| How stains work By Joe Nasvik 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. The acid in chemical stains opens the top surface of the concrete, allowing metallic salts to reach the free lime deposits. Water from the stain solution then fuels the reaction, usually for about a month after the stain has been applied. Other factors that affect the outcome include: * Cement properties and amount * Admixtures used * Type of aggregate used * Concrete finishing methods * Concrete age and moisture content when stain is applied * Weather conditions when stain is applied * Efflorescence In general, cements that produce larger amounts of calcium hydroxide during hydration will show more stain color, and higher cement contents pro-duce more intense colors. Air-entraining or water-reducing admixtures don’t pose a problem. However, calcium-chloride accelerators can cause very mottled, darkened areas, and for this reason aren’t recommended. Nonchloride accelerators don’t cause this mottling effect. If they’re near the surface, calcium- based aggregates, such as lime-stone, take stain readily and deepen the color of the concrete above them. Siliceous aggregates, such as gravel, don’t react with the stain. Open finishes achieved by floating followed by minimal troweling take more stain and produce denser colors than do hard-troweled surfaces. However, open finishes lose color faster because the concrete wears away. Because of this, Gary Jones, president of CP Concrete Systems in Burnaby, British Columbia, Canada, prefers staining hard-troweled surfaces because the stain color lasts longer. "Colors on troweled surfaces also look richer than those on floated surfaces," says Jones. "But you have to sand the surface or use a higher acid concentration to ensure adequate stain penetration." Slabs placed in wet weather result in a richer stain color if the concrete is stained soon after it’s placed. However, wet slabs are more likely to effloresce, lightening the color and causing a more mottled effect in areas where the stain doesn’t take because efflorescing salts hinder penetration. On sunny days, the concrete can become hot and dry, and the stains won’t penetrate as deeply into the concrete. The continued presence of water will cause the reaction to continue for a long time, and concrete stained blue- green will gradually turn brown or even black. Initially, this provides nice variation to the appearance, but eventually, nearly all the blue-green color may change to brown and black. Because of the possible color shifts, some manufacturers advise against using these colors for exterior concrete. Interior slabs must be placed on a well-drained base or sub-grade and have a low moisture content before stain is applied. Jones believes the brown-colored "flowering" of blue-green stains is caused by oxidation of a copper component resulting from water vapor passing through the slab. Others believe the brown color is caused by a fungus, which can be eliminated by using sealers containing a fungicide |
| How Acid Stains Work By Joe Nasvik of the Concrete Network |
Precision Concrete Staining
& Engraving
668 E. Borgfeld
San Antonio, TX 78260
& Engraving
668 E. Borgfeld
San Antonio, TX 78260
| Precision Concrete Staining & Engraving 668 E. Borgfeld Dr. San Antonio, TX 78260 |
Call (210) 274-3801 or e-mail stain@gvtc.com
| Precision Concrete Staining is an established company using demonstrated methods and techniques for Decorative Concrete. The crews are trained in the manufacturers’ recommended procedures to maximize the long-term performance of the products being used. Each step of the preparation, coloring and sealing processes are carefully executed and monitored. This watchful approach ensures that the installation is durable and that the colors are as close to the desired results as possible. The coloring agents used by PCS in the Acid Staining processes are not paint products. Our products are translucent acid stains which cause a chemical reaction to form the color and surface imperfections and inconsistencies are not covered up as they would be with paints. PCS can not be held responsible for materials previously on the concrete to include substances dropped by other building trades, unnatural trowel marks or natural occurrences such as animal marks, tree droppings etc. All efforts will be exhausted to remove such materials prior to staining. The chemical make up or toweling method may also affect the stain color and marbling effects, sometimes prohibiting the stain to react and create the desired color. Finished concrete can have many variations of color from white to very dark gray. The color of the raw concrete will affect the final color of the stain. For instance, a dark gray concrete floor will be dark regardless of the color of stain used. Although we will make every effort to give our customers as close to the color desired, we cannot guarantee that there will not be other colors that appear. Depending on your expectations, some of the effects that reactive stains create may be construed as defects. Color variation will: occur in the concrete due to the particular set of chemical properties of each slab, even in a slab that appears consistent in color. Therein lays the stone-like beauty of this process. Expect to get different reactions from one surface to another and even within the borders of the same slab. Some characteristics are: May not cover evenly Will not cover stain sealed or pained surfaces Will give different color on different batches of concrete Will not give exact color May show concrete defects and blemishes through the stain May show areas of discoloration through the stain Will not change surface texture of the concrete The marbling and variations in color and occasional surface irregularities enhance the natural appearance of the finished surface, and are the reason Acid Stain is such a popular and unique flooring option. |
| ACID/CHEMICAL STAIN DISCLAIMER |
| The information on this page is meant to educate our customers on what they can expect from an Acid Stained floor. Please be cautious and ask questions of your Stained Concrete Contractor. Many will tell you what you want to hear instead of what you need to know........... |
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LM Scofield Acid Stain Color Chart - Interior/Exterior
Concrete Camouflage Acid Stain Color Chart - Interior/Exterior
Kemiko Acid Stain Color Chart - Interior/Exterior
H&C Acrylic Stain Color Chart - Interior/Exterior
Ameripolish Dye Color Chart - Interior Only
Clemens Super Color - Interior/Exterior ** Recomended for Porches & Patio's
Concrete Camouflage Acid Stain Color Chart - Interior/Exterior
Kemiko Acid Stain Color Chart - Interior/Exterior
H&C Acrylic Stain Color Chart - Interior/Exterior
Ameripolish Dye Color Chart - Interior Only
Clemens Super Color - Interior/Exterior ** Recomended for Porches & Patio's
| Select Links Below to View Manufacturers Stain Color Charts |
| How Dyes Work By Joe Nasvik of the Concrete Network |
| How Concrete Dyes Work Essentially, concrete dyes are translucent, penetrating color solutions. Unlike acid-based stains, they do not react chemically with concrete. Instead, they contain very fine coloring agents that penetrate into the concrete surface. Both water- and solvent-based dyes are available, with each type having unique qualities. Water-based dyes, such as Colormaker's Someru, generally produce soft pastel tones. Bolder hues, including red, blue, yellow, green, purple, and orange, are possible with solvent-based products. AmeriPolish from American Decorative Concrete Supply Co, and Dye-N-Seal from Brickform are examples. When applied full strength, dyes can produce dramatic color accents, such as this border stripe. Most dyes are packaged in concentrated form, allowing flexibility in the end color. They can be used full strength to attain greater depth of color or diluted with water or solvents to produce paler shades or simply a light wash of color. You can also intermix different colors of dye to produce your own custom hues. |