Water-based paints include paint compositions that are diluted with water. Lime, plant and animal glues, casein and liquid glass are used as binders in aqueous compositions.
The type of binder also determines the type of paint; There are paints: lime, glue, casein and silicate.
Lime paint is used both outside and inside buildings to cover porous surfaces plastered with lime mortars, brick walls, as well as for painting damp and cold rooms where adhesive paint does not adhere. Adhesive paint is used to cover plastered surfaces inside residential, public and municipal buildings.
Painting with casein paints is used as a more durable paint for better finishing instead of lime and glue paints and is done both inside and outside on plaster, brick, concrete and wood.
Painting with silicate paints is used on wood indoors and for painting facades on plaster, brick and stone.
For manual painting, the following brushes are used: whitewash brushes with special holders for them, paint brushes and fly brushes for painting large surfaces, and hand brushes for layering and painting small surfaces.
PAINTING WITH LIME COMPOSITIONS
Painting with lime compounds is the cheapest type of painting, since the materials used for this painting are inexpensive, and the labor time required for its production, due to the simplicity of the work, is small.Only alkali-resistant, lime-resistant pigments are suitable for painting with lime. A stability test is mandatory, since there are pigments that, while resistant to alkalis, turn out to be unstable to lime.
Painting with lime can be done with the following pigments: manganese peroxide, soot, iron lead, raw and burnt umber, sienna, ocher, orange and red crown, chromium oxide, some types of ultramarine and similar alkali-resistant pigments.
Lime for painting should be of the 1st grade, fatty and white. It needs to be extinguished 10-15 days before use. The lime color will be durable only if the lime has time to carbonize, that is, under the influence of carbon dioxide in the air, it has time to turn into calcium carbonate, which has a crystalline structure.
This requires that the lime paint applied to the surface has the moisture necessary for carbonation for some time.
Therefore, it is better to paint with lime on a slightly damp surface. On a hot day, under no circumstances should you paint surfaces exposed to the sun and dry wind. Lime paint is allowed on not completely dry plaster. The coloring will be fragile if, after drying, it acquires a matte surface, similar to chalk and easily erased by rubbing with the palm of your hand.
When making lime paint compositions, you should not overuse pigments, since a large amount of pigment weakens the paint. It is better to use heavily bleached ones with a small amount of pigment and switch to another type of paint if it is necessary to paint with thick colors.
Many craftsmen prefer to do the priming manually with brushes in order to better rub the paint into the pores of the surface. This can be allowed, but painting must be done using a mechanized method, which significantly speeds up the work and gives a more even coating.
It should be remembered that any paint compositions must be applied in the thinnest layer and that if it was not possible to cover the previous layer at one time, it is better to paint it a second time, since two or three thin layers of paint are always stronger than one thick layer.
Literature used: V. P. Ivanov. "Painting, wallpaper and glass work", M., 1958
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Ceiling - home decoration
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Lime paint is used to cover the surfaces of ceilings and walls in kitchens, sanitary facilities, bathrooms, surfaces in rooms with wet conditions and for finishing facades on plastered stone surfaces.
There are many ways to paint building facades with lime over plaster. The so-called “dry milling” method has long been most widespread. This method involves painting freshly ground plaster and wet lime primer with a lime color.
The durability of painting using this method, compared to other methods, is significantly increased due to the fact that the lime primer applied to freshly ground, moistened plaster penetrates all the pores of the surface and interacts with the remaining moisture of the upper part of the plaster layer. Applying a layer of lime paint onto the still wet soil promotes the simultaneous hardening process of all three layers (in the top layer of plaster, primer and color).
To achieve the greatest strength of the paint layer and obtain a uniform texture (tone) of the surface to be painted, the following sequence of work must be observed.
The surface of the old plaster is completely cleaned of old paint, rubbed with lime mortar prepared on fine sand, and washed with water. Old plaster must be ground because repeated repairs of plaster are usually carried out using plaster solutions of different composition, density and strength. Continuous grinding ensures uniform roughness of the entire surface and equal absorption of moisture from the applied paint composition (primer, color).
