A primer is a material that is applied to a surface to prepare it for further processing or treatment. Different types of primer allow you to achieve different effects, but most often it is used for such works:
- Dedusting the surface;
- Strengthening loose surfaces;
- Protection of surfaces from corrosion;
- Identify defects in finishing (painting, plastering, putty, decorative finishing);
- Ensuring high adhesion to the substrate;
- Protection against mildew and mildew (if the composition contains disinfectant solutions);
- Leveling the absorption capacity of walls, floors, and ceilings;
- Low waterproofing to reduce the consumption of paints or other finishing materials.
The scope of application of the primer is quite large, but it is almost always indispensable when working with plaster, tile glue, wallpaper, when it is necessary to strengthen the loose base of walls, ceilings or floors.
What is a primer?
The purpose primer determined by its composition and technical properties. As a rule, the primer is an opaque liquid based on natural or synthetic substances. Once applied to the surface, the primer dries and forms the thinnest layer with high adhesion, and thanks to its deep penetration into the walls, floor, ceiling, the primer also strengthens these surfaces. After application, the thickness of this film can be from 0.01 mm to 0.1 mm, the primer can be applied in several layers, respectively, the thickness will increase proportionally. Subsequent finishing works (plaster, putty, wallpapering) should be carried out only after the primed surface is completely dry.
Types of primer
Different types of primers can be classified according to different characteristics, for example, depending on their purpose:
- Universal-usually water-based formulations that are used as a preparatory stage for general construction or finishing works;
- Primers for finishing-they are also called “permeable crackers”, are used for deep penetration into the thickness of plaster, concrete, brick, putty. As a result, loose areas are bonded, high adhesion is achieved, and a reliable base for further decorative finishing is provided.;
- Betoncontacts-you may need to buy a primer of this type to improve the adhesion of plasters, putties, tile glue and other building materials. As a filler in the primer, acrylic binders are usually used, which are supplemented with fine quartz sand, gravel, cement and other fillers to increase the contact area with the subsequent finishing.
As a rule, the use of a primer increases the service life of surfaces, protects them from cracking, uneven moisture absorption, and even compensates for minor mechanical damage.
Primer composition
Each manufacturer strives to develop its own unique formula of compounds that affect the technical characteristics of the primer. The following film forming agents can be used for this purpose:
- Natural and synthetic resins;
- Acrylic;
- Alkyd and epoxy resins;
- pvc perchloride;
- Glyptal resins;
- various types of drying oil;
- Polystyrene.
The concentration of fillers and binders may vary, and organic fillers, antiseptics, and colorants may be added. Some types of primers do not have a liquid consistency, but a paste-like one. They are applied with a spatula to the surface and can be filled with chalk, talc, gypsum, sand, mica and other inorganic materials. Some, on the contrary, have increased fluidity and are applied to the surface by spraying or brushing.
Scope of application of the primer
By type:
- Primers with acrylic-mainly used in private housing construction, used to increase adhesion to concrete, plaster, brick and other surfaces. They have a universal application, dry relatively quickly, and do not have a sharp smell (if there are no aggressive fillers). Among the disadvantages, you can cancel the poor interaction with metals, relatively high cost, and the inability to solve special tasks.
- Primer with polystyrene-has well-defined dielectric properties, lays down a thicker layer, is perfectly suitable for processing wooden surfaces, for working in wet rooms. Among the disadvantages-high toxicity, complexity of working with the primer and its high cost. At the same time, this type of priming compounds is one of the best for preparing walls, metal or wooden structures before painting.
- Vinyl perchloride primer is a material specially developed for outdoor use. It is often used to prepare the surface before the next painting, insulation, plaster, especially if due to the age of the building, the upper layer of load-bearing structural materials is destroyed. Disadvantages-toxic, can not be used for interior work.
- Phenolic primer for working with metal and wood — used to level the surface, reduce paint consumption, and also as an additional protection against corrosion.
- Alkyd primer-it can be used on plastic, wood, metal, various lumber, PVC films and containers, on steel products. Allows you to get a surface with high adhesion, because it penetrates deeply into the wood, as a result of which it swells and after 10-15 hours of drying, a strong surface with a large contact area is obtained. It can not be used on gypsum, plaster, putty.
- Mineral-based primer-used specifically for working with bricks, concrete, and silicate gas. As a filler, cement, gypsum, lime is used, after application, the composition usually dries within 2-3 hours. To improve adhesion, depth of penetration and optimize consumption, it is important to choose a primer with a filler that is better suited to your type of walls, ceilings, and floors.