Interest in DIY for restoring headlight lenses?

[Abtin]

Hey guys,
I'm new to the forums.
I just got a Z4 (LOVING IT!) but the headlight lenses were pretty badly damaged from rock chips and road debris. The lenses were far from clear and it really bugged me. I did some research on various "lense cleaning kits" but I wasn't impressed by any of them so I decided to do it my own way instead of wasting my money on a kit.
Here is how I did it.
Someone was borrowing my drill/rotary so I decided to go without tools so no tools are necessary for this method.

Edit: This method is primarily for people with headlights that are scratched, dented, or otherwise physically deformed on the surface. If your only problem is oxidization or discoloring from the sun's UV rays (looks yellow or murky) then there are easier methods for you to try. Generally there are 1 step, wipe on, wipe off type products you can get. However, this method will also help you. I suggest skipping steps 3 and 4 in that case as you probably won't need the 600 and 1000 grit sanding. Just do the 2000 wet sand)

Things you will need:
600 grit sandpaper sponge $3-4
1000 grit sandpaper sponge $3-4
2000 grit sandpaper sponge $3-4
3M Scratch remover / rubbing compound $10 (I read turtlewax rubbing compound is not good for headlights)
2 Terrycloth or Microfiber towels $cheap
1 Roll of blue painters tape (or even less sticky tape) $3-7
Carnuba based Car Wax (I used mequire's gold class)

NOTE: Even though the blue tape is intended to not cause damage, it's still possible that it will peel some of your clear coat/paint off. So you can stick it to your t-shirt or something first in order to reduce it's adhesiveness.

1. You want to start by cleaning your headlights. Either just wash your car first, or wash the headlight area with whatever your favorite car wash soap is. (NEVER use dishwasher soap on your car)

2. Then, mask off area surrounding your headlight. I recommend putting 2 layers of tape down to make sure it doesn't tear or peel. You will find that while wet sanding, the top layer of take might peel in some places while you work so it's good to have 2 layers.




3. Once I finished masking the area, I grabbed my hose and set it to a low water flow and wet the windshield. I continued to let the water flow over the area I was working on while sanding. I started sanding with the 600 grit (the lower the number, the more course/rough the sandpaper will be) You don't want to use less than 500 because it would damage the plastic.

So you want to sand the headlight lens down in the areas that you have chips and dimples from road debris and rocks. Keep sanding while running the hose over the area you're working on until the specs and rough areas are gone. What you're doing is removing the top layer of the plastic until you pass the depth of the dents and scratches so they disappear.
Make sure you keep sanding until you're happy with the level of clarity in the lens (I mean the spots should be gone, the lens will be very foggy)

This is what it should look like when you're done. (Keep in mind, if the lens is still wet, it will look less foggy) I dried my lens for the purposes of the photo.




4. Next, you want to do the same thing with the 1000 grit sandpaper. Except this time, you won't have to sand as much because you're just smoothing this out now. You're not trying to dig into the lens.

Note: Make sure you sand over all areas that you sanded with the 600 (previous grit) otherwise those areas will stay rough.

This is what it looked like dry, after finishing with the 1000 grit.




5. Next, you want to do the same thing with the 2000 grit sandpaper to finish smoothing things out.

This is what it looked like dry, after finishing with the 2000 grit.




6. (optional) you can use 2500 grit for the next stage if you want to smooth things even more. I didn't.

7. Next, you want to dry off the lens completely and apply a quarter sized glob of 3M rubbing compound to your terrycloth towel and rub the compound into the entire surface of the headlight lens in a circular motion (for best penetration)

You may need to repeat this step a few times to thoroughly cover the lens. I had to reapply some more 3M rubbing compound to my towel a total of 3 times.
Once you finish, let it dry for a few seconds, then turn your towel over to a clean side and wipe the lens clean. Fold it over to another clean side to buff it thoroughly.

at this point your lens is almost done.




8. Finally, apply your car wax to the lens the same way you did the rubbing compound. Use a circular motion, then do horizontal, then vertical, then circular again. That way you make sure you get the wax in from every angle. Let it dry.

Use your microfiber towel to wipe the lens clean, then fold your towel over and buff it clean for a final wipe. By now your lens should be nice and shiny.



Finally, CAREFULLY remove the painters tape from your car so you don't peel the paint and you're done!

Here is a before and after of my lens.




I hope this guide helps you guys. I know I'm very happy with the results.


Cheers!

[rsutoratosu]

Looks good.. polisher or by hand ?

[z4mnyc]

Interested

[SHEEDI]

what did you use?

[Abtin]

I just updated the thread with a guide I just wrote up. I hope it helps you guys. Post if you have any questions or comments.

[z4mnyc]

Really nice write-up, thank you!

[Abtin]

You're welcome =)
Oh, I forgot to mention that this method is mainly for people with dents, scratches, chips etcs on the lens surface, not for people with yellow of foggy headlights from UV ray damage. (You can buy easy to use cleaners for that) But this method works for both anyway.

[esqu1re]

Wow. Your original lenses were beat up! Lots of highway miles eh? Good job on the restore and thanks for the DIY. I'm sure we'll all have to visit this DIY page one day.

[CFoote]

That looks awesome! These headlights are so expensive (especially the Xenon ones) that this is a great DIY. I will give this a try this Spring when I have a free Saturday.

Thanks for posting and the detailed steps.

Chris

[CFoote]

Question, how much pressure did you use on the sandpaper? Finger trip pressure? I assume if you press too hard you will leave damage...

Chris

[Abtin]

Thanks for the compliments guys.
Cfoote, I put a pretty good amount of pressure on it while sanding to make sure I got as deep as I needed to. For the most part, I would put my palm behind the sandpaper and press as hard as I could while sanding in a circular motion. If you're using 600 grit or finer it shouldn't cause any damage. Especially because you're going to sand it a few more times with finer grit (1000 and 2000) after.

[Abtin]

Oh and yeah, the cars entire life consisted of mostly highway miles. Good for the car, bad for the headlights and front end lol.