All photos from the article

Painting works are intended decoration building structures and improving their operational and hygienic properties. Coloring technology wooden surfaces provides for their preparation in accordance with the requirements of SNiP 3.04.01-87.

A strong and durable coating ensures the safety of the elements. It protects against warping, cracking and wood damage by insects and fungi.

Painting work can be done by hand without the involvement of masters of a specialized specialty. Instructions for painting surfaces made of wood are given below. To perform such an operation, it is necessary to prepare a building structure, tools and materials. Application coatings allowed when the moisture content of the base is not higher than 12%, respectively, it must dry beforehand.

Preparing wood surfaces for painting

Repair of building structures should begin with their cleaning and alignment. The question arises: how to remove paint from a wooden surface?

Currently, there are several ways to perform this operation, described in a special section below. The surface cleaned from old coatings must be leveled with fillers, carefully primed and degreased. After the base has dried, you can proceed directly to the application of paint.

Methods for cleaning wooden surfaces from old coatings

There are several technologies for removing previously applied layers of paintwork, based on the use of different principles.

Removing paint from wooden surfaces is carried out in the following ways:

1. Mechanical. The work is carried out using sandblasting equipment or rotating wire brushes. On relatively small areas by hand.
2. Thermal. Provides for the use of industrial hair dryers or blowtorches. Under the influence of high temperature, the coating swells, after which it is easily removed with a spatula.
3. Chemical. It implies the use of special compounds applied to the tree. They partially dissolve the paint and ensure its flaking.

Choosing a method of how to remove paint from a wooden surface, you need to take care protective equipment. Goggles, respirators or masks will be required and protective gloves and in the process of work, safety measures must be observed. At the end of the operation, the wooden structure is cleaned of dust and debris manually with a brush or by blowing it with compressed air.

Surface degreasing

The base, from which the old coating has been removed, usually has pollution of a very different nature. They reduce the adhesion of fillers, primers and paints to the surface; they need to be cleaned up. How to degrease a wooden surface before painting and preparation? To carry out this operation, solvents based on white spirit or formulations developed specifically for this purpose can be used.

Tip: It is not recommended to apply the degreaser with a brush for two reasons. First, it increases the consumption of material.
Secondly, the brush does not remove dirt from the base.
It is best to use rags or napkins.

There are other degreasing technologies: immersion in special ultrasonic baths, treatment with solvent vapors or dry ice. This technique involves the use of special equipment, and is used in specialized enterprises.

Agency for Management of Public Institutions

Perm Territory

State budget educational institution

secondary vocational education

"Chernushinsky Mechanics and Technology College"

10 "Master of finishing construction works"

WRITTEN FINAL QUALIFICATION WORK

Topic: Surface preparation technology for painting

Graduate

Botalova Alena Pavlovna Group No. -11

Work manager

Chernushka - 2012

INTRODUCTION

CHAPTER 1. PREPARATION OF DIFFERENT SURFACES FOR PAINTING

1 Preparation of plastered surfaces

2 Preparation of wooden surfaces

3 Preparation of drywall for painting

4 Priming and filling of surfaces

CHAPTER 2. BASIC OPERATIONS FOR REPAIR OF PLASTERED SURFACES

1 Removing oil stains and oil paint

2 Sequence of surface preparation for painting

3 Tools and inventory for preparatory work

4Safety

PRACTICAL PART. CALCULATION OF MATERIAL FOR PUTTYING AND APPLICATION OF GROUND ON gypsum board walls

CONCLUSION

LIST OF SOURCES AND LITERATURE

APPS

INTRODUCTION

The quality of the painted surfaces almost half depends on how the surface is prepared for painting: whether there are bumps, tar and oil stains on it, whether it is smooth. Therefore, before picking up a brush or roller, the hand must work with sandpaper, a spatula and a rag.

In this paper, the technological process of preparing various surfaces is disclosed.

Objective:

to study the technology of preparing surfaces for painting.

Work tasks:

get acquainted with the preparation for painting various surfaces;

get acquainted with the main types of preparatory work - priming and puttying;

find out how plastered surfaces are repaired and with what tool;

What are the safety requirements for painting work?

In the practical part of the work, calculations of the necessary materials for priming and puttying a plasterboard wall are given.

CHAPTER 1. PREPARATION OF DIFFERENT SURFACES FOR PAINTING

The surfaces to be repaired are not the same (made of different materials), so their preparation for painting will be different.