30 minutes before applying lime primer or color, the surface of the dried plaster should be moderately moistened with water using a brush in order to ensure uniform absorption. The humidity of the plastered surface should be such that when applying the paint composition, its adhesive ability is maintained.
Calcareous soil prepared from quicklime (1 kg of boiling water per bucket of water) is filtered through a fine sieve. The primer is suitable for application to the surface within 6 hours. The color is prepared using lime milk (up to 1.5 kg of boiling water or up to 3 liters of thick lime dough per bucket of water) with the addition of 100-200 g of aluminum alum or 100-200 g of table salt or , which is much better, 1 liter of strained herring brine. Aluminum alum or table salt must first be dissolved in hot water, and pigments (dry paints) before adding to the color scheme should be mixed in a small amount of water and, stirring, gradually poured into the lime composition until the desired color is obtained; then strain and, if necessary, dilute with water to a consistency convenient for application.
The color is applied with brushes onto the dried soil in order to prevent it from being washed away, but no later than after two days.
The most durable paint compositions for painting facades are lime-cement-sand.
The procedure for preparing plastered surfaces for painting is the same as for lime painting, with the only difference being that the plaster is ground with a solution of the same composition as the paint.
The lime-cement-sand color scheme is prepared as follows. Lime dough (1.5-2 kg) is mixed in 1.5-2 liters of water and 0.5-1 kg of Portland cement and 4-5 kg of sifted fine sand or marble or dolomite flour mixed separately are added. Then everything is stirred in 3-4 liters of water and filtered through a sieve with 1-1.2 holes/mm 2.
The paint composition is prepared for 3-4 hours of work and during its application to the surface to be painted it is periodically stirred. The surface to be painted must be thoroughly moistened with water before applying the paint composition. Apply the paint composition with a brush or an adapted spray gun.
Lime whitening is rarely used these days. But sometimes situations arise when you have to do this.
For example, renovation of an apartment with elderly parents who do not recognize other options other than lime whitewash. Or renovating the classroom where your children study.
Where is lime whitening used?
Whitewashing with lime is cheap, and lime has antiseptic properties. Due to the fact that lime is a good antiseptic, lime whitewash is recommended for kindergartens, schools, and medical institutions.
You can whitewash a garage or basement with lime - it’s not expensive, and the white walls and ceiling will make it lighter. Whitewashing of walls with lime is allowed. Once dry, lime whitewash creates a strong film, and the whitewash will not remain on your clothes if you lean against a wall.
Lime whitewash is used for finishing wet areas due to its moisture resistance.
Whitewashing with slaked lime disinfects the surface. For this reason, it is used for whitewashing cellars, chicken coops, cowsheds and other livestock premises.
In gardens, tree bark is treated with lime whitewash.
How to whitewash walls and ceilings correctly
Finding a master who will take on this work is now difficult. The work is not the cleanest. The master will not work for low pay. The payment he quotes will seem too high to you. This means you will have to whitewash it yourself.
Do-it-yourself whitewashing with lime is not so much a difficult task as it is unpleasant, and most importantly, dirty. Before starting work, cover the floors and furniture with film if it is not possible to completely empty the room. Prepare protective clothing.
Lime consumption during whitewashing
The consumption of whitewash depends on the method of its application and on the surface being treated. When applying whitewash with a brush, the consumption increases. Brick walls will require more whitewashing than smooth walls.
Approximate consumption is 0.5 liters of finished whitewash per 1 m².
Lime is available in slaked and quicklime varieties. Slaked lime is sold in the form of powder - fluff lime, and in the form of lime dough.
Fluff lime is diluted in a ratio of 3 liters of water per 1 kg of powder. From one package of fluff weighing 2 kg you will get 6 liters of whitewash. This whitewash is enough for 12 m² of surface, provided that it is not brickwork.
