How to Polish a Headlight Lens

Most headlight lenses are made of polycarbonate, commonly known as Lexan. This type of plastic is susceptible to damage by UV radiation from the sun. The lenses can become yellowed or cloudy. They are also softer than glass, so they can also become scratched or gouged.

It takes a little time and effort, but these headlight lenses can be restored to nearly factory-new quality by sanding and polishing them. In this video, the plastic repair experts at Polyvance will show you how to restore a deeply scratched headlight to like-new condition.

Always wear proper safety gear while working!

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Click here: https://www.youtube.com/watch?v=zrUZGBoSe0k

Products Used:

Note: This is a list of the Polyvance products that can be used to make this repair. This list does not include sanders, grinders, or other common tools you will need. If you have any questions, please don't hesitate to call technical support at 800-633-3047.

• 1000 Super Prep Plastic Cleaner (several options available) OR 1001-4 EcoPrep Plastic Cleaner

Video Notes:

• English Closed Captions have been provided for this video. Click on the CC button to turn them on or off.
• The length of this video is in no way representative of the actual time required to perform a complete repair and therefore should not be used for estimating purposes.

Music Credits:

• "Sage" by Slenderbeats
  From the YouTube Audio Library

English Transcript:

Plastic headlight lenses can become dangerously cloudy after years of exposure to UV radiation from the sun. Did you know you can bring back the factory appearance, even on a headlight lens as cloudy and scratched up as this one? The plastic repair experts at Polyvance will show you how in this video.

Most headlight lenses are made of polycarbonate, commonly known as Lexan. This type of plastic is susceptible to damage by UV radiation from the sun. The lenses can become yellowed or cloudy. They are also softer than glass, so they can become scratched or gouged, like this one.

It takes a little time and effort, but these headlight lenses can be restored to nearly factory-new quality by sanding and polishing them. The process is easier if you can remove the light from the car, but you can also polish the lenses with the lights in place if you mask around the edges of the light first. Before you touch the lens with sandpaper, make sure to clean it with a plastic cleaner, like Polyvance’s 1000 Super Prep. Window cleaner or isopropyl alcohol are also good substitutes if you don’t have the professional cleaner.

If there are deep scratches in the lens, like on this one, use 80 grit sandpaper to start. If the lens is not scratched but only cloudy, start with 180 grit sandpaper.

Sand the entire lens with 80 grit sandpaper using a dual action sander. If you don’t have a power sander, you can do it by hand. It’ll just take a little longer.

Most people are surprised by the idea of using a coarse 80 grit sandpaper on a clear plastic headlight lens. It is important to remove all of the surface imperfections on the lens first with the coarse sandpaper, then remove the coarse sand scratches with finer and finer grit sandpaper as you complete the job.

Keep sanding with the coarse sandpaper until all of the scratches and gouges are gone. The lens should look uniformly scratched all over.

After you’re done with the coarse grit, switch to the next finer grit. In our case, we went to 150 grit next. It’s important not to step to too fine of a sandpaper between steps. Here you could use 120 grit, 150, or 180 grit. You do not want to step directly from 80 grit to 400 grit, for example. 400 grit is too fine to remove 80 grit scratches quickly. It’s very important to be able to remove all of the sand scratches from the previous step by using the next finer grade.

After the 150 grit, our next finest grit of paper was 320 grit. You could also go to 220 or 240 grit. Again, make sure you remove all the sand scratches from the previous grit before you move on to the next finer grade.

Grits finer than 320 are normally wet-sanding types of sandpaper. Water helps flush out the plastic particles that might tend to clog the sandpaper, so wet sanding keeps the paper clean and sharp. In this case, we had some 320 grit wet sanding paper, so we used a sanding block to further refine the finish.

After the 320 grit, we went to 400 grit wet sanding. After each stage of sanding, squeegee the lens dry and look closely at the surface. If you see any deeper sand scratches from an earlier stage, go back and remove them now. It’s very important to remove all of the sand scratches from the previous grit before you move on to the next finer grade.

We continued this process by block sanding with six hundred, eight hundred, one thousand, fifteen hundred, and finally two thousand grit sandpaper. At each step we squeegeed off the water and closely inspected the lens to make sure we were removing the sand scratches from the previous stage with the current sandpaper. When you get to the fifteen hundred and two thousand grit sandpapers, the lens will start looking more clear than scratched. Again, this process is not difficult, it just takes time and a little effort.

When you finish sanding with the two thousand grit, apply a coarse polishing compound and polish with a machine or by hand. If using a machine, especially a rotary polisher, be careful not to overheat and burn the plastic. This is a dual action polisher, which is safer than a rotary polisher. If you don’t have a machine, you can do it by hand with a terry cloth towel.

If you have a finer grade of polishing compound, use it next. As you can see, the process of refinishing a headlight lens is simply abrading the plastic with a progressively finer and finer grade of sandpaper or polishing compound until you achieve the result that you want. When you are finished, you should have an appearance that is very close to the new original. You can see the contrast where we started and where we finished. The only difference between these two photos is some effort and the proper sequence and use of the abrasives.

To protect the lens from further UV damage, some companies sell clearcoats you can spray over the polished lens. Despite this, the lens may become cloudy again in the future, but now you know what to do to make it clear again.

Although Polyvance doesn’t have any products to sell you to do headlight polishing, we wanted to share our expertise with you, especially since this process can enhance your nighttime driving safety. Polyvance has been a leader in automotive plastic repair and refinishing since 1981. View Polyvance’s products at www.polyvance.com.

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