Cement Sediment on my paint, how do I get it off?

[AMOCHOSTO]

Hello.

I park my car in an underground parking garage beneath my office building. This structure is in the process of being renovated. A few weeks ago I saw the workmen cutting the concrete in the building with a big street cutting saw that uses water to cool the blade. The next day I saw my car had had water dripping on it from a higher level and had what appeared to be cement sediment in it. I naively assumed that I could use a high pressure water sprayer to simply rinse it off without damaging the paint. As I was going on a 13 day vacation a couple of days later I didn't try rinsing it off for a couple of weeks. When I did try to rinse it it didn't come off.

These are pictures of the roof after attempting to rinse the sediment off.

I fear that wiping off the sediment will result in severe scratching to the clearcoat.

Can any of the experts here please give me suggestions on how to address this issue?

Thank you.

[eclipsisNA]

I would blast the majority off with a pressure washer, then saturate the area with a quick detailer like Synthetic Quick Detailer and let it sit for 5 minutes. Dab off the QD with a microfiber. Do not wipe it off.

[AMOCHOSTO]

Thanks for the advice, I will try to find some Synthetic Quick Detailer I also need to buy a few microfiber towels anyway.

[eclipsisNA]

Originally Posted by AMOCHOSTO

Thanks for the advice, I will try to find some Synthetic Quick Detailer I also need to buy a few microfiber towels anyway.

Here you go:

http://www.chemicalguys.com/Spray_Wa...wac_116_16.htm
http://www.chemicalguys.com/MONSTER_...ic_1100_03.htm

[gmblack3]

http://www.topoftheline.com/cement-c...over-auto.html

[swamp2]

Originally Posted by gmblack3

http://www.topoftheline.com/cement-c...over-auto.html

^ Impressive, a fully green product as well.

To the OP: You could probably get the garage owner/management to cover a exterior detail for you. It would at least be worth pursuing, you already have the pics and proof that the stuff if hard to remove. Make a careful observation of any effect on the clear coat underneath the spots when you get it off. Uncured concrete is very reactive and I bet the slurry is as well.

[bobbyd1961]

take pictures and show it to garage attendant . they should pay for you to get it professionally cleaned. i wouldnt touch it

[AMOCHOSTO]

Originally Posted by bobbyd1961

take pictures and show it to garage attendant . they should pay for you to get it professionally cleaned. i wouldnt touch it

Originally Posted by swamp2

^ Impressive, a fully green product as well.

To the OP: You could probably get the garage owner/management to cover a exterior detail for you. It would at least be worth pursuing, you already have the pics and proof that the stuff if hard to remove. Make a careful observation of any effect on the clear coat underneath the spots when you get it off. Uncured concrete is very reactive and I bet the slurry is as well.

Good points, I have sent an e-mail with pictures and an explanation of the problem to a colleague/friend of mine who deals with our building's management. She will hound these guys for me and she has all the high up contacts to talk to.

Swamp, I believe the stuff on my car is cement that has already set (the original floor of the Garage) and was cut by one of those water cooled cement saws you sometimes see cutting lines in the street. Hopefully there has been no chemical reaction on my paint as a result. I'm more worried about the grittyness scratching the clear coat, but if there is some corrosion of the paint I will seriously be mad.

[signes]

I had a huge cement stain on my E46 a couple years ago that I tried everything to get it off. What finally worked was holding a rag soaked in white vinegar on the area for a couple of minutes. It came off in a few seconds after that. Thanks to Nick at Detailers Paradise for the suggestion.

[BCA]

I'm a former detailer and had a similar material (even worse actually) on the driver side of my first E90 about 18 months ago. I was on an interstate that was under construction and the guys were rinsing off the concrete truck. I had no choice but to drive right through their concrete-infested water.

Yours looks minor by comparison (more of a "diluted" mix of concrete). I think your best bet is to get a bucket of car wash soap, with a stronger-than-normal concentration, and a wash mitt. Soak the area very well with a hose first, and then maybe even let a wash mitt soaked in the car wash soap sit on top of the area for a few minutes to make sure it is as saturated and "soft" as it possibly can be. Then GENTLY wash the stain off using plenty of soapy water and the hose as necessary. I'd imagine that you will be able to get all the residue off. Then follow up with a clay bar and good lube to remove anything that remains. If you do any clearcoat damage, which you probably will no matter how careful you are, polish it out (or have someone else do that). Any medium- or fine-cut polish should take care of any minor clearcoat damage done. I use Menzerna polishes myself.

[MNm3]

Something similar happened to me not too long ago. Mine is either cement or road line paint. Can't be totally sure because it is just little speckles here and there. But I was recommended the clay bar approach, making sure its VERY lubricated and apply a little more pressure than usual.