Restore Headlights - get rid of the yellow

joesturbo

Member
Just thought I would post this up - as it has worked great on my GTI and my wife's Protg and my brothers beater an 88 Ford.

Things to get:
1. 900 - 1200 grit wet sanding paper.
2. Mothers Aluminum polish
3. Rags
4. Spray wax
5. Elbow grease

The plastic headlights after years of sun, environment (rocks etc.) will pit and yellow the plastic on the headlights.

My wife's protg had this yellowing effect + it was not projecting much light to the road. I started thinking on how to "fix" this problem. I tried some of the chemicals sold on eBay and they worked but were short term at best.

When thinking about what the damage is, it is important to understand what is happening. The outside surface is essentially oxidizing; the only way to fix the headlight is to remove this surface. I went out and bought a package of 900 wet sand papers (you may use a higher grade but 900 seems to work fine).
Then I had sitting around a couple of other items I used. I sprayed down the headlight with Mothers spray wax I got with a clay bar kit. Then sanded down the headlight from left to right (re-lube using the wax as necessary keeping the surface wet), cleaned the lens then top to bottom and wiped away the excess wax. When doing this you will actually see the wax turn yellow - I believe this is actually the oxidation being removed.

Once done and dry, I used Mother's Aluminum polish (I tried other wax products but this seemed to work best). Rubbing from left to right, I polished out the headlight. This will take a little time but I kept on rubbing using the same section of cloth until it literally got hot. At this stage you will see the headlight start to clear up and be clear once again.

The results are next to amazing - rock chips, bug stains and the yellow appearance were all gone. Also the light pattern at night returned next to stock. I spent about 15 minutes on each light because I am anal, but I imagine you could do this in about 10 minutes each light...

Joe
 
Nice. Report back to us how long it stays clear for. The main way that alot of people do this is bake the headlight, and remove the lens, and clean the back of the lens. That seems to be the best way, but it looks pretty tough.
 
Scott D. said:
Nice. Report back to us how long it stays clear for. The main way that alot of people do this is bake the headlight, and remove the lens, and clean the back of the lens. That seems to be the best way, but it looks pretty tough.


I have waited for some time (3 months) before saying anything about this just because I wanted to make sure for myself that it would work... Sure enough no yellowing has come back at all and still a perfectly clean surface.

For the most part as long as your headlights have been sealed and never leaked I don't know why you would want to take them appart to clean the inside. I could however see taking the headlight out to get to the underside.

This procedure is no more complicated than waxing your car + you don't have to risk burning up a headlight!
 
I've been doing that for years. I start out with 680g then work my way up to 2500grit. I then use some mothers rubbing compound and top it off with some flitz. Looks better than new when you're done. The same method will work on lexan. Don't use aluminum polish on lexan lenses. It will definitly **** them up. Acrylic lenses are ok.

EDIT: you must remember that most lenses ar no more than 1/8" thick. Excessive use of abrasives can wear them down causing cracks. best to do MY method once then just polish them with some flitz every month or when they start to get dirty. Abrasives are only nesesary on lenses that are extreamly yellow.
 
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I use some coarse compound on mine to clear them up, then regular wax on them. Lasts 3-4 months generally.
 
you know those little nubs on the lenses? they look like they were part of the mold or something. Is it okay to sand those down, or should I go around them?
there's two on the bottom, and one on the top, of each lens
Id hate to cut them down and be left with gaping holes in them!
Mine arent that yellow, so i'll just polish them, btw
 
Sure, you can sand them down if you're confident that you'll never have to properly aim your headlights again. ;)

Seriously, leave em and go around them. Mine almost appear that there would be holes if you sanded them down.
 
Do not bake the headlights, they will yellow much faster. Unless you have a crack or some type of leak in the headlight all the oxidation will be on the outside of the lens. Like the one guy said wet sanding then polishing is the best method.
I use:
600
800
1000
1500
2000
then 3m plastic cleaner
then 3m plastic polish

Comes out very nice
I would recommend repolishing every 2 to 3 months so you will never have to sand again.
 
joesturbo said:
I have waited for some time (3 months) before saying anything about this just because I wanted to make sure for myself that it would work... Sure enough no yellowing has come back at all and still a perfectly clean surface.

UPDATE!!! Still looking like new 6 months after!!!
 
back in the day when I had my 94 escort gt (1st gen protege). I used a mequiars clay bar and buffer with wax and cleaned up awesome as well, almost like new.
 

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