Battery acid on concrete

[29Tudor]

I had to charge a battery for a friend, when I got it home I checked the water and it was quite low. I evidently overfilled it before I charged it. Now I have a large white spot where it bubbled out.
I put a whole box of baking soda on it. The next day I squirted water on it and brushed with a hard bristle brush. It looked good then, but after it dried up the white was back.
Any suggestions on removing this?
The first photo is with baking soda on it, second is baking soda swept off, and the third is with water on it.
Thanks!

 

[vettex2]

in time it will fade but it will never go away

I worked in the battery shop for a year, all the concrete looked like that

 

[EOC_Jason]

Pressure washer maybe?

 

[vettex2]

nope, once the acid seeps in, it's there for life

 

[FMB4]

Pour a warm mixture of B. soda and water on it over the course of several days (allow it to 'dry' a bit between pours). But, like others have said, once the discoloration is there it's there pretty much for good. The water/B soda will, of course, help neutralize it and hopefully reduce/eliminate further surface erosion. Not sure if your floor is painted/stained/colored, but you might even try a very light coat or 2 of similar colored spray latex rattle can paint. I've had good pretty darn good luck with latex paint when it comes to battery acid damage as well as various stains including; enamel paint, poly wood floor coating spills, engine oil, salt erosion, epoxy spills, and even chewing gum.

 

[EOC_Jason]

Sounds like an excuse to epoxy the floor!

 

[rlitman]

Pour a warm mixture of B. soda and water on it over the course of several days (allow it to 'dry' a bit between pours)...

You're using baking soda to neutralize any acid. I'm going to go out on a limb here and say that if the baking soda applied by the OP didn't neutralize the acid, the concrete it etched did. There's nothing left to neutralize, and adding more baking soda now, is only beating a dead horse.

Acid etches concrete. My first thought would be to etch the rest of the concrete to even out the results. You could wash the whole slab with muriatic acid.

 

[Armorpoxy]

This is a concentrated etch so its a one way street and not repairable unless coated.

 

[Amann34]

You could try tsp to clean the rest to match. Tsp cleans oil spots really well. Other than that coating the floor is sure nice

Sent from my LG-H901 using Tapatalk

 

[FMB4]

Concrete does not neutralize acid. Concrete that has had acid spilled on it will continue to erode for years due to it absorbing the acid. Besides, baking soda is cheap and so is water.

 

[TheEquineFencer]

Cover it with water and baking soda, then lay a sheet o plastic over it to keep the water from evaporating, it'll work better that way.

 

[ForceFed70]

Concrete does not neutralize acid. Concrete that has had acid spilled on it will continue to erode for years due to it absorbing the acid. Besides, baking soda is cheap and so is water.

No. That's not accurate at all. Anything acid reacts with neutralizes the acid as part of the reaction. There's obviously been a reaction here.

No different than using muriatic acid to etch which is done all the time.

 

[Shea]

This is a concentrated etch so its a one way street and not repairable unless coated.

Bingo! It's always going to have a different look unless covered with a coating. Grinding the entire surface will lighten the concrete and make it blend in, but you would want to seal it or coat it afterwards.

 

[Shiftless]

Another vote for permanent, unrepairable mark...

Once battery acid (H2SO4) eats into your concrete floor, there is no way to go back. Either live with the deeply etched spot (like I do with my spot from a battery) or grind and coat the floor.
I am among many other GJ members who do work which results in minor damage to the floor. Personally, I just live with it.

 

[stikman56]

I used vinegar and a brush on mine,worked pretty well.

 

[Shiftless]

I used vinegar and a brush on mine,worked pretty well.

Very interesting that you had success using a weak acid, vinegar, to remove damage caused by a strong acid, sulfuric.
When you say it worked pretty well, do you mean it blended in the white area caused by the battery acid to match the rest of the floor?
My floor is rather dark bare concrete, smooth finish, unsealed, 65 years old.

 

[29Tudor]

Thanks for the replies. I didn't think it could be cleaned up, but I don't know everything so figured I would ask. Don't like it, but sometimes those reminders are good. I'll see it most every day and be reminded how it got there. Won't loose any sleep over it.