By the beginning of painting finishing should be: all installation and general construction works on the installation of walls, ceilings, partitions, roofs are fully completed; plastered brick walls and joints of floor panels, partitions, as well as places for passing risers of sanitary pipelines; installed door and mezzanine blocks and inserted cabinets; heating, plumbing and sewerage systems were installed and pressure tested; installed electrical fittings and appliances; the premises were cleaned of construction waste and remnants of materials. Compliance with these requirements will prevent damage to painted surfaces. Painting work is recommended to start, as a rule, from the upper floors.

In the premises handed over for finishing in the cold season, the air temperature must be not lower than +10 ° C, and the relative humidity - not more than 70%, as well as their reliable ventilation. Humidity of plastered and concrete surfaces to be painted should not exceed 8%, and wood - 12%. The application of oil compositions on surfaces with higher humidity is allowed only when using lime, cement, polymer cement and some synthetic coloring compositions. Painting work includes the following processes: preparation of surfaces for painting; harvesting and applying paint compositions of preparatory layers (primers, lubricant pastes, fillers) with their subsequent processing; applying a paint composition, and, if necessary, finishing painted surfaces.

1.1 Preparation of plastered surfaces

New, previously unpainted plastered surfaces are prepared for painting in the following sequence.

First of all, the surface must be cleaned or smoothed first with pumice or bream, then with sandpaper. Cleaning is carried out only on a dry surface in a circular motion. During this operation, weakly adhering grains of sand are exfoliated from the plaster layer, small bumps are smoothed out, and the surfaces become even and smooth.

The second stage: sealing cracks. All cracks are cut with a knife to a depth of at least 3 mm, cleaned of dust, moistened with water and covered with gypsum mortar or gypsum-chalk grease, rubbed well and dried.

Next, remove the existing resin and oil stains. Small areas can be sealed with thin foil; large ones are cut down with a chisel and a hammer to a depth of at least 3 mm, and the resulting irregularities are repaired, similarly to cracks, with gypsum-chalk grease.

Paints do not like dust very much (and there is plenty of it on plastered surfaces), so the final stage of preparation is dedusting, for which you can use brushes or a broom, but it will be much more effective to do this with a vacuum cleaner or a damp cloth.

If you have chosen the wet method of dedusting, then the surface must be dried well before painting.

2 Preparation of wooden surfaces

In preparation for painting new wooden surfaces, we distinguish the following stages:

First, with the help of a chisel and a hammer, we cut down knots and resins. Such drastic measures are necessary, since the knots have a slightly higher density than the main body of wood, and when dried, the knots will protrude on the surface, and the paint in these places will crack; we cut down the resins for the reason that the resin tends to penetrate the putty layer and appear on the painted surface with indelible spots.

The resulting large holes can be sealed with wooden dowels (on carpentry glue or PVA dispersion) or sealed with a thick mixture of fine sawdust and PVA dispersion. Then, with a sandpaper, we remove small burrs and roughness, and we close cracks and small traces of removed knots and tars with a special putty on wood (for pigmented coloring - any, for varnish - according to the type of wood).

The final stage is the removal of oil stains (we use acetone, refined gasoline or kerosene) and dust removal (this time we will give preference to the dry method so that unprotected wood does not suffer from high humidity).

3 Preparation of drywall for painting

The building material drywall is now quite popular in construction. With the help of drywall, it is easy to achieve perfectly flat surfaces of ceilings and walls. For the implementation of all kinds of design solutions, this material is perfect.

The surface of drywall is often coated with various dyes, such as: water-based, enamels, oil, adhesive and dispersion paints. Also drywall is covered with facing decorative tiles. Sometimes embossed decorative plasters and different types of finishing film.

In this paragraph, we will consider how to prepare the surface of drywall for painting. In order for the drywall construction to look very elegant and constantly delight us with its appearance, it is necessary to prepare the drywall surface with high quality, this is the most important thing for decorative finishing.

Over the entire area, carefully cover the drywall with a primer and give time to dry. Before painting or wallpapering itself, you need to putty all the bumps and cracks with putty and a spatula. For high-quality putty between the sheets of joints, sickle is used, this is a tape made of fiberglass. Glue the tape with putty along the entire seam and rub it with the same putty.

After that, let it dry. Then, with sandpaper, you need to carefully sand the entire surface of the drywall, reducing its grain size gradually so that our surface is perfectly smooth and even. It is advisable not to overdo it, grinding to drywall is not recommended. In such places, dull spots may form in the future.

