New Car paint discolouration problem

[QuattroTT]

Quick update....I no longer live in Europe or drive a (black) TT, I've been through a Porsche Cayman R (black), replaced with a Cayenne (Black) and then replaced my wife's Macan with a 2019 MX-5 RF GT....this is where we are today. I love the car, just a gas to drive...but....I hated the big shark fin antenna on the trunk lid so I found on eBay a smaller, knob type antenna like all Porsches have, got it painted to match my car (Mechanic Grey Metallic) and easily enough removed the shark fin and installed the smaller part. Looks great EXCEPT that the paint under where the shark fin was and is now visible, is lighter - almost like a cloud, although the surface is smooth and glossy. I'm guessing damage from humidity when the paint was still new or simply an area of paint that did not oxidize like the rest of the car. The car has just under 2,300 km on it (1,429 miles) and has been a garage queen the whole time I've owned it from new....which eliminates any other causes. The shark fin did not have direct contact with the paint in that area since these parts sit on a perimeter gasket.

Any thoughts on what it might be and what I might try to correct it? Could it correct itself? I have arsenal of Menzerna and other stuff ready to go...and time on my hands. The car will be hibernating under its cover for the winter in about two weeks or less.

[SWETM]

Try to polishing it with the least aggressive Menzerna polish you have and a finishing pad. It's probebly oxidized rubber from the gasket that was between the shark fin antenna and the paint. That's a little hard to clean up. With a fine polish you will clean it up nicely I think. If you can remove the new antenna I would do so so you reach to clean the old stuff off. You can also try with an IPA or a panel prep wipe product which useally is effective on these kind of oxidized rubber stains. Just take your time and work from the outside of the stained spot and in to the hole of the antenna. So you don't spread this stain out on the clean paint. You can handpolishing it too if you want to and the same work from the outside and in. Start with cleaning it as good as possible. Use an APC and see what it takes you. Follow with an IPA or a panel prep wipe product or even a tar remover or mineral spirits a kind of a solvent to see if you are able to desolve most of it or all of it. Change regualar to a clean side of the mf towel you clean and soak up the cleaner you use. Also here when you clean work from the outside and in to the center of the stain. Maybe it's only needed to be cleaned this way or the light polishing will clean up the rest. Clean it up afterwards and put some protection product on it and done.

Don't think since you have driven the car so little and garaged the rest. That the paints base coat color layer has been faded from the UV. So you would be seeing awesome results from it when you are done.

/ Tony

[QuattroTT]

Thanks Tony....I think you may have identified the problem. The Porsche part has only a thin gasket on the perimeter of the part whereas the Mazda part has a full rubber base (presumably because it is twice the size). I'm going to give your prescription a try. Again....thanks very much for your clearly expert advice.

Tack så mycket! (I used to work for SAS hotels)

[SWETM]

Varsågod! (You're welcome)

Cool that you have worked at SAS Hotels! Have you been in Sweden for your job? In the little town I live in called Ronneby in Sweden. They have a big hotel and conferance center that has been owned by SAS if IIRC called Ronneby Brunn. But think that they have sold it but not sure.

Tell us if it worked for you to clean it up this way. On newer vehicals it's useally no problems with doing it. And as always don't let any chemicals dry on the paint and you will be fine. With older paints you can have a big difference in the shade of the color of the paint when you take off like debadge or replace with something else that expose the before covered paint. The UV makes an impact on the base coat color layer over the years. Even if you maintain it great it's going to be some fading to the paint sadly. The less if you have it as a garage queen from the start.

Hope it works for you and happy to help!

/ Tony

[QuattroTT]

Gave it a try with no joy. I've attached a photo that shows the discolouration after I worked on it. Frankly, it has not diminished. It's either all the way through the clear coat or into the paint. It's really only visible in certain like....like daylight, which sucks.

I have been to Ronneby (and Stockholm of course, Malmo, Vasteras, Gothenburg, Lulea, Karlstad, Linkoping, Uppsala, Falun and Gavle...). I think I only went once to Ronneby, pretty town as I remember it (but then, you have to work pretty hard to be an ugly town in Sweden). The hotel there was franchised and I believe it's gone back to being an independent property.

[Bobby B.]

It could be moisture trapped underneath the clear coat. It might correct itself over time in the sun.

[QuattroTT]

It could be moisture trapped underneath the clear coat. It might correct itself over time in the sun.

Does kind of look like that. Well, if we get a few more days of sun before it's tucked away under it's cover for the winter, I'll leave it out....with about 1,500 miles on it, and being garaged, I have to admit it has not spent much time in the sun. Thanks!

[SWETM]

Does kind of look like that. Well, if we get a few more days of sun before it's tucked away under it's cover for the winter, I'll leave it out....with about 1,500 miles on it, and being garaged, I have to admit it has not spent much time in the sun. Thanks!

Does it feels like smooth paint or has it any kind of roughness? If it's smooth like the surrounding paint it's probebly like Bobby B mentions moisture under the clearcoat. I would actually take off the new antenna if you can so the paint dries up under there too.

Did you try to polishing or cleaning?

The world is small sometimes. Ronneby is a very little city or more like a town. I like the surroundings where Ronneby Brunn is with the big park and all. I live in a small village when you drive north to Växjö. So live out on the country LOL. Yeah we many beutieful cities and where they have the really old streets with houses from 1500-1600 still left is very nice.

Wow you have seen and been to all of the places from south to north and west and east and in the middle of Sweden LOL. So you have much of Sweden

Hope you get it sorted out with the stain. Worst case you maybe can put back the old antenna and make a warranty claim of it.

/ Tony