Headlight Crazing. DIY Fix

[Withy]

I've had crazing on front lights for a while, and been looking at previous posts about companies who fix, and also the hundreds of videos on YouTube of how to do it with grades of wet sanding, then coating.  So I decided to have a go myself, and it's a bit of a journey!

First of all, here is the state they were in.  Passenger side worst with a crazing section all down one side.  Drivers side not so bad, but still annoying patches of crazing

Passenger side

Drivers Side:

First step, use the toolkit supplied tool to remove the lights - really straightforward, unclip the wiring harness and take out of the car.

Now the fun (not) starts.  It's really strange to use fairly rough sandpaper on very expensive lights, but I went with 240 Grit to start, soaking the sandpaper, and spraying the lens thoroughly so keep things lubricated.  Goes a really horrible milky residue as the oxidised cr@p comes off

 

It looks quite scary at this point.. like you've ruined your headlights, but watching lots of guidance, the process is to use gradually finer and finer grit sandpaper so that each change of grit helps smooth out the scratches from the previous.  I went 240->320->600->800->1000->1200->1500->2000->3000->5000 using each possible one from the pack I'd bought from Amazon.

At the end of this, it's an interesting change - basically the crazing has gone, but so has so has some of the clarity through the plastic lens, so it's still a bit disappointing.

Most of the other Youtube videos say that the clarity comes back with the clear coat, so I wasn't too worried, and after some research, landed on some 2k Clearcoat which was pricey, but seemed to have good reviews https://www.amazon.co.uk/dp/B004AHH12E

This is where the journey took some interesting turns, the summary is;

 - My skills on applying personal based clear coat are clearly rubbish.  both lights had a horrible orange peel effect, and when spraying the odd drip occurred from the can, and it was just awful looking.  I did think maybe an additional coat or drying time would help but after an overnight, I conceded that I had to do the sanding again to get rid of the newly applied clear coat.  Bugger.
 

- Next was some 3M clear coat wipes.  No pics here, but it was awful.  Streaky, uneven and completely horrible. Do-over, and sanding again to remove the horrid 3M wipe smeary residue.  800Grit through all grades to 5000 again to get back to smoothish, but low clarity

- Then I thought ok, time to look at ready made kits, and Meguiars do a kit which has some handy little 4 stage sanding pads and some polishing compound and a wool pad / drill attachment.  This was a really good improvement, removing a lot of the small scratches https://www.amazon.co.uk/dp/B001O7I7FS   Still lack of lustre tho

So onward and upward.  more YouTubing, and landed on what I hoped would be the final thing.  Ceramic coating.
This was a bit of a game changer.  Really simple to apply, really improved the clarity, and has given a good enough result that the lights are now re-installed in the car, and look significantly better than they did before, with UV protection in place for some time, that I'll just top up every 6 months/1 year.
I opted for a fairly inexpensive version, here https://www.amazon.co.uk/dp/B07DHDF563

Results look pretty good I'd say, but with the lights switched on, it's clear that there is some lower down in the plastic Crazing which I won't be able to fix, but on the whole I'm pleased with the results
 

On the car

If anyone else wants to have a go, in my experience unless you are handy with spraying clear coat, don't bother.  Don't believe the hype of the 3M wipes, but go for the sanding, meguiars kit, and some clear coat.  That way it would be about £40 all in, with some elbow grease and a high sense of satisfaction

Edited February 16 by Withy

[Withy]

Oops, too late to edit, but Sanding, Meguiars kit and Ceramic Coat is the answer

[Terryg]

I have polished quite a few, never used any coating though, if you are trying to do it by hand you are wasting your time to be honest. I have all Festool stuff from my floor sanding days, but at least buy a small cheap rotary or ROS before tackling this job, the time saving and difference in results will make it very worthwhile.

[Amaboknaai]

Good final finish.

The orange peel was caused by two things. You went too fine with the sandpaper before applying clear-coat (1500 max), since it needs a keyed surface. You applied the clear too thickly. First coat, mist coat, then additional coats 10-15 minutes apart. Needs to be 20-25°C for the clear to dry past tack point between coats.

 2K paint is highly toxic and you need a proper respirator, eye protection and no exposed skin. This can't be exaggerated.

I've used 600/800/1000/1500 wet sanding pads on 1/4" drill. Standard clear-coat. Each light takes about 20 minutes.

I've done them with the UV wipes, no clear-coat, too (sanded to 2000), but the finish doesn't last more than 6-12 months.

[andygo]

I'd also point out that once you have activated the clear coat, it goes off in the can within an hour, so you ant faff about with building up several light layers on the lights. I'd also reiterate it's proper nasty stuff.

[Withy]

Thanks, all good tips. 2K stuff was a stretch (and I was using outside/well ventilated and protected as per the very detailed instructions on the can)  Scottish temperature also not helping too I’m sure. Nonetheless, ceramic coating now my favourite thing, and if it’s dry over weekend I may properly clean my Sport Techno’s and give them a coat

Edited February 17 by Withy

[Lonewolfgjp]

I think you did really well and the ceramic coating is the right choice.

I paint for a living and use 2k lacquer daily but through a spray gun, even I can’t get a decent finish out of a spray can.

I agree with the comments that sanding it that smooth wouldn’t help, also heating the can and the light up with a heat gun or hairdryer might of helped it go on a bit smoother.
I doubt a lot of the YouTube videos of the spray can finish lights are great in the flesh but the ceramic coating is definitely the way forward. It should help stopping them fade back and if they do it would only be a light sand or polish to bring them back 👍

[bally4563]

Brave man a job I wouldn’t like to try tackle and this is from someone who rescued a pig up a horses back end .. fair play 

[BrianJ]

Great write-up and additional comments. Thanks all.

[Withy]

Now that I’ve gone through the process, I found this video which is really excellent at explaining it properly, and lands on the same conclusion that ceramic coating is a winner. Worth a watch if anyone is having a go

 

[daz05]

Well done @Withy when I refurbished an old set of lights I tried to use a spray specifically for headlights and it was also a bit of a disaster. Ceramic is the way forward 👍🏼

[alank]

[alank]

Hi withy these were mine after car was covered over our last hot period.  Had them polished out and results are as yours are so you did a good job. Like you say only really noticeable when lights are on. He hand polished them and it literally took a whole day and nakered fingers. Think machine polishing is way to go as did my golf couple of months ago with a £8 kit off Temu and they came up great . That was with a ceramic wipe afterwards 

[Amaboknaai]

My Jag has lasted 18 months so far. I went as far as 2000, and used the Meguiars kit, with ceramic wipe. I clear coated them afterwards but should have not gone higher than 1200-1500. 

I did the Litronics using various wet and dry pads in September I bought on t'internet up to 1500, and clear coated. They definitely came up better this way.

The clear coat is a hard UV protection and they don't have to be re-coated, as with ceramic wipes.

They have come up very well.

[andygo]

W

15 hours ago, Amaboknaai said:

My Jag has lasted 18 months so far. I went as far as 2000, and used the Meguiars kit, with ceramic wipe. I clear coated them afterwards but should have not gone higher than 1200-1500. 

I did the Litronics using various wet and dry pads in September I bought on t'internet up to 1500, and clear coated. They definitely came up better this way.

The clear coat is a hard UV protection and they don't have to be re-coated, as with ceramic wipes.

They have come up very well.

What make of clear coat did you use please?

[Amaboknaai]

Hycote Double Acrylic Spray Paint, Clear Lacquer, 400 ml https://amzn.eu/d/5V15Rxk