The prepared surface and putty must finally dry.

The next stage is a primer, during grinding and puttying, the surface of the treated drywall is rubbed unevenly with putty.

A primer is used to even out the entire tone. It is recommended to prime 2 times. In order to apply the primer, use a brush or brush. After all the preparatory procedures are done, you can start painting or pasting wallpaper.

1.4 Priming and filling of surfaces

Clean, dust-free surfaces without cracks, pits and tubercles should be primed and puttied. Primer and putty for different types of paint and varnish products are produced in different ways.

At the next preparatory stage, the surfaces are primed with liquid paint compositions applied before each putty in a continuous even layer. The need for it is due to the fact that usually a porous base for painting must be impregnated with a composition similar to the coloring one. The application of putties and coloring compositions without a primer will cause uneven drying.

Concrete and plaster surfaces have an uneven porous structure, and if paint or putty is applied directly to the substrate, the pores will draw moisture out of them unevenly, which will lead to peeling of the putty or paint or the formation of local accumulations of paint in the form of bumps. To equalize the “pulling” ability of such surfaces (the ability to suck moisture out of the paint composition), the first layer of the multilayer composition, the primer, is used.

Under lime paint, the surface is primed with a lime primer or a soap maker primer, under glue and casein paint - alum or vitriol primers. The primer can be applied both manually - with a brush or roller, and mechanized - with an airbrush (with the exception of vitriol primer). Apply the primer on the ceiling with a fly brush and a handbrake brush in the direction perpendicular to the direction of natural light (along the window), shade - parallel to the direction of natural light (starting from the window - deep into the room). We apply the primer on the walls in horizontal stripes, and then shade it with vertical movements: such a double shading avoids gaps. The flywheel during operation should be held with a slight inclination to the working surface.

The next stage - puttying - is necessary when preparing for high-quality painting (solid puttying) or if there are significant defects on the surface (partial puttying). In order to obtain a smooth painted surface, these defects must be eliminated. Putties do an excellent job with this task, which are a pasty viscous mass consisting of pigments, fillers and film formers.

Pre-primed cracks widened by cutting in separately damaged areas of plaster and concrete structures, as well as cracks formed on wooden surfaces, are filled with lubricating pastes or putties applied manually with wooden or steel spatulas, followed by smoothing and cleaning to ensure smoothness and uniformity of the base for painting. Putty is applied and leveled with a spatula in two mutually perpendicular movements. After the putty layer has completely dried, we grind with a sandpaper in a circular motion: first - coarse-grained, then - fine-grained. We apply liquid putty with hand brushes, then level with a spatula and smooth with a flute brush, flute.

If necessary, the operations of priming and filling are repeated 2-3 times. In this case, each subsequent layer of soil is applied to the surface only after the previous layer of putty dries out (Appendix 2).

Consider the operations performed with a simple, improved and high-quality finish with various paint compositions.

With a simple painting on wood with oil paint, seven operations are performed: cleaning from dust and dirt, since paint or drying oil does not adhere well to contaminated surfaces; cutting knots, dowels, pitching, cutting cracks or crevices; pro-oiling of the entire product; lubrication of all defects; grinding of greased places; first coloring; second coloration.

Improved coloring requires 15 operations. In addition to those that are included in simple painting, they perform continuous puttying with grinding of dried putty, its priming, leveling the priming with a flute. After a good drying of the primer, it is polished with pumice stone or fine-grained sandpaper, removing all the smallest bumps and sagging.

priming. Then the first coloring is carried out with flattening, drying and grinding and the second coloring with flattening or trimming.

We remind you that the paint should be filtered through a frequent sieve so that it does not contain even the smallest grains or clots. This makes it possible to obtain an exceptionally clean and smooth oil painting.

High-quality coloring requires 17 operations. In addition to the operations that are performed with improved coloring, two more are added - the second puttying and grinding. If some tolerances are still possible with improved coloring, for example, the smallest grains in the paint, then with high-quality coloring this is unacceptable.

When painting walls and panels, you have to draw a strictly horizontal line. It is impossible to do this with a flywheel or other large brush or roller, therefore, a handbrake is used, diverting a strip of paint 10-12 cm wide along a line broken off by a cord or along a ruler. Only after that they start painting with a fly brush or roller. If the walls or panels were previously painted with oil paint, then after painting the ceiling or ceiling with glue paint and the top of the walls with oil paint, first remove traces of glue paint, and then start working with oil paints.

