Painting surfaces with non-aqueous compounds. TTK. Treatment of surfaces for painting with aqueous and non-aqueous compounds. Partial lubrication on top Painting surfaces with oil compositions

Water paint walls

Aqueous compositions, like lime, are prepared on cement, lime, emulsions such as MB, animal, casein or silicate glue. They paint plastered, concrete, brick or wooden surfaces. By quality, water colorings can be divided into simple, improved and high quality.

Preparing a new plastered wall for painting

Work begins with cleaning the walls from dust, dirt, splashes and streaks of mortar, removing various stains. Then the surface is smoothed over the entire area of ​​the wall, removing traces of grout, individual irregularities and protruding grains of sand. The surface of the wall is smoothed with circular movements. Large splashes of the solution are removed with a metal spatula. Small cracks are eliminated by wet grinding of surfaces with a wooden grater. To do this, simultaneously with grinding, the surface is moistened with water.

Large cracks, mechanical damage to the plaster (potholes) are greased. For better filling of cracks with a lubricant composition, they are cut (embroidered) with a metal spatula or a plaster knife to a depth of 2-3 mm at an angle of 40-45 °.
In order for the lubricant composition to keep better in the crack, it must be moistened with water, and with improved glue coloring- prime the entire surface with a specially prepared primer.

Then the grease is applied with a metal spatula, moving it first at an acute angle to the direction of the cracks.
The final leveling of the layer and the removal of excess lubrication mass must be carried out by moving along the crack. After drying, the smeared places are ground with a pumice stone or fine-grained sandpaper, and then the entire surface is primed. The primer composition is used depending on the type of surface and the accepted color.

If you paint the surface of the wall without a preliminary primer, then in those places where it is more porous (in places of lubrication), the paint is absorbed more and matte spots form on the surface, which will stand out sharply against the general color background of the wall.

Lime primers applied to well-moistened surfaces using manual or electric spray guns. Do not wet the wet surface.

silicate primers applied to durable, well-prepared wall surfaces with foam rollers or paint sprayers.

Primer for adhesive paints cooked on blue vitriol, alum or alumina. For applying primers (except vitriol) to the surface of the wall, paint sprayers are used.
During secondary priming for improved adhesive coloring, 6-7 kg of chalk is introduced into the composition of vitriol or alum soil for every 10 liters of it. The second primer is applied in the same way as the first.
High-quality colorings are carried out only with glue and casein formulations.

Casein primer before use, it is necessary to filter and apply to the surface using a paint sprayer.

Cement compositions used for painting surfaces with high porosity.

Before applying the primer (first coloring), first prepare in the usual way surface and abundantly moisten it with water to a moisture content of 37-40%. The primer is applied immediately after the droplet liquid water disappears from the surface. To apply the cement primer, spray guns or spray guns with a nozzle diameter of at least 2.5 mm can be used. However, it is better to use a stiff brush when applying the primer.

When painting internal surfaces waterborne emulsion paints the surface is prepared in the same way as for ordinary water-based paints.

When preparing the surface of the walls for painting modern paints chalk must be thoroughly washed off. Before whitewashing with chalk or lime, vitriol is used.
When painting over oil primer, the surface must be puttied with a putty corresponding to the type of paint.
Emulsion primers usually applied with a roller or spray gun.

For small volumes of work, primers can be applied manually with matting or fly brushes. In this case, a layer of primer is applied to the walls with vertical movements of the brush, followed by shading it in the horizontal direction, with a final shading in the transverse direction.
For high-quality painting, it is recommended to make two continuous fillers with grinding and dust removal after applying each layer of putty. The total thickness of the putty layer should not exceed 1.5 mm.

The first layer of putty is applied manually over the dried surface with a spatula, holding it at an angle of 10-15° to the surface. The putty strip applied in one movement is smoothed out by repeated movement of the spatula, perpendicular to the first.
Best for applying putty steel spatula . At the same time, a putty strip 40-50 cm wide and 1.5-2 m long is applied in one movement of the spatula. To apply liquid putty, you can use a fly brush, followed by leveling the composition rubber spatula. When leveling, the spatula is moved in a direction perpendicular to the brush strokes.

