Head light lenses

bdeuce22

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Jul 16, 2011
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I've tried the cheap stuff & I even went & purchased the $30 McGuires kit. But this lense "buffing" is either a short term fix or I'm doing it wrong. I'm just going to replace the light assemblies.
Any suggestions?
As always thanks
 

Alaric Darconville

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I've tried the cheap stuff & I even went & purchased the $30 McGuires kit. But this lense "buffing" is either a short term fix or I'm doing it wrong. I'm just going to replace the light assemblies.
Any suggestions?
As always thanks

The kit from DoubleHorn Products may get you a bit further, as it includes a spray to recoat the lenses, but that is still not a permanent fix.

See this article on allpar.com: http://www.allpar.com/fix/headlights.html
Also, the thread about my own experience with it here: http://www.candlepowerforums.com/vb/showthread.php?266292-Polish-those-headlights!-(Pic-heavy)

Wish it'd stayed looking like this pic after it was done!
009-lh-sprayed.jpg



We don't know what vehicle you have, but that is almost immaterial. Do not get "aftermarket" or "OE-style" lamp assemblies- get a genuine factory part from the/a dealership. Make sure they warrant that the products are new, genuine OEM [your make or model here] assemblies.
 
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-Virgil-

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I had high hopes for the Doublehorn kit because of the specific hardcoat it includes, but while it gives good short-term results, the benefit doesn't last. There is just nothing you can apply in the field that adequately replaces the factory-applied (in a cleanroom, then heat or UV cured) hardcoat. With any polishing kit or technique, the best you can do is forestall the day when you must buy new headlamps. When that day arrives, be sure to get genuine original-equipment headlamps from either the automaker's dealer or the maker of the original headlamps (e.g., a headlamp in a Hella or BMW box). The aftermarket headlamps are virtually all unsafe dreck.
 

-Virgil-

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"CAPA certification" means less than nothing. It's a marketing program designed primarily to market inferior parts to the auto repair and insurance industry. Aftermarket headlamps are junk -- the only exception is headlamps made by legitimate OEMs, that is, the companies that supply headlamps to the automakers. See http://www.capacertified.org/press/CAPALighting3.pdf , which is writeup of a large US DOT test of OE versus "CAPA certified" aftermarket headlamps. Epic fail for the aftermarket units (see pp 21 and 30 in particular). I am not sure what strategic goal CAPA thinks they are furthering by proudly hosting a writeup that clearly demonstrates their "certification" is toilet paper, but perhaps the fact that they do so shows how thoughtful (or not) the CAPA outfit is overall.
 

bshanahan14rulz

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I bought OEM replacemnt style headlamps just for the clear covers, figuring the clear covers don't have any beam-changing attributes, and it's much clearer, I'll just pop it on the old OEM back and re-butyl it. These things are MUCH MUCH LESS resistant to UV than the OEMs. Within a year they looked about 8 years old. yellowing, looked like crackled glass, which is nice for a wineglass or decorative platter. For a lens, not so much.

So, what kind of a coating exactly, is the coating that the OEMs use? Some magical substance that protects the plastic physically against road debris, protects against UV, and can withstand the temperatures that a halogen lamp spits at it? Or is it a combination of the coating along with a certain type of clear plastic?
 

-Virgil-

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It's any of several approved coatings on any of several approved polycarbonate materials. Coatings are approved for use on particular materials; one can't just select any approved polycarbonate and coat it with any approved coating. This list of approvals is maintained by AMECA. This system kind of breaks the firmly-held party line that North America doesn't have type approval. Fact is, you have to submit your material and coating to this agency and without their approval it's not legal to use, so if that's not type-approval, what is it? The US (SAE) tests for plastic materials take between 3 and 6 years because the test chips have to be left outside in Florida and in Arizona for 3 years, after which they're allowed no more than 30%(!) haze. That is a slow test with a lax "pass" bar, if you ask me. The rest of world (ECE) test is much faster; it involves the use of an electric arc lamp without a UV shield to rapidly age the material, so the test takes days instead of years. The "pass" bar isn't necessarily strict enough on that test, but at least it allows the latest up-to-date materials and coatings on the market. With the US test, the newest materials allowed on the market are at least 3 years behind the state of the art.