It should be remembered that most of the passes during painting occur in the husks of walls and ceilings, that is, where the walls adjoin each other, forming an angle, or the walls adjoin the ceiling, as well as on the cornices. These places should first be carefully trimmed, and then painted in the usual way, shading the paint well and arranging the strokes as indicated earlier, and only after that proceed with staining.

CHAPTER 2. BASIC OPERATIONS FOR REPAIR OF PLASTERED SURFACES

1 Removing oil stains and oil paint

To remove oily stains, the surfaces are washed with a 5% solution of trisodium phosphate (washing powder) or soda ash, diluting them in water with a temperature of 30-40 ° C. Next comes cleaning - removing dust, splashes and streaks of the solution from the surface with metal spatulas, scrapers, steel brushes, rags or mechanically. The same operations include drying individual damp places, removing grease stains, efflorescence, rust, scale with a solution of hydrochloric acid.

Oil stains are removed with burnt magnesia paste mixed with gasoline, toluene or benzene. Oil stains are removed with a paste consisting of two parts fluff lime and one part powder. Stains of non-drying oils are removed with oily clay applied to the stain with a layer of 3-4 mm. After drying, the clay is scraped off and the surface is washed. Efflorescence is removed with metal brushes, the surface is washed with a weak solution of hydrochloric acid (5%), followed by rinsing with clean water and drying. When repairing and restoring surfaces previously painted with chalk, adhesive, casein compounds, they are pre-moistened with water and scraped off; the covering layer of plaster is rubbed again with lime mortar on fine sand and, after drying, primed with a composition recommended for new painting. In case of large damage or contamination of the plaster, it is advisable to replace it completely. When repairing and restoring surfaces previously painted with oil, synthetic or enamel compounds, lagging layers should be removed. If the old paint holds firmly, it is not scraped off, but cleaned with sandpaper. Contaminated surfaces are washed with warm soapy water, and in case of significant contamination - with solvents (turpentine, kerosene, white spirit, gasoline).

Oil paint is removed and by chemical means using pastes that soften the old paint layer, which is then easily scraped off.

The composition of the pastes:

lime dough - 0.5 kg, sifted chalk - 0.5 kg, caustic soda (20% solution);

sifted chalk - 0.5 kg, asbestos dust - 0.5 kg, caustic soda (20% solution).

The softened layer is scraped off with scrapers or spatulas, then washed with a 2% solution of acetic acid, then with clean water, wiped with a rag and dried.

2 Sequence of surface preparation for painting

Consider the main stages of surface preparation for painting. Surface preparation consists of:

Crack jointing.

Surface dusting.

Primers.

Puttying.

grinding.

Re-dedusting.

Surface priming after puttying.

Jointing of cracks is carried out with a knife or a steel spatula to a depth of at least 2 mm for filling with putty. After smoothing and jointing cracks, the surface is carefully dedusted.

The cleaned and dust-free surface is primed to reduce its porosity, to improve adhesion with subsequent layers (putty, paint) and reduce the overall consumption of paint.

To perform these functions, the primer must penetrate deep into the pores of the base and therefore must be thinner and more plastic than the paint that will be used in subsequent paint layers. The primer composition is selected in accordance with the binder of the coloring composition, most often a diluted coloring composition is used. Usually, manufacturers producing paint formulations recommend appropriate primers for them.

Embroidered and primed cracks, potholes, irregularities are filled with putties using metal or rubber spatulas.

First, the cracks are filled with transverse movements of the spatula, then the applied layer is leveled with the movements of the spatula along the cracks, achieving an even and smooth surface. After the putty dries, it is sanded.

Sanded places are dedusted and primed with the same primer that was used to prime the entire surface.

After completing all these preparatory work, the surface is painted.

3 Tools and inventory for preparatory work

For painting work, various brushes, rollers, spatulas, rulers are needed. You can buy these tools or make your own.

Brushes, depending on the type of work, use a different type.

Handbrakes - round brushes are used for painting small surfaces with oil paint.

Flutes - wide flat brushes are used for leveling colorful and varnish coatings made with a fly brush or handbrake. Fleuts can also be used for coloring. In the process of work, these brushes should be wiped periodically.

Maklovitsy - are round with a diameter of 120 m and 170 mm. With bristle lengths from 94 to 100 mm, rectangular. The handle of the maklovits is fastened in the middle of the block tightly or removable with screws. Top coats are recommended to be used on glued ones and require fletching.

