What is an acid-etched surface?
When the concrete skin comes into contact with a low pH-solution (acid), there is a chemical reaction. This creates an acid-etched surface.
The acid (low pH) reacts with the alkaline (high pH) cementitious material and neutralises the top layer of the concrete, which can then be removed – usually, this layer can be removed with a high-pressure water sprayer. As the top layer is removed, the sand/grain matrix underneath becomes visible.
The etching depth is in the range of approx. 0.3 mm and is therefore much lower than the depth achieved by exposed aggregate fine washing or sandblasting, for instance. However, as with vinegar and wine, acidity can mean different things.
What is MICROGEL®?
The brand MICROGEL® refers to a user-friendly range of Engineered Acid Gels (EAGs), a combination of low-pH ingredients and adhesion promoters, made in predefined viscosities. This allows an even application and uniform even results, suitable for both horizontal and vertical concrete surfaces.
When should I use MICROGEL® to obtain an acid-etched surface?
Use MICROGEL® to create high quality concrete surfaces with a natural stone-like finish, or to roughen the surface to improve anti-slip properties. Please ensure that the surfaces you are treating with this product are smooth – age of concrete is of no particular importance.
Here we must remind you to consider health and safety measures when handling acids, even though MICROGEL® is user-friendly and mild by comparison to other popular “sharp” acids such as hydrochloric acid.
Always read the safety instructions first when working with our products please. Should you find fewer references to safety hazards in tech data sheets of competitors’ product, please do not presume they are safer and that the laws of nature do not apply there too.