My tiling book says to sand the concrete with a coarse grit sandpaper and then wash with muriatic acid. A friend of mine thinks muriatic acid is way overkill and just washing the floor would suffice. I'd rather avoid using the stuff. Any thoughts?
(BTW, concrete is interior slab...seems smooth. Troweled surface?)
The purpose of the acid is not to clean the floor but to etch the surface for a better bond. I don't know if it's necessary for tiling but I can tell you it sure is for painting. When in doubt, follow the instructions and ventilate as much as possible.
Steve.
Good advice, thank you.
Don't forget to dilute the acid at least 5 to 1 with water. % parts water to 1 part acid and then rinse well.
The times I've done it I just put down some water and sucked it up with my shop vac. Repeat (and repeat and repeat) until all the areas have been rinsed a couple times. I've not used anything other than water.
Steve.
What's the issue with rinsing? Concrete is very alkaline and will neutralize any HCl residue if you scrub it in and then sponge it up.
I'd try to find an alternative.
Muriatic is (or turns to) Sulfuric (or is it Hydorchloric?) acid. For a small job, it might be manageable. For major square footage, it can get out of hand. Truly Nasty Stuff.
If you gotta do it, take muy mucho serious precautions. The fumes are toxic. You could get a surface coat of rust on any iron-based materials in the area.
And, yeah, after it's done it's work, baking soda or any lye compound will help neutralize the acidity.
Good Luck, Puddin'
"Life is nothing but a competition to be the criminal rather than the victim." - Bertrand Russell
Muriatic acid is usually about 32% hydrochloric acid, and the rest water. Hydrochloric acid is essence of vomit.
It's a real acid. *I* wouldn't have called it "truly nasty", but you do want to treat it with respect.
Nuts! We didn't even wash ours. Just tore up the carpet, vacuumed, and the contractor did the rest. No suggestion made as to cleaning it. Is it bare concrete? In living area?
Underneath the carpet, yes.
Wilco, thank you.
Does your book recommend muriatic acid on the concrete for all installations, or only for special conditions? What concentration? I have used muriatic once, on concrete, outdoors, per label, in preparation for sealing a deck. It is NOT something I would even consider using inside my home.
As I said, sponge it up well. Or puddle some rinse water and squeegee it off. Or use a wet extraction carpet cleaner.
the acid wash leaves a chalky residue when it dries if your painting over concrete you need to remove this residue so the paint will bond to the concrete. (I am assuming your going to paint)
Ha I guess I should have paid attention to the subject.
as Rosanna Rosannadanna says " Nevermind"
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