Trimmers - come in a rectangular shape with a size of 154 x 76 mm, they are made of hard spinal bristles. Trimmers are used to treat freshly painted surfaces. Trimming is applied evenly, smoothing out the unevenness of the paint applied with a brush. Trimming must be clean and dry, so it must be wiped frequently.

Rollers - for painting work. When painting, the rollers form a texture resembling a large shagreen. Rollers can perform different work: prime and paint with various paints both walls and ceilings. Before starting work, fur rollers should be put in water for a while so that the hair acquires the same stiffness.

Spatulas and rulers. In the production of painting work, metal and wooden spatulas, various in shape, are used to level the putty. These spatulas are used for applying and leveling putty on wood and plaster.

In addition to these tools, a knife, a chisel, a steel brush, a bucket, basins, cups, a frequent sieve or gauze are needed for work.

4 Safety

During the performance of painting works, the following apply to employees: harmful factors: dust emission when mixing dry materials with drying oil and when grinding surfaces with sandpaper or pumice, spraying paint, environment with mechanized application, it is on the surface, the release of harmful substances and gases upon drying, and finally, the release of harmful vapors upon removal old paint. Painting work carried out indoors, starting from a height of 1.1 m from the ceiling or ground level, should only be carried out from a firmly installed scaffold. Painting work indoors with the use of harmful compositions is carried out with open windows without allowing drafts, or with ventilation that provides at least two air exchanges for 1 hour. In rooms freshly painted with oil paints or nitro paints.

It is forbidden to stay more than 4 hours, smoke and work with fire. During the production of painting works, workers are provided with overalls, goggles with a dense frame and respirators, gloves.

3. PRACTICAL PART. CALCULATION OF MATERIAL FOR PUTTYING AND APPLICATION OF GROUND ON gypsum board walls

wall drywall putty paint

Given: Three rooms, with a total wall area of ​​93sq. meters. The walls are lined with plasterboard.

Primer calculation.

Considering that the primer consumption is per 1 sq. meter - 100 ml, then 93 sq. meters will require 9300 ml, or 9.3 liters. We multiply the amount obtained by 2 (double priming), we get 18.6 liters.

You can safely buy 2 cans of primer 10 liters each.

Calculation of putty (dry mix).

For puttying joints GKL requires 0.3 kg. dry mix per 1 sq. meter.

3 multiply by our area - 93 sq. meters, we get 27.9 kg. That is, we need a little more than a 25 kilogram bag.

Appendix 2 shows appearance dry mix and primer.

CONCLUSION

As a result of the work, the optimal process of the technology for preparing surfaces for painting was studied, where the elements of operational actions for the implementation of this process were studied. There is also a list necessary tools for painting work.

Safety precautions for this type of work were given.

In the practical part, calculations were made of the material consumption during priming and puttying a plasterboard wall for a given area.

Knowledge of the preparatory work before painting is very important and very much in demand, since not one family now can do without repairing their premises. Knowing this technology, we can get a beautiful appearance of the room after painting. Without knowing this, painting may not give the expected results.

Another important value is the ability to carry out calculations of materials for this type of work. Competent calculation of consumables, saves money.

LIST OF SOURCES AND LITERATURE

1. Ivaliev, A.A. Finishing construction works, textbook. For the beginning prof. Education-4th edition, erased, - M, publishing center "Academy" 2002. - 488 p.

Statsenko, A.S. Technology of building production - ed. 2nd. Rostov-on-Don "Phoenix", 2008. - 415 p.

. "Finishing work in construction". Moscow. Stroyizdat. 1987

Kulikov, O.N., Labor protection in construction. / E.I. Rolin. - M.: Academy, 2004. - 216s.

ATTACHMENT 1

Rice. 1. Brush painting technique

Rice. 2. Roller technique

APPENDIX 2

Rice. 3. Dry putty mix "Universal" and deep penetration primer "Optimist".

Protruding knots on the surface of the product are removed using semicircular chisel to a depth of 2-3 mm, then processed with drying oil and smeared with putty. You can replace protruding knots with wood plugs of the same breed, securing them with wood glue. It is important that the direction of the fibers of the surface and cork match. Wooden a few millimeters inside.

Tar and grease stains

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

Oil stains and paint residue

Such defects are removed chemically, by treatment with acetone, or other means for removing paints. When painting a surface with nitro paint, the old oil paint must be completely removed, otherwise the nitro paint applied to a surface previously painted with oil paint will swell and curl. It is possible by heating it with a professional hair dryer, and the swollen paint should be removed with a metal spatula.

