Repair manuals and support for 4-wheeled passenger and cargo vehicles.

5950 Questions View all

What causes headlight clouding and best fix

I see all these kits for cleaning headlights. Some with just a wipe, others using abrasives. Is this degradation of the polycarbonate plastic or a buildup of deposits. If it can be fixed with just a wipe, what's in that stuff. Would sometime like CLR work just as well?

Does anyone have experience with these products or know what is going on with the lenses?

I found this guide for repairing but it is extensive and involves sanding and resurfacing the lens:

Answered! View the answer I have this problem too

Is this a good question?

Score 2
Add a comment
Mac RAM Kits
Speed up your Mac. Max out its memory.
Mac RAM Kits
Get more memory out of your Mac.

1 Answer

Chosen Solution

mayer, The article you posted is excellent and the thing that attacks(fogging) the exterior plastic headlight lenses the most is probably exposure UV rays from the sun it self, I say this because I have noticed that garage kept cars/auto's seldom need headlights restored. Although there are other harmful stuff like sand/stone chips/acid rain/using Windex or other chemical cleaners not meant to clean plastics,etc. For instance some people like to drive in the draft of large trucks and in doing this the head lights/windshield/paint job are constantly being sand blasted with the debri off the roads. I do not CLR will remove the fogging as the top layer coating or of the plastic will have to be removed unless it is very,very light fogging. As for what is in the kits there is the common buffing compound as for the other wipes perhaps a silicone type substance I am not sure, may be on the label.

I have had success using the mothers type headlight restoration kit with the sanding pads/buffing wheel which attaches to drill, lens polish and sealer. The most important thing I have found was when using the power drill with attached polishing pad was to keep the RPM's down, keep pad a little damp(misting bottle/clean water) and keep it moving(do not run in one spot too long) or you could actually melt the plastic lens. If headlight is easily removable, I will do this sometimes to save from having to masking tape up paint job/ bumper/fenders/etc..

If fogging/scratches are not too severe, you can often get away with just polishing the lens after giving it a good cleaning with car soap. Some people I have noticed on you tube are actually putting a clear coat of enamel on their headlight lenses after doing the restore procedure(this may be iffy) as if you get a scratches there is a possibility you would may have to do extensive wet sanding to remove all the clear coat. I think just use a good compatible car wax in place of clear coat enamel.

So there you have it, if possible park car inside, park with head lights(front end close to a wall to shade from UV rays) and lights will stay good normally or you may have to polish them again in a couple years if left exposed to the outside environment.

Was this answer helpful?

Score 2


Thanks for the really excellent answer ;-)


mayer, You are welcome, hope it helps you and others.


Add a comment

Add your answer

mayer will be eternally grateful.
View Statistics:

Past 24 Hours: 1

Past 7 Days: 8

Past 30 Days: 26

All Time: 124