Things To Know
Concrete Acid Stain is Not a Concrete Paint. It is nothing like a paint.
The concrete must be 28 days old or at least have cured to one uniform color prior to acid staining.
Acid stain works by soaking into the pores of the concrete, and reacting chemically with the cements, limes, and minerals that are already present in the concrete and randomly dispersed at the time the concrete was poured. Therefore each stain color will be unique to that particular slab of concrete. If you were to pour stain out of the same bottle onto 10 different slabs of concrete, then you would have 10 different versions of that color. This is the beauty of acid stain and also why you must always do a test in an out of the way place.
Disregard the color of the acid stain in the bottle, when it is applied to the concrete, and during the drying stage. You will not know what color it will actually be until the reaction time has passed, and the residue which hides the real color has been washed.
While the concrete is still damp from washing the residue, this is what it will look like if sealed.
You can do multiple coats of stain. You can only darken though.
When doing more than one coat of stain, there is no need to wash the residue between coats, just ensure the concrete has completely dried.
Concrete that is very old, has been sanded or grinded will reduce the coverage of the stain and the sealer.
If pouring fresh concrete that is intended for concrete staining, be sure to have a few sample size pieces made at the same time to use for testing later. A great complement to the sample pieces of concrete are concrete stain sample kits allowing you to try out our stain before making a larger investment.
Also when pouring new concrete, be sure to use NO curing agents. To check for curing agents, get down on the concrete and scrape it with a pocket knife. Curing agent will usually scrape off like a waxy substance.
Another thing is the finish. Inside a nice smooth finish will be fine, just don't overdo it as too tight of a slab makes it harder for the stain to penetrate which may lead to needing to do a second coat of stain. Outside a broom finish will be better for traction though it will have more of a stone like appearance, as where a rock salt finish will give you more of a marble look.
Do not allow markers and especially not red chalk to be used on the concrete. It is in the chalk lines that are used by the different construction trades. Insist that they use blue chalk instead, as blue will wash off later and red will not.
Acid stain works on concrete, but it does not work on paints, glues, oils, curing agents, or other contaminants.
Except for only a couple of manufacturers, most acid stain brands do not recommend being used once a slab has been acid washed or acid etched. Concrete Camouflage is one of the few brands still capable of staining an acid washed or acid etched slab, though it is still highly advised that you DO NOT acid wash or acid etch your concrete.
You can sometimes get a lighter version of the color by diluting the stain with water.