Mold removal

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

Washing and grinding

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

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

Surface cleaning and primer

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 fibers.

Grinding

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

Painting works are the final stage of finishing works in construction. The quality of the finish affects the appearance, the duration of the operation of the premises and depends on the correct preparation of the surfaces. Before starting painting work in the premises, it is necessary to complete all construction work (except for laying linoleum on the floors), electrical work, installation and testing of central heating, plumbing, sewerage. Humidity of plastered and concrete surfaces should not exceed 8% before painting, and wooden surfaces - 12%.

Preparation of surfaces for painting includes the following operations:

Surface cleaning, drying damp places;

Priming;

Jointing and filling of cracks and shells;

Grinding.

Preparation of new plastered surfaces. New, unpainted previously plastered surfaces must first be cleaned, smoothed with a pumice stone, then with sanding paper by hand or using a grinder. Surface cleaning is to remove dust, dirt, streaks and splashes of the solution from them. Even the smallest amount of dust reduces the adhesion of the paint or primer to the surface. In case of minor contamination, the surfaces are swept with dry brushes or brushes. In case of severe contamination, the surface must be washed with water. Streaks and splashes of the solution are cleaned from the surface with steel spatulas. Smoothing is carried out only on a dry surface in a circular motion. During this operation, weakly adhering grains of sand are exfoliated from the plaster layer, small tubercles are smoothed out, the surface becomes even and smooth.

Rusty spots and efflorescence may appear on a freshly plastered surface. Rusty spots are cleaned and primed with nitro-lacquer or enamel. Efflorescence is removed with metal brushes, the surface is washed with a weak solution of hydrochloric acid (1 part of 30% hydrochloric acid to 5 parts of water), followed by rinsing with clean water and drying.

After careful preparation of the plastered surface, it is primed.

Preparation of wooden surfaces. Preparation of wooden surfaces for painting includes the following steps:

Correction of tree defects;

grinding;

Removing oil stains.

First, with the help of a chisel and a hammer, knots and resins are removed. Knots have a higher density than the main wood, and when dried, the knots will protrude on the surface, and the paint will crack in these places. In place of the cut knot, a piece of wood of the same species is glued. The direction of the fibers of this piece of wood must match the direction of the fibers of the main product.

Resins are cut down, as the resin can penetrate the putty layer and show through later on the painted surface. Resins are not cut down deeply - to a depth of 2 ... 3 mm, so these places are smeared with a thick paste from a mixture of fine sawdust and PVA dispersion.

Then fine burrs and roughness on the surface are removed with sanding paper. Cracks and traces of removed knots and pitches are sealed with a special putty on wood.

The final stage is the removal of oil stains and dedusting. Oil stains can be removed with acetone, refined gasoline or kerosene. Dust the surface with dry brushes.

Preparation of metal surfaces. Metal surfaces must first be carefully inspected for rust and scale. Detected defects are cleaned with metal brushes, sanding paper manually or using grinders. It is almost impossible to completely remove rust products mechanically. Therefore, in such cases, rust converters are used. To do this, use the "Auto Rust Converter", a special paste "Auto Rust Cleaner", as well as special primers - rust converters.

Primers- rust converters - not only convert rust, but also create a polymer film on the metal surface. They contain phosphoric acid, which converts corrosion products into insoluble iron phosphates. The primer is chosen taking into account the type of metal and operating conditions. For such purposes, universal primers GF-021 and GF-0119 are used. The indicators of these primers are shown in the table

Preparation of previously painted surfaces. The preparation of surfaces painted with different compositions is different.

Surfaces previously painted with lime or adhesive compositions , completely cleaned of whitewash - old paint. Nabel can be removed in a dry way - by scraping it off with scrapers or spatulas. If the paint is not completely removed, then the surface is moistened, preferably with warm water. When the paint gets wet, it can be easily scraped off with a metal spatula.

Another way to quickly remove the nabel is to rinse the surface with a 1-2% hydrochloric acid solution. The chalk, which is part of the adhesive paint, begins to decompose, the paint swells and is easily removed.

After applying each of these methods for removing whitewash, the surfaces must be washed away with clean water using a fly brush or a brush-brush.

Preparation of surfaces painted with oil paints, enamels and varnishes, depends on the state of the previous coverage. If the paint adheres well to the surface and has not cracked, then you can simply rinse the surface with a weak (3%) solution of ammonia or baking soda, and then with clean water.

