There are two ways to achieve the geometric correctness of walls and ceilings - plaster uneven surfaces or sheathe them with sheet materials on profiles. In both cases, the final leveling is the treatment with special dry mixes. Putty of drywall for painting has its own characteristics that must be considered when carrying out repairs.
How and how to treat the surface so that the paint lasts a long time? This will be discussed in this article.
Types of putties
Modern putty in its physical state are of two types: dry and pasty. In the first case, the mixture must be diluted with water before use. Paste putties are ready for use without preliminary preparation, it remains only to open the packaging lid. In both cases, these are finely divided compositions. This distinguishes them from plasters, which are designed to eliminate large surface defects.
The cement, polymer, gypsum acts as an astringent in dry compositions. Paste-like leveling mixtures are made mainly of polymer binders. The scope of the putty depends on the main component. Traditionally, leveling finely dispersed compositions are applied to the surface in several layers. The first layer is the leveling (preliminary, draft) mixture, the second - the final (finish).
What putty should be putty to put drywall for painting?
Mixtures on a gypsum binder are used in dry indoor spaces. This species is now the most common. Such compositions are easy to apply and grind, while the color of the material remains white. And this is a determining factor in subsequent painting.
Plaster is incompatible with hydrohardening binders. These are cement mixtures. Therefore, the use of such compounds on gypsum substrates is prohibited. Plasterboard putty for painting should not be based on cement. In general, it is allowed to process gypsum plasters with cement leveling mixtures, but only with a high-quality primer.
Polymer putties are an ideal base for painting. Their grain size is very small (almost imperceptible), it is due to this that a flat surface is achieved.
Mixing Technology
Building materials are supplied to the consumer, accompanied by instructions for their use. Most of the requirements for different types of putty are the same.
Leveling dry mixes are prepared before work, diluting them with water in the ratio indicated on the package. The properties of finished putties are valid for a certain time. For each type of mixture it is different. The average "lifetime" of putties ranges from 5 hours to a day, then the ability to evenly distribute along the surface is lost.
Putty of drywall for painting with your own hands is carried out with a spatula. There are stations for the automatic application of such compositions, but they are used on large-scale construction sites. And as a putty, polymer compositions are used.
The technology of applying the mixture: the main stages
The surface on which it is planned to put the first rough coat of putty should be cleaned of dust, grease stains. Gypsum plasterboard trim should not contain irregularities at the joints and protruding parts of the fasteners. If there are any defects, then the joints are cut with a knife, and the heads of the screws are deepened by 1 mm.
The technology of plasterboard putty for painting consists of the following stages: preparation of the base, application of the starting mixture, finishing composition, primer, grinding of the surface after each coating and dust removal.
The composition is laid in seams with the first layer, each cap of fasteners is smeared. So that the joints do not crack after painting, a reinforced paper tape is attached to the dry first layer along the joints of the gypsum boards. After 12 hours of drying, it is necessary to sand, dust and prime the surface.
This treatment is necessary to even out the absorbency of the substrate. Drywall putty for painting requires a two-layer rough application of leveling compounds. And the second time you need to create a continuous cover.
The final stage before painting
When the covering layer dries, it is ground. If up to this point the starting putty was used, then the third layer is created by the finishing composition. It helps to achieve a flat and smooth surface due to small particles in its composition. That is, finishing plasterboard putty for painting is mandatory. It can be neglected before wallpapering, as the bumps under the layer of roll material will be hidden.
The final coat is applied very thinly before painting. There is a special technique for applying the finishing composition, referred to as "on the sidir." This is when, after applying the mixture, it is removed with a spatula perpendicular to the surface. As a result, the smallest irregularities are filled with microparticles, and an even base is obtained.
After complete drying, the surface is cleaned, dust is removed from it. Next you need to go through a primer. These actions will ensure uniform distribution of paint on the surface. If you do not prime the finish coat before painting, then the consumption of the coloring material will increase.
Spatula work
Putty of the ceiling from drywall for painting and walls is carried out using two special blades - spatulas: wide (300 mm) and narrow (90 mm). A smaller tool takes the leveling mixture and transfers it to a larger one.
