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Shelf Life of Muriatic Acid
Q. What is the shelf life of Muriatic Acid? I have a small area of concrete I am treating with acid. So I need only a small amount. My neighbor has some he has had stored in his workshop for years. He has offered to give it to me. My question: Will this stored acid do the job or should I buy new?H. Nick Prillaman, Jr.
Home Owner Renovation - Atlanta, Georgia, USA
A. Hi Nick. My understanding is that the shelf life of basic inorganic chemicals like this is infinite if they were well sealed. That's because there's little interaction that can happen with HCl dissolved in water. But HCl easily vaporizes (in fact, HCl is a gas, not a liquid), so if the container wasn't well sealed it may have lost substantial strength.
Please don't touch it without proper safety instructions though, and without an understanding that you can ruin any stainless appliances and other metal things in your house if you don't know what you're doing. Good luck.
Ted Mooney, P.E.
finishing.com - Pine Beach, New Jersey
Striving to live Aloha
A. If you are etching concrete for a coating application, a high pressure water sprayer will do a similar thing and not have any risk with controlling the etch or handling the runoff and rinses or the "oops" that several people have brought up at this site.James Watts
- Navarre, Florida