Goi paste is thin. GOI paste for polishing: what is it, how to use

Scientists of the State Optical Institute in the 30s of the XX 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. In addition to chromium (III) oxide, the paste contains auxiliary substances that bind abrasive particles into a single piece.

Types of GOI pastes

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

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

Application of the paste

Application GOI pastes does not require any special knowledge. However, a large number of people are in the dark 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 elimination of which will require additional effort. The paste must be applied to a soft cloth, which should be used to wipe the item to be cleaned. It is best to use a felt wheel installed in the chuck of an electric drill and set in motion by it for polishing.

Purchase of pasta

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

Summary

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

Sometimes on the Internet there is information 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 particles or dust can fly from the paste, which cannot be inhaled and which is rather difficult to clean.

After handling the paste, wash your hands and the processed product well with soap and water, especially if it comes into contact with food (for example, silverware). The product not in contact with food can be cleaned with a solvent - kerosene is perfect.

		Gloves "Buy Color" (Ansell) s. 8.5-9

Preparation for grinding with GOI paste

The product to be processed must be cleaned of dirt and dust, you can lightly grease it with industrial oil. The paste should be applied to a cloth slightly dampened with gasoline, kerosene or other non-aggressive solvent. If a grinding or buffing wheel will be used for polishing, then the paste should be applied to it. Lightly rub a layer of paste on an unnecessary piece of metal to break up large lumps.

The paste must be applied to the 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 is very thick, and you are uncomfortable using a solid composition, it can be diluted with machine oil, kerosene or other solvent.

A polishing cloth should be chosen the more rough, the harder the object being polished. That is, jeans, burlap, felt are suitable for metal processing, and velor, flannel, velvet are suitable for a smartphone screen.

Grinding

The process of grinding with GOI paste is very simple - you need to gently, without strong pressure, grind the product on a circle or rub it with a prepared rag with paste until a smooth surface is achieved. In the process, to speed it up and achieve the best result, you can lightly grease the thing with oil.
The deeper the damage, the coarser the paste you need to start sanding, however, do not use a coarser paste than No. 2 for plastic. To complete polishing of any product can be done with paste # 1, this will give it the maximum possible smoothness and shine.

When sanding and polishing, occasionally wipe down the object with a dry cloth or paper towel to monitor the progress of the process and see what results have been achieved.

Evgeny Sedov

When hands grow from the right place, life is more fun :)

Content

For grinding metal at home, it is recommended to use a popular and time-tested tool called GOI paste. Several varieties of such household products prevail in free sale, but the task is one - polishing the surfaces of products from different materials. The tool is affordable for the money and effective in the end result. Therefore, the paste for metal polishing deserves special attention, it will definitely come in handy for every master.

What is GOI paste

In fact, it is a solid mass of green color, which is chemical product and specially developed at the State Optical Institute. This is how the name (abbreviation) stands. This abrasive material is intended for high-quality processing and polishing of metal, plastic, glass and other hard surfaces, depending on their characteristics. Such universal paste can be produced in the form of a smooth bar or packaged in liquid form in special jars. The purpose and decoding of such chemical products does not change from the peculiarities of the packaging.

Compound

The main active ingredient is chromium oxide, which can predominate in chemical composition in different concentrations. Other components are auxiliary, necessary to enhance the desired effect and convenience of everyday use of the Goi mixture. In this case, we are talking about soda, kerosene, silica gel, fat and stearin. Such chemical formula gives the paste a rich green color, makes it convenient and available as a polishing material. The production of such chemical products strictly complies with GOSTs.