Putties applied mechanized way immediately level with a rubber trowel or a spatula with a rubber blade - in two mutually perpendicular directions.
After complete drying, the putty layer must be sanded with pumice stone or sandpaper until a smooth surface is obtained. Then the surface is wiped from dust with a rag or a dry flat brush, after which it is primed a second time. After drying, the surface is ground and primed for the third time with a composition that includes chalk and those pigments whose color will prevail in the color of the wall surface.

Preparing old wall surfaces

If the painting was done many times, then a thick paint layer is formed on the surface - nabel to be removed. A small weak nabel is simply washed off with water using a bast brush or fly brush. Strong adhesive nabelas are moistened 1-2 hours before the start of work hot water and then removed using metal spatulas or scrapers. Strong casein, silicate, as well as adhesive nabes are moistened with a 2-3% solution of hydrochloric acid and cleaned after softening. After removing the whitewash, the entire surface is thoroughly washed with water and rubbed with a wooden grater.

Preparation of wood and stone walls

Before lime painting, the wooden surfaces of the walls are cleaned, moistened with water and primed. When painting brick and concrete surfaces lime and silicate compounds the walls are pre-cleaned and primed with the appropriate composition: for lime painting - with lime soil, for silicate - with silicate.

Elimination of defects in the preparation of walls

The surface to be painted may be heavily soiled, with greasy or rusty spots, soot stains, etc. If the stains are not removed from the surface before painting, they will show through the layer of paint film.
Grease spots non-drying mineral oils and soot stains are washed with a 5% solution soda ash. To prepare such a solution, 400-500 g of soda is dissolved in a bucket of water. Soot stains can also be removed with a 2-3% hydrochloric acid solution.

Rusty water stains are washed with a 2-3% hydrochloric acid solution. After drying, the surface is primed with grass - 10-15% solution blue vitriol. If the spots are large and appear on the surface, they can be covered with rosin varnish or quick-drying white enamel paint.

Walls to be painted with non-aqueous compounds

Non-aqueous formulations include oil, varnish and enamel formulations.
Oil and enamel compounds cover plastered, wooden and metal surfaces, and varnishes only wood and metal. In terms of quality, non-aqueous paints, with the exception of paints for metal, are divided into simple, improved and high-quality ones.

Preparation of plastered walls

Smoothing the surface of the plaster and cutting cracks is done in the same way as in preparation for water-based paints. The surface is then oiled.
Surface pro-oiling is carried out using paint sprayers, and for small amounts of work - manually with brushes, shading the composition in an even layer so that there are no gaps. After the surface has dried, the damaged areas are smeared with paste for oil painting. Putty the surface with oil, varnish or oil-emulsion putty. Putty compositions are applied using the same methods and tools as for water-based paints.

After grinding and cleaning from dust, the surface is primed. With improved and high quality colorings the primer layer is fluted, i.e., shaded and leveled with dry fluting, and after drying, polished with a fine sandpaper.

Preparation of wooden surfaces

The compositions for painting and the methods of their application remain the same as for the preparation of plastered surfaces for oil painting. In order for the drying oil to soak the wood well during pro-oiling, it is recommended to warm it up a little.
Some defects in the wood must be removed with a chisel, scraper or sanding before the surface is pro-oiled.

Troubleshooting in preparation for non-aqueous stains

Removal of rust, grease and other stains from surfaces is carried out in the same way as with water-based paints. Wall surfaces previously painted with oil paint, but contaminated during prolonged use, are washed with hot water and soap or soda.
Three methods are used to remove the old oil film: mechanical, thermal and chemical.
mechanically the film is removed with metal spatulas, scrapers or chisels. However, this can damage the outer covering layer of the plaster. This method is used for all surfaces except wood.

thermal method It consists in the fact that the paint is heated with hot air to such a temperature that it begins to swell and peel off. For this purpose, building hair dryers are used. Cooling quickly, the paint becomes hard again, so it must be cleaned off directly in a stream of hot air, using a metal scraper with a wooden handle.
Working with building hair dryer requires caution. First of all, its nozzle, which is very hot, can be seriously burned. Work should be in glasses, protecting all parts of the body. Need to follow the rules fire safety. Heated - the paint emits toxic gases, so it is impossible to work with a hair dryer indoors.

chemical method It consists in the fact that a chemically aggressive mixture is applied to the paint, which is absorbed into it and destroys it. As a rule, the paint also swells and softens. Removing it does not require much physical effort. In this case, liquid mixtures are used, sold under the name "wash for old paint».
Flaw chemical method- the surface is impregnated with alkali, so it has to be washed with a 1% solution of hydrochloric or acetic acid. This method is applicable only for plastered and wooden surfaces.

