I'm thinking of ways to remove the concrete cream from my concrete in preparation for epoxy finish. Rather than grinding, I need to use chemicals. Initially was thinking muriatic acid but it's in a basement, although pretty well ventilated and someone told me mixing the standard ratios of acid to water might cause fumes that can be even lethal (that's what he said). They suggested etching solution as a less harmful alternative but that requires a little more hands on approach and attention.

I am interested in the pros and cons of these two competing materials. I have three rooms to clean, totalling about 400 sq ft.

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    Someone is incorrect. Muriatic acid is the trade name for the hydrochloric acid you used in high school chemistry. It's already in aqueous solution so adding it to water will result in a lower concentration of HCL(aq). Applying it to concrete off gasses CO2, and you would need copious amounts of acid to yield lethal levels. All that being said, you should still have good ventilation because there's no telling what else it will react with. Random surface grime may yield some pungent odors. Oct 22, 2019 at 22:38
  • Mat ,, you have no idea what you are talking about, you have a weak understanding except for the name of the acid with no practical knowledge, it is NOT a trade name, I don’t buy by brand. The same as other acids I buy to anodize aluminum. Are you in high school?
    – Ed Beal
    Oct 23, 2019 at 1:26

1 Answer 1


I use muriatic in confined spaces, yes it is bad and needs to be vented. You are the highest risk when diluting the acid. Always add acid to the water, a 70% water 30% acid will do just about any floor. If it is clean , just needs to be etched I have used 15% acid with good results, when it quits bubbling the acid is close to consumed by the reaction. (Note this is by volume I think the acid available at home stores and pool supplies is 36% if some one wanted to get technical so the real value is only about 10% acid).

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