Ready lime dough is diluted at the rate of 1 kg of dough per 3 liters of water. Remembering that one liter of whitewash can whitewash two squares of walls, it is easy to calculate how much lime paste is needed.
Quicklime, lump, must first be quenched, then diluted with water.
To slak the lime, add water in a 1:1 ratio. As a result of quenching, you will get a powder. If you add three times more water, you will get a lime dough. The powder or dough for preparing lime for whitewashing is diluted with water. From 1 kg of quicklime you get 10 liters of whitewash, ready for use.
It is difficult to calculate whitewash consumption with an accuracy of square. Lime is an inexpensive material, so nothing bad will happen if you buy a couple of extra packages.
How to dilute lime for whitewashing
Lime is diluted with water according to the proportions indicated above.
Quicklime is first slaked with precautions. When lime is slaked, a large amount of heat is released and steam is formed. Slaking lime may splash out of the container. Rubber gloves, safety glasses and thick clothing will help you avoid burns if lime gets on your skin.
After slaking, the lime is not immediately used for whitewashing; the solution must sit for at least two weeks. And only after you have waited a certain period of time, the solution can be diluted with water and whitewashing can begin.
It is better to buy slaked lime because it is easier, faster and safer to prepare for work.
Add 2 tbsp to diluted lime per 10 liters. spoons of drying oil, 100 grams of table salt and paint blue. Before adding, salt and blue are diluted in hot water. Salt and blue make the whitewash white, and drying oil promotes better adhesion of the whitewash to the surface and gives the whitewash strength.
The saturation of the whitewash solution depends on the method of its application. When applying whitewash with a brush, the solution becomes thicker. When applying whitewash with a sprayer, the mixture should be more liquid and must be filtered through several layers of gauze.
Surface preparation
Puttying the walls before whitewashing helps to get smooth, beautiful ceilings. But because whitewashing with lime is a cheap finishing option; usually the walls are not leveled or puttied.
To ensure that the whitewash lays evenly and does not peel off after a week, the surface is cleaned and all contaminants are removed.
When whitewashing a ceiling with lime, the chalk whitewash is completely removed. If the ceiling was previously whitewashed with lime, you can leave the old whitewash if it holds well or remove it partially.
Yellow stains on the ceiling left after neighbors were flooded are washed with white. Copper sulfate solution works well for removing stains. But keep in mind that during further repairs, if you decide to paint the ceiling with water-based paint, stains may appear again. Only they are no longer yellow, but green.
The surface to be whitewashed must be absorbent. Whitewash is not applied to oil paint.
Don’t listen to advice that the walls and ceiling need to be primed with a regular primer! The primer creates a film on the surface, on which the whitewash will roll or collect in drops on the ceiling. This is exactly the case when priming is to your own detriment.
What tools are used for whitewashing?
Whitewash the walls and ceiling with a brush, spray or spray gun.
Do not use a roller for whitewashing. When rolling out the second layer of whitewash with a roller, the first, dried layer of paint will not withstand the load and will move away from the surface.
A special brush is used for whitewashing. Before use, soak the brush in warm water for a couple of hours.
Brick walls can be whitened with a regular brush with natural bristles. When whitewashing with a brush, streaks remain. To prevent brush streaks from being noticeable, the second layer of whitewash should be applied in the direction of the light flow.
Whitewashing with lime using a spray gun gives the best results. The whitewash goes on smoothly; the consumption of lime when whitewashing with a spray gun or spray is less than when applying with a brush.
Spray guns are mechanical, more often called manual or electric.
A hand-held spray gun is convenient because it has a long rod and a long hose for feeding whitewash into the sprayer.
This spray gun is convenient for whitewashing high ceilings without the use of stepladders.
For electric spray guns, the power button is located next to the spray gun, so when working you cannot do without stepladders.
It is difficult to whitewash large rooms with such a spray gun - only with special stepladders.
