March/April 2008 Vol. 8 No. 2

Water-based Stains: Will They Last?

by Amy Johnson
Water-based stains hold tantalizing promise for the field of architectural concrete — low VOCs, low odor, simple application and cleanup, and bright hues not possible with reactive acid-based stains. But do they deliver the wearability, durability and ease of application that would help make concrete colored with water-based stains more appealing to customers?

How they work
To the newbie, water-based stains may seem to be just the “green” counterpart to acid-based or reactive stains. After all, both are applied in a similar manner. In fact, understanding the differences between how these two products function is the first step to setting accurate expectations for a water-based stain project.

Acid stains work by reacting with the ingredients on the surface of the concrete to create a chemical change that results in variegated, natural-looking color. Water-based stains color concrete with pigments, not by chemical reactions. The most important ingredients are water, binder and pigment, according to Chuck Brunner Sr., owner of Smith Paint Products. The water is the carrier — it allows the material to flow. The binder, which can be, for example, an acrylic polymer or a silicate, locks or “glues” the pigment into the cement matrix. The pigment imparts the color.