If the old paint does not hold well, cracked, peeled or swelled, then it must be removed. With a metal spatula, only weakly adhering paint can be removed, and even then not all. This method is time-consuming and ineffective, so the oil paint is preliminarily softened. You can melt old paint with hot air using a hot air blower (fig. 1). The paint remover is held so that its tip is about 25 mm from the surface and is moved along a small area. Softened and swollen paint is removed with a scraper or spatula. In this case, it is necessary to protect adjacent surfaces from damage. For example, when removing paint from window frames, do not direct hot air at the glass - it can crack. You can also burn paint with a blowtorch, but this method is very flammable.

Figure 1. Removing old paint with a thermal blower

To remove old paint, you can use chemical compositions - washes, for example, DUFA Abbeizer (Germany), which softens and removes old paints from painted surfaces, which consists of dichloromethane and methanol. With its help, water-dispersion, oil, synthetic paints and enamels, nitro-enamels, parquet varnishes are removed. This composition is applied to the surface with a brush. After some exposure, the swollen paint is removed with a spatula. The cleaned surface is then wiped with a cloth moistened with alcohol or mineral turpentine, or thoroughly washed with water. When removing several layers of paint, the process is repeated. Work with Abbeizer wearing rubber gloves, avoiding skin contact.

To soften the paint, industrial washes BEM-2, AFT-1, SD or self-prepared pastes are also suitable.

washes- liquid compositions, which are mixtures of organic solvents.

Washer BEM-2 is designed to remove coatings from oil, glyptal and nitrocellulose enamels. It works in 10 ... 30 minutes. AFT-1 wash is a colorless liquid. It is used to remove oil and varnish coatings based on cellulose nitrate. It works 20 minutes after brushing or spraying.

The SD remover is used to remove oil and varnish coatings from metal surfaces. After 3 minutes after application, the coating begins to swell and wrinkle, after which it is easily removed with a spatula.

In the absence of a chemical wash of industrial production, a layer of old paint can be removed using self-prepared pastes:

1) mix ammonia - 2 parts, turpentine - 1 part, chalk - to the desired consistency;

2) mix soda ash - 1 part, slaked lime - 3 parts, add 5 parts of water;

3) mix equal parts of the sifted chalk and lime dough and dilute the mixture to the density of putty with a 20% solution of caustic soda (at the rate of 250 g of soda per 1 liter of water).

The paste is applied to the painted surface with a spatula and left until the paint softens (0.5 ... 1.5 hours). Then it can be easily removed.

Preparation of problem areas. Rusty spots, soot and leaks sometimes appear on previously painted surfaces. If these defects are not eliminated, they will appear on the new color.

You can remove them in one of the following ways:

The old dried rusty stain is washed with water, dried and primed with nitro-lacquer or enamel;

A damp stain from a leak is first dried, having previously eliminated the cause of dampness, then primed with an oil composition;

The smoked surface is washed first with a 2-3% hydrochloric acid solution, then with water, after which it is primed.

Cracks often appear on the surface of the plaster. All cracks must be repaired before painting. Small cracks are embroidered - cut and deepened with an angle of a spatula or a plaster knife to a depth of at least 3 mm. This will prevent the crack from expanding in the future. Then it is cleaned. Next, with a clean brush, moisten the crack and the surface around it with water. Then the crack is filled with putty or gypsum mortar, rubbed well and dried. Larger cracks are filled with special sealing masses or acrylic. First, a large crack is expanded, cleaned and primed with a dispersion primer. Sealers and acrylic masses are available in tubes. The mass squeezed out of the tube with a special gun. To insert the tube into the gun (Fig. 2), you need to turn the plunger with the teeth up and pull it out until it stops. Having inserted the tube into the gun, it is necessary to turn the plunger with the teeth down. A hole is cut out in the spout of the tube through which the sealing mass will flow. The spout is inserted into the crack (Fig. 3). With gentle pressure on the trigger, the mass is squeezed out and fills the crack. Then the treated area should be smoothed with a spatula and washed with a damp sponge.

The surfaces intended for painting work are first prepared, then treated with auxiliary materials, and only after that they are covered with paint compositions. New plastered surfaces are first of all smoothed and cleaned of large grains of sand with bream, 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 fly brushes (floors should be covered). If there is a thick coating, it cannot be limited only to washing, it must be removed. For this, the surface is abundantly moistened with water, the soaked paint is cleaned off with a scraper. Silicate and casein coatings are removed with great difficulty. In such cases, the nabels are washed with a 2-3% solution of hydrochloric acid: the chalk swells, and the nabels are easily removed. On the surface of the plaster, there may be faded areas, rusty spots, which appeared as a result of the wetting of the plaster and the formation of water-soluble colored compounds. Rusty places and faded areas are washed with a solution of hydrochloric acid, then they are primed with a strong vitriol primer - grass.