The video shows whitewashing a ceiling with an electric spray gun.
Spray guns are expensive tools. It is not advisable to purchase them for whitewashing one room. For whitewashing, you can use an old-style vacuum cleaner. The inconvenience is that the container for whitewashing is small - usually a 0.5 liter jar is used. It is necessary to frequently interrupt work in order to add a new portion of whitewash.
For whitewashing, you can use plant sprayers. Such sprayers create pressure sufficient to spray whitewash. Sprayers are available in capacities from 15 to 5 liters.
Whitewash is poured into the container, then air is pumped in and when the button is pressed, the whitewash is sprayed evenly. With a small sprayer you can whitewash the walls and ceiling in a small room.
The sprayer with a capacity of 5 liters has a rod; with this sprayer you can whitewash a room with high ceilings.
Operating procedure
Video. Whitewashing walls and ceilings with a spray gun.
How to remove old whitewash.
Operating principle of a hand sprayer.
Whitewashing with a vacuum cleaner.
Lime is used to prepare primers and water-based paints for interior and exterior work, not only as a pigment, but also as a binder. For tinting lime paint compositions that are alkaline in nature, only alkali-resistant pigments are used.
Lime compounds can be applied to damp surfaces in damp and cold rooms.
Lime paints are used for whitewashing (painting) plastered facades, walls and ceilings in basements and other damp rooms, as well as for dry rooms. For example, ceilings can be whitewashed with lime (milk of lime), and plastered walls can be painted with lime paints.
Lime whitening is the easiest and cheapest way to clean and disinfect walls and ceilings. You can whitewash a kitchen, bathroom, or toilet with a lime composition - it is resistant to water and temperature changes.
Place the crushed lime into pieces in a large metal, enamel or wooden bowl, fill with cold water and stir with a wooden spatula until a thick paste is obtained. When slaking, lime splashes and generates a large amount of heat, so be careful not to get lime in your eyes or on the skin of your face and hands.
Lime that gets into your eyes should be immediately rinsed with running water for 10-20 minutes. After this, you should immediately contact an ophthalmologist.
If you had to inhale slaked lime powder for some time, you should definitely inhale water vapor after that. Place a few crystals of citric acid in the water for inhalation.
If the skin is burned with lime, remove the remaining lime with mineral or vegetable oil, and apply a compress of a 5% solution of citric acid or vinegar to the burned areas.
When slaking lime and when working with lime compounds, it is recommended to wear rubber gloves and safety glasses. If you don’t have gloves, you can lubricate the skin of your face and hands with any cream.
To whitewash walls and ceilings, lime milk is used, which is obtained from 1 part freshly slaked lime and 3 parts water. Lime milk is a strong disinfectant. It destroys bacteria and prevents the accumulation and reproduction of bedbugs in residential areas.
To obtain a snow-white color when whitening with lime, add a little laundry blue to a bucket of lime milk. To prevent the lime from becoming sandy (not to stain your hands and clothes), add 100 grams of table salt dissolved in a separate bowl or drying oil to 10 liters of the composition, then mix thoroughly.
Lime paints should contain only lime-resistant pigments, such as red lead, chromium oxide, umber, mummy, and soot. These paints are diluted with water. The amount of added pigments should not exceed 100 grams per kilogram of lime.
The pigments are mixed in water to the consistency of a thick porridge and kept for 4-5 hours, then with vigorous stirring they are added to the lime porridge, which is then diluted with 2-3 times the amount of water to obtain lime milk, which is filtered through a sieve.
To increase the strength of the coating and prevent swelling of the plaster, you need to add 10-15% latex paint or the same amount of wallpaper glue to the lime milk.
Before applying paint, thoroughly dampen the base with water, then apply a thin layer of paint with a short-bristled round brush or sprayer. Apply the paint the first time from left to right, the second time after the first layer has dried from top to bottom. When painting with a brush, you should strive to keep your hand movements smooth and uniform.
