Headlight restoration didn't work

[jb90304]

I have had success restoring headlight on my own car but having trouble with my neighbor's which is in a significantly worse condition. I'm not sure what I'm doing wrong but I plan on giving another try tomorrow. What am I doing wrong?

I first cleaned the surface then sanded it down using 3M sand papers. I used 800, 1000, and 2000 on my personal car before but since this one was in much worse condition, I decided to use 600, 1000, and 2000. After wet sanding them horizontally and evenly for a good amount of time on a wet surface, the headlight did feel smooth, it also appeared cleared up, but still hazy as expected after sanding it. So then I cleaned off all the mess with some water and dried with it a microfiber towel.
Next step I performed - I put some 3M rubbing compound on a wool compound pad attached to a drill. I worked that compound all over and turned the drill on. Well, the headlight just became more cloudy again and it wasn't at all crystal clear. It seems to become more hazy as it dries up more. It looked the to be most clear right after I sanded it with 2000, but that didn't last very long. I'm not sure what I did wrong...

When this didn't work, I went to the store and bought a 400grit sandpaper - with the same results. I'm not sure what I should do. The surface felt smooth but the headlight still appeared as thought it had some "rough" spots regardless of feeling smooth. Should I use even lower grit sandpaper? What did I do wrong? I'd greatly appreciate any advice, thanks!!

[allenk4]

I suspect that skipping the 800 grit is the problem

You also need to alternate directions when sanding.

- 600 grit up & down
- 800 grit left to right

etc.

It will take a while for a drill to remove 2000 grit scratches, even with a wool pad and rubbing compound.

[808_detail_nut]

thanks for posting this, im looking forward to seeing what everyone has to say about this issue. I just bought the 3m kit and have 2 practice cars lined up. I just have one question, what sort of UV protection are you applying after sanding/polishing?

[natewood70]

The damage that you are seeing could potentially be on the inside of the headlight. My wife's 325I had an issue like that, luckily it was only on the outside edges of the lens.

Would it be possible to post pictures of the lights you are working on?

[Dr_Pain]

I agree that pictures would be helpful.

[asalesagent912]

I just did my headlight of 11 years old. used the 3 m kit. When you first sanded with 600 and 800 did you do it without water ? I did it dry and then went to the 3000 pad and wet sanded then

[jb90304]

Sorry. Don't have pictures. I am 99% this isn't happening on the inside although it may look like it. That is a common myth. I had a similar issue when I was successful with my own car a month ago and it was definitely on the outside.
You are supposed to sand it wet regardless of which grits of sand paper.

I'm thinking my problem this time was that I didn't sand it evenly and as persistently.
Also, my wool pad might not be doing the job because it is a bit "raggy"- but I'm really not sure until I try it again tomorrow

If anyone has any suggestions, please let me know.

[Evan.J]

1. I wouldn't go below 800 grit

2. How much heat did you generate when you were sanding and compounding?

3. I wouldn't use the 3M rubbing compound. Try Megs M105 or Ulitmate Compound.

4. I would re-think going to 400 grit as I feel 800 is low enough even with the worst headlights.

I am thinking you might have generated too much heat and caused the plastic to deform or you did not remove all the sanding marks fully.

Photos would be a great help.

[Rsurfer]

I am thinking you might have generated too much heat and caused the plastic to deform or you did not remove all the sanding marks fully.

Photos would be a great help.

:iagree:A wool pad on a high speed drill with a heavy compound on plastic, can do some damage.

[allenk4]

Sorry. Don't have pictures. I am 99% this isn't happening on the inside although it may look like it. That is a common myth. I had a similar issue when I was successful with my own car a month ago and it was definitely on the outside.
You are supposed to sand it wet regardless of which grits of sand paper.

I'm thinking my problem this time was that I didn't sand it evenly and as persistently.
Also, my wool pad might not be doing the job because it is a bit "raggy"- but I'm really not sure until I try it again tomorrow

If anyone has any suggestions, please let me know.


Not from what I have read.

Maybe it is different on headlights?



This is the advice I have seen

- Dry up to 800 grit

- Damp 1000-2000

- Wet above 2000

[natewood70]

Sorry. Don't have pictures. I am 99% this isn't happening on the inside although it may look like it. That is a common myth. I had a similar issue when I was successful with my own car a month ago and it was definitely on the outside.
You are supposed to sand it wet regardless of which grits of sand paper.

I'm thinking my problem this time was that I didn't sand it evenly and as persistently.
Also, my wool pad might not be doing the job because it is a bit "raggy"- but I'm really not sure until I try it again tomorrow

If anyone has any suggestions, please let me know.


Its not a common " myth." The headlights were cheap after market replacements that had adhesive failure around the edges which created a clouding effect on the inside.

What year make and model is the car? Maybe someone who has specific experience with it can chime in.

Sent from my SCH-I545 using Tapatalk

[jb90304]

1. I wouldn't go below 800 grit

2. How much heat did you generate when you were sanding and compounding?

3. I wouldn't use the 3M rubbing compound. Try Megs M105 or Ulitmate Compound.

4. I would re-think going to 400 grit as I feel 800 is low enough even with the worst headlights.

I am thinking you might have generated too much heat and caused the plastic to deform or you did not remove all the sanding marks fully.

Photos would be a great help.

I first tried to with 600, 1000, and 2000.
Once that was finished, I was still able to feel the roughness significantly. So then then I did it with 400 which then made the surface completely smooth. With that said, I believe the only way to make the surface smooth is to go lower than 800 (on this particular headlight).
If that is the case, and also if I did indeed create too much heat and caused too much damage, how do I restore this headlight? It seems like If I go low enough to get it smooth, it will cause damage which apparently I can't polish those scratches, but if I stay within 800, I can polish the scratches back up, but the surface still remains rough and not "restored".
I will be trying this tomorrow by the way so I will let you know how it goes. By the way, it is a 2005 Chevy Impala.

EDIT: I really don't know what went wrong today (especially that I had success w/ the same method just a month ago) and there doesn't seem to be a clear answer here so far - I guess I'll be trying again tomorrow and I will most likely use 400 - 800- 1000- 2000. This time I will sand it more evenly and more persistently with a good amount of force. I will also use a more fresh wool compound pad when I polish the scratches. I actually use it on a drilling adapter so it's not very high-speed. At times, I would polish it with my own heads (just really freaking fast and with good force, which also worked fine to a sparkling headlight on my last car).

[dcjredline]

Not all headlights (just like paint) are created equal. Furthermore not all "cloudyness" is the same either. Others have asked you what vehicle these are on and for some pictures to better help you but you seem to be ignoring/missing those requests.

[jb90304]

Not all headlights (just like paint) are created equal. Furthermore not all "cloudyness" is the same either. Others have asked you what vehicle these are on and for some pictures to better help you but you seem to be ignoring/missing those requests.

I've already mentioned what kind of car it is.

[GenesisCoupe]

i have NEVER used a grit below 2000 on anything car related. I did plenty of headlight restorations with 2000, 2500, 3000 and 3500, followed by a polish such as M205, sealed with BFWD. I typically start with the 2500, followed by 3500 and see what results it gives me. Gotta remember that the polish will do some work as well so not sure why the 800 grit talk is here. No way, ever ever will i go that low.