why dont the turn signal lamps on cars where its seperate from the headlight never oxidize?

 

because they don't put out the same amount of heat as the headlamps and aren't subjected to a lot of road debris and as much sun.

 

^^so ur saying oxidation is a result from heat from inside the housing? cus the turn signal housing and headlight housing on cars are subject to the same enviromental conditions

 

Heat generated from the bulbs isn't the only factor but does contribute to acceleration of damage. Your headlight bulbs put out a lot more heat than the taillights and turn signals and the plastic expands as the temp goes up. I restored some lights on a Chrysler Crossfire with some very nice projectors. The projectors in the position furthest out were also a lot closer to the lens. Once I started sanding, you could see it was starting to craze in the area with smallest distance (from the lens and projector). Polycarbonate is very prone to damage from high temps. Also, look at the position the headlights are in compared to the other lenses. They not only face forward but up as well. Sidemarkers are angled and off to the side. Tail lights are.... well, you get the point. The h/l lenses take most of the debris (mud, dirt, pollen, bugs, salt, rocks, tar, etc) then the heat opens up the surface (like pores) and all this stuff gets baked in there, especially where the debris has chipped a away the shiny protective UV layer. The sun also starts to fade the top surface of the plastic much like anything else you leave out for weeks or months. Because of the headlight's position, it gets to work on its tan a lot longer than the other lenses. As plastic fades and ages, it turns yellow or foggy. The other lenses see some of this damage as well but on a much smaller scale. Look at some old Chevy Suburbans/Tahoes and you'll see the tail lights or marker lights are also dull. Keep in mind it takes years for this damage to finally show up so during the car wash, you may not catch the gradual changes until it's too late and I'm handing you my business card.

 

If you wish to bring back the clarity of your headlight covers the 3M Headlight Restoration Kit will do exactly that, just like new better than any other process/kit on the market....
Gary

 

looks good. anyone try this with a polisher?

 

I used a product called Brite Shine (comes in a yellow tin have had it for years) to take off the bulk, then used Meguirs PlastX to finish it off. In the pic I had done the drivers side with the Brite Shine only (at that stage I didn't have the PlastX).

 

I just use a little ClearKote Vanilla Moose Hand Glaze and some muscle. Pretty much back to new. I have a 3M kit that I'll use if the yellow haze returns.

 

I found that Meguiars ultimate compound works really nice with a light use of a buffer. I wish I took pictures but it's used to get swirls out of paint but on the back I read that it makes rubbing compounds obsolete so I decided to try it out n it did a great job.