How to use Muratic Acid?

[bjaspud]

My new home has some cast concrete steps leading from the garage intot he house. The steps have 2 or 3 ugly stains on them. It appears someone spillled something liquid on them that stained the concrete. I tried power washing the stain (twice) but cannot remove it.

The previous owner left a bottle of Muratic Acid.

Can I use that to clean the steps?

How do I safely use this stuff?

Thanks,
Spud

 

[shovelhead91701]

Muriatic acid will not likely remove your stains unless they are shallow enough that the etching process removes the material that they are in. If there is no sealer on the concrete you can use TSP or a good degreaser to remove them with a brush. I have had some success with organic stains on pool decking by crushing up vitamin C tablets and making a paste and letting it set on the stains(ascorbic acid).

 

[EOC_Jason]

Have you tried soaking it with simple green, then power washing it? There are also some other heavy duty degreasers you can get at HD/Lowes... Maybe try that purple stuff, be careful though it is caustic...

Using acid will only etch the surface so if it has soaked in, it's not really going to help.

 

[SVIPD]

You need to tape off any areas that you dont want to get harmed and spray the acid on and let it sit for ten minutes and then you use a new red brick to rub against the old brick and the new red color will transfer to the old bricks and then after you let it sit for 30 min you wash it well with water to delute the acid. Should look new when you are done.
You can use a plastic spray bottle or small garden sprayer.
Wear gloves and eye protection

 

[RW-7]

Man be careful with that stuff. I was cleaning some brick with it one day and I had on tennis shoes. PPE everywhere else. Didn't even think about my feet. I got some on my shoes and it burned my feet. Never have I felt a chemical burn like that and nor do I care to EVER again. Had to call poison control and soak my feet in soda for a few hours.
So please, BE CAREFUL!

 

[Boyd]

You need to tape off any areas that you dont want to get harmed and spray the acid on and let it sit for ten minutes and then you use a new red brick to rub against the old brick and the new red color will transfer to the old bricks and then after you let it sit for 30 min you wash it well with water to delute the acid. Should look new when you are done.
You can use a plastic spray bottle or small garden sprayer.
Wear gloves and eye protection

That commercial drives me crazy.

 

[ddawg16]

pressure washer...bleach....pressure washer....more bleach...

 

[SGKent]

it depends what the stain is. Acid will dissolve concrete. You may end up with a worse looking surface than the stain. If the stain is mildew or mold then bleach will help. If it is oil based then the simple green solution or ammonia may help. If it is tannic acid from leaves it will bleach out in next summer's sunlight.

 

[Herb]

pressure washer...bleach....pressure washer....more bleach...

x10. People often overlook or don't know the abilities of regular, inexpensive bleach. I had a garage apron that I had planned to seal. It had a bunch of different stains on it, oil, rust, tannin stains, brake fluid. I tried Simple Green, some kind of oxidizing deck cleaner, brake clean, carb clean, muriatic acid, concrete cleaner from H.D., Dawn, and phosporic acid pool cleaner and CLR. Every product was allowed to sit and was scrubbed as directed and then powerwashed off, but none of these removed the rust or oil stains completely. Out of frustration, I tried some plain jane no- name houshold bleach- VOILA! stains gone, nice bright cement and a clean fresh smell. Yes, try bleach, it's cheap and easy!

 

[LSU]

On a low humidity day:

Find some really cheap bleach (wal mart store brand).

Get some cheap towels and put them on the steps and soak the towels with bleach. Let the bleach soak through the towels and "sit on" the steps.

I've had good luck with this process on smaller areas.

Be care with that acid. Like other posters I've had my problems. If you do decide to use it wear some serious eye protection

 

[Train]

VOILA! stains gone,

Actually, they weren't gone. They were just made transparent. Not that it matters, just putting it out there.

 

[DanCo]

To dispose of a body?

Dan

 

[RivennHewn]

it depends what the stain is. Acid will dissolve concrete. You may end up with a worse looking surface than the stain. If the stain is mildew or mold then bleach will help. If it is oil based then the simple green solution or ammonia may help. If it is tannic acid from leaves it will bleach out in next summer's sunlight.

Muratic acid will actually remove the top layer of the concrete if you leave it on too long.

Be sure to wash it off quickly.

It deactivates in about 30 seconds after it's flushed with water.

 

[cide1]

I've had good luck with oil stains of just letting the sun and rain take care of them. After several weeks of summer sun, they are pretty much gone.