Crackled Paint
Tin-top wing repainted. I flatted down the old paint, fillered a couple of minor holes, and Halfrauds spray painted with primer (maybe the mistake)
and paint, then clearcoated it. It looked great for a year or two, but started to look dull. This last 18 months or so it has started to crack
everywhere - around the filled holes, all over the upper sun-facing surface, but not on the vertical surfaces. Thoughts on how not to repeat it?
Crackled Paint
Looks similar to the bonnet on the hairdressers.
It's either Halfrauds lacquer or a reaction between the colour coat and the residue from polish etc left on the surface when you painted it.
Did you properly de-grease before colour coating?
I'll watch in case someone more knowledgeable comes along.
Yeah I properly degreased everything and sanded most of the way through the old lacquer before washing with alcohol wipes and then drying. It's taken a very long time to do this and I'm wondering if it's heat or UV exacerbated, because the bulk of the panel is fine. I think I went a bit thick with base coats but nothing crazy. I then baked it with an IR heater for about 2 hours.
I was told many years ago by a very good bodywork guy, that crazing like that, was caused by excessive paint thickness. Usually original paint not rubbed back far enough plus new put on to thick.
The more I search online, the more I think you're right adithorp. I'm not really sure how I'm going to correct it without starting from scratch or pulling the whole thing back to bare metal to be honest - not a task I wanted to do.
Let's aork on the basis the panel needs to be stripped to bare metal and start from scratch. Symapthise that's a hell of a task and not one
many of us would want to take on either.
If it's a front wing, would it be an option to get a new wing, paint it off the car, then fit it?
If it's a rear wing (often welding and more effort required) then that may not be an option.
Alternative - get a couples of bodyshops to price up repainting it for you?
I think Adi is correct. I had exactly the same problem on a rear arch.
I sanded it back smooth and put on another coat of base and clear, it was OK for a week but slowly came back
Then I decided to cut it back as is, with G3 Premium. It took a while and was messy, but has been OK for about a year 
This was with uPol paint, so not a branding issue.
Knock it back as far as the original undercoat I think... as long as that's not crazed as well.
Used to see it a lot where people had a cheap respray done. Cheap because they just flatted the old paint.
Might get away with a good wet and dry rub back and relacquering?
Eesh I think a weekend of painting is in my future. I might pay someone to sandblast it back as I can't be bothered sanding it all back and while
I would normally just whip on a new wing, these aren't available anymore and it has a bloody great snorkel mounting arrangement crafted into it.
The bonnet needs taking back to base too because of lacquer peel and I'm sure I'll cut through the base so I might as well just admit I need
to bare metal both. I was hoping this would be a cheap task but when it comes to paint it never is!
quote:
Originally posted by coyoteboy
Eesh I think a weekend of painting is in my future. I might pay someone to sandblast it back as I can't be bothered sanding it all back and while I would normally just whip on a new wing, these aren't available anymore and it has a bloody great snorkel mounting arrangement crafted into it.
The bonnet needs taking back to base too because of lacquer peel and I'm sure I'll cut through the base so I might as well just admit I need to bare metal both. I was hoping this would be a cheap task but when it comes to paint it never is!