Mike Miller, owner of “the concretist,” a decorative construction company based in Benicia, Calif., is probably the first known person to use dye stains for decorative concrete. He started using them in the early ’90s, several years before he was aware of anyone else using them. Miller purchased them at paint stores to resolve color issues with acid stain applications and to add colors beyond the range of acid stain colors. But he began to appreciate the color effects of using dyes as the only coloring agent and that became part of his offering.
Dye stains originally were developed for penetrating wood stain applications, but in recent years, using them to add color to concrete has become a major decorative technique. Coloring decorative diamond-polished projects is where they’re used most frequently.
What are dyes?
It’s difficult to define what a dye stain is because several different chemistries are marketed today, providing a wide range of appearances. Dyes can penetrate concrete surfaces to create translucent finishes—adding color while preserving the appearance of the concrete, or be mixed with polymers to provide opaque color, blocking the look of the concrete underneath.
The common thread among all dyes is their color formulation. They are made from organic compounds and are susceptible to deterioration from UV radiation to one degree or another. Some colors are more UV-resistant than others: blue and black colors are fairly stable, while yellows and reds have long-term stability issues.
Many different solvents and dispersants can be used to apply dye finishes. One of the most popular is acetone because it provides nice color gradations and the reaction is immediate. However, acetone is very dangerous to work with. Acetone vaporizes quickly and the vapor is heavier than air remaining close to the ground, so it’s very volatile—the tiniest spark can cause an explosion. Applicators have been killed and projects have been damaged after explosions. In the interest of safety, the industry introduced dyes that can be dispersed in water, although they are not waterborne. Water-dispersed dyes can provide a range of coloration, from translucent to opaque.
How to apply them
Dyes are packaged in a variety of ways. Some come in powdered form so you mix them into the solvent you intend to use for a project. Some are packaged in liquid form, making them easy to mix with the solvent of your choice. Dyes also come premixed with solvents, making them ready to use. Miller says different products and different colors have different strengths, so it’s wise to do a small sample area to see if the color is what you desire.
Unlike acid stains, which leave a calcium chloride residue on the surface when the reaction is complete, dyes leave the surface clean and ready for the next construction step.
The easiest way to apply them is with spraying equipment, because sprayers achieve a very even appearance. Spraying also makes it possible to have light coloration in one area with a smooth transition to darker color in another. However, contractors also use paint rollers and paint brushes to apply dye color.
Miller adds that dye colorations always look different down the road. This also can be said about any coloring system due to efflorescence. He warns his clients of the chance of variation and suggests they not be overly concerned with the exact color they want during the installation process.
Stan Stratton is the director of technology for L.M. Scofield, Douglasville, Ga.