Paint defects - trying to figure them out

[SRTSean]

A friend has a '99 Mercedes C43 AMG with silver paint. I've detailed it a couple times, each time noticing a few areas of straight lines that look like scratches. They polish out, and then come back the same as they were before after about a month, and in the exact same spots.

I'm almost thinking that the clear coat is cracking. The marks aren't from washing/drying - I've personally helped him buy all the right stuff and shown him how to properly take care of the paint.

Any ideas based on the picture below?

 

[Mike PhillipsMike Phillips is verified member.]

I'm almost thinking that the clear coat is cracking.

Clearcoats can crack. They can look like scratches but they're cracks running throughout the layer of paint.

Happens most I think on flexible body components like Urethane bumpers, spoilers and anything really that's flexible.

 

[Mike PhillipsMike Phillips is verified member.]

The side panels on the 1982 Corvette with the original paint had cracks running throughout the clear layer of paint. Somewhere on my old laptop I might have pictures of the cracks...


April's Corvette. April is also known as "The Vette Lady"

Here's a model of her car

This is a 1982 Special Edition with the original factory clear coat and graphics. The clear coat is not perfect but considering all the changes taking place in automotive coatings and the switch from single stage to basecoat/clear coat paints in the early 1980's it's actually still in very good condition.

 

[Mike PhillipsMike Phillips is verified member.]

Dang... forgot I had this article on the topic with pictures....

Clearcoat Fracturing versus Clearcoat Failure


Pictures courtesy of Jacob aka timaishu
The term Clearcoat Fracturing by Dave aka tuscarora dave


Clearcoat Fracturing

 

[SRTSean]

Mike, HUGE thank you for the pics you posted. Unfortunately, that is EXACTLY what these trouble spots of paint look like.

 

[KMdef9]

I see alot chips from driving too.