Compositions for removing old paints and varnishes

"Unikrongel" - wash to remove coatings. Provides excellent flushing action - no more than 20 minutes for one layer of paintwork.
Used to remove old paint and varnish coatings from metal, wood, concrete and plastered surfaces.
To remove the old paintwork, a carefully mixed wash is applied in an even layer on the surface to be cleaned with an area of ​​​​not more than 0.5 m2 and left in this form for 10-20 minutes. After complete softening and peeling of the old coating, it is removed from the surface with a spatula and the cleaned surface is thoroughly wiped.
Work is carried out at a temperature environment 10-30°C.

Composition of AFT-1 used to remove old oily nitrocellulose paints. After loosening or swelling of the old paintwork, it is removed with a brush or spatula, then the surface is wiped with a highly volatile solvent.

Alkaline means "Vivaklin" ("Vivackean") used for cleaning interior and exterior surfaces before painting. It can be used to clean previously painted surfaces from dirt, grease, oil, wax. Water is used as a solvent.

"Rapidone" ("Rapidone") - jelly-like water-washable product for removing old paintwork from wood, metal, stone or glass surfaces.
For application use a brush or brush. After peeling, the paint is removed with a metal spatula, then the surface is washed warm water. The solvent is water.

Composition of SP-7 serves to remove old paint coatings, enamels VL-515, ML-165, AK-194, MS-3 and putty EP-0010, as well as the old complex coating, consisting of an electrophoretic primer VKF-O92, synthetic enamels such as ML-12, ML-197, epoxy primer EP-0228.

Not water compositions(oil, lacquer and enamel) paint the following plastered areas in residential buildings: kitchens, sanitary facilities and walls staircases, while continuous painting of the walls is unacceptable, since due to the airtightness of the paint film, the natural ventilation regime of the premises is violated. Non-aqueous paint compositions are widely used for protective and decorative coatings wood and metal surfaces.

Non-aqueous compositions paint only dry surfaces, covering them with a thin, even layer. It is impossible to increase the hiding power of the paint by increasing the thickness of the paint layer, since in a thick layer it first dries out and forms a film surface layer, and then the rest of the mass of paint. The uneven drying of the paint layer leads to the formation of roughness, wrinkles and cracks. Therefore, the surfaces are painted twice, and in case of poor hiding power of the pigments, three times, allowing each layer to dry. In order to increase the hiding power in non-aqueous formulations, it is recommended to introduce solvents (turpentine, etc.).

Oil paints are used to create decorative surface, as well as to protect the structure (pipelines, metal structures) from moisture and corrosion.

According to the nature of the texture and mechanical strength of the paint layer, oil paint is divided into glossy, characterized by high mechanical strength, and matte, less durable. Glossy coloring provides surface protection from mechanical damage, atmospheric influences, corrosion, etc.; matte coloring is mainly decorative and is used for interior decoration.

Glossy colors are used for painting exterior surfaces, including metal roofs, as well as surfaces periodically exposed to moisture (window sashes, exterior, entrance and balcony doors etc.).

For wall decoration, matte colors are used, which are usually prepared centrally in accordance with approved samples.

The surfaces to be painted must be cleaned of dirt and dust, and then covered with a layer of drying oil "Oksol" using a brush or roller. To level the surface, it is puttied, after which a primer is applied over the dried putty with a paint sprayer or roller (thickly grated paint diluted in Oksol drying oil). Oil paints are applied to the painted walls and door leafs with fly brushes or fur rollers, window frames and metal lattice structures are painted with hand brushes, and large surfaces are painted with paint sprayers.

Oil paints are usually applied in two layers with an interval of 1-2 days, which is necessary for the first layer to dry completely.

During the last painting of surfaces, the following directions of shading the paint layer must be observed: on the walls - vertically, on the ceilings - towards the window; on the wooden products- along the fibers; on metal structures and pipes - along the product. When painting and shading, the brush should be held perpendicular to the treated surface, since only in this case the area of ​​the treated surface will be the largest, and the brush hair will be worked evenly. Protective devices are used when painting window casings, platbands and similar products.


