GOI pastes - general information. Polishing with GOI paste: a universal product for all types of surfaces Composition of GOI paste 1

Scientists at the State Optical Institute in the 30s of the 20th century developed an effective polishing paste, which later became known as GOI paste (GOI is the abbreviated name of the institute). It is based on trivalent chromium oxide, which gives the paste its green color and basic characteristics. The composition of the paste, in addition to chromium (III) oxide, includes auxiliary substances that bind abrasive particles into a single piece.

Types of GOI pastes

Depending on the size of the abrasive grains, four types of GOI paste are distinguished:

• No. 4 - intended for rough (primary) grinding and removing scratches. After treatment, the surface becomes matte. The paste is characterized by a light green color. Removes a layer of material 40 - 18 micrometers deep.
• No. 3 - used for medium (secondary) sanding and removing scratches. After treatment, the surface acquires an even shine without streaks. The paste is green in color. Removes a layer of material 17 - 8 micrometers deep.
• No. 2 - used for general polishing. The treated surface becomes shiny. The paste is characterized by a dark green color. Removes a layer of material 7 - 1 micrometer deep.
• No. 1 - intended for final polishing. After treatment, the surface becomes mirror shiny. The paste is black with a green tint. Removes a layer of material 0.3 - 0.1 micrometer deep.

Application of paste

Application GOI pastes does not require any special knowledge. However, a large number of people are unaware of how to use it correctly and make mistakes that only worsen the condition of the polished surface.

To polish a metal or plastic surface, you do not need to apply the paste directly to it - this increases the risk of making scratches, the removal of which will require additional effort. The paste must be applied to a soft cloth, which should be used to wipe the product to be cleaned. It is best to use a felt wheel for polishing, installed in the chuck of an electric drill and driven by it.

Purchasing pasta

There may be a problem with purchasing GOI paste, since not everyone knows where to buy it. It is sold in construction stores, as well as in stores for military personnel, where they sell badges, stars for shoulder straps, etc. The price of a piece weighing about 30 grams can be around 30 rubles. Not expensive, and lasts a long time.

Summary

The paste, developed in the 30s, is still popular today because it effectively performs its function of polishing the product. The paste is divided into four types depending on the size of the abrasive grains of chromium (III) oxide. The larger their value, the higher the number the paste is designated. When using it, you cannot apply the compound directly to the product being polished; it should be applied to a soft cloth, and polishing should be done only with it. Otherwise, scratches may occur, the removal of which will require additional effort.

GOI paste is one of the most popular means for polishing products made of various materials in our country. It is produced in the form of a green bar, similar to a soap bar, or in jars. It is worth noting that initially GOI paste was developed directly for grinding metal surfaces. But over time, its use spread to other areas of human activity. The product received its name in honor of the State Optical Institute - the enterprise where it was first obtained.

Classification and composition

The main compound in the GOI paste formula is chromium oxide. Its concentration affects the granularity of the substance and, accordingly, the performance characteristics. The higher the percentage of chromium oxide in the GOI paste, the rougher it is (varies from 60% to 85%). Depending on the grain size, there are several varieties, each of which is assigned an individual number:

• No. 1 - fine for final polishing and giving a mirror shine;
• No. 2 - thin to achieve a uniform matte surface;
• No. 3 - medium for removing small irregularities;
• No. 4 - rough to remove visible scratches.

Types of paste differ in composition, structure and color (from light green for fine to black and dark green for coarse).

In addition to chromium oxide, GOI paste contains fatty binding compounds, as well as activating components in the form of various solvents, adsorbents and other reagents, for example, silica gel, kerosene, stearin, bicarbonate of soda.

What materials can be polished with GOI paste?

The main purpose of GOI paste is the processing of metal products (from of stainless steel, cast iron, silver, aluminum, etc.), but it can also be used for polishing other surfaces: glass, plastics, ceramics, hard polymers. It is worth noting that this product has found wide application both in industry and in everyday life.

In everyday life, GOI paste is used for polishing kitchen knives, scissors or other products made of steel alloys. It is very popular among numismatists, who use it to remove corrosion from ancient coins and restore their shine. Fishermen use GOI paste to clean artificial fishing baits, increasing their specularity. Hunters use a mixture of this product to polish gun barrels.

