Headlight scratches, what to use?

[LanaB]

Just replaced headlight globes and did an adjustment on them, after getting a couple of "flashes". Anyway, when finished, I decided to give them a good clean with water and vinegar, and had the lights still on, which amplified the marks on the lenses. What I noticed was some very small "holes" in the coating (probably stone chips) but also heaps of very fine scratches. I am guessing that these have come from quick wipe over with dirt still on them over the years. So I did a search on google, as to how to remove the scratches, I know I cant remove the small chips (easily anyway). I also know not to use abrasives eg toothpaste. So my question is, what have others used on this plastic clear coat scratching?

[Ian Johnston]

A lot of people use toothpaste for headlights. I have used Brasso, and daughters partner has done some for me with cutting compound and a buff.
Worked great.
I have used scratch x, but wasnt impressed.

[LanaB]

thanks for replying Ian, was that on glass headlights or polycarbonate (plastic)? Mine are clear as, so I am not trying to remove haze/oxidation, its just scratches in the protective coating.

[hinsch]

Get the finest wet / dry sandpaper you can find, MUST feel like paper, grit is very very fine like 2000grit, give them a rub with the paper if you can use a rubbing block to keep it even, make sure it stays pretty wet then polish with brasso and soft cloth works a treat.
The lights will look like crap after you use the paper but they will improve after the brasso.
This is not a five minute job takes a fair bit of effort, time and elbow grease.
This will get the light scratches out but obviously if they are deep nothing will get them out.

[George Whiley]

I use cutting compound and the hit them with some wax, works well on my NM

[Les PK Ranger]

LanaB, heya. How's that ol' Triton going ?

Besides the PDR (paintless dent removal) I do headlight restorations, and the fine scratches you have should be able to be removed, but it takes a fair amount of process and elbow grease.

Are the scratches really affecting anything ?
Light should still go through ok, probably close to 100%, unlike when they are yellowed or dull from the 3 main things to affect the acrylic construction . . . these are 1) the UV coating has started to break down, 2) the acrylic gets finely sandblasted form general road driving, but especially highway speeds, and 3) heat from the headlights.

If the above is correct, maybe leave them, but if you want them gone . . .

To remove the scratches, you would need to rub them out, starting with a grit coarse enough to take off the acrylic fast enough, perhaps 600g W&D (wet and dry) using enough water to keep them clear of rubbing lolly water and such.
Then you get to 800g, 1200g, 1500g, and then 2000g then sometimes 3000g to save polishing time.

The scratches might be ok to start with 800g, hard to say without seeing them, but you do need to remove all the UV coating once you start anyway, so 600g will do this faster.

You should remove all (of any) existing UV clearcoat on the lens, the material applied to the lenses originally in the factory during this process, this has to happen or you will get a patchy look.

When wet the lenses will look almost like you want them to, but when they dry they will look sort of hazy from the 2000 / 3000g W&D, which brings us the the next stage.

They need to be polished.
We use special polish for acrylic, helps strip the last remnants of the UV coating.
You can polish with a general auto cutting compound, and should be fine for this.
You can do it by hand, or use a lambswool pad on a drill backing pad first, then final hand polish.

Then they should be recoated with the right UV coating to protect the acrylic, just like the factory coating.
This is where you could come unstuck, as it isn't something you'll find easily.
The coating we use lasts up to 10 years, depending on some of the elements mentioned earlier that cause the problems (vehicle in sun all day, driving a lot on highways at speed, a lot of night driving / or lights on during the day).

If this UV coating isn't reapplied, your acrylic surfaces can break down a lot faster, could be a matter of months before they are yellowing without the protection, so best to get it done right.

If you need any advice, please reply here or PM.

[LanaB]

Hi Les, nice to see you again. I did actually think of you when I asked the question. The scratches are very fine like the lights have been "cleaned" in a hurry with little or no "water", and when I looked closer, some of the clear coat has begun to "flake" at the corners. I will leave it for now, seems there is quite a bit of work in it, so next time our other group has a get together I will seek your opinion and go from there, seems you all had a ball last weekend. It was way too far just for one day for me cheers.

[Les PK Ranger]

The flaking is the old UV clearcoat.
You should get onto this within say 3 - 6 months if possible, UV light will start to affect the acrylic without the coating present.

Next time you come up to town, let me know (PM here or on Earth) and if you want I can do them for you, takes say and hour and you can wait / have a chat, have them done properly (mates rates).