Chemical stains can be applied to
new or old, plain or colored concrete surfaces.
Although they are often called acid stains, acid
isn’t the ingredient that colors the concrete.
Metallic salts in an acidic, water-based solution
react with hydrated lime (calcium hydroxide) in
hardened concrete to yield insoluble, colored compounds
that become a permanent part of the concrete. Several
companies manufacture chemical stains that are variations
of three basic color groups: black, brown, and blue-green.
