home · Networks · Preparing a wooden surface for varnishing. Painting wooden surfaces. Degreasing, applying primers, leveling wood. Selection of colors. DIY bog oak

Preparing a wooden surface for varnishing. Painting wooden surfaces. Degreasing, applying primers, leveling wood. Selection of colors. DIY bog oak

The appearance and durability of any coating is determined by:

  • correctness, thoroughness and quality of surface preparation before direct application of paint and varnish;
  • the quality and brand of paint and varnish products used, taking into account the characteristics of further use of the surface;
  • correct preparation paint and varnish material to work and the correctness of subsequent application of coatings to the surface.

Surface preparation for painting during construction and repair includes:

  • removal of loose surface areas, including residues old paint(and rust if it is metal), complete removal of old paint if it is incompatible with the newly applied one;
  • repair of damaged surfaces (rough leveling, sealing cracks, sinkholes, chips, etc.);
  • drying the surface before applying protective and decorative materials;
  • mandatory hardening priming of the surface;
  • final leveling surfaces (puttying followed by sanding);
  • dust removal and, in some cases, degreasing of the surface;
  • priming with an opaque primer to increase adhesion (adhesion) to the paint and varnish material.

Thus, the tasks of preparing a surface for painting are leveling, strengthening and increasing adhesion to paint and improving appearance.

One of the most labor-intensive operations when preparing a surface for painting is the first. Most often it is done manually using brushes, spatulas, scrapers and other means.

Drying the surface is extremely necessary step when preparing the surface.

Priming with an opaque primer reduces paint consumption and increases the adhesion of the protective and decorative coating.

Great impact on quality and durability paint coatings provide climatic conditions when performing painting work: air temperature and humidity, temperature of the surface to be painted, surface moisture.

Natural drying paints and varnishes are recommended to be applied at temperatures from 5 °C to 35 °C. If painting work is carried out during negative temperatures The presence of ice and frost on the surface is not allowed. It is also not allowed to paint during rainfall or on a still wet surface.

An indispensable condition when painting is to ensure air humidity below 85%, since when relative humidity air above 85%, the rate of evaporation of solvents from the paint film sharply decreases and the danger of moisture condensation on the surface increases, which can cause severe bubbling or peeling of the surface.

Preparation of surfaces for various types of paints and varnishes

Before the beginning painting works everyone finishes in the premises construction works(except for laying linoleum on floors and laying parquet), electrical work, installation and testing central heating, water supply, sewerage. The surface to be painted must have a certain humidity (for plastered and concrete surfaces no more than 8%, and for wooden ones - 12%). IN winter conditions Internal painting work is carried out in insulated and heated rooms at a temperature of the coolest surfaces above 8 °C. Wooden structures must be well secured, free from cracks, burrs and other defects. Window and door blocks are delivered to objects painted once (i.e. all processes preceding the first painting are carried out by the manufacturer).

Preparation of surfaces for painting with aqueous compositions consists of performing the following technological operations: cleaning the surface; priming the cleaned surface; filling cracks and cavities; dust removal; partial lubrication of uneven surfaces; sanding greased areas.

In addition, the junctions with ceilings, walls and partitions of built-in cabinets, if according to the project they should be covered with gauze. It is also used to paste over the protruding corners (crests) of partitions made of gypsum boards or products.

Clean the surfaces and cracks on it from dust, dirt, splashes and drips of solution, grease stains and efflorescence using scrapers, mechanical emery and non-emery wheels, as well as brushes and vacuum cleaners. A surface grinder is used to smooth plaster and concrete surfaces.

After smoothing the surface with a knife or steel spatula, cut and clear the cracks, while holding the knife or spatula at an angle of 60° to the surface.

Dust is removed using a grass brush or vacuum cleaner. In this case, it is necessary to use a respirator and safety glasses.

After cleaning, contaminated surface areas are washed with water and dried. Before washing with water, grease stains are wiped with a two percent solution. of hydrochloric acid. Efflorescence that appears on the surface is cleaned off with brushes and washed with water. Reappearing efflorescence should be swept away with a brush without further washing.

Before gluing with gauze, coat the surface adhesive composition and a strip of gauze 8-10 cm wide is placed on the damp film, smoothing it with a hand-bristled brush dipped in the adhesive. Finally, level the freshly glued gauze with a steel spatula, while removing excess adhesive.

