My car is a black 997S and I live in a high rise condo in Atlanta with open-air parking garage. Even though it's covered parking, whenever we get a rain with a lot of humidity, the entire inside of the garage gets covered with moisture that drips from the ceiling onto the cars. It leaves these awful white concrete colored water spots that will not fully come off with a normal wash. I'm now left with white rings where all the water spots dried - very noticeable on my black car.

Anyone else have this problem or have suggestions? I washed it the very next morning after the rain cleared but it still left spots. Will it do more permanent damage if I wait a while to have the car detailed?

 

The damage can be made worse the longer you let things go. A simple polish and waxing will help minimize further damage and will most likely clear up what you have. Once you have a proper wax on the car, it's easy for you to either wash off the spots or simply use a mild paint cleanser to remove stubborn spots.

Here's a good kit that'll get you started:

http://www.glisteningperfectionstore...Wax-Kit/Detail

 

I don't want to pretend to be any sort of expert detailer here. I'm not.
Take Mo's and Phil's advice.
BUT...let me suggest that it's possible that you're in a world of hurt. (Sorry)
Moisture condensation from concrete is corrosive and wickedly difficult to extract from dark paint.....at least in most cases it is. Maybe you get lucky and it isn't, for you.
Not trying to be alarmist, but I read an account of one owner who tried to have a similar problem corrected at a dealership..... it didn't work out well.... at all.
I guess the point is here is this - before you do anything, do a bunch of research, here and elsewhere. Proceed stepwise, starting with the least aggressive method you see. If you decide to have someone else do the work for you, have a long conversation about exactly they'll go about it. Make certain they're insured.
And get yourself a good car cover, or maybe one of those art-fair booth things.
Best of luck.
I'm really not trying to be alarmist.

 

A very good point Tom. I'm hoping the damage the OP asked about isn't too sever and can be remedied with a mild polish like 1Z Paint Polish. The wax should help him avoid sever damage should the problem persist.

 

If not removed very quickly, this can cause permanent damage. The lye in the concrete is highly accidic, and can severly damage the clearcoat. You will probably have to have the areas wetsanded, but with the thin paint on Porsches, it's very important to take paint thickness measurements before wetsanding. In the future, keep a very durable sealant like Nanoskin on the paint, and it should hold up better.

 

Since there are a lot of different concrete formulations plus various additives, sealants, and things that may leeched into the concrete, there's no way to know for certain what's on your paint. Sadly, you'll need to experiment.

Check out this link:
http://www.ls1tech.com/forums/appear...pots-help.html
for some possibilities. They follow the 'least aggressive first' method.
Good luck. I hope it works out.

 

Good advise for he removal of 'water spots', however-

Calcified Water Marks

Often found from parking in municipal or underground parking facilities, calcified water spots on paint and glass, water and concrete spots are pretty much the same chemically; they are consist of calcium (Ca) and magnesium (Mg) both of which are basic (alkaline pH 10) with the concrete being cross-linked with water

Correction
· These can usually be removed by using detailer's clay to remove any hardened surface deposits
a) Apply 1:1 ratio distilled water with distilled White Vinegar (Acetic acid) solution, and using a spray bottle, spray that mixture on the spots and let them "soak." Then rinse with water and repeat as necessary.
b) If the ambient temperature water/vinegar mix does not work, warm (100-120 degrees) 100% distilled White Vinegar, saturate a clean kitchen sponge with pure vinegar and hold the sponge over the concrete spots for a few minutes
c) If the above do not remove them try equal parts distilled water, isopropyl alcohol and distilled white vinegar. The acid in the vinegar will help etch and dissolve the concrete.
· Rinse the area thoroughly with water after the vinegar and then reapply wax or sealant to that area.
· To remove any surface etching use a machine polish ( Optimum Polish, Optimum Compound, Z-PC Fusion Dual Action Paint Cleaner or Klasse All-In-One (AIO) and a cutting (LC Orange or Yellow) foam pad (speed # 4-5.0 ) to level the surface (use the least aggressive polish/foam pad first, if this doesn’t remove the problem step-up to a more aggressive set-up)
· Work on a very small area at a time (2-foot x 2-foot) until the polish has run out
· Repeat this process two or three times, as necessary
· If none of the above methods remove the etched water spots consider wet-sanding the paint finish
· Reapply surface protection once spots have been removed

 

Good advice, no doubt TOGWT.
Posts #16 and #17 from the previous link
http://www.ls1tech.com/forums/appear...pots-help.html
recommend exactly the same methods.
That topic also contains some less aggressive suggestions, which I'd agree are also less likely to be 100% effective. But that's where I'd start. Who knows. Maybe JTAYLORGT's paint sealant/wax/whatever was especially effective and he's lucky. Hope so.

 

Thanks guys for all the help - I ended up taking it in to my detail guy who's really good and knew exactly the issue. He sees this commonly with cars parked at the airport or in city garages all the time. The lye and calcium in the concrete leaves calcium deposits on the car even after washing. Fortunately, I caught it in time and was lucky the car had been sealed with TechShield Polymer Sealant just 3-4 months prior - so I was protected.

Regardless, the spots still required special treatment. As some of you have recommended, they had to wash the car, apply an acetic acid spot treatment, re-wash the car, then polish and re-seal it with the polymer sealant. About $125 later, problem solved - the car was covered with these spots so the price to remove them was well worth it.

Next move - a good car cover for when I'm out of town. Can't risk this happening again! More long term plan is to move out of this high rise condo with open-air garage parking and get a house with a proper enclosed garage!

Thanks again for everyone's help!

 

I'm glad it all worked out well for you...

 

Glad this had a happy ending.