What is this paint defect?

[BlackPearl09]

Hi,

I have started trying to improve the paint finish on my 2009 w211 but have noticed this paint defect on the boot lid. It isn't anywhere else on the car and it has never been repainted. It appears to be deep in the paint and concentrated in the middle third. So far it has been suggested it might be a reaction to the boot being made from aluminium or that is was always like that and I have just seen it due to me giving it extra attention. It is really hard to photograph but hopefully you will see the distortion, especially around the house windows.

Thanks for looking!

 

[Petrol Pete]

Its a 12 year old mass produced car , looks OK to me for the price.

 

[markjay]

Could it be the result of bird droppings that have been left for longer than they should? By a previous owner, perhaps?

 

[BlackPearl09]

Could it be the result of bird droppings that have been left for longer than they should? By a previous owner, perhaps?

Cheers, only one previous owner and that is my father in law. While not really into detailing he did keep washed and garaged in the main. Another thing to consider though, but really curious it's just in this band across boot lid. Black does seem to show every defect though!!

 

[BlackPearl09]

Its a 12 year old mass produced car , looks OK to me for the price.

Didn't mention a price pete and it looks amazing for 12 years old. I stand back and can't quite believe it myself, doesnt stop me wanting to get the best out of it though. I will post some better pics when I have finished a few more bits.

 

[markjay]

[QUOTE="BlackPearl09, post: 3050309, member: ...it's just in this band across boot lid...[/QUOTE]

The bird's flight path.....?

BTW, I am not convinced that it can't be polished-out with a DA and a mild rubbing compound (though the entire boot will need to be done, not just the affected areas).

 

[BlackPearl09]

[QUOTE="BlackPearl09, post: 3050309, member: ...it's just in this band across boot lid...

The bird's flight path.....?

BTW, I am not convinced that it can't be polished-out with a DA and a mild rubbing compound (though the entire boot will need to be done, not just the affected areas).
[/QUOTE]

Cheers Mark,

Probably going to get a DA before I polish again before winter. Still a novice but loving the result I am getting, the advice received on here as been very useful.

 

[LTD]

Is it just due to the curve of the metal ?

 

[LeeJV]

Its really difficult to see buddy, generally bird etching is more prominent on black paint, it may be that, if so could polish out depending on how bad it is

Try a 2 stage correction buddy, if you can get a really good gloss level it become less noticeable

 

[BlackPearl09]

Is it just due to the curve of the metal ?

I will have a look that might explain why they are focused in that area. There is hundreds of little pimple like marks and once you see them you cant unsee them, very hard to photograph though.

 

[BlackPearl09]

Its really difficult to see buddy, generally bird etching is more prominent on black paint, it may be that, if so could polish out depending on how bad it is

Try a 2 stage correction buddy, if you can get a really good gloss level it become less noticeable

Hi Lee,

I always value and appreciate your input. I have spent lots of time googling and trying to sort an answer myself. The only pictures online that look anything like are air trapping, dirt contamination and pinholing. The defective is definitely under the clearcoat. The car is looking amazing though having followed some of your tips. The snow cannon works a treat and the hose from direct hoses is a god send getting around the car without dragging the machine.

 

[oldguy57]

Pimple type marks all over a panel can be associated with trapped moisture or a poor paint application, like some have seen on Fire Opal red cars. I doubt that machine polishing will cure it unless the problem is confined to the clear coat. Worth a try though. Otherwise a bare metal respray of the boot is the only real way to eliminate. Painting on top will inevitably see a recurrence. I wonder whether the boot was damaged prior to original sale and the bodyshop gave it a quick respray to cover up.

 

[BlackPearl09]

Pimple type marks all over a panel can be associated with trapped moisture or a poor paint application, like some have seen on Fire Opal red cars. I doubt that machine polishing will cure it unless the problem is confined to the clear coat. Worth a try though. Otherwise a bare metal respray of the boot is the only real way to eliminate. Painting on top will inevitably see a recurrence. I wonder whether the boot was damaged prior to original sale and the bodyshop gave it a quick respray to cover up.

Hi,

This is my gut feeling to be honest, I am going to try and improve the gloss like Lee suggests. I think I am going to have to try not to look at it, you can only see it from certain angles. Thanks for your reply

 

[LeeJV]

Ah, if its a pimple effect, then as above that would suggest solvent popping.

There are several reasons for this.
Base coat primer hadn't flashed correctly prior to colour and clearcoat, resulting in the thinners gasses getting trapped under the clearcoat.

Or it could also be that a sealant was applied to the paint too soon after painting, if the clearcoat hasn't gassed then it would cause the pimple.
There's quite a few reason why this happens over a period of time, and not uncommon, mainly seen more on red paint, or poor smart repairs