[Chazz]

I am posting this message on behalf of a friend who stained his concrete driveway with battery acid from his golf cart. Does anyone have a method that will actually totally remove these kinds of stains? I had one on my driveway, left by another friend's electric golf cart, and tried everything, including pressure washing with heavy duty concrete cleaner, with no success. Ultimately, we covered ours up with pavers. That is not an option for my friend as he lives in a villa.

[`willy]

Most strong acids like battery acid will actually discolor (or “burn”) the concrete when not neutralized within a short time of the spill. These sorts of stains tend to look like brown-orange, puddle-shaped areas on the driveway. The stain is often quite deep, and no products on the market today will satisfactorily remove this orange stain once it been on the cement for an extended amount of time. Too often, pressure washers are used to blast the surface clean when attempting to remove rust stains, which amounts to peeling off a deep layer of the concrete to expose a surface that is less stained. This is not doing the customer any favors they would probably prefer the rust stain!

found this in a book I had. Hope it helps
Willy

[Villages Kahuna]

I'm not certain that any damage to the concrete done by the battery acid can be corrected. But using a base chemical like a heavy baking soda and water or ammonia mixture on the affected spots might help. If after applying a base the acid stains are still there, they may be permanent.

The key to avoiding battery acid overflow is to never overfill your batteries. More importantly, never fill them just before charging them. That sequence will often result in a "boiling over" of battery acid. The best time to fill batteries is in the morning after the batteries have been fully charged overnight.

[chuckinca]

I use Kitty Litter on oil spills, maybe it might help with the acid - grind it in with the ball of your foot (with a shoe on).

[LB]

Muratic acid will help, but it also will etch the concrete, so should be done carefully and cautiously. Muratic acid is available in pool stores and usually Home Depot. It is very nasty to use, and must be handled extremely cautiously!! LB

[Chazz]

Thanks all for the suggestions! I'll pass them on to my friend for his use, and I'll keep an eye on this thread for possible additional ideas.