Headlight restoration ?

[java]

Do you have to sand the whole headlight lens or just the yellow/oxidize area before using opti-lens? The other part of the lens is in excellent shape, only the top part is starting to yellow out and can I apply right over the spot that are in great shape without sanding? I'm not sure if the yellowing could buff out without sanding.

[Setec Astronomy]

It's going to kind of depend. Yes, you can polish off the yellow depending how deep it goes. Sometimes there is a demarcation line between where the coating is good, and where it is bad, and sometimes that line has some really hard old coating that needs to be sanded. If you have what appears to be a smooth transition, then by all means try polishing the top part and see how it looks before moving to sanding.

And yes, you can just go over the good existing coating with Opti-Lens.

[dcjredline]

DP Headlight restoring polish...that is all that needs to be said. Search that or look at the product page.

The general consensus here on the forum is "least aggressive method first"

[java]

It's going to kind of depend. Yes, you can polish off the yellow depending how deep it goes. Sometimes there is a demarcation line between where the coating is good, and where it is bad, and sometimes that line has some really hard old coating that needs to be sanded. If you have what appears to be a smooth transition, then by all means try polishing the top part and see how it looks before moving to sanding.

And yes, you can just go over the good existing coating with Opti-Lens.

After polishing, how can you tell if the yellowing is completely remove? I have Gtechniq panel wipe to wipe any polishing oil off but not sure if panel wipe can be used on clear plastic.

[java]

Thanks for the replies guys!

[Setec Astronomy]

After polishing, how can you tell if the yellowing is completely remove?

Um...it won't be yellow anymore? I guess you need to look at it under the right lighting, I usually do it outside, but if you use a daylight bulb or a real white LED flashlight you should be able to tell if the yellow is gone.

[java]

Um...it won't be yellow anymore? I guess you need to look at it under the right lighting, I usually do it outside, but if you use a daylight bulb or a real white LED flashlight you should be able to tell if the yellow is gone.

On a different car I compound the lens and it look good and clear but when it got wet you will see the yellow back and then when it dried up yellow was gone. It was hard to see in direct sunlight if the yellow was gone.

[Setec Astronomy]

On a different car I compound the lens and it look good and clear but when it got wet you will see the yellow back and then when it dried up yellow was gone. It was hard to see in direct sunlight if the yellow was gone.

Well, sounds like you need to get it wet after compounding and see if it looks yellow.

[java]

Well, sounds like you need to get it wet after compounding and see if it looks yellow.

That car has been trading in already, but it was a learning experience. My 1st generation Porter Cable 7424 was that good at cleaning up the yellow bogs down to easy. Right now I'm gathering info and supply for when temperature warm up a bit I can tackle it. Thanks for the advise!

[java]

Forget to mention if you got any advice or tips please share. Thanks