Optimum surface preparation for further processing is being achieved by using primer compositions selected in accordance with the nature of the surface material and the intended finish. If you don’t know why priming the wall before finishing or boubt do it or not, read this article.
One of the main purposes of the surface priming is to reduce moisture absorption. Let’s consider, for example, the wallpaper pasting: without a pre-primer, glue would be quickly absorbed with the surface. In this case, the wallpaper, with a very large probability, fall off the walls.
Adhesion will be much better at the treated with primer mixture wall, because the glue would be absorbed slowly, pulling the wallpaper evenly. The film, created by primer, improves the adhesion with the applied material and increases the strength of the treated surface. Using primer reduces the expense of finishing materials or, in the case of pasting wallpaper, glue. This is especially true if you use expensive paints, decorative plaster or liquid wallpaper.
Types of primers and their purpose
- Primer for metal is characterized by not only improving the adhesion to the subsequent paint coating, but also providing the corrosion protection. There are primers that can be applied on corroded metal – they perform the function of binding and preventing the spread of corrosion and the emergence of new one. It also improves the stability of the applied paint from burning in the sun and temperature changes. Primer differs for ferrous and non-ferrous metals.
- Primer for wood closes the pores of the timber, increases its antiseptic and antifungal resistance, thereby prolonging the service life. Of course, the consumption rate of paint or varnish, which is required to create a decorative coating, decreases. Before applying the decorative plaster or paint on the walls you should also use a primer. In this case it should be a primer for mineral bases or primer for particular type of paint or plaster. This preparatory layer will help to prevent the formation of cracks, the appearance of protruding spots or streaks.
- There are primers for surfaces that do not absorb moisture. For example, glass or ceramic tile.
Sometimes, to economize the material, people use water-based paint instead of the primer. This should not be done, since the savings would be negligible, and the paint is not capable of providing those qualities giving by the correctly chosen primer.