Headlight restore - 1) pitting 2) to lacquer or not?

Alan_uk

A2OC Donor
Hi guys. Just restored the NS headlight today as I felt it might be a MOT fail. I only did this about 18 months ago using a headlight restore kit that included a UV protection paste so bit disappointed to doing it again, especially since my mileage has been greatly reduced in recent times.

Here's today's before picture. It was very cloudy in patches.

Ready to restore.jpg


I used 400, 600, 1000, 1200, 2000, 3000 and 5000 wet & dry, alternating from vertical to horizontal between each grade and using a hand spray bottle with water to continuously wet. During the initial 400 the water was coming off a pale yellow colour.

Here's after the 5000 sanding:
After 5000 wet and dry.jpg


And then after polishing cream:
After polishing.jpg


I then switched on the dip and main beams:

Main on.jpg


Eagle eyed will notice some pitting particularly to the left side. I'm convinced this is on the inside of the headlight or within the plastic.

Comments welcome on this pitting and also any views on spraying the headlight with a clear lacquer before the UV paste.
 
It is worth sealing the headlight after sanding. The paste is more to level the surface and balance the finish rather than long term UV, salt, grit, oil etc protection. For that you need to use a UV stabilised lacquer.

Something like this

1600199193744.png
 
Any 2K clear car lacquer will do the job of keeping out the UV and this keep the lense clear. Don’t go too far on the polishing 1200 wee and dry is about right for lacquer any finer and you rush it having no key

Paul


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Thanks guys. I do have some UV paste in the restore kit but it does seem to last. Maybe I didn't use enough or didn't re-apply frequently enough. Originally I did both headlights at the same time but the OS has faired much better than this NS one.

depronman you seem to be suggesting a lacquer also provides UV protection. i.e. need UV paste or lacquer. My reasoning for a lacquer is that it will be more hard wearing.

Bret is correct, the term is crazing and is within the polycarbonate plastic - I found this article
Have to live with it.
 
Thanks guys. I do have some UV paste in the restore kit but it does seem to last. Maybe I didn't use enough or didn't re-apply frequently enough. Originally I did both headlights at the same time but the OS has faired much better than this NS one.

depronman you seem to be suggesting a lacquer also provides UV protection. i.e. need UV paste or lacquer. My reasoning for a lacquer is that it will be more hard wearing.

Bret is correct, the term is crazing and is within the polycarbonate plastic - I found this article
Have to live with it.

Yes use lacquer to provide the up stability
It works on paint was my reading some years ago so should work on the head light lense
I did mind some years ago now and they are still perfectly clear. The lacquer does also provide some protection against wear and stone chipping

Paul


Sent from my iPhone using Tapatalk
 
Hi guys. Just restored the NS headlight today as I felt it might be a MOT fail. I only did this about 18 months ago using a headlight restore kit that included a UV protection paste so bit disappointed to doing it again, especially since my mileage has been greatly reduced in recent times.

Here's today's before picture. It was very cloudy in patches.

View attachment 69951

I used 400, 600, 1000, 1200, 2000, 3000 and 5000 wet & dry, alternating from vertical to horizontal between each grade and using a hand spray bottle with water to continuously wet. During the initial 400 the water was coming off a pale yellow colour.

Here's after the 5000 sanding:
View attachment 69952

And then after polishing cream:
View attachment 69953

I then switched on the dip and main beams:

View attachment 69954

Eagle eyed will notice some pitting particularly to the left side. I'm convinced this is on the inside of the headlight or within the plastic.

Comments welcome on this pitting and also any views on spraying the headlight with a clear lacquer before the UV paste.
Hi Alan,
My splittable headlights have this as well it looks like crazed lacquer internally, but not sure , it may just be dirty interior surface that needs cleaning with glass cleaner etc
Hth
Keith
 
It is worth sealing the headlight after sanding. The paste is more to level the surface and balance the finish rather than long term UV, salt, grit, oil etc protection. For that you need to use a UV stabilised lacquer.

Something like this [E-TECH Restored Headlight Headlamp Protect Clear Coat Lacquer Sealer 200ml]

Out of stock on many websites including the manufacturer but found some on ebay seller ignitionline. £8.99 including delivery for Saturday. Will cut back first using 1000 grit.
 
Be careful that any coating doesn’t change the refraction rating of the lens. This can and has happened, I found this when I looked into it for my video on restoration of lights.



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Personally I'm not a fan of lacquering: it makes it much harder to restore the lights later on as you need to remove it before making progress. I much prefer just to leave them as polished plastic and quickly re-polish every six months or so (which is never as bad as the first time).

I simply go to about 1500 then use G3 in the rotary polisher, then keep waxed thereafter. Simples!
 
Well I can see there are mixed opinions about clear coating. After watching some YT videos I decided to take the plunge and order some E-Tech.

I first sanded down with 800 wet & dry (wet) and cleaned. It of course went cloudy but the YT videos showed that it will go clear after the clear coat is applied. I applied 1 thin coat and and then more and more coats - up to about 6 - as it did not clear. I decided to leave it a few days to harden:

After 800 wet & dry and clear coat.jpg


I was not a happy bunny! I didn't test it at night but I'm sure the light would scatter. I tried to polish but that made matters worse. So in the end I stripped it off start again at 1000 and working up to 5000 plus a lens polish and then a coating of Meguiar's headlight protectant. Took about an hour.

After 2nd restoration without clear coat lr.jpg


Not perfect but hopefully good enough for driving and the MOT. Just need to remember to regularly apply more Meguiar's.
 
From another Audi Forum, it seems that using clear film wrap as protection after refurb is a good idea, protects against stone chips etc, as well as UV. Effect on light output is said to be minimal.
There seems to be availability on ebay.
Similar producta are available under Oraguard, Xpel Ultimate, and Llumar brands.
Simply passing this on, no experience myself.
Mac.
 
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I’ve used 2K car lacquer after 800grit wet to great affect
I think applying the first coat too lightly was were you and wrong. The first coat would need to be a wet coat as it is this coat that makes the ‘glass’ clear. I’ve always done them in the garage off the car and therefore can have them more flat. Plus the 2K lacquer can be applied quiet heavy before it even thinks of running
The problem with aerosol paints is they are over thinned to allow the product to come out of the aerosol and therefore are over probe to running
I hate rattle cans with a passion
I us a small airbrush Hooked up to a compressor for lights wheels small touch ups etc. Works really well and is much easier to clean the gun afterwords with about an egg cup of thinners

Paul


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Thanks guys. I do have some UV paste in the restore kit but it does seem to last. Maybe I didn't use enough or didn't re-apply frequently enough. Originally I did both headlights at the same time but the OS has faired much better than this NS one.
That is probably related to that you park the car so OS headlight is in the shadow while the NS see much more direct sunlight.

BTW: I have never managed to achieve that headlamp restore by polishing to last 18 month... I have 5 off A2s that I serve and have to restore headlamps as a yearly exercise, since 2009, and mine are NOT OK after a year.
I have tried quite a number of compounds though with a much similar result... my chief mechanic have all the time said that I stop before I have reached high enough temperature.
When I noticed this thread I was actually making a jig to hold 4 off A2 lamps and 2 off A6 4F lamps in as horizontal as possible and let "mr airbrush" in my area put on 2K lacquer... it will cost more than doing it my selves, but, he will rework them for free if they degrade within two years...
He instructed me to wet-grind up to 800, starting with 240.

cheers
dieselfan
 
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