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Polishing Hella glass fog lights

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2011z4
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Polishing Hella glass fog lights

Post by 2011z4 » Mon Sep 11, 2017 12:17 am

So, I figured I would try to sand out the pitting on my fogs instead of dropping over $120 on a new set. Finding ones that are the larger and longer in size has been quite an issue, and even with the part number I thought was correct, I ordered the shorter ones by mistake.

Here is a step by step process with photos on what I did. Please make sure you wear a mask since sanding glass is not healthy at all!

Original Condition:
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1. Sanded with 40 grit for about 15 mins on each changing the paper frequently. You have to watch and alternate between each light so they can cool down since too much heat causes them to crack.
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2. Worked my way up from 40 grit to 60 grit, then 80...then 120...then 200...then 320.

3. After 320, I took them on my buffing wheel with the black compound and polished until smooth. Have to watch the heat here too!
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4. After the polishing wheel, I used 3M Glass Polish with the small pads on my orbital buffer.
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2011z4
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Re: Polishing Hella glass fog lights

Post by 2011z4 » Mon Sep 11, 2017 12:18 am

You can see, some of the pitting is still there, but these were pretty bad! I am very happy with the way the turned out. I was ready to throw them out, but I am glad that I tried this method since I really didn't have nothing to loose. The whole process took about 3.5 hours.
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Hope this helps and have fun!
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Re: Polishing Hella glass fog lights

Post by zinnocoupe » Mon Sep 11, 2017 3:12 am

That looks pretty good. 40 is pretty coarse, do you think you could start with something less aggressive and still achieve the same result? I've got set thats pretty pitted as well and have been thinking about this. Nice work
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2011z4
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Re: Polishing Hella glass fog lights

Post by 2011z4 » Mon Sep 11, 2017 11:03 am

zinnocoupe wrote:
Mon Sep 11, 2017 3:12 am
That looks pretty good. 40 is pretty coarse, do you think you could start with something less aggressive and still achieve the same result? I've got set thats pretty pitted as well and have been thinking about this. Nice work
It is, but I actually tried starting at 80 on a spare that was just as bad, but that did nothing for the deeper pitting. I then moved down to 60 and still not any better. It will all depend on yours, but as they say, start with less aggressive first and if that doesn't get you a result, you can always move to a more aggressive grit.

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Re: Polishing Hella glass fog lights

Post by hornhospital » Mon Sep 11, 2017 5:50 pm

What kind of sander were you using? Obviously you can't hand sand the lights with sufficient vigor to get them hot.

I wonder if it's the heat from sanding that cracks them, or the sanding itself? Those lights get finger-blistering hot in use. I cannot see how sanding them could generate more heat than the Halogen bulb does.
Ken Kanne
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2011z4
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Re: Polishing Hella glass fog lights

Post by 2011z4 » Mon Sep 11, 2017 6:28 pm

hornhospital wrote:
Mon Sep 11, 2017 5:50 pm
What kind of sander were you using? Obviously you can't hand sand the lights with sufficient vigor to get them hot.

I wonder if it's the heat from sanding that cracks them, or the sanding itself? Those lights get finger-blistering hot in use. I cannot see how sanding them could generate more heat than the Halogen bulb does.
I used a 5" random orbital. I was just trying to be careful not to crack them. Either way, I was just cautious.

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Re: Polishing Hella glass fog lights

Post by PTFunk » Sun Oct 15, 2017 12:58 am

What type (mfger, material) sandpaper did you use?

Do you think wet sanding would take less time or otherwise have an advantage?
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Re: Polishing Hella glass fog lights

Post by dwcains » Sat Oct 21, 2017 3:42 am

Nice work. I had no idea you could sand and polish glass. Mine were also quite pitted, but I took the easy route and covered them with vinyl film, which also allowed me to change the color to yellow:

Image

Image

I also used some clear flim to protect the new Hella BiFocus low beams (the right one is filmed, the left bare):

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2011z4
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Re: Polishing Hella glass fog lights

Post by 2011z4 » Sat Oct 21, 2017 4:04 pm

Looks great Dean! What was the actual product that you used?

As for the question of wet sanding, I didn't try and the sandpaper I used was just the Gator brand I found at Lowes. Through each grit, I went through about 3-4 pads per.

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Re: Polishing Hella glass fog lights

Post by sansouci » Sat Oct 21, 2017 5:15 pm

I was just reading a how-to manual on autoglass repair including polishing. I think the 3M product you used is cerium oxide powder which can be mixed with water to a slurry and used with either a DA or orbital polisher.
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Re: Polishing Hella glass fog lights

Post by dwcains » Sat Oct 21, 2017 5:24 pm

This is what I used on the fogs, and I applied two layers to get the color density I wanted:

https://www.amazon.com/inches-Adhesive- ... +tint+film

And, on the headlights:

https://www.amazon.com/iJDMTOY-12-48-in ... light+film

Application is fairly simple, and there will be plenty extra in case you screw up the first time, and you'll need a heat gun. A credit card works fine as a squeegee.
Dean
Lutz, FL

'85 635 CSi Euro #9402254
'87 Spider Veloce
'92 Spider Veloce
'08 350Z

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Re: Polishing Hella glass fog lights

Post by zinnocoupe » Thu Oct 26, 2017 3:53 am

Those yellow fogs really look good Dean. I have some yellow glass paint I was going to paint a second set of fogs with, but I like the idea of the film better.
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Re: Polishing Hella glass fog lights

Post by dwcains » Fri Oct 27, 2017 3:36 am

Daniel Tern has instructions for making yellow fogs using transparent yellow spray paint, but I think the film is both easier to apply and more durable. I'd like to think it offers some protection, which is why I filmed the brand new headlights, but the stuff I used is not nearly as thick as the 3M, and other, films made specifically for that.
Dean
Lutz, FL

'85 635 CSi Euro #9402254
'87 Spider Veloce
'92 Spider Veloce
'08 350Z

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