wet sanding severely damaged fog lights/head lights

**A4 2000** · 01-09-2010, 11:24 PM

My fog lights have deep rock chips and scratches which have taken a lot of the clarity away from the lens. At the moment the most abrasive sand paper I have is 800 grit. I`ve been going at it for a while but it can`t seem to cut down deep enough. The most abrasive sand paper for wet sanding at the auto parts I saw is 250 grit. Should I try it out and see if that will solve the problem or do you think that it`s a lost cause? Thanks in advance.

**ABQDetailer** · 01-10-2010, 01:05 AM

Sometimes "good enough" is "best".

**ezemsm444** · 01-10-2010, 01:08 AM

Originally Posted by A4 2000

My fog lights have deep rock chips and scratches which have taken a lot of the clarity away from the lens. At the moment the most abrasive sand paper I have is 800 grit. I`ve been going at it for a while but it can`t seem to cut down deep enough. The most abrasive sand paper for wet sanding at the auto parts I saw is 250 grit. Should I try it out and see if that will solve the problem or do you think that it`s a lost cause? Thanks in advance.

The lowest I would go would be 400 grit. From experience 250 grit is way to abrasive and it would take FOREVER to take them out. 400 grit will take about a 1/2 hour or more per light depending on the damage. Honestly I would start with the highest grit and keep sanding. Hopefully the scratches diminish before you get to 400. From what I have learned, the lighter the grit you stay at the cleaner the finish. Sometimes it takes much more time to get the scratches that you put in by sanding than the just sanding the existing scratches longer with a lighter grit.

**Invigor** · 01-10-2010, 01:17 AM

I got my *** handed to me by some headlights off an Audi TT. I don`t know what they`re made of, but I ended up using 320grit on them before I could get any results. I started with 1500 and it barely even scuffed the surface, so I tried 800, and still barely anything...so I whipped out the 320 and had at it. Of course you have to pyramid back up from 320 until all the scratches are removed enough so you can polish what remains. I think I went 320, to 600, 800, 1500 and then moved on to the wool pad and some Farecla G3. Generally, 1500 grit is enough, with the ODD occasion you have to whip out the 800 to really dig in, but these lights were something else.

**Accumulator** · 01-10-2010, 12:09 PM

Is there any issue with removing too much material from headlights by doing this stuff?

And, heh heh...I`d probably be wondering how expensive replacement lenses were, rather than making some huge project out of this. But hey, that`s just me...

**nrengle** · 01-10-2010, 12:13 PM

I seen this post over on EPhatch. The fogs and the headlight lenses can be quite pricey for our cars (02-05 Civic SI). I know a set of projector headlights (OEM) are 600 and up. The fogs are about 150 and that`s not always OEM.

**Accumulator** · 01-10-2010, 12:19 PM

Well, yeah...the headlight capsules for my S8 are really pricey. But that`s not always the case. Just got some turnsignal/corner light lenses for the V8 for $60 per and I can get the lenses (separately) for the Jag`s foglights cheap too.

**A4 2000** · 01-10-2010, 01:26 PM

Originally Posted by nrengle

I seen this post over on EPhatch. The fogs and the headlight lenses can be quite pricey for our cars (02-05 Civic SI). I know a set of projector headlights (OEM) are 600 and up. The fogs are about 150 and that`s not always OEM.

Hey, you`re on ephatch? ha, ha, I used to own an `05 si, and now I have a `00 Audi a4. I came here and posted there too because the people on the Audi forum that I go on seem to not know very much about this subject. Anyways, I guess I`ll try the 400 grit connected to a drill to see if I can get some better results. It seems like I found the right forum now

. Thanks everyone for the advice.

**IkeRay** · 01-10-2010, 10:31 PM

Originally Posted by A4 2000

Hey, you`re on ephatch? ha, ha, I used to own an `05 si, and now I have a `00 Audi a4. I came here and posted there too because the people on the Audi forum that I go on seem to not know very much about this subject. Anyways, I guess I`ll try the 400 grit connected to a drill to see if I can get some better results. It seems like I found the right forum now

. Thanks everyone for the advice.

I wouldn`t put it on the drill....

you want to crosshatch with the sandpaper, go horizontal and then vertical with the next level (eg 400 grit left and right, 600 grit up and down, 800 grit left and right, etc). then when you polish you want to polish in circles (via a rotary/DA or maybe get away with a drill with powerball or w/e attached). you`ll want to follow up with a coating to prevent it from yellowing in a month or so because you`re taking off all the UV protection