How to use GOI paste

Each package contains instructions that describe in detail the composition of the GOI paste, the rules for use in direct contact with certain hard surfaces to eliminate defects. Before starting the application, it is required to decide which paste will be relevant in a particular case. In the free sale, several practical options prevail at once, among them the following numbers:

1. No. 4. For rough processing.
2. No. 3. For a matt finish without streaking.
3. # 2 and 1. To provide glossy surfaces.

The procedure itself is simple, the main thing is to strictly follow the general recommendations and not damage the surface to be treated. Polishing with GOI paste can be carried out in the following sequence:

1. To avoid scratching the surface to be treated, you must first find a piece of cloth, for example, flannel, soak it in gasoline.
2. Apply a small amount of paste to a rag, then wipe it on an unnecessary metal object for the disintegration of large crystals of the GOI composition.
3. Rub the object with gentle movements until its body starts to shine. This cleaning takes a few minutes, but it is important to beware of large Goi particles and scratches.
4. After the end of the session, it is required to additionally treat the surface with gasoline or dip the polished object in kerosene.

For metal

Before polishing with GOI paste, it is important to decide on the type of metal. For example, there is often a need for high-quality cleaning of silver cutlery - forks, knives, spoons (over time, they darken and turn green). In this case, it is important not to spoil the surface of the noble metal with small scratches, but to proceed in the sequence given below:

1. Wash silver cutlery.
2. Rub with a toothbrush and powder until shiny.
3. Separately pour into a glass of water, add a little ammonia, soap, powder.
4. Boil cutlery in this composition.
5. Then proceed to the processing of metal with the composition of the GOI.

If we talk about other metal bases and products, it is worth emphasizing that steel things are cleaned on a special device, and it is better to completely refuse to clean gold in this way. This is explained by the fact that you can erase the top layer of this precious metal. When polishing a metal watch with paste, it is important to remove the watch mechanism first.

For glass

For example, it may require polishing the display of a mobile phone or any other gadget. In this case, you definitely cannot do without this miraculous paste. When working with glass surfaces, it is recommended to use the composition of GOI No. 2, additionally use a soft flannel rag. The cleaning process available at home, the sequence of actions is as follows:

1. Take a piece of rag and rub it well with a bar of technical means so that a layer of paste remains.
2. After that, you can start high-quality grinding of the glass, but do not press hard on the fragile product.
3. With little effort, in just a few minutes the glass surface will be rubbed to a shine.

For plastic

For plastics, it is also recommended to use the composition of GOI No. 2 of a viscous or solid consistency. Take a rag again and rub it with a bar or apply a thin layer of a gel-like paste. In the latter case, before proceeding to more intensive sanding of the plastic, it is important to rub any metal surface (to avoid scratching the plastic). Then use the technical means for its intended purpose similar to the above examples.

How to soften GOI paste

If the composition has not been used for a long time and has dried up, you should not rush to think about how to replace the GOI paste at home, since this technical tool is still really "revived". For example, it can be thinned with technical or machine oil. To do this, chop off a dried piece and grind into crumbs, mix separately with the selected oil base. After that, you can use it as directed by photo or video instructions. Another option than to dilute GOI paste is kerosene, but the polishing effect is not always preserved.

Goi paste is a versatile surface polishing agent. There are several types of paste, depending on the material to be polished. This instruction will tell you why you need goi paste how to use it on metal, glass and other surfaces.

In addition to the correct choice of paste material, correct polishing is required.

Goi pasta got its name from the first letters of the State Optical Institute, where it was invented in the 30s of the last century.

Composition and types of GOI

Previously, the active ingredient in the GOI paste was chromium oxide and it had a pronounced green color. GOI paste is still actively used, but it has lost its green color. Chromium oxide is a poison and carcinogen, its use is strictly prohibited by regulatory authorities. Green pasta can still be found and bought, but the production of this particular pasta has already been closed. The color of modern Goi pastes is white and red. Red is suitable for whiter intensive polishing, and they are made from aluminum oxide. White paste useful for better polishing of a smooth surface.

This polish comes in the form of a green bar or a thinner paste in a jar.

