Auto headlight lenses

[IlliniDave]

Does anyone know of an effective way/hack to restore the transparency of auto headlight lenses that have become cloudy (oxidized I think) over the years. I've seen ads for products that claim to do this, but was wondering if there was a good way to do this without buying one (I don't trust most things advertised on the high-number cable channels).

[JasonR]

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[Sclass]

YouTube has a ton of videos.

Here is basically how I like to do it. I use power tools and some store bought abrasives because it goes faster than just rubbing with a single fine abrasive with my hands and a rag.

1. Mask of the lens, better to remove it but masking will protect your paint.

2. Sand the damaged material down with 400 grit wet dry sand paper till the yellowed out damaged surface is entirely removed.

3. Clean it with soap and water and make sure you've removed all traces of 400 grit.

4. Now sand with 600 grit wet dry. Sand till all the 400 grit wet dry scratches are ground away and 600 grit scratches remain.

5. Soap and water wash remove all grit.

6. Get a tube of Flitz and a Flitz buff ball attachment for an electric drill. These are cheap and work well if you don't own a pneumatic die grinder and buffing wheel (which I prefer). Now buff out the lens till its smooth.

7. If you want that "optically" flat surface go over it with a finer polish like chrome polish. Edit - do not use the same buff ball from step six. It's now impregnated with flitz grit.

8. The most important step. Now that you've cut it down to the nicest flat virgin material, go out and buy some UV stabilized clear coat from the auto parts store and spray a layer on to seal your work under or you'll be doing it again soon.

Have fun.

Or, you can go on to eBay and price out some new lens covers.

[Slevin]

@Sclass has the method correct here. IMO it is a pain in the ass and the last time i did it, I ended up eating away some paint near the headlight. Nowadays if it is an older car the replacement part is $30 or less and is a lot less headache. I know a couple of people who can restore headlights in a couple hours to nice looking, but I'm just no good at it...

[Gilberto de Piento]

+1 for toothpaste. Try this before anything else.

The $30 replacement lenses are OK but lower quality than OEM. I found the fit to be bad. Read reviews before buying.

[Sclass]

+1 for toothpaste. Try this before anything else.
.

Yes, try this. When you get tired or you realize how slow it is progressing, spring for the real abrasives...or the new lenses.

Ok, seriously, the headlight lens is designed to take years of sandblasting on the open road. 70mph wind full of grit day in day out. Tooth paste and a hand are too slow going. How do I know? I tried it.

[JL13]

+1 for toothpaste. Try this before anything else.

The $30 replacement lenses are OK but lower quality than OEM. I found the fit to be bad. Read reviews before buying.

I've heard they're notorious for leaking.

[Gilberto de Piento]

Yes, try this. When you get tired or you realize how slow it is progressing, spring for the real abrasives...or the new lenses.

Ok, seriously, the headlight lens is designed to take years of sandblasting on the open road. 70mph wind full of grit day in day out. Tooth paste and a hand are too slow going. How do I know? I tried it.

I think it depends what problem you are trying to solve. I used toothpaste to remove yellow oxidation and it worked in a few minutes. That's what Dave is looking to do too. If you need to buff out deep scratches then I agree, toothpaste is not going to be abrasive enough. Maybe Dave will try it and report back.

[Dragline]

I wonder what your results would be with toothpaste and the buff ball/electric drill.

[Sclass]

I stand corrected. Try the toothpaste first. It's easy and cheap.

[enigmaT120]

I have some blotches to clean off mine. I was standing at my work bench cleaning some parts with brake cleaner, not noticing that some was splattering behind me. Where my car was parked.

I think I'll need the abrasives. I wonder if polishing compound would work, skipping the sand paper stages. I can't feel the marks.

[tsch]

++ for toothpaste, but I've also used Bon Ami, the OLD formulation (red can w/yellow print, 1886 formula—you may have to order online). Do NOT use the more common formula out there now, the shiny gold can w/red print.

I'm due for this again and will probably try the Bon Ami and follow it with toothpaste.

The Bon Ami did a great job on my windshield, which had had some kind of rain visibility treatment which caused more problems than it solved and really needed to come off. Older car and I tested a small area first; not sure I'd go for it with a newer windshield.

[Chris]

I've had luck with this headlight kit (after failing with toothpaste). The clouding is caused by UV. So you need to first sand and polish, then apply the UV sealant to prevent clouding. Takes less than an hour to do it by hand. The 3M kits for power tools wouldn't work with me due to the shape of my car's headlights.

On my car, the headlights stayed clear for about 2.5 years. I supposes parking the car in the shade or indoors would prevent reclouding.

[Sclass]

There is a video on YouTube where a guy uses bug repellent. It was fast

Careful, this can take off your paint. I haven't tried this but it was shockingly effective.

http://youtu.be/AYmbBZntuY8

[IlliniDave]

Thanks for all the ideas. If I can get the lenses off without too much hassle I think I'll try the bug repellent first. If not I'll try the toothpaste. The vehicle is 14 years/198,400 miles old, so any improvement in transparency I'll consider a victory!

[Gilberto de Piento]

Sorry to be a downer on this topic but I recommend against the bug spray. The serious reviews I've read indicate it's a temporary fix that could damage the lens plastic permanently. I haven't tried it myself though. Here's an example review: http://www.autogeekonline.net/forum/pro ... lastx.html