Priming consists of applying special compounds to the surface. As a result of this, the surface to be painted acquires the ability to equally absorb the liquid binder from the subsequent paint layer.

Alum primer is used to coat surfaces containing lime. To prepare it, pre-soaked and swollen glue is dissolved in a glue maker. Planed soap is poured into the hot glue solution obtained by further heating, and then drying oil is introduced with rapid stirring. In a separate bowl hot water dissolve the alum and gradually, with constant stirring, pour the alum solution into the emulsion, and then water to the full volume and chalk. Apply the primer hot at a temperature of 50-60 °C. The same composition is used to prime indelible stains for adhesive painting.

Soap primer is intended for surfaces that do not contain lime. In a separate vessel, with rapid stirring, prepare an emulsified solution of soap and drying oil. In another vessel, the lime is poured with water (the mass of which is one and a half times the mass of lime). While the lime is boiling, the solutions are drained, mixed and diluted with water to full volume.

The remaining three types of primers are used:

  • casein- for casein coloring;
  • silicate- for silicate, cement and polymer-ment paints;
  • latex or emulsion- for emulsion painting.

Before use, the finished primers are filtered through a sieve (1200 holes/cm2). The viscosity of the finished primers should be about 15 s according to the VZ-4 viscometer.

Filling cracks, cavities and smearing uneven surfaces is done by applying putty compounds to the surface with spatulas. The putty should be a homogeneous, non-separating mass, easy to level, and not leave grains or scratches when spread in a thin layer.

The consistency of the putties is determined by dipping a standard cone. It should be 6-8 cm for manual application, 12 cm for mechanized application.

Residual xylene solvent putty (RSP) is used regardless of the binder with which the paint coating will be applied.

Dry-free latex putty (BLSH), sometimes called CLM (carboxymethylcellulose latex chalk), is used for all types of water-based paints.

Polymer cement putty is also used for all types of water-based paints.

Alum-glue putty is used only for adhesive painting. To prepare it, alum is dissolved in 20-30% of the volume of boiling water. Add chopped soap to the solution of pre-soaked glue and pour in drying oil while quickly stirring. A mixture of gypsum and chalk, taken in a ratio of 2 (chalk) : 1 (gypsum), is poured into the resulting emulsion solution with continuous stirring until a homogeneous mass of working consistency is obtained.

Casein putty is intended only for casein painting.

Emulsion putty is used for emulsion painting.

Silicate putty is used for silicate, cement and polymer cement painting.

Surface treatment for simple painting consists of one primer. Prime the surface with a fly brush or fishing rod. Primers based on vitriol, alum and alumina are applied only with a hand brush, while neutral soap and lime soap can also be applied with a fishing rod.

To apply the composition with a hand brush, it is immersed in a tank with the composition and, when pulled out, the excess is squeezed out. Apply the composition with a smooth movement of the brush to the right and left, holding it at an angle of 70° in the direction of movement. As the primer composition is consumed on the brush, it is rotated around its axis.

Treatment of surfaces for improved painting consists of the first primer, greasing of cracks (followed by grinding and priming of the greased areas) and the second primer.

The first primer on the ceilings and walls is carried out simultaneously. This is done with a spray gun using a soap composition.

To fill the cracks, use a spatula. Fill the cracks with transverse movements of the spatula, tightly spreading the putty. This operation is completed by smoothing the putty layer by moving the spatula along the crack. The putty is applied in a thin layer (on the peel), avoiding thickening on the surface. The dried compound is sanded using a surface sanding device.

The greased areas are primed with a brush so that thickened areas of the paint composition (veins) do not form.

The second priming of the walls is carried out with a spray gun, roller or brush, depending on the future painting method. Before painting with a roller, the primer is also made with a roller. This is due to the fact that when applying the primer composition with a roller, the surface acquires a rough texture, which is further emphasized in the process of applying the paint composition with a roller. In the event that there is a need to obtain more smooth texture, ©The primer for painting with a roller or spray gun is done by shading with a hand brush.

To obtain smoother surfaces in primers chalk is introduced (per 10 liters of composition for the first primer 2-3 kg, for the second - 6-7 kg).

Treatment of surfaces for high-quality painting, in addition to the processes performed for improved painting, involves puttying, which ensures smooth surfaces.

Putty on carefully primed surfaces, avoiding any gaps. This work is performed with hand spatulas or mechanized methods.

Manual putty. When puttying, the spatula is held at different angles to the surface. This allows you to adjust the thickness of the applied layer.

