All about solvents of grades 646 and 647- What is the difference and what to use for- Instruction + Photo and Video

All about solvents of grades 646 and 647- What is the difference and what to use for- Instruction + Photo and Video Solvents grades 646, 647 and p4: composition, GOST, what is the difference. Solvents 646, 647 and 4 are just a few of the large family of "number" organic solvents. Their distinctive features are low price, efficiency, wide range of application, namely in everyday life, in production, during repair work, construction and when degreasing surfaces.

But although they are similar to each other, there are differences in composition and technical characteristics, as well as in application. So what are they, 646, 647 and 4?

Solvent brand 646

Specifications, composition

This composition used for thinning / dissolving paints and varnishes, removing stains, cleaning instruments and surfaces from varnishes and paints.

According to GOST, the composition is as follows:

  • All about solvents of grades 646 and 647- What is the difference and what to use for- Instruction + Photo and Video Acetone - 7 %.
  • Ethyl cellulose - 8%.
  • Butanol - 15%.
  • Butyl acetate - 10%.
  • Ethyl alcohol - 10%.

  • Toluene - 50%.

The characteristics of solvents of grade 646 change if they are made according to TU, since in this case the content of acetone and toluene is reduced. This is due to the fact that these components are sometimes used for the production of drugs.

The following characteristics are included in the description of the solvent of this brand:

  • Appearance - colorless or transparent liquid with yellowness without suspension, does not give sediment, does not stratify.
  • Boiling point - 60 degrees.

  • Flash point - (-7 degrees).
  • Auto-ignition temperature - 404 degrees.
  • Does not freeze.
  • Does not produce whitish and dull spots.


Thinner 646 is used to dilute and dissolve paints and varnishes.

At first it was used to dilute nitro enamels and nitro paints, but after that it was found out that this type of solvent is no less effective for other paints and varnishes, as well as for putties, alkyd, melamine amide, epoxy paints and varnishes and glyphthalic primers, and the film is distinguished by its strength and shine.

It is used to bring putties and paints to the desired viscosity level, to dilute thickened paint, film-forming varnish, putty and gives shine. When the composition dries, there is no solvent odor and no white film. Varnishes and paints with the addition of solvent 646 are taken much faster by film than without it. They are also used for nitro enamels, nitro paints and nitro varnishes.

The product is quite aggressive, especially for plastic, and therefore use on plastic surfaces is unacceptable. You can also use it to degrease the surface, as this composition is the most effective, but consider the type of surface, as the agent is active. If you need to degrease plastic, use a milder product.

Consumption of solvent 646 per 1 m 2 is approximately equal:

  • For the surface outside - 0.149 kg
  • For surfaces made of metal and wood indoors - 0, 125 kg.

  • For application to concrete - 1. 4 kg.

The indicator is 0. 17 kg per 1 m 2 for a solvent applied to surfaces over which there is an effect of aggressive factors and water.


This type of solvent is dangerous, and the environmental hazard class is 3.

With prolonged inhalation, we get a narcotic effect - dizziness, headache, eye irritation, respiratory putley, disorientation, effects on the liver and gastrointestinal tract. There is a likelihood of liver damage to toxins, as well as bone marrow and a change in the composition of the blood, which further leads to serious consequences. For this reason, when working with solvent 646, a good supply and exhaust system must work, or all operations must be carried out outside. Use a respirator (at least the same "petal") to protect the respiratory tract.

If the product comes into contact with the skin, it does not cause burns, but with prolonged contact there is a possibility of dermatitis.

Do not let the product get into the eyes, carry out all work with protective glasses and gloves, and if the product comes into contact with the skin, rinse immediately.

The substance is classified as flammable and volatile, so you need to be extremely careful when working. If solvent catches fire, extinguish with sand, foam, or water spray. You need to store it in a container, always sealed, and the sun's rays should not fall on the product, the permissible storage temperature is from -40 to +40 degrees.

Do not store outdoors! When storing indoors, do not allow at least some sparks.

Do not smoke when using the substance.

P 646 can be purchased in a metal barrel for industrial volumes and in standard cans with a volume of one to ten liters for domestic needs. It is ready to use immediately, no additional preparation required. The composition retains its properties for 1 year.

Solvent brand 647

Technical characteristics, composition

Another popular and inexpensive means is solvent number 647.

From R 646 it differs in the field of application and composition. This thinner has no acetone at all and is therefore considered less aggressive + can be used for plastics.

The following characteristics are included in the description of this brand of solvent:

  • All about solvents of grades 646 and 647- What is the difference and what to use for- Instruction + Photo and Video Appearance - a transparent liquid with yellowness (sometimes colorless) without suspension, homogeneous.
  • Water content - no more than 0.7%.