Lime paints should be painted on cold and humid days.
For medium-rough lime plaster, 200-220 grams of white per 1 square meter of surface are required.
Before lime whitewashing, you can use a primer on lime paste with salt: lime paste - 2.5 kilograms, table salt - 50-100 grams.
K category: Painting works
Painting with lime compounds
Lime compositions are also used for interior decoration of residential, public and industrial buildings on fairly smooth plastered surfaces, as well as on prefabricated textured ceiling slabs, while lime painting can be considered quite equivalent to adhesive. This type of painting is done using spray guns.
To ensure that plastered and concrete surfaces are sufficiently smooth, they are treated with lime or lime-gypsum putties, immediately before filling, wetting the surfaces with water using a spray gun. The technology for applying lime paint is simpler than adhesive paint, which significantly speeds up the work. The ceilings are painted with brushes twice, applying the paint transversely towards the light with brush movements, and shading longitudinally. The walls are also painted twice, carefully shading the paint, first with horizontal movements of the brush, and then with vertical ones. When mechanized painting, lime compounds are applied using a spray gun, painting twice. When painting panels, before applying the color, beat off the border of the panel with a dusted cord and make a layering with a hand-bristled brush. The strength of the lime paint film depends on a number of reasons: the strength of adhesion to the base, the conditions under which the paint film was applied, and the formulations of the compositions used.
The strength of adhesion to the base is explained by the deep penetration of the paint composition into the thickness of the base, jamming it in the pores and irregularities. As the film dries, carbonization of calcium oxide hydrate occurs simultaneously, i.e., its transformation into crystalline calcium carbonate:
Ca(OH)2 + CO2 = CaC03 + H20.
For the strength of the film, it is absolutely necessary that the crystalline calcium carbonate consists of intergrowths of crystals, between which particles of pigments are grown. It should be noted that the transformation of calcium oxide into calcium carbonate goes through an intermediate stage - the transformation of amorphous calcium oxide hydrate into crystalline with the formation of crystals of 3-5 microns, which precipitate from a supersaturated lime solution. Height
crystals and the formation of new crystals and their intergrowths are possible only in a humid environment. Therefore, surfaces must be well saturated with water before painting. Sometimes it is necessary to saturate the finished lime paint with water, preferably lime. Within a week after application, the lime paint film, absorbing carbon dioxide from the atmosphere, is transformed from crystalline calcium oxide hydrate into crystalline calcium carbonate and becomes quite durable.
When painting on an unmoistened surface in a hot time of day or in a large draft, due to the rapid evaporation of water, partial crystallization of calcium oxide hydrate occurs, not in clumps, but in separate crystals. Due to this, the paint film does not have the necessary strength and is easily destroyed by friction.
The strength of the paint film also depends on the type of lime used for painting. Thus, a paint film on hot freshly slaked lime (calcite) gives almost 100% carbonization after just seven days. Lime-dough gives a slightly lower percentage of carbonation during the same period. A lower degree of carbonization, and therefore the strength of the film, is shown by lime painting made on fluff lime.
The strength of the lime paint film is increased by the introduction of sodium, calcium or ammonium chloride into the composition. These additives, capable of accumulating moisture from the air in the paint film, create conditions for more normal crystallization of calcium oxide hydrate.
Adding aluminum-potassium alum to lime compositions strengthens the paint film. It turns out to be more dense and adheres more firmly to the base. The viscosity of these colors is much higher and reaches 40-45 seconds according to the VZ-4 viscometer.
Lime compositions with the introduction of 2 to 5% drying oil also have good painting properties, giving a denser, non-swelling paint film with a strength that is 10-25% higher than the strength of the film of purely lime compositions.
In cases where there is a build-up on the surface and there are concerns that the base is not strong enough, the surfaces are primed with a lime composition prepared according to recipe 28 and painted with a composition prepared according to recipe 26.
- Painting with lime compounds