The coatings themselves incorporate physical protection against abrasion and optical protection against UV degradation. They're usually an engineered polymer applied under clean-room conditions and then cured (crosslinked) by UV or heat. Definitely not something that can be sprayed, brushed, or rubbed on in the driveway, garage, or paint booth.

Of course, the aftermarket headlamp manufacturers don't feel any qualm about bogus DOT and SAE or E-markings on their products, so they certainly don't care about compliant materials. Whatever clear plastic they can get the cheapest that won't immediately melt is what gets used.
 

Alaric Darconville

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I bought OEM replacemnt style headlamps just for the clear covers, figuring the clear covers don't have any beam-changing attributes, and it's much clearer, I'll just pop it on the old OEM back and re-butyl it. These things are MUCH MUCH LESS resistant to UV than the OEMs. Within a year they looked about 8 years old. yellowing, looked like crackled glass, which is nice for a wineglass or decorative platter. For a lens, not so much.

Interesting. I had the same idea, myself -- but figured the whole relensing process would have been quite a pain. Knowing this makes it sound like an even worse idea. (Besides, even buying the "OE-style" lamps just for the lenses would have given money to the makers of such a craptastic, noncompliant product.)
 

ray6

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Apr 23, 2012
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I've tried the cheap stuff & I even went & purchased the $30 McGuires kit. But this lense "buffing" is either a short term fix or I'm doing it wrong. I'm just going to replace the light assemblies.
Any suggestions?
As always thanks

Having headlights restored is a viable option. When done by a pro, they will look like new if restorable. The DIY kits are crap. They don't contain the proper tools and materials that pros use. A pro job should cost less than $60 in most areas and won't have to be aimed. If you do replace, go OEM. Stay away from Chinese imports. They have a history of poor fit and quality and many will leak after time.
ray6
 

Alaric Darconville

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When done by a pro, they will look like new if restorable.
And only look that way about 3-6 months, depending on where the car is driven and parked. Once the lens is all buffed out and shiny and nice, there's no more protection left-- and the sprays, creams, cremes, crèmes, waxes, liquids, gels, poultices, and the like that are ostensibly designed to keep them looking new don't really work that well.

This was all covered in the thread in December 2011.
 

bshanahan14rulz

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Ray6,
Your posts have me intrigued. Be sure to let us know your progress with your development of headlight re-finishing and protection product. We'd all like to see a product that protects against UV comparably to the OEM hardcoat. It would simply be icing on the cake if it could be packaged into a non-crap DIY kit ;-)

Also, as Alaric Darconville mentioned, there is a previous thread about another well-known headlight restoration product on the forums here, it ought to have some useful info for you to peruse.
 

-Virgil-

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Having headlights restored is a viable option.

No, it really is not. All you can do -- whether you're working in the driveway with a DIY kit or having a "professional" do it for you -- is postpone the need to replace the lamps. Polishing by any means removes the anti-UV hard coating from the lens, and there is no field-applicable coating or other substance that can effectively replace it. Once the original hard coat has been polished off, UV will attack the polycarbonate itself; each subsequent polish job will be less effective and last a shorter time.
 

2000mc

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Sep 13, 2010
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the problem with the meguiar's kit is that its only good for the finishing step, not nearly aggressive enough on real cloudy lights. i think the 3m kit you can get at walmart works well, only tool you need is a drill.
of course its not as good as new lights, but if you dont want to buy new oem assemblies, i think its the next best option. new oem lights would probably cost half the value of my car. the finish might not last as long, but you can always redo it, and it would take years in between refinishing for my lights to get as bad as they were before the first time i refinished them.
 
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