Deep ground
Tiefgrund (also deep primer ) is a primer for painting and wallpapering work on walls and ceilings, usually on the basis of alkyd or acrylic resin . It is used on mineral substrates such as plaster , gypsum or concrete in order to limit or even out the absorbency and to strengthen the surface. Its use aims to reduce the amount of paint required for painting or the amount of paste for wallpapering, as well as easier separation of the wallpaper from the substrate when it is removed later .
There are deep grounds on the basis of solvents as well as "solvent-free" or water-thinnable. For " sanding " surfaces, for example very old plaster or poorly processed concrete, a solvent-based primer is recommended, as it can penetrate deeper into the substrate and contribute more to the consolidation. This is countered by the odor indoors and possible health hazards from the outgassing of solvent residues, which in certain circumstances can persist for weeks after application. “Solvent-free” deep primer, on the other hand, avoids such pollution as far as possible, but also achieves the technical goals only less. In the form of microemulsions they have a better penetration capacity, but not that of solvent-based systems.
Some products are colored to make it easier to recognize surfaces that have already been treated during application and to be able to assess the absorbency of the substrate. The less clearly the color remains, the stronger it is.
In any case, in order to achieve the desired goals, the substrate must be treated until it is "saturated", i.e. no longer absorbing primer material , but not "oversaturated", i.e. a shiny film of excess binding agent forms on the surface and the Adhesion of subsequent paints or wallpaper impaired. If several coats are necessary to saturation , this can be done “wet on wet” depending on the product and other circumstances or only allowed or useful after the previous layer has dried.
Individual evidence
- ↑ Entry on inlet means. In: Römpp Online . Georg Thieme Verlag, accessed on December 29, 2014.
- ↑ Kurt Schönburg: Damage to visible surfaces: Assess, eliminate, avoid . Beuth, 2009, ISBN 3-410-17430-3 , pp. 219 ff . with illustration.