Headlight sealing after restoration?

SayNoToPistons

New member
I recently restored a pair of headlights. They weren't in terrible condition but showed signs of hazing and yellowing. I used 2000 grit sand paper then SSR 2.5 with a 4" pad on a PC. It turned out great.



Now the question is... What is the best and more durable way to seal the headlights? I am sure that the headlights came with some sort of protective coating which deteriorated over time. I'm looking for more than just a simple LSP one would use on paint because it doesn't seem like it would do an adequate job on plastic headlights.... Or does it?
 
I've used Collinite 845, Krylon Clear spray gloss, and other paint sealants. All in the past 6-7 months. No problems yet. My next try is going to be the 50/50 of mineral spirits and valspar clear gloss acrylic.
 
The Krylon sort of diffused the clarity a bit, bringing me a 1/4 step backwards. I then polished the Krylon coating to restore the clarity a bit. The car owner was thrilled with the results, but although it was a HUGE improvement, I was a little less than thrilled.

Of course, I'm no expert rattle can painter, so maybe it was the way I applied it?

Not sure, but after seeing that little bit of diffusion, I knew my search for a perfect sealant hadn't ended.

My next set of headlights will get the Valspar/mineral spirit mix.
 
That's exactly the Krylon I used. I waited about 45 minutes, hoping it would get a little clearer as it dried. Then I polished.
 
Is it possible to restore headlights by hand without a orbital buffer? I have 2000 grit sand paper but I don't have a buffer. :(
 
Yes but you will have a lot of work to do. You need some type of polish like McGuiars Scratch X, or better Men. SIP. Use Plexus Plastic Cleaner to maintain a clear finish.





tquill said:
Is it possible to restore headlights by hand without a orbital buffer? I have 2000 grit sand paper but I don't have a buffer. :(
 
Should I still use the sand paper though? I did a little test spot with the sand paper and it definitely fogged the area up a bit. If I followed it with scratch X or Plexus plastic cleaner would that shine it up again?
 
When you follow up with the polish it will become clear again. Good luck, been there, done that.



tquill said:
Should I still use the sand paper though? I did a little test spot with the sand paper and it definitely fogged the area up a bit. If I followed it with scratch X or Plexus plastic cleaner would that shine it up again?
 
tquill said:
Should I still use the sand paper though? I did a little test spot with the sand paper and it definitely fogged the area up a bit. If I followed it with scratch X or Plexus plastic cleaner would that shine it up again?



Plexus is a great product for cleaning, protectant and maintaining a clear finish but it will not remove sanding scratches. We recommend using a drill or machine polisher, foam pads and plastic polishes to restore the shine and clarity.



Take a look at the Headlight Restoration Guides at Autogeek
 
I like Collinite or Klasse on Headlights.



I've been doing it for the past year and have not had a problem with fogging or oxidation.
 
jason@autogeek said:
Plexus is a great product for cleaning, protectant and maintaining a clear finish but it will not remove sanding scratches. We recommend using a drill or machine polisher, foam pads and plastic polishes to restore the shine and clarity.



I just did my headlights this weekend and removed the sanding scratches (from 1500 paper) using Turtle Wax polish and a 6" Ryobi buffer with the Terry cloth bonnet. My point being that since plastic is so soft pretty much any polish (which would normally have been used on glass or metal) should work. In this case the polish quickly eliminated the scratches, but more polishing past that point dropped little 2-3 mm blobs of polish onto the lens. The blobs wiped off easily with a paper towel, and the regions under them didn't look any different than elsewhere on the headlight. Probably I used too much polish. Finished up with PlastX, which didn't make the lenses any clearer, since they were already very clear, but hopefully protected them a bit from UV.



On two other cars I have used PlastX every 6 months or so. In one case it has been 4 years starting on 3 year old headlights, and the other it was 10 years on brand new headlights. Neither car's lights hazed at all. I'm a lot less confident that PlastX will protect these sanded headlights (on a "new" used car) that well though.
 
another qx4 said:
It seems like the oxidation on the headlights I polished is coming back after a few weeks.





This has been my experience, too. The condition returns and is often worse. I've seen some severe problems on VWs to the point the lights are just barely usable at night :nervous:



I agree with Jason's recommendation on the PLEXUS. That's what I've been doing and it seems to slow the detioration way down. I bought a can of PLEXUS 6 years ago and I think it's still half full. You don't need much and it's an excellent product to have on hand for all sorts of apps.



The only other long-term solution I've seen (apart from not driving the car) is that 3M/Xpel type of laminate which is the film that is applied when the lights are still in good condition, if not when brand new. However, I've heard of people having problems with this stuff when they attempt to remove it. This car has the film over the headlights and high beams and everything still appears as new:



75195639.jpg
 
I have had good results with 303. I douse the lens with it, let it dry for a few hours then do a spray and wipe application, I then do a spray and wipe after every wash.
 
gofastman said:
I have had good results with 303. I douse the lens with it, let it dry for a few hours then do a spray and wipe application, I then do a spray and wipe after every wash.



There are a bunch of products along these lines that can be used to treat headlights: Plexus, PlastX, 303, and many others. None of these are permanent or even close to it. Even things that have names which suggest permanence are not. For instance, there is "Diamondite Clear Plastic Liquid Armor", which sounds like it should last forever, but in its own literature says "provides UP TO 3 months of durable protection against pollution, moisture, and UV rays" (emphasis mine).



So for a more permanent surface treatment the only real option that I know of is clear coat, or a near facsimile. In the latter category, some folks apply Helmsman Spar Urethane 50/50 with paint thinner on a rag. They claim to be able to apply it in a smooth coat, and I guess I believe them, even though when I have used urethane on wood it tends to have very obvious surface texture when dry. Here is a link discussing this method for headlights:



Headlight Restoration-new UV sealant idea - Auto Geek Online Auto Detailing Forum



However, Minwax's site indicates that that stuff is supposed to "amber", ie, yellow. The water based version, on the other hand, is supposed to dry "crystal clear", ie, not yellow. This stuff is pretty tough, as it is designed for protecting wood in marine environments. Difficult as its intended environment is, it is not really, really hot, which the surface of a headlight can be. Long term results (measured in years) for any of these "permanent" solutions are very hard to find on the web. What is "clear" is that if they fail these protective coats can be a pain to remove.



The original factory headlight surface treatment seems to be fairly involved, requiring light triggered polymerization, see:



Headlight coating



and



The Next Generation in Weatherable Hardcoats for Polycarbonate - Archives - Paint and Coatings Industry



Which is probably why one doesn't find the chemicals for this on the shelf at the local Autozone, ready to be wiped on a recently sanded headlight.
 
Any thoughts on the combined usage of a paint sealant and one of the dedicated plastic UV protectants? I wondered if one could top the sealant but I have no idea about the polymer chemistry that might be involved.
 
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