Chemical Stains / Reactive Stains /
Acid Stains

How Acid Stains (Reactive Stain/Chemical Stain) Work?

Acid stains consist of a mild acid - usually hydrochloric acid – mixed with water and metal oxides, also called metallic salts that penetrate the surface and generate a chemical reaction with the free lime (calcium hydroxide) in the concrete.

The active ingredient in an acid stain is the metallic salt and the acidic solution lightly etches the surface which allows the metallic salt to penetrate into the concrete and react with the free lime that is present in the concrete. The resulting oxides fill the pores in the paste layer of the concrete, permanently changing the color of the surface. The color development is a total chemical reaction and is concrete-dependent.

Not all concrete slabs have the properties to be stained with every color. What’s more, every color has a different chemical reaction and requires different levels of free lime. It is the varying amounts of calcium hydroxide (free lime) that cause the mottling and marbling variegation in the translucent acid stain pattern.

The colors you get from acid stains are stone tones or earthy colors, like rust, deep chocolate, copper patina, amber and golden colors. Acid stains are UV stable; therefore they can be used inside or outside. Acid stained colors are very hard to reproduce because every concrete surface is unique and there are several factors that come into play during the chemical reaction and color development.

Patinaetch

Patinaetch is a mildly acidic water based solution designed to etch and stain concrete or masonry substrates. The chemical reaction with the substrate results in naturally variegated earth tones similar to the oxidation of a copper or the patina of a bronze sculpture. Unlike paints or coatings, Patinaetch does not cover the surface; it rather works with the existing surfaces and possibly highlights irregularities.

Color Effects

Patinaetch comes in seven custom colors. The colors produced from these standard stains are unique to each concrete surface and could differ significantly from the color chart. Various color effects can be created by…

• Spray different Patinaetch colors on top of each other
• Blend two or more Patinaetch colors prior to staining
• Broad casting chemicals such as fertilizer, miracle grow, etc.
  

Factors that affect the outcome of the chemical stain (acid stain)

• Cement properties and amount
• Type of aggregates and admixtures used in concrete
• Concrete finishing methods
• Concrete age and moisture content when stain is applied
• Efflorescence
• Curing methods

COLORCHART : : White Base
Aged Buff	Amber	Azul	Blue Copper	Ebony
Lapis	Sumatra	( 1 ab : 1 bc )	( 1 eb : 1 la )	( 2 eb : 1 ab )
Legend: ab = aged buff, az = azul, bc = blue copper, eb = ebony, la = lapis, su = sumatra

 

COLORCHART : : Grey Base
Aged Buff	Amber	Azul	Blue Copper	Ebony
Lapis	Sumatra	( 1 ab : 1 bc )	( 1 eb : 1 la )	( 2 eb : 1 ab )
Legend: ab = aged buff, az = azul, bc = blue copper, eb = ebony, la = lapis, su = sumatra