Continuous putty involves spreading the mixture with a non-thick layer onto drywall. Moreover, when applied from left to right, the spatula is held so that its left side is lower than the right. It turns out that smooth application is on the left of the tool, and a putty layer is formed on the right, which is removed from the wall or ceiling and used for the next installation.
The size of the applied layer is regulated by the angle of inclination of the spatula to the base. The smaller it is, the thicker the putty strip. The standard angle for application is 60 degrees. At 15⁰ to the surface to be treated, smoothing is performed, which must be performed by overlapping the previously smoothed strip by 2 cm.
Joint sealing and corner processing
The joints between the gypsum sheets are sealed using paper tape so that no cracks appear after the final cladding. Initially, putty is put perpendicularly to the seam with a putty knife, after which its excess is removed by moving along the seam from the bottom up. Such manipulations are performed when the plastering of the walls of plasterboard for painting occurs. When working with transverse joints on the ceiling, excess building mixture is removed in the direction "from itself."
In both cases, a reinforcing tape is applied to a dry layer, and the joints are reprocessed with a spatula.
External corners are closed using perforated elements. And in the internal corners a sickle is laid, and the spatula is used indirectly.
Mixture quality
Putty of the ceiling from drywall for painting at the exit implies a perfectly smooth surface. Until its painting, it is possible to check the quality of the leveling layer. To do this, use a flashlight and level. You must install the tool against a wall or ceiling and hide a small light source behind it. If there are no gaps between the level and the surface, then there are no differences and roughness. And this is a sign of high-quality grinding.
If nevertheless small irregularities are present, it is better to go again with sandpaper or a grinding machine. Finishing putty is cleaned with a fine-grained abrasive. This applies to gypsum mixtures. Because of their high ductility, polymer compositions do not require grinding.
Recommendations for a better result
The application of leveling compounds should occur at an ambient temperature of +5 to +30 gr. The same temperature should be putty surface. Avoid direct sunlight when leveling. But this applies more to outdoor work.
To putty plasterboard for painting after completion of the repair did not give cracks, it is necessary to observe the technology of work. A common mistake is incorrect preparation of the solution. It is necessary to clearly add water according to the instructions and thoroughly mix the composition. Cracks can occur when laying mortar with a layer of more than 1.5 mm at a time. Therefore, the use of a primer at each stage of work helps to achieve a thin coating.
Do not neglect the expectation that the putty will completely dry before the next stage of installation. It is a misconception that for a better grasp of the material, forced ventilation of the room is required. Drafts are the enemy of unhardened plaster. An important condition for achieving a high-quality result is the choice of high-quality material.
What putty should be putty to put drywall for painting? Reviews about Knauf
At construction forums, a picture of the leaders among the leveling mixtures used in modern repair is revealed. Knauf, Ceresit and Vetonit mixtures became popular putty compounds for internal gypsum plasterboard works.
TM “Knauf” is known for its gypsum-based building materials. The manufacturer for puttying the interior has developed a technology for the work and adapted its products for it. It is proposed to use the product “Fugen” and “Uniflot” for sealing joints between GCR. For the finish line, the Rotband Profi line has been developed, which is delivered ready-made, which eliminates the possibility of making a mistake in preparing the right solution. Reviews on the materials of this TM are positive.
If you put the finish of “Rotband Profi” “on the strip”, you get a smooth and thin strip of white. For comparison: “Vetonit LR” putty (polymer) is more liquid in consistency, and this is a minus in ease of application. In addition, after its leveling, furrows remain, which indicates insufficient plasticity of the material. And the color after laying it on the surface is not quite white.
Which putty to choose for drywall for painting, the master will tell. If the repair will be carried out on their own, it is better to try to buy Knauf products.
In the end
Putties, primers, dry mixes must be bought at the same price level. It is not worth collecting materials cheap and expensive at the same time, otherwise their incompatibility may arise. Each manufacturer produces a line of its products, designed for a specific technology of work.
And if you choose TM “Knauf” for sealing joints between sheets of drywall, you should purchase a primer, filler mixes and a finishing solution of the same company.