Features of paint thinning for spray guns. Rating of electric spray guns - the best air and airless models Viscosity of water-based paint in din for a spray gun
At all times, paint has been used as universal remedy for interior decoration. However, when working with oil compositions, the coating takes a long time to dry, and the mixture itself releases bad smell. What cannot be said about solutions on water based. In this article we will describe what water-based paint is (technical characteristics, advantages and method of production of the composition).
Method for producing water-based paint
The whole process can be divided into several stages. The first is the combination of a solution of an aqueous polymer dispersion with a pigment and filler. Second, the resulting mixture undergoes dispersion (grinding solid and liquid bodies). The third is the addition of additives that are necessary in accordance with the specifications. The fourth is packaging the finished material into jars.
Dispersion of ingredients is carried out in special dispersants (mills). These devices have several chambers, and in them there is a shaft with disks. It is with its help that grinding occurs. The resulting mixture is placed in a dissolver (mixer) container. Thorough mixing takes place there, components are added according to the specifications.
The timing of mixing all ingredients depends on the properties of each component, the total volume of the mixture, as well as the technical power of the dissolver and dispersant. As a rule, 30 minutes are enough for each operation. In this case, all work must be carried out at a temperature of +5 °C.
On last stage containers are prepared and mesh filters. It is through them that the finished paint will be poured.
Advantages and disadvantages of water-based paint
Water-based paint for walls and ceilings has a number of advantages compared to oil-based paint compositions. First of all, she dries faster. Sometimes it only takes a couple of hours for the coating to dry. Secondly, absolutely safe and harmless to humans and environment. This means that during painting work there is no need to urgently leave the premises.
Third, the paint does not have a pungent odor, which usually persists for several weeks after completion of the work. Fourthly, the coloring composition can be given almost any shade by adding special pigments. A special colorless composition is even sold for this purpose. Construction stores usually offer a catalog of colors and matching pigments.
Fifthly, The paint application process is quite simple, and all tools are easy to clean plain water . No need to use any solvents. Among the disadvantages, only a few can be highlighted: work can only be carried out at a temperature of +5 ° C, the material is not cheap. For exterior work, you need to choose the most expensive paint, since outdoor conditions are significantly different from indoor conditions.
Water-based paint: technical characteristics
Water-based paint for ceilings and walls has the appropriate technical characteristics. These include: composition, consumption, specific gravity, viscosity, storage conditions and shelf life. Compound water-based paint : latex, thickener, fillers, antiseptic. Consumption per layer about 150-200 ml/m2. The number of layers depends on the absorbency of the base.
Viscosity water-based paint is determined by a viscometer and should average 40-45 s (when applied with a brush), 20-25 (when using a spray gun). Essentially, viscosity is an indicator that determines the degree of dilution of paint with water. That is, water is added to the composition to a certain level, and then a measurement is taken with a viscometer.
Specific gravity water-based paint is about 1.35 kg/l. Adhesion on average equal to 2.0 mPa. Drying time ranges from 2 to 24 hours. It all depends on the temperature and humidity. The desired temperature is about +20°C, and humidity is 65%. The paint should be stored in a dark place (away from sunlight).
Water-based paint: technical characteristics and production method
Water-based paint, technical characteristics - how do they affect the work process? What material parameters are important to know? About this in the video tutorial.
High-quality painting is not only the result of the correct application of the coloring composition, but also a combination of certain characteristics of the material that determine decisions in this direction. When painting and varnishing, the key to success is the selection of such an indicator as paint viscosity in DIN. The table of optimal values presented in this article will help in this matter.
What depends on viscosity?
The concept of viscosity itself hardly requires additional explanation. But here are some other characteristics that the conditional viscosity itself can influence:
- If the dye is too viscous, it will be difficult to distribute it evenly over the entire surface. Excessive layer thickness will result in too much drying time. The final strength of the coating, on the contrary, decreases.