  • Substance volatility - from 7 to 12.
  • Acid number - not more than 0.065 mg KOH per 1 gram.
  • Coagulation number - not less than 63%.
  • Solution density - 0.

    89g / cm 3.

If the solution is used to dilute nitro enamel, the film does not turn white after the solvent evaporates. Surface scratches and streaks are smoothed out after covering with diluted enamel.

According to GOST, the composition is as follows:

  • Butanol.
  • Butyl acetate.

  • Ethyl acetate.
  • Toulol.


P 647 is often used in order to increase the viscosity of materials containing nitrocellulose. But what is the difference between number 646 and 647 in terms of application?

The solution of grade 647 is less active, and therefore it can be safely used for plastic, as well as for bodywork, removing paint and varnish film, degreasing any surfaces, if in practice it is important to respect the treated surface. This solvent is added to paint and varnish soluble materials, and is constantly mixed, and you need to add it in special proportions, which are indicated in the instructions for the varnish or paint.


Precautions are similar to those for P 646:

  • The solvent should be store in a closed container and place that is safe, away from sunlight.
  • The room where the work will be carried out must have good forced ventilation, since even if there is no acetone in P 647, it is still toxic and cannot be inhaled.
  • Avoid contact with eyes. Work only with gloves and goggles, if the solution gets on the skin, immediately wash everything with soap.

Like solvent grade 646, P 647 is sold for household needs in a canister with a volume of one to ten liters, and for use on an industrial scale in steel barrels.

Solvent grade P 4

Technical characteristics, composition

P 4 is organic solvent, which contains:

  • All about solvents of grades 646 and 647- What is the difference and what to use for- Instruction + Photo and Video Ketones.
  • Aromatic hydrocarbons.
  • Ethers.
  • Toluene - 62%.
  • Butyl acetate - 12%.

  • Acetone - 26%.

All of these components in a single composition perfectly thin and dissolve paints, resins, varnishes and other organic substances. There is a subspecies, or rather a variety - R-4f solvent, a feature of which is the absence of butyl acetate in the composition.

This product is produced in accordance with GOST and produced with the following series of technical characteristics:

  • Appearance - transparent liquid, sometimes yellowish, has no suspension.
  • Water content - 0.


  • Solution volatility - from 6 to 16.
  • Acid number - not more than 0.076 mg KOH g / cm 3.
  • Coagulation number - not less than 26%.


This tool is used in order to dissolve and dilute putties, varnishes, primers, enamels and paints on which there is a marking of XB, HSL , HS, EP, Vinikor, Evinalgrunt - HS-500 enamel, Vinicolor, Evikor.P-4 is also used for washing tools, hands, brushes and utensils after working with paints and varnishes.

It is also suitable for dissolving and thinning varnish, enamel, primer, as well as for putty marked with PVC, XC, MS, XV EP-0020, but not suitable for gray and protective XB-124 enamel. The solution is volatile, on which its use was based: it quickly hardens and is taken with a film.

Please note, that water must not be allowed to enter this type of solvent and its subspecies, P-4a.

this can lead to whitening of the film, since acetone and water mix easily, and there is enough acetone in the composition.


The P 4 grade solvent is fire hazardous, explosive and toxic, and therefore safety precautions should be observed when working with it:

  • Store the composition in a well-ventilated and fireproof area, away from sunlight and in an airtight container.
  • Handle solvent in a well ventilated area.
  • Use safety goggles to avoid eye contact.
  • Use protective gloves, avoid contact with skin, but if this happens, wash well with water and soap.

Since the solvent is fire hazardous, the room where it will be stored should not contain any sparks, smoking, and even more so open flames. In case of fire, use foam, water spray, carbon dioxide to extinguish. Remember that vapors of the components and the solvent itself are much heavier than air and can therefore accumulate in the floor area and thereby create an explosion hazard.

The substance is toxic, and this is manifested in narcotic effects (headache, dizziness, disorientation, turbidity), as well as cough, irritation of the eyes and other mucous membranes. If you inhale the vapors for a long time, there is a possibility of administration, and it will look like food poisoning, but with elements of toxic damage to the central nervous system.

For this reason, when working with the composition, use all protective equipment, work in a room with good ventilation, and if necessary, seek medical attention immediately.

This brand of solvent can form explosive compounds with oxidants and acids (hydrogen peroxide, nitric and acetic acids). Sometimes it is aggressive towards some types of plastic.


As you can see, solvents 646, 647 and P4 are easy-to-use and available compositions for diluting paint materials, as well as for degreasing and cleaning surfaces. They can be purchased at any hardware store, and the applications are enormous.

It is important that you follow the safety precautions when using, as the substances are flammable and toxic.