GOI paste is also used for polishing mirror, plastic and glass surfaces (including plexiglass). Data technical means You can partially restore CDs, mobile phone screens, watches, jewelry, etc. GOI paste perfectly removes scratches and chips on car headlights, and also effectively removes their cloudiness and blackening.

Thus, GOI paste is the most important tool in metalworking, as well as in fine, high-quality polishing of various surfaces without the use of special equipment.

How to use?

Apply GOI paste to the surface using a special polishing wheel or a soft cloth moistened with a solvent, for example, a rag or gauze. It should be remembered that the wetter the rag material, the longer the processing, but the better the result of the work done. It is possible to use kerosene, diesel fuel or other hard-to-evaporate, non-aggressive liquid as a solvent.

Polishing a product with GOI paste includes the following steps:

1. Apply GOI paste to the rag material. It is strictly forbidden to add the product to the polished surface, as this may lead to the formation of new damage.
2. Before grinding, to crush large particles, it is recommended to rub the product on a metal surface.
3. To speed up the process, lightly treat the polished surface with liquid industrial oil.
4. To avoid new scratches, polish with GOI paste without sudden movements or strong pressure. During the procedure, it is sometimes necessary to wipe the surface of the workpiece dry to control the quality of grinding.
5. Upon completion of work, thoroughly rinse the product in solvent; if this is not possible, remove all signs of GOI paste from the surface with water.

Features of polishing products made from various materials

It is important to note that products made from various materials, require a certain polishing technology with GOI paste. First of all, it is necessary to select the type of technical means and fabric with which the surface will be treated. After this, in order to get the maximum result and prevent the formation of new damage, you should decide on the polishing process,

1. For polishing glass and plastic, it is recommended to choose GOI No2 paste and a soft-pile cloth, such as cotton or flannel. In this case, the product must be generously rubbed onto a piece of rag material, and the surface of the product must be cleaned of debris and dust. After preparatory work, you can start polishing the surface. To do this, it is necessary to grind the product for several minutes without brute force, applying light pressure. It is worth noting that when processing the screen of a mobile phone or watch, you must carefully use solvents and oil so that they do not penetrate inside the case.
2. Silver jewelry tends to lose its original shine over time. Will help restore the appearance of products correct use GOI pastes No3. As a processing fabric, you should choose a material with a more rigid structure, for example, a tarpaulin or felt circle, or a piece of felt boots. After applying GOI paste to the fabric, you must thoroughly rub the product against it, completely covering the darkened surface. The final step is to polish the jewelry with a softer cloth until the final shine is achieved. To achieve the greatest effect, before starting polishing, it is recommended to boil silver products in a solution mixed from: 300 ml of water; 2 teaspoons aqueous solution ammonium hydroxide; 50 g grated soap; 50 g washing powder.
3. To polish knives or scissors, GOI paste is applied to a wooden block. You can also glue sandpaper to the board and rub it with this technical product, slightly moistened with a solvent. Then the steel alloy products should be ground against a block using a reciprocating motion at different angles.

What products cannot be polished with GOI paste?

It is worth remembering that polishing products made from some materials with GOI paste may be ineffective or even cause damage to the appearance. It is not recommended to process with this technical means:

• gold-plated products (the outer layer can be erased);
• steel, except for knives and scissors, and nickel (as a rule, they are not polished by hand, but with a special tool);
• metal watches (can be polished with the mechanism removed);
• sapphire watch crystals (grinding with GOI paste is ineffective).

Harmful to humans?

Concerns are often raised that the chromium oxide contained in GOI paste is toxic. These judgments are justified, since a given compound, depending on its valence, can exhibit different properties. Hexavalent chromium oxide is toxic and hazardous to human health. Meanwhile, in the production of GOI paste, a non-toxic trivalent compound that has passed examination is used.

At the same time, excluding the harmfulness of GOI paste to human health, it is recommended to use protective glasses and a mask when using it. This is due to the fact that when polishing products, dust is generated, which can cause irritation of the mucous membranes.