The solution, which is thick in consistency, will not fill uneven surfaces. This means the grip gets worse.
- Large layer thickness is the reason for the formation of smudges and other similar defects.
- Finally, an inexpensive spray gun simply cannot cope with materials that have too high a viscosity. Main principle works for pneumatic sprayers - low pressure in the air stream, paint suction from the tank. They help those who are interested in how to determine the viscosity of paint.
If the pressure drop is not enough, the devices will have to be disassembled and then thoroughly washed. Paint diluted with additional effort is also harmful. The number of layers required for high-quality processing increases. The time spent on this or that work increases, including those involving a spray gun.
Measurement Features
In what units?
For domestic producers It is typical to indicate this parameter in seconds. But imported materials require the use of a different designation - DIN. What meaning lies in these combinations? And how is the characteristic measured?
They are needed only to indicate the time (in seconds) after which the composition passes through holes of a certain diameter, known in advance. If the paint is more liquid, it leaves the container faster. In the case of a thick composition, this takes longer. This does not affect how to use the viscometer.
About methods and tools
Viscometer – special tool, used when measuring liquid, is a small funnel, strictly having a capacity of 100 milliliters. There is also a hole with a diameter of up to 4 millimeters. Instruments with sufficient accuracy for effective application in everyday conditions they cost from 200 to 500 rubles. They are used for routine viscosity measurements. Devices used in laboratories are much more expensive. Sometimes the cost reaches hundreds of thousands of rubles.
The instructions for using this device are extremely simple:
- First you need to fill the funnel by plugging the inlet hole with your finger.
- The stopwatch starts as soon as the hole opens.
- All that remains is to record the time elapsed until the container is completely empty. Individual drops are not taken into account for paint viscosity in DIN, the table confirms this.
The temperature of both the paint itself and the surrounding air should not exceed 18-22 degrees. Any composition will thicken with more low temperatures. And when the indicator is increased, on the contrary, it decreases. Because of this, the experiment on paint viscosity will not be as effective.
What values are considered optimal?
The manufacturer usually writes on the packaging about what indicator is considered optimal in certain conditions. But information is easy to find on the official website, including for viscous liquids.
Determination of paint viscosity in DIN and table of recommended values
Viscosity of the paint material in DIN, shown in the table - key parameter when carrying out repairs. What values are considered optimal?
Water-based paints are currently very popular, high-quality, affordable and promising repair material. They are easy to apply to cleaned surfaces (concrete, gypsum concrete, wood and pre-plastered), are environmentally friendly and very practical. And in combination with the color scheme, you can always choose the color scheme necessary for the interior.
Advantages of water-based paint
Water-based paint is in demand due to the following characteristics:
- no peeling over a long period of use,
- no cracks or unpleasant odor,
- ease of application,
- fast drying process,
- acceptable cost.
Besides, water-based paint wd allows you to get almost any shade by adding special pigments. Often, hardware stores provide a catalog of colors and matching pigments.
The main disadvantages of water-based paints
Such paints have practically no disadvantages. At the same time, it should be noted that it is extremely undesirable to apply them to metal and glossy surfaces, due to the presence of a large volume of water in the paint.
Today, obvious fakes of “water-based emulsions” are increasingly appearing on the market, which disappoint consumers. They adhere very poorly to the surface to be painted, are characterized by excessive consumption, get dirty during the drying process and are washed off if water gets in.
Technical characteristics of water-based paint
Water-based paint has the following composition: latex, thickener, various fillers and antiseptic. Average water-based paint consumption is 250 grams per square meter. The number of layers applied will directly depend on the absorbency of the surface being painted. The viscosity of the paint is determined using a special device - a viscometer. This indicator should be within 45 s. (when using a brush), and 25 s. (using a paint sprayer). By definition, viscosity is an indicator that characterizes the degree of dilution of paint with water. The specific gravity of the paint is approximately 1.35 kg/l. Adhesion is 2.0 mPa, final drying time is from 2 to 20 hours (depending on temperature conditions). The paint must be stored in a dark and cool place (away from sunlight).
