Removing Concrete Residue, Courtesy of the Hurricane

Just got word from the caretaker who looks after my friends' garage in FL where I store my car. She says that while the garage is intact, the roof leaked, leaving dried concrete residue on my car (and some of theirs too).Apparently it came through the car cover and dried on the paint (won't know for sure until I fly down tomorrow evening and take a look). Does anyone have any experience in removing this stuff without damaging the paint? Thanks.

 

YEEEEK. Can't help ya there buddy.

 

You should be able to just hose it down, then carefully wipe it off. Once concrete dries, its really no different than a rock. The cement and various Calcium components of concrete are very basic and would damage your paint in their raw forms, but once it sets, I don't think it can harm anything. It shouldn't be any different than dried on dust/dirt.

 

Make sure you do not use high pressure. Just pour some wter on it first, let it soak for awhile, DO NOT LET IT SIT IN THE SUN. The sun will "bake" it on harder. Do you have the car clear coated?

 

Yeah, my initial inclination (not having actually seen it yet) is to soak the hell out of it and try to gently clean it off once it's been rehydrated. I'm hoping that the cover kept this to a minimum . . . Thanks.

 

once you wash off the main residue, you may be faced w/ some minor etching of the paint since a component of portland cement is lime. But it shouldn't be too bad since the cover acted like a filter for most of the direct contact.

 

be very careful removing the car cover. i remember having ice form on a car cover - only to have it permeate the cover (which it wasn't supposed to do) and adhere to both teh cover and the car. when i took the cover off with a bit too much force, the clearcoat was a bit damaged. i should have just melted it off, but i was in a rush and being an idiot.

doody.

 

Assuming the cover is still on the car (I'm not sure if the caretaker tried to remove it) I plan to wet it down and let it soak before trying to pull it off. I'm hoping that the cover filtered out most of the residue and prevented too much etching, but I guess I'll see . . .
Once the cover is off I guess I'll run it over to a laudromat and wash it in one of those big commercial washing machines. Thanks to all for your suggestions.