Hey guys me and my gf cars both have the yellowing lens problem on our headlights, I took mine apart to paint the housing and cleaned and sanded the lens before I put it back together but it keeps coming back, can I just buy 4 new lens covers or do I have to buy 4 new headlights? Thanks for the help guys

 

perhaps putting clear protective film after restoring them again might be a better solution.
And if that still fails, THEN look into new lens/headlights

 

The protective measures help though only for so long. The eventuality is that the lenses will need to be replaced.

 

By cleaning and sanding them you've removed any form of UV protection. Take it to a shop and have them spray a new coating of UV clearcoat after you clean them. I read that it should last about 5+ years.

 

you sanded the outside, not the inside, right?

Right now, you don't have to replace the headlight if you're willing to polish the headlights every 2 months with rubbing compound.

lexus doesn't sell just the headlight lens.

spraying a clear coat might cut down on the clarity of the lens, especially if there's orange peel.

Our headlights won't last in the california sun.

 

This is the big downside to plastic/polycarbonate headlights. They yellow after a while from exposure to sunlight. Once they yellow your protective barrier has deteriorated. Only thing you can really do is wet sand polish, put some sealant on them and repeat every few months or spend a ton of money on a new set of headlights. I tried Opti Coat Headlight sealant and it does not work either. Normal clearcoats won't last in the sunlight not to mention certain chemicals like gasoline will cause a bad reaction/them to fail. Only thing that might work better is a 2K clear sprayed on them but I think you would need some other kind of pre spray on them so the 2K bonds to the surface properly.

 

and that 2k combined with adhesion promoter will cut the light output if you can't get it glass smooth

When I bought my 07, I knew the headlights would yellow, so I waxed it frequently since day 1. Apparently it wasn't enough.
These days I just polish (no sanding) and wax as necessary.

 

Look into Optimum Opti-Lens. It's expensive at $70, but you occasionally you can find them on sale with coupons. It goes on thin and is 'invisible'. Most UV sprays and clear coat will leave a film that affects light output. With Opti-lens, you can't even tell it's there.

My Lexus headlights use to yellow two weeks after I polish them (wetsand but never protected). It's been months with lots of Southern California UV exposures, and my headlights haven't yellowed. By the way, the opti-lens kit should be enough for multiple car applications. Since you've stripped all of the UV protection on your headlights, you might need 2 or more coatings.

 

I have tried it, waste of money. Does not last more then a few months, not really any longer then a good sealant. I have applied it 3 times to freshly polished headlights putting on 2 or 3 coats with the same results..

 

How long ago since you've applied it, and how did you prep the lens? I've done at least 10 cars, with the oldest one being 2 years, and they haven't yellowed.

 

So it seems like some have good experiences with Opti-lens and others not?

Clear coating after wet sanding is not guaranteed either for fear of orange peeling.

So what are we left with? Applying UV film and ultimately new OEM replacements?

 

A lot of problems people are having with opti-lens is the result of prep work. After wetsanding with fine sandpaper, you would use a polish to get it looking clear again. What most don't realize is that the polish contains oil, and as long as there is something between the plastic lense and opti-lens, durability will be an issue. You need to remove all traces of oil/contaminants, and you don't remove that by taking a towel and wiping it day. Even car soap will leave some sort of residue behind.

I've had 3 instances where someone came to me because opti-lens (they applied it) didn't last more than a month. I started fresh and removed everything on the lens and re-applied the coating. I see these cars once every couple of months and they are still free from oxidation.

 

I've seen optilens long term tested in hawaii on another forum, and it appears to work well.

I just can't justify spending $70 on something I will rarely use. I wish they sold it in smaller sizes.
If optilens lasts a long time, then why would I need 10 applications' worth of it?

Right now, a quick polish with my DA polisher isn't much trouble, so I stick to that and wax

 

Because you can use it on multiple cars. Imagine if they sold enough just for 1 set of headlights. Package would be a nightmare because all you need is approximately 0.5cc per headlight.

If you don't mind using a polisher and wax, then keep on going.

 

well then 4 or 5cc and half the price, and I would consider buying.

I would say most people only have 2 cars.