Sometimes you can find information on the Internet about the high toxicity of GOI paste. In fact, hexavalent chromium oxide is a highly toxic substance, and another chromium oxide, trivalent, is used to produce GOI paste. However, when working with the paste, use gloves, safety glasses, and when using a grinding wheel or other equipment, a respirator or mask and protective clothing, as the paste may release particles or dust that should not be inhaled and is quite difficult to clean.

After handling the paste, wash your hands and the processed product thoroughly with soap, especially if it will come into contact with food (for example, silverware). A product that does not come into contact with food can be cleaned with a solvent - kerosene works great.

		Gloves "Bai Color" (Ansell) r. 8.5-9

Preparation for grinding with GOI paste

The product to be processed must be cleaned of dirt and dust; you can lightly lubricate it with industrial oil. The paste should be applied to a rag lightly moistened with gasoline, kerosene or other non-aggressive solvent. If a grinding or polishing wheel will be used for polishing, the paste should be applied to it. The paste layer should be lightly rubbed onto an unnecessary piece of metal to break up large lumps.

The paste must be applied to a grinding wheel or rag, and not to the product itself, since in this case there is a risk of scratching it even more.
If the paste has become very thick and you find it inconvenient to use a solid composition, it can be diluted with machine oil, kerosene or another solvent.

The rougher the polishing cloth, the harder the object being polished. That is, jeans, burlap, and felt are suitable for metal processing, and velor, flannel, and velvet are suitable for smartphone screens.

Grinding

The process of grinding with GOI paste is very simple - you need to carefully, without strong pressure, grind the product on a wheel or rub it with a prepared rag with paste until a smooth surface is achieved. During the process, to speed it up and achieve better results, you can lightly lubricate the item with oil.
The deeper the damage, the coarser the sanding paste should be, but for plastic do not use a coarser paste than No. 2. Complete Any product can be polished with paste No. 1, this will give it the highest possible smoothness and shine.

During the sanding and polishing process, occasionally wipe the item being treated with a dry cloth or paper towel to monitor the progress of the process and see what result is achieved.

GOI paste is a multifunctional, highly effective and, at the same time, inexpensive domestic polishing agent, popular among professionals in a variety of industries, and is also excellent for household use. It can be used for polishing the most different materials, from something as rough as metals to the delicate plastics of mobile phone displays. And chrome surfaces, after being treated with paste, acquire their original specularity and shine.

This wonderful remedy was invented back in the thirties by a group of Soviet scientists. They developed a product that is simultaneously capable of: protecting the surface from adverse external influences, restoring damaged surfaces, and improving the reflective qualities of the surface. The work was carried out at the State Optical Institute, abbreviation - GOI. Hence the name of the popular pasta.

The paste was originally developed for grinding glass and lenses. Soon it began to be widely used in a wide variety of areas of industry and everyday life: it is used by jewelers, sharpening knives, polishing car windows and headlights, and even the badges of soldiers’ belts in the army.

What causes such a multifaceted effect of the paste? The mass applied to the damaged surface fills cracks and chips, restoring the integrity of the structure and improving its transparency. And after polishing and grinding, the reflection of the light beam improves significantly, which affects the aesthetic component of the procedure.

Composition of GOI paste

GOI paste is a dense mass of different shades of green. The paste is based on fine granular chromium oxide powder. It is this that has an abrasive effect and gives the paste its characteristic green color. The paste also contains organic solvents and various chemical reagents, such as stearin, fat, kerosene, silica gel and others. Depending on the ratio of these substances, the grain size and, accordingly, the abrasive ability of the paste changes.

There are 4 types of pasta in total.

Paste No. 4– has a light green color. Composition: 81 parts of trivalent chromium oxide, 2 - silica gel, 10 - stearin, 5 - split fat, 2 - kerosene.

Paste No. 3- Green colour. Composition: 76 parts of trivalent chromium oxide, 2 - silica gel, 10 - stearin, 10 - split fat, 2 - kerosene.

Paste No. 2– dark green. Composition: 74 parts of trivalent chromium oxide, 1 - silica gel, 10 - stearin, 10 - split fat, 2 - kerosene, 2 - oleic acid, 0.2 - bicarbonate of soda.

Paste No. 1– black, with a green tint. Composition: 74 parts of trivalent chromium oxide, 1.8 - silica gel, 10 - stearin, 10 - split fat, 2 - kerosene, 0.2 - bicarbonate (baking) soda.

And although, at first glance, the differences in the compositions of these 4 types of pastes are insignificant, it is they who give the pastes not only different colors, but also properties, and, accordingly, scope of application.

What are 4 used for? various types paste?

The main parameter that determines the type of paste is the size of the abrasive particles. If you use a paste of the wrong particle size, you can only cause harm to the surface being treated: larger particles will scratch the surface, smaller particles will spoil the reflective properties of the material.

Paste No. 4– the size of abrasive particles is 40-18 microns. This coarse paste is the most expensive, but also the most popular. Its main purpose is rough grinding of the surface, resulting in the removal of scratches of varying degrees of depth and size on the surface. It copes well even with deep scratches on metal. After processing it gives a matte surface.

Paste No. 3- the size of abrasive particles is 17-8 microns. Used for sharpening steel and further grinding. The result is a clean, streak-free surface with an even matte sheen.

Paste No. 2- the size of abrasive particles is 7-1 microns. Designed for fine polishing. After treatment, the surface acquires a mirror shine.

Paste No. 1- the size of abrasive particles is 0.3-0.1 microns. Its action is similar to paste No. 2, it is intended for finishing and gives the surface an ideal shine.

The choice of paste should be made taking into account the material to be processed and depending on what effect you want to achieve. Thus, with paste No. 3 you can achieve an excellent matte shine on the surface of the car. And paste No. 1 will help remove scratches from your mobile phone screen.

If there are many different defects on the surface of an object, including deep ones, then first the surface is treated with paste No. 4, then paste No. 3 is used, and the treatment is completed with paste No. 2. Paste No. 1 is used to achieve the final shine.

How to use GOI paste

The paste is produced either in the form of solid bars, or in a jar in the form of a viscous mass. In both cases, it is quite dense and hard, and the hardness of the paste increases during storage. Therefore, before starting work, the paste must be softened. For this, ordinary liquid machine oil – “spindle” – is used. You need to break off a piece of paste and apply a few drops to it. The resulting mixture must be mixed well. After obtaining a homogeneous consistency, the paste can be used. To do this, it is applied to a cloth, which will be used to treat the surface. To obtain maximum effect, dirt should first be removed from the surface to be treated.

It is important to remember that the GOI paste itself should not be applied directly to the surface to be treated! This may destroy the paintwork. The paste is applied only to the fabric! And it is very important to choose the right fabric to use for sanding. Here you need to remember one rule: the rougher and harder the object being processed, the rougher the fabric should be. Thus, denim and felt fabrics are best suited for metal processing. And for glass processing, a soft flannel cloth will give the maximum effect.

So, the paste was diluted to the desired consistency, and a cloth was selected depending on the material being processed. How to proceed? A small amount of paste should be applied to the fabric and rubbed on a piece of scrap metal. This is necessary in order to remove large pieces of paste from the napkin that can scratch the surface being treated. Before starting work, it is advisable to moisten a cloth in gasoline for refilling lighters. The chromium oxide contained in the paste dissolves well in gasoline, and this simple trick will increase the effectiveness of polishing. Next, apply a couple of drops of “spindle” to the surface of the object and begin polishing with soft circular movements, periodically dripping oil or gasoline. When polishing, you should not make sudden movements or press hard on the surface - this can cause harm and lead to the formation of new scratches. Continue polishing until desired shine is achieved. After finishing work, rinse the product in kerosene to remove any remaining paste. In the absence of kerosene - at least in water.

To make the work go faster, you can use a polishing wheel for this procedure. The paste, also previously diluted with machine oil, is applied to the felt circle itself.

Features of using paste depending on the material being processed

Using paste to polish a knife. If you need to fine-tune a knife blade, then you need to rub the paste on a smooth wooden surface, or even better, on leather stretched over a smooth surface. For example, take a board for straightening knives. Next - make methodical movements of the knife, similar to those done when sharpening on a regular grindstone. The blade should be moved along the surface treated with the paste.

Using paste for glass and plastic. Unfortunately, over time, scratches may appear on the surface of a watch glass, car headlights, or mobile phone screen. You can restore the former evenness and smoothness at home without much difficulty. To do this, take a cloth with soft bristles and paste No. 2. Rub the fabric with the paste so that the layer is noticeable. And with this flap, rub the surface of the glass or plastic for several minutes, without applying too much effort. But you should remember that gasoline and oil cannot be used when processing your phone!

Using paste to clean silver items. Silver jewelry and cutlery lose their shine over time and acquire a dark coating. You can return them to their former beauty using paste No. 3, a piece of soft fabric and a piece of felt. The felt should be rubbed with the paste and the surface of the product should be treated with light movements until the deposits are removed. And then sand it with a soft cloth for a few minutes.

What things should you not use the paste for?

No matter how wonderful GOI paste is, it is not magical and cannot restore and polish everything. And if used improperly, it can even cause harm. So, she should not handle gold-plated items. Otherwise, the top, most valuable layer will remain on your rag, and you will get a polished base metal.

Metal watches can be polished, but they must first be disassembled so that the paste does not get into the mechanism.

If the surface is too damaged, you should not start polishing immediately with pastes No. 2 or 1, as this will make the defects even more noticeable.

You should not polish sapphire crystals on watches with GOI paste - it will not polish them.

And yet, despite some restrictions in use, GOI paste is truly universal. Let us recall once again what objects and materials this wonderful paste can bring to a “like new” state:

Products made of stainless steel and non-ferrous metals.
Glass, including optical and organic.
Polymer and plastic products.
Ceramic, porcelain, clay objects
Surfaces of soft and hard wood products.

It is not surprising that this practical, universal and inexpensive remedy, invented by Soviet scientists, has received recognition throughout the world.

The most popular polishing agent, perhaps, can be called GOI paste, since it can be used on a wide variety of surfaces, from rough metals to glass and soft plastic of mobile phone displays.

The name of the paste is deciphered as follows: State Optical Institute, where this useful product in the 30s of the last century.

Paste GOI": appearance and composition

GOI paste is made in the form of sticks from pale to dark green, depending on the content of chromium oxide powder in it (can range from 65 to 85 percent), which forms the base of the paste. In addition, it also contains organic (fatty) binders and auxiliary substances (activating and intensifying additives), such as solvents and chemical reagents such as stearin, kerosene, silica gel (silicon dioxide, white porous mass with absorbing (adsorption) ability), etc.

GOI paste is available both in the form of a paste and in the form of impregnated felt soft polishing wheels.

What surfaces is GOI paste used for?

This product is used for polishing and grinding steel alloys (including thermally hardened ones), non-ferrous metals, glass (including optical glass), hard polymers and plastics, and ceramic materials. GOI paste is easy to apply and adheres well to polishing wheels.

Paste "GOI": classification and varieties

The most widely used paste is No. 2, since it is perfect for polishing jewelry or other surfaces made of non-ferrous metals, glass, hard polymers and plastics.

Paste "GOI": application

Few people know how to use this remedy correctly. Below are instructions that will help you cope with polishing with GOI paste without any problems.

Apply a small amount of product to a polishing cloth (soft cloth, flannel is ideal) or to a polishing wheel. Do not apply the paste directly to the surface you are going to polish.

Before applying the product, you can rinse the cloth in kerosene or lighter gasoline. This will significantly improve the dissolution of this paste.

Then add a couple of drops of “spindle” (industrial liquid oil) onto the surface to be polished and begin polishing the desired surface.

Periodically you need to drip oil onto the product. And when polishing, do not make sudden movements with your hands, do not press the surface too hard, because... This may not only not remove existing scratches, but also add new ones. Polish until desired shine is achieved.

At the end of the work, rinse the product well, preferably in kerosene. If it is not there, remove the remaining GOI paste with water.

This is such an effective and easy to use remedy.