Rusty places are well covered with a composition of lime, slaked in milk and diluted to a 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 a vitriol primer.

If the plaster is impregnated with resinous and oily substances, the defective places are removed in the following way. With relatively small areas of the surface, the plaster is sealed with thin sheets of foil, which is one of the best means insulation from oils, then primed and putty in the usual way.

The prepared surfaces are then treated with putty and primer compositions in order to remove the remaining roughness. The number of operations during surface treatment depends on what kind of finishing of the room is planned to carry - simple, improved or high-quality. The higher the finish category, the smoother the surface must be, and this will require a large number of operations.

Surface treatment for simple painting with aqueous compositions includes smearing cracks, grinding and priming in one layer.

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

It is much more efficient to make lubrication with gypsum paste. In this case, there is no need for preliminary priming of cracks. Gypsummel paste, due to the increase in gypsum in volume during setting, fills the cracks more completely.

Priming of surfaces for water painting is carried out in order to equalize the ability of the surface to absorb moisture (“pulling” ability), which is not the same even within the same wall due to the unevenness of the pores of the Turkish piece.

If puttying is carried out 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, the putty cannot be applied 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 event that a surface that strongly absorbs moisture is painted without preliminary priming, significant accumulations of paint in the form of bulges (“natasks”) are formed in separate areas. Such areas always differ in color from the rest of the surface.

Under lime paints, lime or soap primers are used; for adhesive - alum, vitriol or soap. To fix fragile plasters, an emulsion primer is used.

It is necessary to introduce 2-3 kg of chalk per 10 liters of the composition into primers for finishing on new plaster for simple glued painting (with this amount of chalk, a whitewash is formed that hides roughness).

All types of primers, except for vitriol, can be applied manually and mechanized; vitriol primer is applied only by hand. Large areas are primed with a fly brush or maklovitsa. Small surfaces and surfaces at the junction of two planes painted in different colors, primed with a handbrake brush. The primer is applied with 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 a barely noticeable roughness, a second priming is carried out; at the same time, 7-6 kg of chalk per 10 liters of the composition are 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 coloring, continuous puttying is carried out on the 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 on adhesives, the concentration of which should not exceed 5%, since the stresses that arise in the putty layer during drying must 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 plaster but its entire thickness with the formation of cracks.

In addition, when glue painting on putties with an excess amount of glue, marble-like spots often appear on the surface. This is due to the fact that during painting, the glue swells in the putty with its simultaneous dissolution and penetration (diffusion) into the paint film. It is difficult to fight this phenomenon; sometimes you have to peel off the entire putty layer for this.

The putty is applied with a spatula or spray gun. The thickness of the putty layer is 1-1.5 mm. The putty layer applied by the gun is immediately smoothed out with a rubber spatula (“po-luter”), making two mutually perpendicular movements. When applied with a spatula, it is placed at an angle of 60 e1 to the surface to be treated. With a smaller angle of inclination, the layer is thicker, at an angle of 80 ° - the thinnest layer of putty. When using a cut spatula (10 -120 ° to the longitudinal axis), when it moves, the putty is removed from the shortened side of the spatula without residue, and from the elongated one it slides off with 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 a high-quality finish with aqueous adhesive, casein compositions, the following operations are performed: surface cleaning and smoothing; jointing of cracks; first primer; partial grease; grinding of greased places; the first continuous shnatlevanie; surface grinding; the second priming (when coloring with casein compounds is not performed); the second continuous puttying and grinding. Only after all operations have been completed, painting and trimming is carried out.

In some cases, for example, when the requirements for decorativeness are less stringent or when the surface is painted sufficiently smooth and without defects, it may be sufficient to perform basic preparatory operations, after which lubrication and grinding of lubricated areas is carried out.

Since lime compositions are usually used to paint plastered, concrete or brick surfaces in various utility rooms where there are no requirements for decorativeness, surface preparation is also simplified and includes cleaning, wetting with water, smoothing, jointing cracks, -handling, partial lubrication and grinding of these areas. After this, coloring is done.

Surface treatment 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 closed with gypsum melamine 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.