Construction and Industrial College of Yoshkar - Ola

Agrarian and construction technical school of the village of Vyatskoye

G B P OU RME

"Mari Polytechnic College"



GR R J E IU M FL O ND H L T SZ R V BUT NOT Q E O Y To WS R J BUT FW W DQ E V H N H S O L Y R P YV O ZR AT FG E U R Y X R H F O J With U T S And AT F O G D R H Z S J M Q And W With W O L With U T Y BUT SZ AT N BUT R M J And F Repairing a previously painted surface with aqueous solutions


Lesson topic

Repair of a previously painted surface with water-based compounds


  • 1. Who is renovating the school for the start of the new school year?
  • 2. Who allocates money for the renovation of the school, the purchase of paint?
  • 3. How much money is needed to renovate the school?
  • 4. Would you like to take part in the renovation of your class?
  • 5. What kind of work can you do while renovating your classroom?
  • 7. What do you think: do the walls get dirty or crack quickly at school? Why?
  • 8. What do you do to avoid damaging the classroom walls?
  • 9. Can you do a partial surface repair.
  • 10. What kind of paint are the walls at school and classrooms painted with?
  • 10. What do you know about water-based paint?




Water formulations

Non-aqueous formulations

Enamel, Oil paint, Water based paint, Alkyd, Acrylic.


Water formulations

Non-aqueous formulations

Water based paint

Acrylic

Oil paint

Alkyd


Sequence of work

Instruments

Surface cleaning

Spatula or

Primer

Filling cracks with putty

Spatula and fixture

Surface leveling

Spatula wide

Grinding

(after drying)

Sandpaper or a special emery grater


  • Everyone understands that it is here in the school workshop the choice of the future professions, looking for life lessons how to work and how not to work.
  • What did the guys take in their "future".

Surfaces to be painted with non-aqueous compounds must be dry, dust-free after sanding and primed.

small flat areas walls are painted with a handbrake brush, fur rollers, and large surfaces - with paint sprayers.

Window frames, metal lattice structures are painted with handbrake brushes, flute brushes.

The painting of the walls begins with beating the top of the painting with a cord dyed with dry pigment. The resulting line is taken away with a handbrake brush.

To paint the wall, the brush is first dipped into the paint for half the length of the pile and the excess is squeezed out on the edge of the container. Coloring begins with vertical sections (Fig. 1), then the paint is distributed in zigzag movements and shaded with vertical movements.

Oil paints are applied in two layers, keeping the first layer for 1-2 days.

Figure 1. Sequence of application of non-aqueous formulations by brush

When painting on the surface, bumps and brush marks often remain.

To obtain a smooth and glossy surface, the freshly painted areas are flattened. And to get rough, matte texture- facing.

Flattening (Fig. 2) is performed with a dry flattened brush without pressure, only with the very tip of the pile, with vertical movements.

Figure 2. Flattening with a dry brush

To trim the surface (Fig. 3), they take a dry trimming brush and strike the paint layer (once). Facing allows you to create a smooth, evenly diffusing light, rough surface.

Figure 3. Surface trimming

The walls are painted with a roller vertical stripes. To do this, first it is lowered into a bath of paint and the excess is squeezed out, rolling it over the grid.

The roller is applied to the wall and moves it up and down along the surface.

Each subsequent painting strip should overlap the previous one by 2 ... 3 cm. Paint the surface with a roller until it gives up all the paint, shade it with a dry roller in reverse motion.

When painting doors, brushes and rollers are used. smooth surface doors start painting from the upper left corner, then cover areas nearby. Further, going down, paint the entire door. If the door is with contour trim, then it is more expedient to paint it first, and then the door leaf or panels.

The painting of windows begins with the movable sash, then the gratings of the fixed sash are painted, and finally the frame and window sill.

To prevent traces of paint from remaining on the glass, shields made of tin, cardboard, plywood are used. The edge of the shield is cut into a chamfer so that there are no non-paints left. You can also apply paint adhesive tape, gluing it to the glass along the perimeter of the surface to be painted.

After work, it can be easily removed from the glass, leaving no traces of paint.

When painting wood door panels and window casings, the final shading is performed along the fibers of the wood.

Painting of pipes, radiators and other gratings metal structures produced with shaped brushes, handbrake brushes, a double roller, zigeyka mittens, a spray gun.

