Polycarbonate outer lenes v glass

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Railwayman

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My car is of an age where yearly cleaning/ polishing of the head lights is required to counter UV light damage. Who like me would prefer glass, yes much more fragile and prone to stone damage but as long as the design incorporated easy replacement of the glass only, I for one would be inclined to go for that. Thoughts?
 
Remove headlamp unit. Wet and dry (wet) with 600 down to 1200 grit to remove all yellowing. The scratching and scuffing left by the 1200 is not an issue and will fill with 'paint'. Buy a 2K can of clear coat from Amazon (provides robust UV protection and longevity). Mask up the headlight except for the polycarbonate. Give 2 or 3 coats. Problem solved for next circa 10 years.
 
Remove headlamp unit. Wet and dry (wet) with 600 down to 1200 grit to remove all yellowing. The scratching and scuffing left by the 1200 is not an issue and will fill with 'paint'. Buy a 2K can of clear coat from Amazon (provides robust UV protection and longevity). Mask up the headlight except for the polycarbonate. Give 2 or 3 coats. Problem solved for next circa 10 years.
I used this last year on daughter Mini. Worked a treat.

Holts HREP0031A Headlight Restoration Kit Restore Clarity in Cloudy Yellowing & Oxidized Headlamps to Like-New Condition, Easy to use Drill Attachment Repairs Restores & Protects https://amzn.eu/d/gELh96c
 
Who like me would prefer glass, yes much more fragile and prone to stone damage but as long as the design incorporated easy replacement of the glass only, I for one would be inclined to go for that. Thoughts?
Glass will never be used again for two reasons, polycarbonate is cheaper and saves weight, plus it will not interfere negatively with pedestrian crash test results.
 
Buy a 2K can of clear coat from Amazon (provides robust UV protection and longevity)
Just to mention you need a proper mask for spraying 2K paint (they contain isocyanates) :)
 
Glass will never be used again for two reasons, polycarbonate is cheaper and saves weight, plus it will not interfere negatively with pedestrian crash test results.
Glass headlight are not legal in the UK on any car introduced to the market after about 1995....I can't remember the exact date... but it was somewhere around then.
 
Glass headlight are not legal in the UK on any car introduced to the market after about 1995....I can't remember the exact date... but it was somewhere around then.
Not sure how relevant it is but you can pass an IVA test with glasses lenses.
 
I think that the issue that the OP describes isn't really about glass Vs plastic as such, instead the actual issue is that glass lenses can be replaced independently of the headlamp body, while the plastic ones are usually integrated with the headlamp. In other words, if the plastic lenses could be easily and cheaply replaced, then this would have resolved the OP's issue. The paradoxical fact here is that the independent glass lenses rarely need replacing due to normal wear and tear, but the integrated plastic ones do deteriorate over time....
 
They can be easily be polished back to clear though....This does of course remove all the factory UV protection which means they will yellow much faster next time. You need to spray them with clear UV resistant lacquer after polishing and then they will last years. If you don't you will be polishing them every few months after the first time.
 
Yes have wet sanded the lenes a few times over the years and used various anti UV light coatings (will try the Amazon one recommended above) to no lasting effect, but the point markjay makes is what maybe I'm alluding to, polycarbonate lenes that could be replaced as opposed to the whole unit would be nice. The right to repair movement happing in the USA is gaining momentum, would it not be good to have items that are more modular and accessible as opposed to the purposely built in obsolescence we have now, looking at you Apple and many others.
 
Yes have wet sanded the lenes a few times over the years and used various anti UV light coatings (will try the Amazon one recommended above) to no lasting effect, but the point markjay makes is what maybe I'm alluding to, polycarbonate lenes that could be replaced as opposed to the whole unit would be nice. The right to repair movement happing in the USA is gaining momentum, would it not be good to have items that are more modular and accessible as opposed to the purposely built in obsolescence we have now, looking at you Apple and many others.
The "right to repair" mob don't understand how much money these complex units save

Open up a 1970's car, telly or radio and you'll see all the glorious, hand-assembled complexity of the construction.

You can build a mobile with replaceable parts, but not with the same reliability and low cost. Modern vehicles cost peanuts compared to their predecessors, and it's all because components are made in absurd volumes by outsourced volume suppliers who know exactly how to shave cost out of components - from headlights to steering wheels.

(And the brilliant news is that it's easier to source and recycle parts than it's ever been, thanks to the Interweb and PC inventory systems. No more climbing over cars down at Silverlake)

The solution to the headlight problem, as with paintwork, is to clean, polish and refinish, and then to apply a protective coat to seal the finish.
 
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Whilst you make some valid points I suspect the main reason is manufactures would much rather you buy new than repair £££££££££££££££
 
....The right to repair movement happing in the USA is gaining momentum, would it not be good to have items that are more modular and accessible as opposed to the purposely built in obsolescence we have now, looking at you Apple and many others.


This is how it's done;) :

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I think that the issue that the OP describes isn't really about glass Vs plastic as such, instead the actual issue is that glass lenses can be replaced independently of the headlamp body, while the plastic ones are usually integrated with the headlamp.

I had a Vauxhall where the plastic lens was a separate piece ... I know this because one of them fell off :D I found it in the road (undamaged) and bonded it back on again.
 
Currently doing battle with a de-humidifier, 90p micro switch faulty, buried deep in its innards that I cannot access, bloody case glued together, cost £80 13 months ago. Now where did I put that Dremel ..............
 

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