Puttying is done in stripes from left to right, as well as from top to bottom and bottom to top. The spatula is held so that the left side of the canvas is slightly lower than the right. In this case, the putty mass moves along the blade during laying, forming on the left side smooth surface, and on the right is a ridge. When applying the next strip, the ridge is removed and smoothed out, but at the same time a new one is formed on the right, which is also smoothed out when the next strip is made.

Sanding the putty layer is done after it has dried. For sanding, use sanding paper No. 8-12, clamped into a hinged float. Dust is swept with a hair brush. This cannot be done with a rag, since dust is rubbed into the pores of the putty, which subsequently leads to peeling of the paint film.

Preparation and surface treatment of reinforced concrete panels and decking

Usually reinforced concrete panels and floorings are produced by factories with a smooth, uniform texture that does not require grouting or continuous puttying, therefore, surfaces are treated for painting with water-chalk and adhesive colors in the following sequence: prime the surfaces with a spray gun rod, using a neutral soap-based primer; paste over with gauze the places where the built-in cabinets adjoin the ceilings and walls; putty over gauze, leveling the gluing surface flush with the plane of the wall and ceiling (minor surface defects are corrected with putty); sand the putty areas with sanding paper No. 8-12; Prime the surfaces a second time, using a spray gun for ceilings, and a roller or brush for walls. When the surfaces of panels and decking are of poor quality, puttying and grinding operations are introduced.

Preparation of new plastered and wooden surfaces

Preparation for oil painting start by cleaning the surface. This is done in the same way as for surfaces to be painted with water-based paints.

Preparation of compositions for treating surfaces using oil paints. When preparing primer and putty compositions, all the components specified in the corresponding recipe are introduced. This will ensure good paint adherence during application and the necessary film strength.

Chalk for lubricating and putty compositions is introduced until a working thickness is obtained. Drying oil is done with drying oil. Large surfaces are oiled with a roller or a hand brush weighing 200-300 g, and small surfaces with a hand-bristled brush.

At the border of two colors, they work with a tap ruler, setting it exactly along the border line.

When working with a roller or hand brush, at the border of oil and glue paints, a line is beaten off with a dusted cord. Below this line, a strip 10-15 cm wide is dried with a hand-hand brush. Also, with a hand-handle, a layer is made at the baseboards and places where planes intersect during subsequent painting with a roller. When working with a roller, use a tray with a mesh. Excess drying oil is squeezed onto it. When drying with a hand brush, the drying oil is first applied with wave-like movements of the brush, and then shaded in the transverse direction.

Grouting of cracks and other defects is carried out on the surface that has dried out after drying with oil or grease putty. At the same time, the places where the plaster adjoins the platbands and baseboards are lubricated. When greasing cracks and flaws, use a spatula, and at the junctions - a rubber plate measuring 7x10 cm, 5-6 mm thick. The dried grease is cleaned with sanding paper No. 8-12, stretched over the block. Sweep away the dust with a brush or brush.

Puttying surfaces for painting with non-aqueous compounds is done manually with spatulas. The working methods are the same as for adhesive painting. For improved coloring, putty is applied in one layer, for high-quality paint - in two, and sometimes three layers. Each layer is smoothed with sanding paper No. 8-12 stretched over the block.

The strength of the putty layer and low water absorption make it possible to apply a second coat without priming. The last layer - straightening - is applied with a metal spatula over the primed surface.

Putty surfaces are primed with a non-aqueous liquid primer to match the color of the future paint job. Apply the primer to large surfaces with a roller or brush weighing 200-300 g. When priming with rollers, inaccessible places, as with drying, are pre-painted with hand-held brushes.

Processing of carpentry and wooden partitions performed in the same way as processing plastered surfaces, using the same work techniques. Putty compositions are taken depending on the operating conditions - wooden products. When finishing carpentry built into external enclosing structures, only 1% oil putties are used, and when interior finishings- 3% oil or glue.

Treatment of wooden floors This is done using drying oil with dry pigments (for drying oil) and oil putty (for lubrication). Dry and prime the floors with a roller of silt using a hand brush, without oversaturating the primer film. A metal spatula is used for priming and puttying. They do this using dried drying oil, firmly smearing the putty into the flaws.

The dried layer of putty is sanded with sanding paper No. 25-40, carefully removing dust with a hair brush. The second puttying is carried out using the same techniques, sanding with sanding paper No. 8-12 and carefully removing dust.

