Headlight cover yellowing

Hi,

what do people do to prevent the headlight covers from gradually “yellowing” ? Is there anything I can apply?

My previous car’s (2012 GT86) headlight covers started looking yellowish after 8 years or so.

Ben

If you are feeling brave, try this to restore them before adding any lacquer or protection.

https://www.amazon.co.uk/3M-39008-Headlight-Restoration-System/dp/B001AIZ5HY/ref=sr_1_9?crid=376QCQ85FBQLV&dib=eyJ2IjoiMSJ9.t_KyMDLQdOiJttGtiRolI7plHhIdWBXVp33OfX7-3_nwdrLqL0CwuzPrV5TYHIXKQZ6Sko6gadb02OTqJv_kqCqJ4VpQzdwKRlm5MSv4NJZVS-ZjaGu4e0B85o3ut3-G0h-QDLTOVilQ8kI0UKNaI4E5CgksALT28r8scw8P78icWtlbpmauR52BV9tPpkv_M28VTrUQtmmkqQGOCK3igMbEYpe_e7aPKLEGr01C_MAb3vPnucGCEEpFpQZJJ4ZZhjso_9drpb51COOiz5w-IXZGwkCo4wxw5YtRVIHHmDA.RMtdSD4VmuDaRxhsevVYE8V60l6pjnYfj592YsSIROw&dib_tag=se&keywords=3m%2Bheadlight%2Brestoration%2Bkit&qid=1719136193&sprefix=3m%2Bheadlight%2Caps%2C81&sr=8-9&th=1

I had a birdy !Removed! on top of one unit, it "ate" (not the bird, the poopy) into the plastic. Although not on the front lens it did look unsightly.

I bought from an eBay seller and didn't pay Amazon's inflated price.

That 3m kit did the trick. There is a very useful Youtube video of it being used. I haven't followed up with any u.v. protection.

Why does that stupid filter accept poopy and not that without the y? Absolutely illogical and ridiculous! Must be set up by a 12 year old?

5 hours ago, benchan said:

Hi,

 

what do people do to prevent the headlight covers from gradually “yellowing” ? Is there anything I can apply?

My previous car’s (2012 GT86) headlight covers started looking yellowish after 8 years or so.

 

Ben

I did my previous Prius headlights every year just before the MOT using a product called Peak.  It’s a kind of metal polish but works a treat for yellow headlights 

After I’d polished them with Peak I then applied any polish or wax I had to hand to seal them 

I did use to do them using a machine but found doing them by hand with Peak far easier and the end result was always amazing and it brings them up like brand new with not that much effort 

You could probably get away with using something like T-Cut or even toothpaste at a pinch but the best I ever used was Peak polish 

Try Toothpaste 

7 minutes ago, Tommy X said:

Try Toothpaste 

Absolutely that will do if you have nothing else to hand

3 hours ago, Tommy X said:

Try Toothpaste 

Good suggestion, that worked well on my old car

These headlights restoration kits works wonders but you need to use wipes or clear coat to protect the new shiny lenses. I did mine last year but didn’t use wipes and they have become yellow again. Will do them again this year and use the wipes with too coat,. 

Fine grinding paste. Put it on like you would T Cut. Lasts about 3 months then you do it again. Toothpaste does work (it's that grinding effect) but doesn't last as long. Though spiders will give your lights a wide berth...

Alex

The reason they yellow is they're made from polycarbonate plastic, which reacts with UV light over time and causes the yellowing.

Normally they are coated with something to block the UV, but it gets worn off over time.

You can polish off the clouded layer, but you really need to put the UV-blocking coat back on as soon as possible or the sun will started to make it yellow and it'll be even faster because there's nothing protecting the polycarbonate.

It's one reason all eye-glasses come with high-strength UV protection for 'free' nowadays - they don't  just do it for your benefit; It's to stop your specs going cloudy within a few months of daytime exposure because almost all the lenses are made of optical-grade polycarbonate!

54 minutes ago, TonyHSD said:

These headlights restoration kits works wonders but you need to use wipes or clear coat to protect the new shiny lenses. I did mine last year but didn’t use wipes and they have become yellow again. Will do them again this year and use the wipes with too coat,. 

Surely its a chemical reaction with the uv over time. Therefore all you are doing is scraping off the top affected layer.