Main types of paints
Depending on the polymer present in the paint, there are four main types of water-based ( water-dispersion, latex or emulsion) colors:
Even among such a small variety, a potential consumer involuntarily has a question: “So which water-based paint is better?” Let's take a closer look at the characteristics of each of them.
Acrylic water-based paints – quality comes first
This type of paint is most popular among professional craftsmen, and among ordinary consumers trying to carry out repairs on their own.
Based on the name, it becomes clear what is contained in the paint acrylic resins as the main component. Such paints are applied to surfaces made of brick, wood, glass, concrete and plaster. The most common representative is water-based paint VEAC 1180.
The main disadvantage of such paints is their high cost. Therefore, analog paints with acrylic copolymers have become widespread. Their price is much cheaper than real acrylic ones, and the quality is not much inferior to the original. Sometimes, to increase elasticity acrylic coating, latex is added to the paint, resulting in effective resistance to moisture.
Painted coatings can be safely washed with water without fear of spoiling the applied paint. Manufacturers indicate in the technical characteristics of water-based paint that it can withstand up to 5,000 wash cycles with water. When applying a double layer of acrylic-latex paint, you can mask cracks on the surface (up to 1 mm thick). And they dry out in conditions room temperature in just a few hours.
Silicone water-based paints - ideal for rooms with high humidity
In silicone paints, silicone resins predominate in the composition. They are a universal coloring and masking agent for all surfaces, hiding two-millimeter gaps from prying eyes. Silicone paint is also expensive, but it has vapor-proof properties, ideal for damp areas of the house that are prone to moisture formation. Thus, the paint will also actively fight the emerging fungus, preventing its reappearance.
Silicate water-based paint - an indicator of durability
Silicate water-based paint It is a mixture of liquid glass, water with the possible addition of colored pigments. It is characterized by weather resistance and a long service life (up to 20 years). But for excessively wet surfaces it is better to use a different type of paint.
Mineral water-based paints
In the process of manufacturing mineral water-based paints, they add slaked lime or cement. They are used for any surfaces in the process of painting walls and ceilings. Their main purpose is painting work with bricks and concrete surfaces, which are subject to significant hydraulic loads. Distinctive feature Mineral paints have a short service life, so they gradually cease to be in demand.
Types of water-based paints: advantages and disadvantages
Advantages of water-based paint. The main disadvantages of water-based paints. Main types of paints. Technical characteristics of water-based paint
Varnishes and paints for household pneumatic spray guns
According to the factory instructions for the Sturm SG9660 spray gun offered for rental:
"- max. paint viscosity 50 DIN
Nozzle diameter 2.6 mm...
Paints and varnishes suitable for use: water-soluble and other solvent-based paints, varnishes, primers, two-component paints, cleaners, car cleaners, sealants, preservative sealants, stains.
Paint and varnish materials that cannot be used: wall paints (emulsion), etc., alkaline and acid paints. Materials with a flash point below 21 °."
In fact, the factory instructions in one paragraph allow the use of any “water-soluble and other solvent-based” paints, and in the next paragraph prohibits any “wall paints (...) and the like.” One can assume such a contradiction by the subtleties of the work of Chinese translators from English (German) into Russian.
Studying the instructions for similar models of spray guns and the experience of their use gives the following recommendations:
- can be used with a spray gun, enamel and glaze (translucent glazes) paints, primers, oils, impregnations, water-based, water-dispersion, water-emulsion and solvent-based varnishes (white spirit, 646, 647, 450...) with a viscosity of up to 50 DIN, including: alkyd, acrylic (synthetic latex), two-component, antiseptics, stains;
- it is forbidden spray liquids that are aggressive to plastic and have abrasive components that wear out and clog the sprayer channels: gasoline, ammonia, paints with acid and alkaline thinners, polyurethane paints containing lead.
- not suitable for spray gun paints with difficult atomization and drop formation with a viscosity of more than 50 DIN, sparingly soluble, designed for application by brush or spatula: thick emulsions, thick latex (styrene-butadiene), thick dispersion (glue, PVA), textured, silicate or liquid glass, hammer paint, enamels for metal, rust, wood oils.
Painting
Successful use pneumatic spray gun requires some skill, training and adjustment, preparation for a specific paint. Why take care of a supply of paint and solvent for test painting and washing the spray gun.
Follow the instructions on the packaging of paintwork materials and the tables in the factory instructions for the spray gun on diluting paintwork materials to the required viscosity using a viscometer from the spray gun kit and try painting, evaluate the result and adjust the viscosity, try again. For some paintwork materials, for uniform spraying, additional dilution is contraindicated or unnecessary; others, like some enamels, two-component paints, require additional filtration from large inclusions and undissolved clots. Moreover, filtration of paintwork materials may be required in preparation for painting and after thickening some time later. Assess the need for filtration based on the quality of the test paint surface.
Keep in mind that thinning the paint reduces its hiding power and it may be necessary to apply an additional layer; it is advisable to evaluate it on a test sample.
When working with enamels and glossy paintwork materials common mistake is neglect of filtering the air at the inlet to the compressor and keeping the channels of the spray gun and the air supply hose from the compressor to the gun clean. Regular cleaning of the compressor inlet filter will remove dust particles from the glossy layer.
It is better not to delay washing the spray gun for an hour or two, otherwise the paints will dry in the channels and body of the spray gun and dissolve or wash them off even with a strong solvent for a very long and difficult time. Some synthetic and organic paints and varnishes polymerize irreversibly or are chemically aggressive, eat into plastic and are no longer susceptible to solvents; it is preferable to apply such paints and varnishes with a brush, roller or metal spray gun.
Water-dispersion or water-based paints
Which is correct, water-dispersion or water-emulsion paints?
What is the difference between paint and enamel?
Dispersion is a formation of two or more elements that practically do not mix with each other and do not react with each other chemically. In this case, the first substance (dispersed phase) is finely distributed in the second (dispersion medium).
Emulsion is a dispersion system consisting of microscopic droplets of liquid (dispersion phase) distributed in another liquid (dispersion medium).
Thus, emulsion is one of varieties of coarse system (in this case liquid). Natural emulsions include, for example, milk, consisting of butter, casein and water.
Both dispersion and emulsion are a mixture of one small amount of substance with another. It is a mixture, not a solution, since the transition of molecules from one phase to another does not occur.
In the case of water-based paint, the first substance (synthetic polymers) is distributed in the second substance (aqueous medium). Paint particles are suspended in water and equidistant from each other. When the paint dries, the water evaporates, and the particles come closer together and form a dense film on the surface.
Thus, the phrase “water-based paint” is not entirely correct, since emulsion means a mixture of precisely liquid elements with a liquid medium.
But no one pays attention to these nuances anymore. Just like the fact that, for example, a solution of cement with water and sand cannot be a solution from a chemical point of view, but is a suspension.
Suspension(lat. suspensio, literally - suspension, from lat. suspendo - suspend) - a mixture of substances where the solid substance is distributed in the form of small particles in a liquid substance in a suspended (unsettled) state.
You can also refer to GOST 28196-89, which applies to water-dispersion paints, which are suspensions of pigments and fillers in aqueous dispersions of synthetic polymers with the addition of various auxiliary substances (emulsifier, stabilizer, etc.).
However, GOST 28246-2006 indicates that water-dispersion paint is a “liquid or paste-like pigmented paint material, having a paint and varnish medium in the form of a dispersion of an organic film-forming substance in water and, when applied to the surface to be painted, forms an opaque paint and varnish coating.”
Classification of water-dispersion paints
In addition to pigments and fillers, water-dispersion paints contain a number of different auxiliary additives, but we are more interested in the type or substance (film former) by which all paintwork materials are classified.
Popular the following types water-dispersion paints, according to the nature of the binder:
Acrylic;
Silicone;
Styrene acrylic;
Acrylic silicone;
Vinyl acrylic;
Butadiene-styrene;
Polyvinyl acetate (PVA),
Polyurethane (quite rare and expensive on water, but the most durable and wear-resistant).
Acrylic paints
The binder (base) is polyacrylic (acrylic) latexes (polymers).
Advantages: due to their characteristics - strength, elasticity and durability, they are the most expensive of water-based paints. Acrylic paints are practically not afraid of the sun, water, and temperature fluctuations. Like other water-dispersed paints, they can be diluted with water, and after drying they become resistant to water. Suitable for both internal and external exterior finishing premises. Due to low gas permeability, they protect against corrosion reinforced concrete. Over time, acrylic paint pays for itself due to its durability and long service life. Can be used for outdoor work.
What is the difference acrylic paints from acrylate?
Essentially it's the same thing. Acrylate polymerizes to acrylic. We purchase acrylate paint and apply it to the surface to obtain a coating in the form of an acrylic film. Thus, speaking of acrylic paint, we mean an acrylate binder.
What is the difference between acrylic paints and latex paints?
With the development of paint and varnish products, marketers have to come up with and introduce more and more new expressions into the product description, emphasizing the superiority of the product over competing analogues. Manufacturers often call waterborne paints polymer based latex. If natural latex is the sap of rubber plants, then synthetic latex used in paints is a dispersion of polymers that make up the paint base. Therefore, the use of the term “latex” in the names and characteristics of paints is just tricky marketing ploy manufacturers to give their products additional benefits. Naturally, no one added any latex; the phrase “acrylic latex paint” is the same as “milk butter” (although the example is not very good).
Thus, a manufacturer can release 5 types of the same water-dispersion paint onto the market, calling the products, for example, latex, acrylic, acrylic-latex, acrylate, water-based paints (you can also more titles come up with, the main thing is to occupy the shelves in stores). And everything will be sold successfully. And the buyer suffers from the problem of choice. As a rule, well-known brands will not take such a step, as they value their reputation.
Glazing paints and impregnations
– translucent compositions based on organic solvents or water, interesting for protecting and adding color to wooden surfaces of walls, floors, stairs, and furniture. Can be used as a single coating or with additional protection with varnish.
The composition of glaze paints includes polycrylate dispersion, water, as well as various chemical additives, natural oils. Consumption is about 100 grams per 1 square meter. Impregnations are sold ready-made colored or transparent, which can be tinted in almost any color according to the manufacturer’s tinting tables or using separately purchased dyes on the same base (aqueous or organic solvent). You can tint either manually yourself or by machine at points of sale. As a percentage, the amount of colorant should not exceed 100% of the total volume of the material, but in fact 3-10% is enough for a wide range of color shades. Colors according to factory tinting tables are obtained by mixing several colorants, but when choosing independently, a beginner only needs to use a colorant of one or two colors, for example, by adding white to lighten the second colorant. Tinting tables for mixing two or more colors yourself can be found on the Internet.
The time for complete drying depends largely on temperature regime and humidity indicators. So when high temperature(above +20 degrees Celsius) and low humidity, setting of the material can occur in just an hour. When working and drying indoors with compounds containing organic solvents, it is important to create good ventilation.
Gloss level
The degree of gloss is measured as the amount (in %) of light specularly reflected from the surface in the total reflected light flux.
There are six gloss levels of paints and varnishes:
intense matte 1 - 10% gloss
matte 11 - 30% gloss
semi-matte 31 - 50% gloss
semi-gloss (or satin) 51 - 70% gloss
glossy (or bright satin) 71 - 90% gloss
high gloss - over 90% gloss.
To select and evaluate the gloss, you can do a test paint on a sample. For wood, keep in mind that glossy varnishes absorb less and create a thicker film, smoothing out roughness and hiding the texture. Glossy surfaces are more slippery, wash better, and emphasize surface defects or, on the contrary, the degree of evenness.
What is the difference between enamels and paints?
The difference between enamel and paint and what does “enamel paint” mean?
Initially, the term “enamel” meant a thin glassy coating obtained by high-temperature treatment of oxides on the surface of metals.
This is most likely how the term “enamel paint” appeared in the descriptions for compositions that form a strong, smooth film on the surface. Moreover, GOST 28246-2006 already directly indicates that the term “enamel” means “a liquid or paste-like pigmented paint and varnish material that has a paint and varnish medium in the form of a solution of a film-forming substance in organic solvents and forms when applied to the surface to be painted opaque paintwork". In the previous GOST 28246-89, the terms “paint” and “enamel” meant the same thing.
Thus, enamel implies a solution of a film-forming substance, in contrast to ordinary watercolor water or oil paint which do not have such properties and remain simply “paints”.
The difference between enamel paint and enamel covering metal utensils, for example, is obvious - these are completely different technologies.
| VZ-4, DIN4, sec | FORD4, sec | Physical viscosity, centipause |
|---|---|---|
| 11 | 10 | 20 |
| 12 | 12 | 25 |
| 14 | 14 | 30 |
| 16 | 18 | 40 |
| 20 | 22 | 50 |
| 23 | 25 | 60 |
| 26 | 30 | 80 |
| 30 | 35 | 100 |
| 34 | 40 | 120 |
| 38 | 44 | 140 |
| 42 | 50 | 160 |
| 45 | 54 | 180 |
| 49 | 58 | 200 |
| 52 | 62 | 220 |
What are the standards for viscosity cups?
There are several standards for cups: funnels VZ-246(according to Russian GOST 9070-75), the European analogue of DIN (DIN 53211-87), as well as FORD funnels(ASTM D 120087) for American products. These are cups in the form truncated cone with a wide neck and a narrow hole of a certain diameter located at the bottom.
In accordance with European standard There are five cups of the same shape with a capacity of 100 ml, but with different diameters of the bottom hole - 2, 3, 4, 6 and 8 mm. FORD cups have holes that differ from this row.
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| Rice. 1. |
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| Rice. 2. |
How to determine the viscosity of a paint and varnish material using a funnel VZ-246, DIN4
For viscosity determination The paint and varnish material is poured into the cup to the brim with the bottom hole clamped. Then the hole is opened and the liquid begins to flow out.
How larger diameter holes, the greater the physical viscosity of the test product at the same flow time.
The time required to measure viscosity using a funnel is minimal (2-3 minutes), but this test allows you to fairly accurately determine one of the main parameters of the material.
Watch a video of determining viscosity using a VZ-246 viscometer
Dynamic viscosity according to Brookfield
The viscosity of paintwork materials with pronounced pseudoplasticity is determined using equipment that makes it possible to record the flow rate (for example, using the method Brookfield).
To determine dynamic viscosity, Brookfield viscometers are used. The operating principle of the Brookfield viscometer is rotational. Viscosity is measured by recalculating the torque required to rotate the device spindle at a constant speed when immersed in the medium under study.
This is the minimum you need to know about this method of determining viscosity, because it is unlikely that you will use it.
All manufacturers of paints and varnishes are required to indicate the delivery viscosity of their products on the packaging
Using the above test, it is easy to check whether the material has not been altered in any way during delivery, which is often carried out through intermediaries.
After adding a thinner to a paint and varnish material, its viscosity is significantly reduced. In addition to reducing the viscosity of the material, this also leads to a reduction in its dry residue and, consequently, the thickness of the paint film.
However, the dry residue is quite difficult to check without special laboratory conditions, but it is possible to control the viscosity of the paintwork material and compare it with the data for the original product from the technical specification.
Manufacturers indicate the amount of added thinner (by weight or volume) required to give the paint material a working viscosity for application with a certain type of equipment.
This amount is set by the paint manufacturer and is valid under standard conditions, which include an ambient and paint material temperature of 20 C and air humidity of 50%. In practice, these conditions are met very rarely.
If the temperature of the paint material is lower, its viscosity increases and, therefore, more thinner is required to give the product the required processability.
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Cocktails are different, and not all of them are intended to be taken “on the chest”. Paints and varnishes that we use for restoration paint coating car - these are, in fact, also cocktails - properly prepared mixtures of several ingredients. And since we strive to ensure that the restored car (fender, door) after repair sparkles brighter than a new one, and the paint lies evenly, then our “paint cocktail” must be prepared competently, carefully and carefully, and not concocted anyhow. Today you will find out IngredientsFirst of all, let’s decide on the type of our “paint cocktail”: will it be regular acrylic enamel (which is less likely), or metallic or pearlescent paint (most likely). Regular acrylic enamel is two-component, with a hardener. The “ingredient kit” for such materials consists of three jars. For example, a liter of paint, half a liter of hardener and 100-150 ml of thinner. That is, when buying a liter of paint, you actually get about 1.6-1.7 liters of diluted paint. In the case of “metallic”, the base paint is necessarily covered with a transparent varnish on top - without it, spectacular coatings look inconspicuous, and the weather resistance of two-layer coatings is much higher. Transparent varnish, like acrylic enamel, is two-component, with a hardener. But the “base” does not need a hardener - it is one-component. Thus, the “set” for two-layer coatings already consists of five cans. For example, a liter of “base”, 500-700 ml of thinner for it, a liter of transparent topcoat varnish, half a liter of hardener and 100-150 ml of varnish thinner - a total of 3.3 liters! At the same time, the diluted paint itself was no longer there, the same 1.7 liters. Making a batchBefore filling the gun, you should mix the components of the purchased paint. For proper mixing of the components, which produces a painting material of the required viscosity, the following conditions must be met. DishesIt is important that the container in which we mix is strictly cylindrical in shape (flat bottom and vertical walls). Only in such a container can you mix the components evenly and measure their quantities correctly. It is better if it is a special measuring container in the form of a transparent plastic jar with a lid. Such cans are marked with markings that allow mixing materials in the required volume ratio (1:1, 2:1, 3:1, 4:1, 5:1, etc.).
Measuring containers are available in different volumes, ranging from 100 ml to almost half a bucket Also, for dispensing and mixing paints and varnishes, it is convenient to use a special ruler with marks that determine the volume fractions of the components. Pour the base into a cylindrical container to a certain division, and then add the hardener (if added) to the required mark, then the solvent. Mix everything with the same ruler - and you're done. Often, a measuring ruler is sold along with a set of paint, and all branded cans indicate the proportions according to these rulers.
It is convenient to measure the required amount of components using a measuring ruler. Then I chatted with the same ruler - and that’s it. ProportionsGiven the abundance that has reigned on the paint and varnish market, it is, as they say, impossible to give one recipe for all occasions by definition. Yes, and you don’t need to do this. There is TDS - you know who the rest is from. However, it would be useful to provide some general guidelines. In principle, we already talked about them a little higher: up to 50% hardener and 10-20% thinner are usually added to two-component products. The degree of dilution of base enamels usually ranges from 50-80%. Well, look at the exact proportions in the instructions for a specific product: all can varnishes and enamels have instructions in the form of pictograms that inform you in what proportion you need to dilute the paint with the hardener (if the material is two-component) and thinner.
We remind you: only thinner is added to one-component materials (alkyds, base enamels, 1K primers); In two-component materials (acrylic enamels and varnishes, 2K primers), a hardener is first added, then the mixture is brought to the desired viscosity with a thinner. If you order paint for selection in a laboratory, then you will be given a set of components (usually ordered as a set), by mixing which you will get a ready-to-use material with a working viscosity - as they say, “for a spray.” Or they will give you paint that has already been diluted (of course, this only applies to the base, since the lifetime of two-component materials after mixing is strictly limited). SupplementsA description of recipes for preparing paint cocktails would be incomplete without mentioning additives - materials used to change the individual characteristics of enamels, varnishes or primers. For example, to create a rough surface - very often they are painted this way. plastic bumpers SUVs - there are structural additives of varying degrees of granularity. In general, to prevent paint on plastic from cracking, 20-40% plasticizer must be added to it. There are matting elasticizers designed to reduce shine and coloration. plastic parts type of side trims of Mercedes-Benz cars. When painting with spectacular two-layer coatings, these additives must be mixed with the topcoat varnish (it is recommended to add a plasticizer to the filler primer as well). Read more about additives and their use. Measuring viscosityAny painter should be able to control such a vital important indicator, like viscosity. For what? So that it corresponds to the recommended value. Again, why? To evenly apply the material to the surface and obtain a coating of the required thickness with the planned properties - beautiful and durable.
For what?
FilteringThe prepared paint and varnish material must be filtered before filling into the spray gun tank, since it may contain foreign inclusions that got there during the preparation process, clots, etc. Otherwise, guarantee receipt high-quality surface This is not possible, because all this debris may ultimately end up on the surface being painted. For filtration, it is convenient to use disposable paper funnels with a nylon filter insert (mesh size, usually 190 microns). I inserted the funnel directly into the tank, strained it - ready, you can paint!
We fill the paint tank only using a filter funnel. Basic mistakesAchieving consistently high quality of work performed is possible only by following technological recommendations for the use of certain materials. There is no other way for those who want to repair modern cars and quality repairs are simply not possible. Meanwhile, ignoring technological requirements remains the main (!) cause of defects and errors. As they say, “...how many times have they told the world”... But “free morals” have always been and will be: we adjust the spray gun “by ear”, we mix the paint “by eye”, we forget about the strictly defined “lifetimes” of products prepared for use. For example, in an hour the varnish changes its viscosity by an average of 100%. It's thickening. Before lunch we stirred it, measured the viscosity - 20, went away to eat satisfied, returned 50 minutes later, and it was already at 40! Of course, the material can no longer be used. But how often does anyone consider such “trifles”? How often does anyone remember that a material into which we have not added enough hardener will no longer be able to properly harden, no matter how dry it is. Acrylic two-component materials are cured in the same way: due to a chemical reaction between the acrylic binder (base) and the substance for cross-linking molecules - polyisocyanate (hardener). And only the paint manufacturer can know what number of -N=C=O units (present in the hardener) is necessary to react with a certain number of OH units (found in the base) and transform the material into a durable polymer film(more on this). So it turns out that if we do not pour enough hardener, there simply is not enough crosslinking material to properly cure the film. The coating is soft and uncured. The opposite situation - with an excess of hardener (and, accordingly, an excess of -N=C=O units) has the opposite effect - the coating turns out to be too hard, but at the same time inelastic, highly susceptible to peeling, cracking, and chipping. So if the can of varnish says to dilute it in a ratio of 2:1, then you need to take the time to measure exactly two parts of varnish and one part of hardener. No more, no less.
Correct polymerization of two-component materials is possible only if the correct mixing proportions with the hardener are observed Well, the fact that acrylic materials can be cured only with original hardeners is not subject to discussion at all. In acrylic systems, the copolymer and polyisocyanate are carefully selected for each other, and if we take a hardener from another varnish or another manufacturer, we will get a different polymer with completely different properties. The jar with the remaining hardener must be tightly closed, since the hardener reacts with air moisture, resulting in its cloudiness and loss of crystals, sometimes gelling. To prevent air from entering the partially used can of hardener, it is recommended to turn it over and place it on the lid, and store it in this position. |
