America

I just washed my car after a month of winter driving and notice the mud splash on the rear fenders did not come off. On closer inspection I believe it's concrete or at least some very hard dirt. I have soaked the splash repeatedly and it will not soften up. Anyone have a solution or an idea? Thanks.

Long Duck Dong

Muriatic Acid is good for removing concrete from metal, but I have NO clue if it will damage the paint. Maybe try an unconspicuous spot to test it.

Computamedic

I think I'd be inclined to pick at it with my finger nail to shift the bulk of the concrete and then just persevere with water/WD-40/white spirit/meths to remove the rest of it. I can't say I'd be enthusiastic about any sort of acid on the paintwork though.

Hope that helps.

Regards

Dave

GG Allin

How about a pressure washer.

America

The stuff is really stuck to the paint. I used my finger nail to scrap one off and the clear coat came off. I'b going to try some WD when I get home.

Gary R.

I would try muriatic. It's been used to clean concrete trucks since time began. Don't get it in your eyes or on your skin, on bare metal either. Have a good strong soap solution handy and wash it immediately afterwards. Of course do this all at your own risk, but that is what i would do..

ltc

You could also try sending a PM to Anthony Orosco (hope I spelled it right); he is a detailer who posts frequently in the Rennlist Concours &Car Care forum.

Anthony Orosco

Hello,

Use muratic acid. As already noted it is used by cement truckers to remove it from their vehicles. Here is the procedure.

Wear gloves if your skin is sensitive, perhaps some eye wear also.

Mix up some car soap in a bucket, have a sponge and drying towel handy also. Water hose handy also.

Pour the acid in a shallow metal pan and allow a terry cloth towel to soak in it. Apply the towel to the area being treated, let it soak for a bit then lightly begin to agitate the area...do this "lightly"....you are just trying to break the cement up a bit, loosen its bond.

After a few minutes of this rinse the area with water and then wash it with the car soap and mitt. Check your work and repeat as needed.

After it is removed you'll then want to polish the area and wax it.

Anthony

Gary R.

I would modify Anthony's sage advice just a tad by saying to apply the pure muriatic directly to the concrete spots by either using an eydropper (if these are tiny spashes, which I assume they are) or just putting the soaked rag on top of them and then, after a few minutes, just hit the area with a high pressure garden hose. Remember that even tiny concrete splashes consist of dried cement (abrasive) and sand (very abrasive) and when broken down and wiped accross your paint will do real damage. Muriatic acid reacts to the alkalinity (11) in concrete, it will simply dissolve it if you take your time.

America

Thanks guys, I resolved the problem. After spraying the car repeatedly with water and regreaser about 30 minutes, I used my dull finger nail to chip off the paint. It took me 40 minutes to finish. What a pain in the butt. Just glad I'm finished.