New wooden floors with sealed seams and planed floors are not washed before drying, as this leads to increased moisture in the wood, but are cleaned with scrapers, removing dust with hair brushes.

Preparing for coloring metal surfaces heating pipes and radiators, gas and water pipes, gratings, staircase and balcony railings) consists of cleaning with steel brushes from splashes of solution, rust and degreasing the surface.

Surface priming metal structures do immediately after cleaning, carefully covering the surface with a primer. This protects the metal from corrosion, which occurs after preparation. For priming, natural drying oil or “Oxol” is used with the introduction of grated pigments (usually red lead). Primer compositions are applied to large surfaces with hand brushes weighing 200-300 g, rollers, and on small surfaces - with hand-operated brushes. The viscosity of the composition for application with brushes and rollers is 30-40 s according to the VZ-4 viscometer.

Protruding knots on the surface of the product are removed using a semicircular chisel to a depth of 2-3 mm, then treated with drying oil and covered with putty. You can replace protruding knots with wood plugs of a similar species, securing them with wood glue. It is important that the direction of the fibers of the surface and the cork coincide. Wooden a few millimeters inward.

Tar and grease stains

Resin spots are cut out and treated in the same way as knots. Grease stains are treated with a 5% solution soda ash. Rust is removed with a 10% solution copper sulfate or 3% hydrochloric acid solution. If greasy spots or the rust does not wash off, they can be painted over with white enamel paint.

Oil stains and paint residues

Such defects are removed chemically, by treating with acetone or other paint removers. When painting a surface with nitro paint, the old oil paint should be completely removed, otherwise the nitro paint applied to a surface previously painted oil paint, will swell and curl. You can use a professional hairdryer to heat it, and remove the swollen paint with a metal spatula.

Mold Removal

If mold is present, the surface should be washed with a hypochlorite solution to remove mold, according to the manufacturer's instructions. After treatment, the surface is rinsed clean water.

Washing and sanding

To clean the surface from grease, stains and various contaminants, the surface must be washed with a brush, sponge or rag, rinsed with clean water and left until completely dry.

Sanding is carried out after the surface has completely dried, using sandpaper until the roughness is destroyed and the surface becomes matte. The remaining defective areas are leveled using wood putty. The entire surface should not be treated with putty to preserve its fibrous structure.

Surface cleaning and priming

At the end of grinding, the surface is cleaned for painting from dust and small mechanical particles with a brush or scraper. The primer mixture is applied to the surface with a brush or soft brush, carefully blending along the wood grain.

Grinding

After the primer mixture has dried, you need to go over the dried layer with fine-grained sandpaper. The prepared surface should be flat, smooth, without scratches.

Has very important. This preparation is part of the paint application system. The basis of such preparation will be cleaning the surface of all excess, degreasing and polishing it; only after performing all these procedures will the surface have good adhesiveness. Adhesiveness determines how long the surface coating will remain in good condition. Next we will consider stages of surface preparation for painting.

To calculate paint consumption, you can use paint consumption calculator.

Initially, you need to remove loose material, such as dirt, scale, body fat, oxide film, etc. This will help the paint adhere better to the surface.

Attention: If there is dirt on the surface to be painted, uniform application of the paint layer on the surface will be difficult, because the contaminant will prevent the uniform and dense application of paint.

After cleaning the surface from dirt, it is necessary to increase the surface area of ​​the base; for this purpose, its roughness and metal standard are increased. To determine the operations for preparing surfaces for painting, you can use the table below.

Table for preparing surfaces for painting.

If there are no special conditions for painting certain surfaces, then abrasive sandblasting Sa 2.5 SIS 05 5900 can be used.

Often non-ferrous metals need painting, for example, zinc, bronze, aluminum, copper, etc. They are used in construction and industry, they are painted for protective or aesthetic purposes.

So, aluminum Often used in aviation, shipping and construction, it is important to prepare the surface well to ensure good adhesion of the paint layer. To do this, it is necessary to remove dirt, oil and grease, after which the surface is sanded using power tools or sandblasting. The next step is to apply the primer with a specially formulated coating. This principle is used when cleaning bronze and brass.

Contamination on metal, its effect on paint adhesion.

More difficult to prepare galvanized steel. Sometimes paint systems do not work when used on this type of coating. This occurs due to insufficient surface preparation or lack of required soil. If you do not clean the surface, then the following scenarios are possible: when the copper-acid solution reacts with the surface, the color may turn black; if fat or oil remains on the surface, the color will be bright metallic.

