Headlight Restoration Peeling/Flaking?

[btvm92]

I restored my headlights less than 6 months ago with the spar urethane/mineral spirits method.. It appeared to work perfectly and this is the only headlight I've had do this to me. It appeared to happen overnight, I just noticed it one day, now it's just slowly flaking away. I'm about to redo it but I'm wondering what caused it? Especially considering I've been swearing by this method since I've done it..

[alien_brain]

the coat was too thin / diluted too far? my guess. you came into contact with derbis / road acid

[Racin2redline]

could have been surface contamination that caused a reaction with the finish.

being spar varnish is oil based my guess is some water got under the finish

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[V1nny]

https://www.amazon.com/3M-39045-Head.../dp/B004GFTC0E
urethane coating is a wrong way of doing it. Once lens plastic changed it's optical properties, it needs to be removed, not coated.

[arjun90]

Lol, check out my headlights, someone used the wrong-grit sandpaper on my driver-side headlight *cough*
Pictures to follow...

I still haven't tackled the damage, but do intend to use the right grit-sandpaper in increments followed by "Clear Coat"
Hopefully, will look great at the end

[bpark1210]

I have the same issue on both my headlights. I went w/ the urethane spar/mineral spirits dilution but less than 6 months later it's peeling. Prob didn't help w/ all the rain we get and driving over 100mph through the mountain passes. I bit the bullet and bought some Opti Lens Permanent coating as some others have suggested. I'll be reporting back on my build thread once I get my lazy a** to start my S6 project again.

[V1nny]

why keep coating, when opposite is needed?

[alien_brain]

so vinny youre saying to polish is the right way

[forcefed7]

If that was my car, i'd sand that headlight down real good, then buff it good, wash it good, then spar it again.

[alien_brain]

the spar needs a textured surface to hold onto. ok so maybe polishing is a better idea for longevity. otoh my other headlight didnt peel yet. yeah ill bet a contaminant got in there. if you do it in a garage where you smell oil in the air, well theres your answer. oil from the air got onto the headlight surface before you spar'd it. either that or derbis chipped a small bit enough for high pressure water to get into and behind the layer of urethane.

[V1nny]

https://www.amazon.com/3M-Headlight-.../dp/B00WY5L09O
and a good corded drill is all you need, it even includes UV protecting compound. It takes a good amount of work to remove your urethane coating, then remove yellowed layer of plastic (bonus: getting rid of pitting), then polish. Headlights will look like new for years, as long as you reapply UV protectant stuff couple of times a year.

[CJKaz]

Get the X-Pel film. Did mine almost ten years ago, still in perfect condition.

http://www.xpel.com/headlight-protec...A6/Sedan/2.7T/