What is this?

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Strangest thing I've seen in 13 years of polishing paint. These are pics of the driver side decklid of a 2011 E550 I just completed. If you look closely you'll see a ring roughly 10 inches in diameter. The ring essentially surrounds the only area on the car that had any rids. And there are a lot of them in the area. Also, the only area of the car to have any "noticeable" swirls was the decklid and there were a lot of them.

None of this was visible until I hit it with SI 1500. The clear coat is in good shape. 105 microns which is slightly above average for the entire car. It really jumped out on the first pass. I compounded it with FG400 but it didn't resolve.

Any ideas?

 

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...I spent 10 hours on the car and the owner had me drive it to his country club and leave it in the parking lot in a downpour.
:dunno:

 

[jrs1418]

To me, it looks like maybe the customer parks on a hill that allows the hard water to pool onto an area that water would normall run off of, and left a hard water stain/etch.

The rids was probably the customer trying to remove that ring himself

 

[dcjredline]

Most likely an etching from something that sat on the car too long. If FG400 wont get it out then you may be at the point its better to leave it or respray. You could try wet sanding but probably not worth it.

 

[Hokie335i]

I've seen marks like that from leaves sitting on the paint for too long in certain conditions or when the leaf has something on it when it hits the paint.

 

[AutowerxDetailing]

I see this all the time on cars that have been cheaply repainted. if there is severe oxidation on the surface, and if the panel is not properly prepped, there will be outlines of the previous damage after the new paint film is applied. It looks exactly like what is in your picture. Do you know if this vehicle has been repainted?

 

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I don't know for certain if the decklid was repainted but I will ask the owner. My suspect is it was repainted. Compared to the rest of the car, there were a lot scratches and swirls on that area of the decklid. The quarter pane/bumper area just below it had a few lousy touchups and a few remaining deep scratches from a minor scrape.

My theory is whoever did the bumper/quarter panel "touchups" caused the ring and tried to cover it up. Maybe let something evaporate that penetrated the paint system. But if that were the case then their coverup was a heck of a lot more professional than their touchup. :laughing: