Thinner 646: technical characteristics and application

Solvents are special volatile compounds, their purpose is to effectively liquefy other materials. They can be of both organic and inorganic nature and are used to give varnishes and enamels a consistency suitable for repair work..

One of the most popular solvents is the composition of the 646 brand – it has found wide application both in everyday life and in industrial construction..

Properties and composition

Thinner 646 has a multicomponent formula, it is an active substance that is commonly used for all types of repair, finishing and construction work. It is necessary when working with nitro-based enamels and paints, and is also optimal for dissolving epoxy and glyphthalic primers. It is noteworthy that after all volatiles have evaporated, the surface takes on a slightly shiny, glossy shade..

Typically, the solvent is colorless. But in some cases, the appearance of a slight yellow tint is allowed, it has a pungent unpleasant odor.

The structure of the substance is composed of the following active components:

  • acetone – 7%;
  • ethyl cellosolve – 8%;
  • ethyl alcohol – 10%;
  • butyl acetate – 10%;
  • butanol – 15%;
  • toluene – 50%.

The production of solvents is allowed in mandatory compliance with existing GOSTs, in this case, the standard 18188-72 is in effect – this is a forced measure, since a solvent of this brand is often used to make synthetic drugs.

For the same reason, active technical work is now underway to change the composition of the solvent in such a way as to limit the scope of its illegal use..

The popularity and wide scope of use of solvent 646 is due to its high consumer characteristics:

  • affordable price – this tool is sold in all hardware and hardware stores and has a low cost;
  • practicality – especially for consumers, the label contains complete information and the method of using the composition, thanks to which each person, even without any experience in finishing, can figure out the peculiarities of the work;
  • functionality – the solvent has a multicomponent structure, so it can interact with almost any type of material;
  • used for high-quality degreasing of surfaces, after work does not leave any traces on the surface;
  • after surface treatment gives it a glossy shade;
  • contact with this substance does not cause burns and irritations on the skin.

    The solvent also has disadvantages, the most significant are:

    • high degree of toxicity – the material is classified as hazard class III, which is why all work must be performed strictly using personal protective equipment (respirator, glasses and gloves);
    • fire hazard – it is strictly not allowed to work near sources of fire, smoking is prohibited near the place of work;
    • sharp chemical odor – surface treatment should be carried out in a well-ventilated area, and care should be taken to protect the organs of vision, since the fumes of this solvent can irritate the mucous membrane of the eyes;
    • special storage conditions – it is necessary to use sealed closed containers, the solvent can only be stored outside living quarters.

    The high demand for the product gave rise to an unpleasant phenomenon – today the market is literally flooded with a large number of counterfeits, and in addition, users note a deterioration in quality characteristics even in products manufactured by well-known manufacturers.

    Many consumers confuse solvents of brands 646 and 647. And in fact, in terms of their functionality and physical and technical properties, they are quite similar, in addition, both compositions are produced in small tanks of 0.5 l and 1 l, for household needs and in drums – for industrial. They are produced in Russia and are widely used..

    The difference lies in their composition. So, M646 includes ethanol, toluene, butyl acetate and ethyl cellosolve, and 647 has the same components, except for acetone. Therefore, it is less aggressive and more suitable for delicate surfaces that need careful handling..

    It should be noted separately that the use of solvent grade 646 requires accuracy and adherence to the necessary safety rules, since the composition belongs to the category of highly active, therefore it interacts well with glyphthalic and epoxy compositions, as well as nitro varnishes and nitroenamels..

    But the 647 brand is more often bought for diluting nitrocellulose materials in order to give them the required viscosity, it allows you to smooth out strokes and paints on the surface.


    Composition 646 in its structure has hazardous volatile components and exhibits special physical and technical properties:

    • colorless or light yellow tint;
    • t spontaneous combustion +403 degrees;
    • boiling point +59 degrees;
    • t flash -7 degrees;
    • material density – 0.87 g / cm3;
    • does not freeze, therefore, an indicator such as freezing t is not calculated;
    • does not change viscosity.

    In addition to the indicated indicators, one should separately dwell on the solvent passport, which for an ordinary person far from the production of paints and varnishes will not say anything, however, the technologists of manufacturing enterprises always pay attention to a number of indicators, depending on the numerical value of which they can be prohibited or, vice versa , recommend the use of this or that product. For the product in question, these characteristics correspond to:

    • acid number – 0.06 mg / KOH / g;
    • octane number – 40g / 0;
    • mass fraction of water – 0.09%;
    • volatility degree – 12;
    • specific gravity – 0.68kg / l.

    Shelf life does not exceed 1 year in case of absolute tightness of storage.

    Application area

    The first thing you need to know about using solvent 646 is that work with it can only be done in the temperature range from +5 to +30 degrees, while the humidity should not exceed 85%.

    The solvent is introduced into the working medium in small portions and vigorously stirred so as to achieve the required consistency.

