Hey Kev.....if they are already yellow they make a restoration kit you can buy to buff them out and make them clear again......also if they are still clear you can buy a plastic lens polish made just for headlights to help keep them clear...Jim
The kits are probably the best, but I have been very successful with micro fine wet and dry sandpaper and rubbing compound, finishing with finer compound. Especially on really bad ones. Just like you would do with a fine paint job. I have done this on ones you can not even see through. They come out perfect, but lots of work.
yeah I understand the reconditioning- sand, polish etc, was wondering if there is a care product ie we all spray an armorall on dash - just thinking those car washes have got to be harsh on that clear plastic - remember vinyl tops ? without care they were degraded quickly-
My shop installed thousands of vinyl tops for 13 years. One of my competitors would not guarantee them if you used Armorall. He thought it decreased the life of the vinyl. I recommended just keep it clean and out of the sun as much as possible.
I do not know of a product that protects plastic, although there are plenty that claim to.
I think it's UV radiation (don't know if UVA or UVB, or both) that kills plastic. The best protection is an internal coloring or external paint that stops the UV at the surface of the part, leaving the bulk of it unaffected. Trouble is, of course, that the light you want to get through (for lighting) is also stopped. It makes me wonder why there isn't a market growing for replacement lenses made of glass. Retractable headlamps assemblies probably helps, but more expensive, heavier, and troublesome.
Very best vehicle lighting system I have for seeing on dark roads at night is using that four rectangular system like on my 82 motorhome. Halogens cost six bucks each, if a stone hits one, out six bucks, no frosting problems, use glass. Each head lamp can be adjusted individually in both the horizontal and vertical axis to optimize each setting.
With these newer vehicles, back to the light bulb, can pay as much as 23 bucks for a bulb for extra brightness, but would be lucky to get two months use out of it. With a single bulb, dims and brights have to be compromised, set the dims a tad bit too high, and the brights are going into outer space. Then most vehicles only have the vertical adjustment and those plastic way overpriced pieces of crap will frost up. And swear I need a guy swinging a whale oil lamp walking in front of me so I can see where I am going.
Not really concerned about getting every small scratch out, to do so, have to start off with 600 grit and work up to 2,500 with wet sanding then polish and polish. So just use Turtle wax polishing compound, very wet with a high speed buffing wheel, and very low pressure. Only takes a few minutes,
Other major problem with these things is moisture, just the tiniest crack or split where the clear lens is suppose to make contact with a perfectly welded seal. When the bulb heats up, causes expansion, this is okay, but when it cools, creates a vacuum and sucks in moisture. Normally can cure this with epoxy after a good cleaning around that bead. Or run up my credit card bill, but no choice if a stone hits it, has to be replaced.
Do they really call this improvements? But these plastic head lamps look cool in the showroom, maybe they should stay there.
I believe plastic headlamps are vented. Under some conditions, moisture gets in there, but later drys up. A little leakage elsewhere would not matter much if they put the vents at the bottom, but they don't, so the water collects faster than it can dry. I have saved many a leaky headlamp by merely drilling a drain hole at the bottom.
I polished the cataracts out of our Corolla's lamps with Nu-Finish. It's a Cleaner/Polish, orange-colored bottle. Something else might have cut faster, but NuF got it done. Probably 15 mics per lamp the first time I did it. Now they need a touch-up every six months or so. I understand the plastic has a coating that slows the clouding down and once it's gone they'll cloud again sooner. Some of the kits have a finish coat that's supposed to buy more time. I have a bright friend who says applying "303 Protectant" helps a lot to keep them fresh.