I'd have to agree with Keith on this one, your best bet to do anything is remove existing paint completely and start over,

 

I did... I removed all of the paint. Sanded it off until it was smooth and buffed until it was clear. Cleaned with soap + water. Cleaned with rubbing alcohol. Could not see nor feel any residue. I spray some paint on, and the paint slowly separates into the 'cracks' in the picture, which seemed to have literally come up out of the plastic on its own.

I think I'm just going to buy a new headlight.

 

Highlighted a few thing i want to point out

1:d buffed until it was clear
what did you use to buff? compund? wax?

being you are putting paint on top of what you just did it wouldn't be bad idea to leave some roughtness so buffing is kind of pointless, the best time to buff is after all your paint is on and your clearcoat is laid down and hardend then wet sand and buff then

2: Cleaned with soap + water.
What kind of soap did you use? depending on the soap it could leave a wax(carwash soap), scented can leave the scent extract or any with lotion in it would leave loation on the surface

3: Cleaned with rubbing alcohol
how long did it sit before you went to paint?
What % achohol was it?

different % alchohol will evaproate at diffent rate

i use wax and grease remover befor any painting and have not had an issue, it's designed for the job so why not
4: I spray some paint on
Just paint? no adheasion premoter? heavy coat or light coats? did you give time between each coat?

being it is a plastic paint doesn't adear greatly to it thus needing a primer (adhesion promoter is a clear primer and works great)

i could be wrong on some of my points as i do not do this for a living, but it does seem like a prep issue, rember 80%prep 20 % paint

 

that is a strange issue. I Dont think i would have the patience to keep redoing it. Good Luck

 

I used a product intended for clearing oxidation from headlights. Forget what it's called. You sand with 500gr, then 800, then 3000 then rubbing compound and a foam buffer. It's all part of the kit.

If I left any of it rough, the headlight wouldn't be clear and there would be rough spots easily visible against the clarity of the reset of the headlight? I don't see why you would recommend that.

You might be on to something with the soap... I just used a hand soap. Didn't aggravate any of the lens that wasn't already damaged though.

Rubbing alcohol... couple of minutes. Not sure what %. Bought it at walmart or something.

As far as prep, I've done it the way I did it before and it has always worked fine for me. The only problems occurred in those specific spots. I've never needed an adhesion promoter before.

Basically what I did to temporarily fix it was re-sand it, cover it in a layer of the same vinyl, then spray over it. The 'cracks' don't show through. So it worked as a temporary fix. I am pretty sure what it is is that I somehow managed to burn some of the adhesive backing on the vinyl literally INTO the headlight plastic, so there really is no fixing it. That's just what it seems like to me.

 

Maybe your lights are haunted by ghost ? Maybe ?
If you replace, I would replace them with something like
below "Ghost lights ~>

It is the season 4 them

Sorry 4 the highjack

 

Looks like an adhesion issue to me. I have seen this happen on other things not a headlight. How hard did you lay down the spray on it? You could sand and clean it up one more time and just barely dust the stuff on as light as possible and multi-coat it. It may solve the issue your having. If you buffed that super smooth that may even have prevented the adhesion. But again light dustings over and over would probably solve this.

Best of luck I know exactly what you are going through having had some projects go sideways on me a few times.

 

Looks like an adhesion issue to me. I have seen this happen on other things not a headlight. How hard did you lay down the spray on it? You could sand and clean it up one more time and just barely dust the stuff on as light as possible and multi-coat it. It may solve the issue your having. If you buffed that super smooth that may even have prevented the adhesion. But again light dustings over and over would probably solve this.

It would actually fill the rough area and make it no longer exist when finished. When you go through the process before you buff the surface and it is still rough from that 3000 grain paper. Take a dab of water and get a spot wet because that will show you better what I mean. It may still look slightly rough with just water but it will be much more clear than areas that are dry and rough. The stuff you spray will fill in that roughness completely as if it were never there at all and it will also adhere very well to the surface making it last quite a bit longer too.

Best of luck I know exactly what you are going through having had some projects go sideways on me a few times.