On Wed, 03 Sep 2014 22:48:24 -0400, ng_reader wrote:

Question:
I applied a concrete stain to a large 8-year-old concrete patio in Reno,
Nevada€”an area subject to somewhat extreme temperature variations. I
initially washed the patio with a mix of muriatic acid and water to
clean it. I hosed it off, waited a day or so, and applied the stain with
a sprayer, following the manufacturer's directions. Two years later, the
patio now has areas of peeling. I would like to re-stain the whole patio
again to make the color more uniform. I have heard that if you have
washed a patio with muriatic acid, you cannot acid stain it. I am trying
to find an expert who can tell me how to properly prep the surface,
apply the stain and protect it. The stain I initially used was an
acrylic.

Answer:
The product you used€”a tinted acrylic stain€”is not an acid-based
concrete stain. It is a translucent concrete paint and is topical, which
means it forms a colored coating on the surface of the concrete that
will wear over time if not maintained. The surface preparation for these
types of stains usually requires acid etching to open the surface to
allow the acrylic to adhere to the concrete. But once concrete has been
acid etched, the ability of a true acid stain to take is diminished. You
will need to do a test to see how the acid stain takes to get a true
indication of color and effect.

As far as your particular situation, you should strip off the remaining
acrylic stain and clean the surface with soap and water and a clean
water rinse. After the area dries, apply the stain, following the
directions provided by the stain manufacturer. If you're concerned an
acid stain won't take, you may want to reapply the same acrylic stain
after cleaning the surface. No matter the stain you use, protecting it
with a sealer and proper sealer maintenance will be key to keeping the
stain looking good. In your area, plan on resealing every 12 to 16
months.

Thanks ng for the response but I see this is for Nevada on an open patio.
My climate here in Illinois is much different than that and like I already
mentioned this is in an enclosed breeze way that connects the back door of
the house to the garage.
I'm wondering if the instructions you posted would apply to my situation?