tl; dr version: Numerous attempts to restore clear plastic headlight lenses to like-new finish result in massive fail. About to commit suicide.
So the story started when I took apart a BMW 6 series headlight that had developed a crack leading to condensation inside the headlight. The headlight was leaking badly and all sorts of sand/condensation gathered up inside. We sealed the leak (luckily in the headlight housing, not the clear lens) and while we were at it, we decided to clean the headlight thoroughly. Unfortunately, my friend decided to clean the plastic headlight lens with car wash soap, thinking it would be safe for the clear finish. To my surprise, the plastic developed some nasty water spots from the inside and became quite hazy. Well, we were going to sand down the headlight to remove the oxidation and yellowing anyways, so I didn't think that removing the haziness was going to be a challenge. Boy was I wrong...
I started the process to remove yellowing, oxidation, and pitting from both sides of the headlight's plastic lens, since I had the headlight completely dissembled at this point. I dry sanded the headlight with 320 grit sandpaper, and then proceeded to 500 grit. After that, I wet sanded all the way from 800 to 1000, 1500, 3000. I kept checking the progress taking my time between all these steps, both inside and outside surfaces of the plastic lens was smooth, but we still had haziness and light swirl marks (the swirl marks are only visible in direct light).
After I finished sanding, I applied some Meguiar's 105 cutting compound, with a Griot's Garage 3" Random Orbital polisher set on high-speed (5-6) and then some 205 compound also set on high-speed. All sanding/polishing was done with the polisher. Low speeds were used for sanding, high-speeds were used for polishing. Pressure used throughout all the steps was medium pressure. I am cleaning after each sanding process and taking my time to remove all previous scratches I could notice.
My issue: The headlight still looks like crap. The yellowness and extreme haziness is definitely gone. But the headlight now has some sort of slight haziness all over it. Like condensation just starting to build up. The plastic is NOT 100% clear and has a lot of swirl marks the moment you shine some light on it. Most of the big scratches from road debris are gone. A side by side comparison with a "good" headlight from the same car, shows what I mean (see picture below). I repeated the process 4 times on both sides (which equals 8 times). I researched thoroughly, and I took my time sanding over and over again, but the result only marginally got better.
Product & Equipment Used:
* Griot's Garage 3" Random Orbital Polisher
* 3M 3" sandpaper discs (grits: 320, 500, 800, 1000, 1500, and 3000)
* Meguiar's 105 and 205 compounds
* Meguiar's PlastX
* Buffing & polishing pads
So the story started when I took apart a BMW 6 series headlight that had developed a crack leading to condensation inside the headlight. The headlight was leaking badly and all sorts of sand/condensation gathered up inside. We sealed the leak (luckily in the headlight housing, not the clear lens) and while we were at it, we decided to clean the headlight thoroughly. Unfortunately, my friend decided to clean the plastic headlight lens with car wash soap, thinking it would be safe for the clear finish. To my surprise, the plastic developed some nasty water spots from the inside and became quite hazy. Well, we were going to sand down the headlight to remove the oxidation and yellowing anyways, so I didn't think that removing the haziness was going to be a challenge. Boy was I wrong...
I started the process to remove yellowing, oxidation, and pitting from both sides of the headlight's plastic lens, since I had the headlight completely dissembled at this point. I dry sanded the headlight with 320 grit sandpaper, and then proceeded to 500 grit. After that, I wet sanded all the way from 800 to 1000, 1500, 3000. I kept checking the progress taking my time between all these steps, both inside and outside surfaces of the plastic lens was smooth, but we still had haziness and light swirl marks (the swirl marks are only visible in direct light).
After I finished sanding, I applied some Meguiar's 105 cutting compound, with a Griot's Garage 3" Random Orbital polisher set on high-speed (5-6) and then some 205 compound also set on high-speed. All sanding/polishing was done with the polisher. Low speeds were used for sanding, high-speeds were used for polishing. Pressure used throughout all the steps was medium pressure. I am cleaning after each sanding process and taking my time to remove all previous scratches I could notice.
My issue: The headlight still looks like crap. The yellowness and extreme haziness is definitely gone. But the headlight now has some sort of slight haziness all over it. Like condensation just starting to build up. The plastic is NOT 100% clear and has a lot of swirl marks the moment you shine some light on it. Most of the big scratches from road debris are gone. A side by side comparison with a "good" headlight from the same car, shows what I mean (see picture below). I repeated the process 4 times on both sides (which equals 8 times). I researched thoroughly, and I took my time sanding over and over again, but the result only marginally got better.
Product & Equipment Used:
* Griot's Garage 3" Random Orbital Polisher
* 3M 3" sandpaper discs (grits: 320, 500, 800, 1000, 1500, and 3000)
* Meguiar's 105 and 205 compounds
* Meguiar's PlastX
* Buffing & polishing pads
