Headlight Restoration for NCT

I was posting about this in another thread but probably better to split it since I've issues.

My car failed on a "foggy" headlight. I didn't take any pictures from before cleaning it but it was pretty bad in fairness, didn't even realise it was an issue to sort.

So now I've a e28 repeat fee test on Wed.
I tried to clean as per the thread on here with the 1500/2000 grit and clear coat.

While the sanding alone did a fair bit of improvement, as soon as the clear coat was put on it made them worse... The videos of people using it show the light "clearing" as its applied.

I'm now in a predicament where I feel as though I should just replace the light.
But I'm torn that maybe the pass rate isn't as strenuous and I'm not personally looking for crystal clear lights... Its just a run around car and the paints a mess(Red Corolla).

Picture is how it currently looks.

Obviously the test is somewhat computer based but there must be some visual aid to help in what passes?.

I'm tempted to go to town and buy white spirits and try remove the clear coat and reapply... Is that worth at least the effort?(I read it removes it but maybe that's when its wet?, a sanding there wouldn't even remove it).

I need to sort this by tomorrow as my NCT is early Wednesday and don't want to fail again and possibly run over the month and need a full test.

shietpilot

After the clear coat, do a light (and I mean super light) wet sand with the 2000 grit. The lights will still look similar but they will be smoother.

You then need a microfibre cloth (or a polisher machine if you have one) and some normal bodywork polish. Put it on and rub it hard. It will take a while but the light will look like new eventually!

shietpilot

I did a post a while back, you can see the difference between after the clear coat and after polishing:

Pov06 wrote: »

Hi all,

Today I decided to try and do a permanent fix for yellow/hazy headlights. This methods involves wet-sanding the headlight, spraying it with clear lacquer and then polishing it.

You will need:

1. Sandpaper (2000 grit, 1000 grit for worse situations)
2. Clear lacquer spray (I used Simoniz Clear Lacquer)
3. Polish (I used Autoglym Super Resin Polish)
4. Finishing product (I used Autoglym Extra Gloss Protection)

The headlights:



These lights weren't too bad. There was a bit of a haze but originally they had a yellow haze. I used to use the toothpaste method of cleaning them but it wouldn't last long.

Step 1
Decide whether you will want to do the job with the headlights in the car or if you want to take them out. I decided to take the headlights out instead of masking the bodywork around the headlight.

If you want to keep the headlight inside the car be sure to mask it off.

Step 2
Clean the headlights properly with water to make sure the surface is 100% clean. When you have them clean you can begin wet-sanding with the 2000 grit sandpaper.

Basically dip the sandpaper into a small bucket of water and keep sanding until the headlight doesn't have anymore yellowness to it.

After a bit of sanding here's what my headlight looked like:


So YEAH, the headlight will look a lot worse than it was after sanding. This is normal and don't be scared to continue.

Step 3
Lacquering time. Wash the headlight again to remove any sanded particles off the headlight. Follow the instructions on your lacquer.

I did a total of 4 coats. The first coat was very light. I applied each coat with a 15 minute drying time in between. After the 4th coat I allowed the headlight to dry for 2 hours.

Here's the lacquered headlight:


As you see the headlight now has a matte surface too it. Looks a lot worse than it was, still.

The surface will be quite rough looking with dots from the spray of lacquer.

Step 4
The next step is to wet-sand the lacquered surface with 2000-grit sandpaper. You pretty much have to keep wet-sanding until the little dots have gone away from the surface.

You need to make sure to do all 4 coats of lacquer properly to have a thick enough lacquer layer left after sanding.

If you don't sand down the lacquer enough in this stage you won't have a 100% clear headlight after polishing.

Step 5
Time for polishing. Apply your polish and polish the surface properly until it's transparent. After applying the polish make sure to wipe the surface down with a clean microfibre cloth.

You may have to repeat this step a few times. I did it 3 times.

If after polishing the surface the headlight isn't clear you will have to repeat step 4.

After I was happy with the finish I applied my Autoglym Extra Gloss Protection as I would with bodywork.

This is what the headlight looked after polishing:


Finished headlight VS lacquered headlight:


Both headlights back in the car:


The clear lacquer should provide permanent protection, or at least a lot better protection than just polishing the headlight.

If any of the more experienced detailers have something to add, please do. I'm quite a newbie with this and I decided to take the plunge and try it.

I was really happy with the results :P

Atlantic Dawn

If you want a quick temporarish fix that will keep it clear for a few months or so just use toothpaste and a toothbrush...

https://www.youtube.com/watch?v=rXHTXdlWw1w

shietpilot

Atlantic Dawn wrote: »

If you want a quick temporarish fix that will keep it clear for a few months or so just use toothpaste and a toothbrush...

That's exactly the effect that polish will have, it's just that it takes a while, especially after you've clear coated the lights

biko

My own toothpaste adventure

Atlantic Dawn

Atlantic Dawn wrote: »

If you want a quick temporarish fix that will keep it clear for a few months or so just use toothpaste and a toothbrush...

https://www.youtube.com/watch?v=rXHTXdlWw1w

I tried the toothpaste option initially. It helped a TINY bit but then again they were REALLY bad so even water would have took a bit off.

I'm just curious to know to what standard they have to be to pass the NCT, surely they don't have to be 100% .

This is their current level as of this evening.
Improved them a bit doing another blast this evening but still unsure to risk the retest.

biko

They don't have to be 100% but the beam needs to be somewhat focused so it can be tested.

The trick with clearcoat is to get light perfectly smooth and then spray thin thin layers of coat. Rather 10 superthin coats than 2 thick ones.

shietpilot

biko wrote: »

They don't have to be 100% but the beam needs to be somewhat focused so it can be tested.

The trick with clearcoat is to get light perfectly smooth and then spray thin thin layers of coat. Rather 10 superthin coats than 2 thick ones.

The OP has done a good job of the clear coat already. The clear coat that you spray will always make the headlights hazy and it's very important to polish the headlights after spraying them.

I think the problem is that the OP hasn't polished them for long enough and that's why they're not fully clear. It will be very hard to polish them without a machine. When I was doing it I used one of those LIDL €30 crappy polishers but I spent maybe 15 minutes polishing. If you do it by hand it will take much longer.

Just to provide closure on this as I'm sure someone will come along and wonder "How clean do they have to be" and its something that you can't get an answer on as such.

So I passed on the light at this condition. I gave it another solid go yesterday, a long sanding, clean dried, polished but realistically it didn't really improve it any further or remove the first clear coat that ran.

So there you go, you can pass once its somewhat clean, doesn't have to be restored to an immaculate level.

Thanks for the help, appreciated it.

Glad I didn't spend e60 odd replacing it after e25 on the cleaning materials.

Alun

The kits you can get for doing this have several grades of abrasives ending in 2000 grit or higher AND a liquid polish as a final step. Even after the 2000 grit sanding there's still a good bit of haziness present, and it's not until you use the polish that you get anything like a smooth finish in my experience, and I've done a few.

You see stuff from 3M and other US companies on the net, but this company, here in Ireland, has some good kits, such as this one ...

http://www.glasspolishshop.com/plastic-acrylic-restoration/plastic-and-acrylic-diy-restoration-kit