Galvanized steel must be degreased from the very beginning, after which the surface must be thoroughly washed to remove soluble salts. After removing dirt and degreasing, it is necessary to clean the surface; for this you can use a light abrasive treatment along with sandpaper. All this will have a positive effect on the quality of paint adhesion to the surface.

If you work with masonry, concrete or plaster, then this has its own characteristics. New concrete Before the painting process, it must harden for at least 4 weeks. The surface is thoroughly dried and cleaned using mechanical means, sandblasting or acid blasting remove laitance that may be on the concrete. It is necessary to understand that hardening components and oils will reduce the adhesion of the coating to the base, so you need to get rid of them. Sandblasting using a non-metallic unit is the best means of obtaining a good quality surface.

For acid etching, a solution of hydrochloric acid (10-15% concentration) is required. However, on reinforced concrete you need to use organic acid, it reacts with the calcium components in the cement, this can be seen when bubbles appear. After this it is washed fresh water the reaction product is calcium chloride.

To remove old coating from concrete you need a rotating chisel or mechanical flails. This method is suitable for areas that need to be repaired using mortar for the purpose of reprofiling the surface.

If needed prepare the wood surface, dry plaster or plywood for painting, then the moisture content in wooden material should not be more than 15%. All protruding parts must be fully protected. Wooden surfaces are treated with a solvent, and it is important to treat the connecting parts. For creating flat surface you can use sandpaper.

It often happens that there is already paint on the surface and new paint needs to be applied, so first remove old coating. However, it is not always possible to simply apply any paint after this, because the old coating still affects new system which they want to apply. First you need to carefully examine the grounds. The surface must be checked for dust, adhesion, and cleanliness. Try to find any defects. The surface can be cleaned with a degreasing solution and fresh water if the existing paint layer is not damaged, then it is dried. But sometimes there are some peculiarities.

So, the process of preparing the surface for painting plays an important role. After all, it will depend on this appearance material to be painted. Therefore, take this seriously!

Surfaces intended for painting work are first prepared and then treated auxiliary materials and only after that they are covered with colorful compositions. New plastered surfaces are first smoothed and cleaned of large grains of sand with sandpaper, and then dust is removed from the plaster. If there are cracks, they are cut with a knife to a depth of 2-3 mm at an angle of 45° and cleaned of dust.

Previously painted surfaces are cleaned of dust and washed with warm water using brushes (the floors should be covered). If there is thick plaque, you cannot limit yourself to just washing; it must be removed. To do this, the surface is generously moistened with water, and the soaked paint is cleaned off with a scraper. Silicate and casein coatings are difficult to remove. In such cases, the plaques are washed with a 2-3% solution of hydrochloric acid: the chalk swells and the plaques are easily removed. On the surface of the plaster there may be discolored areas, rusty spots that appear as a result of the plaster getting wet and the formation of water-soluble colored compounds. Rusty areas and faded areas are washed with a solution of hydrochloric acid, then primed with a strong vitriol primer - grass.

Rusty areas are well covered with a mixture of lime slaked in milk and diluted to paint consistency. If after surface treatment the defects cannot be completely removed, the washed and dried surface is painted with oil white and then primed with vitriol primer.

If the plaster is saturated with resinous and oily substances, remove the defective areas in the following way. With comparatively small areas the surface of the plaster is sealed with thin sheets of foil, which is one of the the best means insulation from oils, then primed and puttied in the usual way.

The prepared surfaces are then treated with putty and primer compounds to remove any remaining roughness. The number of operations during surface treatment depends on what kind of finishing of the room is intended - simple, improved or high-quality. The higher the finishing category, the smoother the surface should be, and this will require large number operations.

Treatment of surfaces for simple painting with water-based compounds includes priming of cracks, sanding and priming with one layer.

Cracks in the plaster are smeared with a spatula, and the plane of the spatula should be inclined at an angle of 60" to the plane of the surface being treated to the right (when moving again, to the left). The smeared and dried areas are sanded; the dust is swept away with a brush.

It is much more effective to apply gypsum chalk paste. In this case, there is no need for preliminary priming of cracks. Gypsum chalk paste, due to the increase in gypsum volume during setting, fills cracks more completely.

