speed is recommended, however, my polisher only has two speeds.
Using a clean soft cloth, wipe the surface and inspect as needed. If sanding marks are still present, then continue polishing.
Step 12: Applying a Protection
Considering some of the UV coatings have been removed, there is now no protection. For this, I will be a wax, the same as what is used for protecting the paint. A sealant or nano coating can also be used depending on your preference and budget. Make sure the lenses are clean, for my method using wax, apply it to an applicator and work it across the surface. Wax will need to be applied every 4-6 months depending on your climate and what type of wax is used for maximum protection. As for a commonly asked question applying a clear coat. This cannot be done after the polishing process. Due to the polished surface, the clear coat will have an adhesion issue and this will cause peeling in the future.
Allow the wax to set up, times can vary depending on what product is used so always consult with the product’s specifications. Remove the wax and polish using a microfiber cloth.
Step 13: Final Results
When done, here you can see the final finish. This should easily last a year, however, this can vary depending on your climate and your final results. Areas exposed to higher concentrations of UV light may have the lights fade quicker. If your vehicle is parked indoors, the headlights will last longer. There should also be an improvement of light output depending on the severity of the fading. Other areas that can affect poor light output can include improperly aimed lights, ages bulbs showing deterioration, the lens or protectors if equipped are dirty, or an electrical issue where the light isn’t receiving sufficient voltage.
I do have a little condensation inside the lens which most likely came in from the backside when washing. It’s a small amount and should evaporate either after headlight usage or a couple of hours in the sun.
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