The situation is especially special with the preparation for painting of previously painted surfaces during the repair of buildings. Before proceeding with the preparation of such surfaces for painting, it is necessary to establish the reasons why the painting has become unusable, and take measures to eliminate these reasons, if they are associated with the faulty state of building structures.
Major damage to existing paintwork includes:
  • color change, usually expressed in lightening, "fading" under the influence of daylight;
  • airborne dust and soot pollution;
  • "efflorescence" - traces of soluble salts that have appeared on the surface of the painting, appearing as a result of either delayed drying or periodic wetting of the surface, if such salts are present in the thickness of the structures;
  • local contamination by products contained in the thickness of the structure, observed mainly on the painted plaster in the area smoke channels located in brickwork, as well as from contact with various items and due to temporary moisture;
  • the presence of a network of shrinkage cracks, which are the result of either incorrect drawing up of painting compositions, or the influence of atmospheric influences;
  • "shallowing" of water-based paints, which is the result of either an insufficient amount of binder in paint compositions, or improper work, or destruction of the binder under the influence of atmospheric influences;
  • delamination of paint layers under the influence of atmospheric influences, or insufficient strength of the bases on which the painting was made, or due to improper work, which consists in painting on a contaminated or insufficiently dried base.
Preparation for painting with aqueous compositions of surfaces previously painted with the same compositions must be carried out in compliance with certain rules.
Insignificant thick layers of old paint should be removed only in cases where the connection with the base of these layers is broken, as well as in case of excessive contamination with soot and dust. Significantly thick nabel should be removed in all cases, since they cannot serve solid foundation for a new color.
Removal of a thin layer of adhesive coloring can be done by rinsing off with warm water, and lime, casein, silicate and multi-layer adhesive coloring can be done mechanically with preliminary wetting of the removed coloring with water. After such removal, the plaster is ground lime mortar with fine sand.
A strong vitriol primer is used to eliminate stains on adhesive coloring. For other water-based paints, as well as when the use of a vitriol primer is insufficient, the pre-washed and dried surface is covered with zinc oil white diluted in turpentine or rosin varnish. In case of large pollution that cannot be eliminated in this way, it is advisable to replace the plaster with damaged area surfaces.
If the surfaces are to be painted with compositions that differ from the previous ones, then the old nabel should be cleaned in all cases, regardless of the state of these nabel.
When painting with compositions on especially strong binders, such as casein glue, liquid glass, perchlorovinyl varnish, old nabel must be removed completely, and weak plaster is replaced with a new one.
If surfaces are painted previously painted with oil and other non-aqueous compounds, then old coloring removed only if the bond between the paint layer and the base is weakened, when there is a large number of cracks and color lags behind the surface.
The remaining contaminated surfaces are washed with warm water and soap, and in case of significant contamination with turpentine, kerosene, thinner gasoline (white spirit) or other solvents.
Removing the old oil paint often presents great difficulty. Only if the paint has a very low strength can it be cleaned with a scraper, a steel spatula or a chisel! Usually you have to resort to burning or remove the paint chemically.
Old oil paint is burned out with a blowtorch. Directing the flame of the lamp so that it touches the surface, slowly move the lamp as the paint film softens and swells. Immediately, following the flame of the lamp, until the film has cooled and strengthened, the paint is cleaned with a steel spatula. The work is done by one painter. Blowtorch the painter holds in his left hand, and right hand cleans the surface with a spatula.
To destroy the film of old oil paint, as a rule, the following composition containing strong alkali is used.

Composition with chalk or lime to remove old paint

Ground chalk or lime dough - 0.5 kg
Asbestos dust - 0.5 kg
20% caustic soda solution - Until a paste is obtained

Such a composition is applied as a putty with a wooden or steel spatula and left on the surface until the paint layer softens, after which the composition is cleaned from the surface along with the softened paint with a steel spatula.

The cleaned mass can be reused several times after adding a solution of caustic soda to it until the required viscosity is obtained. To neutralize the alkali remaining on the surface cleaned of paint, the latter is washed with a 1-2% solution of any acid and rinsed clean water. After burning or cleaning, the surface is prepared for painting in the usual way. Previously painted roofs must be cleaned of all loose paint and all rust removed.

Ivanov V.P. Painting, wallpaper and glass works, M., 1958.

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