    The composition dissolves the primer, putties, all kinds of varnishes and enamels, and in addition, it can clean the varnishes and paints accidentally found on the surface and clothes, as well as return the rollers and brushes to workable condition after painting..

    More precisely, the scope of its effectiveness involves working with nitrocellulose, glyphthalic, as well as acrylic, melaninoamide and epoxy varnishes, paints and enamels..

    It is used as an active ingredient in the production of these materials and in everyday life, in order to dilute them to an optimal state before use..

    This the reagent is often added to putties and primers to create a functional consistency that will create perfectly flat surfaces.

    Separately, one should dwell on the issue of using a solvent to degrease surfaces. This part of the work is extremely important, since non-degreased materials significantly reduce adhesion during painting and varnishing, as a result, the applied layer becomes stained or peels off..

    Yes, the use of a solvent copes with this task, but its use has its own nuances. To begin with, it should be borne in mind that this composition is one of the most aggressive among all analogues, therefore, the work requires caution and accuracy, since the components of the composition can dissolve the base. With this composition, you can degrease the bath and other metal objects, cleaning the nozzles is also within the power of the composition. But for the preparation of plastic, such a solvent should not be used – acetone is aggressive towards plastic, so 647 should be preferred when working with it..

    The recommended material consumption for degreasing is:

    • external coatings – 0.147 kg / m2;
    • metal and wood coatings – 0.120 kg / m2;
    • concrete surfaces – 0.138 kg / m2.


    As already mentioned, in recent years, the quality of 646 solvents on the market has deteriorated, and in addition, a wide variety of counterfeits have appeared. Therefore, it is very important to purchase a product from a manufacturer who has won the trust of consumers due to its exceptional quality and reliability, as well as stability over the years. Users recommend giving preference to products from several manufacturers:

    • Dmitrievsky chemical plant. This company is one of the oldest in Russia, but at the same time one of the most dynamically developing ones. The company manufactures products for the needs of the paint and varnish, leather, rubber and food industries. Products of this brand are known far beyond the borders of our country – products have been supplied to 70 countries of the world for several decades..

    • Verkhnevolzhskaya paint and varnish company. It is another leading supplier of enamels, paints and varnishes in our country, as well as in the CIS countries and far abroad. The assortment list of goods includes a wide selection of paints and varnishes, solvents and primers.

    • “Polycom”. Domestic brand specializing in the production of household and industrial chemicals. The enterprise is fully automated, and the manufactured products meet all major international standards. In addition, users note the universal solvent “Tex”, which is consistently in high demand in the modern market..

    All these brands are characterized by increased attention to quality control, they work and produce solvents in strict accordance with the current GOST standards..

    Safety engineering

    Thinner 646 has special operating and storage conditions. The composition is bottled in special containers: from 0.5 liter bottles to 200 liter barrels.

    When transporting and storing the composition, one should not forget that the product belongs to the category of flammable, therefore:

    • the glass or metal container in which the material is contained must be sealed and closed without fail, water is strictly not allowed, and contact with direct UV radiation and high temperatures should be avoided;
    • the room where the composition is stored must be well ventilated, it must be absolutely free from ultraviolet rays and sources of fire.

      In order for construction and finishing work using a solvent to be as safe as possible, all the following requirements must be met:

      • you must always remember that it is extremely toxic;
      • it is important to protect your eyes from solvent contact;
      • during surface treatment, it is necessary to use glasses, gloves, and a respirator;
      • in case of contact of the solvent with the skin, if it gets on the mucous membranes, wash the affected area with plenty of room temperature water.

      If you neglect these safety rules, then the consequences can be the most unpleasant:

      • irritation of the eyes and respiratory tract, bronchopulmonary spasm;
      • poisoning – substance vapors can be absorbed not only through the respiratory system, but also by the skin, therefore they can cause serious damage to the central nervous system, and in addition, to the kidneys, organs of the gastrointestinal tract;
      • with prolonged contact with this solvent, severe dermatitis may appear on the skin;
      • long-term exposure of the product to the human body causes a change in the state and structure of the bone marrow and blood.

      Special attention should be paid to fire safety issues when “communicating” with this product, namely:

      • the storage area and workspace of the solvent should be protected from contact with fire and its potential sources (sparks, unextinguished cigarettes, heating devices);
      • the storage container must be tightly closed, since the mixture of solvent vapors and air is explosive, and the accumulation of a critical dosage of vapors in the air, if the tank is left open, can occur very quickly;
      • it is necessary to exclude the contact of the solvent with hydroperite, as well as caustic nitric and acetic acids, otherwise there is a high probability of the formation of an explosive mixture;
      • the reaction of solvent 646 with substances such as bromoform and chloroform has a similar effect.

                  Keep in mind that solvent vapors spread to the bottom, since they are much heavier than air, which is why any ignition can begin even at a distance from the fire source, especially since the composition, when combined with air, can reach a critical concentration even at a temperature of 20 degrees – so do not expose yourself and your loved ones danger, try to create the most “closed” conditions for storage and use.

                  Find out more about solvents in the next video..

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