I just got done cleaning a set of used headlights. I'm going to do the same procedure on my old ones that are yellow and nasty.
Here are some pics, and then I'll tell you how I did it. It's pretty involved.
Pics are so-so....I'll try to get pics of them on the car.
![Image](http://www.main.experiencetherave.com:8080/subaru/images/newheadlight1.jpg)
![Image](http://www.main.experiencetherave.com:8080/subaru/images/newheadlight2.jpg)
![Image](http://www.main.experiencetherave.com:8080/subaru/images/newheadlight3.jpg)
Things you will need.
320, 400, 600 wet/dry sand paper
Clear coat spray paint
acetone (optional)
A guy at a body shop told me about this. If I sand the lenses down and clear coat them, it would protect them from yellowing. He said I'd probably have to do it every so often....but I don't think he thought I'd go to the steps I did to remove the existing yellow.
I'm going to explain everything and then throw in the optional step.
You basically start with the 320 sand paper or 400, depending on how oxidized the lights are. Do this wet.....so the sand paper doesn't completely chew up the lenses. I did mine in my sink...hahaha.
Sand things down and smooth as you can with that grit, and then move to the next highest grit. Like I said, I did this using water for all grits.
Once I was satisfied with things I then cleaned them up, and prepped them to be clear coated. I was talking to my body shop guy and I was asking about what causes "orange peel" in paint, because I got a decent batch of it on the one light. I re-did it. What he said was it is caused by drying time, and how well the paint flows. So with that in mind, I would think that the paint would dry slower in colder weather, and therefore would have less chance to orange peel. I did one light coat, and then a heavy one. The clear coat seemed to be sucked up and looked better the longer I let it set.
Now for the optional part. Some point along my work, I ended up using acetone on one of the lenses.....well acetone is a solvant and it sorta ate the plastic.......but what it was eating was the yellow oxidation......so I kept using it until I got no more yellow on the paper towel. The only problem is that it leaves a nasty mess on the lense, and you need to really work at sanding and getting rid of it. Which was why I went with 320 grit sand paper.
It is definitely more work to use the acetone, but the results and chances of yellowing are probably slimmer.
When I get around to doing my other lights, I'll do a before and after pic.