On Tue, 30 Apr 2013 18:30:41 -0400, "Baron"
wrote:

"Oren" wrote in message
.. .
On Sun, 28 Apr 2013 12:53:42 -0400, Frank
wrote:

I had access and use of hydrochloric acid in the lab but had bought the
gallon when I moved into my new house and wanted to paint the basement
floor. I wanted to clean and etch the concrete with the muriatic acid.

I've always heard the muriatic acid WAS used to etch concrete slabs
for paint or epoxy coatings.

I was just given (10 days ago) a two part epoxy floor coating (Behr).
Enough to do the single garage. Watching a videos I see they use the
two packets (white powder crystals) of Citric Acid Anhydrous to etch
the floor and scrub it. This breaks the seal if you have one.

One that acts almost like muriactic acid is a tile and grout cleaner I
have used. Sulfamic Acid crystals (treat the same as muriatic - add
to water - not the reverse). I spilled a drop on an paver and the
spot looked like a new paver.

I'm not a chemist. Care to comment on each?

Citric acid as a fairly weak organic acid but it chelates metals like
crazy. It's a great descaler so it does not surprise me that it can be used
to etch concrete. It's used in dishwashers when drinking glasses start
coming out with a haze on them. Sulfamic acid is a pretty strong acid but
not as strong as sulfuric acid. It is, however, much safer to use. It is
certainly strong enough to etcgh concrete as it is also used a s adescler in
things liek CLR.



Thank you.