Do Coatings Have UV resistance?

[Ronkh]

I don't think that a CC failure would really let us know if there are UV blockers, as there are far to many variables that could cause that.

good point

 

[SonOfOC]

I think the real world tests (cars with coatings) have proved they have enough UV protection to last at least 2 years
I've coated many cars over the last couple of years and to this date have seen no failures (oxidation, clear coat failure) as of yet!
I agree with silverfox, they would be pointless to some extent without UV blockers

I disagree, 2 years is a long time for coatings, but it is a short time for OEM clearcoat failure. When's the last time a 2 year old vehicle had clearcoat failure? With the cars you mentioned above, it is likely that a spray wax would accomplish the same thing.

This is pretty interesting. Which ones did you see last the longest?

Never really kept exact tabs, but whereas OEM headlamps can easily go 3-5 years before showing any signs of yellowing, the coatings I've applied all yellowed in less than 2 years—some as quick as 6 months. The one that seemed to last longest were ones that had multiple coats, which goes inline with what Rasky mentioned below.

The OEM coatings are also sprayed on and likely 25-50 microns thick vs. 1-2microns with hand applied coatings, so I would expect them to have much less UV protection. From my understanding of headlight restoration you also have to fully remove the failing OEM coating before you apply a new coating, if you want it to last anyway.

I agree with you regarding the thickness. Additionally, the OEM robotically sprayed coating is cured in a oven.

I don't think that a CC failure would really let us know if there are UV blockers, as there are far to many variables that could cause that.

True. I'm really surprise that manufactures of coatings don't show us some kind of UV lab testing, but they show us plenty of scratch resistance and water beading demonstrations. A clear piece of glass coated on one half can easily be measured as to how much UV gets through, in the similar way a pair of sunglasses are tested for UV protection. The buzz word with detailing product is "UV protection", but NEVER does any manufacture back up the claims with any numbers. So it is plausible that product X that has 1% UV protection—"technically" —provides UV protection.B)