Priming of surfaces for water-based painting is carried out with the aim of leveling the surface’s ability to absorb moisture (“pulling” ability), which is not the same even within the same wall due to the unevenness of the pores of the compound.

If puttying is done on an unprimed surface, the binder from the putty will penetrate into the thickness of the plaster, which can lead to peeling of the putty along with the paint. In addition, in the absence of a protective primer, it is impossible to apply the putty in an even layer, since the liquid phase of the putty is absorbed by the surface, as a result of which it dehydrates and thickens, and the surface becomes rough.

In the case when a surface that strongly absorbs moisture is painted without prior priming, significant accumulations of paint in the form of bulges (“patches”) form in certain areas. Such areas always differ in color from the rest of the surface.

Lime or soap primers are used for lime paints; for glue - alum, vitriol or soap. To fix fragile plasters, use an emulsion primer.

In primer compositions for finishing new plaster for simple glued paint, it is necessary to add 2-3 kg of chalk per 10 liters of composition (with such an amount of chalk, a coating is formed that hides roughness).

All types of primer, except vitriol, can be applied manually and mechanized; vitriol primer is applied only by hand. Large areas are primed with a fly brush or brush. Small surfaces and surfaces at the junction of two planes, painted in different colors, primed with a hand brush. The primer is applied in two mutually perpendicular movements; The walls are first primed, making horizontal movements, and then vertical, and the ceilings are perpendicular and parallel to the direction of light.

To obtain a smoother surface with barely noticeable roughness, a second primer is carried out; in this case, 7-6 kg of chalk per 10 liters of composition is introduced into the primer. It is impossible to perform priming without chalk, since the film will be very thin and will not hide surface roughness.

When processing the surface for high-quality painting, continuous puttying is carried out on primed surfaces; At the same time, chalk is not introduced into the primers, since in the presence of chalk, brush marks remain on the leveled surface, which are visible even after painting.

Putty compositions for adhesive paints are prepared using adhesives, the concentration of which should not exceed 5%, since the stresses arising in the putty layer during drying should be less than the strength of the plaster on which they are applied. Putty with an excessive amount of glue can tear off the primer layer and even the entire thickness of the plaster with the formation of cracks.

In addition, when painting with adhesive over putties with an excessive amount of glue, marble-like spots often appear on the surface. This is explained by the fact that during painting the glue in the putty swells with its simultaneous dissolution and penetration (diffusion) into the paint film. It is difficult to combat this phenomenon; Sometimes this requires removing the entire putty layer.

The putty is applied using a spatula or a spray gun. The thickness of the putty layer is 1-1.5 mm. The putty layer applied with a gun is immediately smoothed with a rubber spatula (“scraper”), making two mutually perpendicular movements. When applied with a spatula, it is positioned at an angle of 60 e1 to the surface to be treated. At a smaller angle of inclination, the layer is thicker, at an angle of 80° - the most thin layer spar-levki. When using a cut trowel (10 -120° to the longitudinal axis) during its movement, the putty from the shortened side of the trowel is removed without residue, and from the elongated side it slides off like a roller. The short side of the spatula is applied to the already putty surface at an angle of 10-15°, overlapping it by 2-3 cm. After drying, the putty is sanded and dust is removed.

Thus, with high-quality finishing with aqueous adhesive and casein compositions, the following operations are performed: cleaning the surface and smoothing it; bridging cracks; first primer; partial lubrication; sanding greased areas; first continuous shnatling; surface grinding; second primer (not used when painting with casein compounds); the second continuous filling and sanding. Only after all operations have been completed are painting and trimming performed.

In some cases, for example, when the decorative requirements are less stringent or when the surface being painted is sufficiently smooth and without defects, it is sufficient to carry out basic preparatory operations, after which greasing and grinding of the greased areas is carried out.

Because the lime compounds usually painted plaster, concrete or brick surfaces in different utility rooms where there are no requirements for decorativeness, surface preparation is also simplified and includes cleaning, wetting with water, smoothing, filling cracks, rounding, partial lubrication and grinding of these areas. After this, coloring is carried out.

Treatment of the surfaces of sheathing sheets (dry plaster) consists of the following operations: sealing seams (joints); insulation of nail heads (if the sheets were fastened with nails); priming of surfaces with vitriol, quartz or soap primer. The walls of the sheets are sealed with gypsum chalk paste. Nail heads are painted with oil paint or nitro-enamel, which dries faster. Further processing does not differ from the processing of plastered surfaces.