Even when GOI was green, it had three varieties, depending on the level of grinding. Now the size of the abrasive particles has received another value. GOI No. 4 is intended for rough surface treatment, preparing the area for further polishing, No. 3 makes the surface evenly matte without scratches, with the help of No. 1 and No. 2 they bring the surface to an ideally glossy result.

How to use GOI?

The principle of operation of this polish is based on the careful removal of the top layer, which also contains abrasions. This should be done with a soft cloth dipped in gasoline. Gasoline is needed to dissolve too large pieces.

Advice! If you do not have a car and do not know where to get the gasoline, you can drain it by carefully opening the gasoline lighter.

• Before using the paste, you need to wipe it a little on a piece of unnecessary metal.
• If the paste remains in the paste during use large pieces, you can achieve the opposite result - to scratch the surface.
• Polishing is a filigree process in which details are important. The paste should be mashed and the cloth as soft and smooth as possible.
• You can take a polishing wheel and apply GOI paste on it, but in no case should you start polishing by applying the paste to the surface to be treated. The product can be lightly greased with liquid oil - "spindle".

Can GOI deal with deep defects?

The paste copes with fairly severe scratches if the thickness and strength of the material allows. It is necessary to use all four stages of polishing, and then rinse the object with carbine. Pharmacy kerosene will do. If you don’t have one, or the polishing item cannot be treated with kerosene, running water will do. This will wash off the microparticles.

Polishing car parts

Polishing and sanding car parts is important not only for the good looks, but also to protect against rust and further spread of damage.

Scratches appear on the headlights, from this they fade; the paintwork rubs, damage begins to threaten the body; dashboard loses appearance from scratches. Suitable for plastic, glass, paintwork and metal green paste and her followers.

Information! Grinding and polishing are two sides of the same process. Sanding is a rough procedure using an abrasive to remove a damaged layer. Polishing - softly bringing an object to a shine. It usually follows after sanding. Glass surfaces of a car, be it headlights, rear-view mirrors or windshield, are polished with flannel. The body is easier to work out with felt.

For headlights and other glass products, the following algorithm is suitable:

• Start by degreasing the surface: wash with a car spray, wipe with alcohol or glass cleaner. If there is even a little dirt on the glass, it can cause additional scratches.
• Polishing should be done with a felt drill or a special grinder. Handmade you only need to remove the dullness, otherwise you cannot do without a special apparatus.
• To polish, add a drop of machine oil to the GOI paste, apply the mixture to the polishing wheel.
• Treat the desired places without unnecessary pressure, or gently walk over the entire surface of the glass.

• Polishing movements can be made in any direction, but it is better to use the principle of overlapping strips.
• To control the result, wash the GOI with a paper towel: when the surface is perfectly smooth and transparent, you can finish polishing.
• When polishing a separate part, it is better to cover the rest of the surface with a film, otherwise you will need to wash the whole car later.
• It is better to fill in deep scratches with a special transparent compound.
• For glass, only GOI No. 1 or 2 can be used.
• The glass can become hot when rubbed. This must be carefully avoided, as unevenly heated glass can crack.

The body is polished in the following sequence:

• Clean the surface to be treated well.
• Apply a paste to the wheel and speed up the machine to 1100 rpm, then sand the body at a slight angle.
• Rinse off the remaining product with water under a gentle pressure.

Polishing jewelry with GOI paste is the same as any other. You just need to take paste # 1. Jewelry made of gold and silver is perfectly polished in this way.

The only difference is that they require special cleaning. Silver needs to be brushed with toothpaste. Then you need to boil in an enamel bowl with ammonia and soap shavings. To use knife paste, it is applied to a leather belt stretched over a block of wood.

No matter how versatile the GOI paste is, there are surfaces that it is better not to touch. It is not necessary to use for glass of watches and their other metal parts. A mechanical watch is a delicate and fragile movement. Soft versions of the paste do not give a good result on the watch, and coarse ones will simply wipe off the coating from the metal. If the watch is covered with a sapphire glass, then there is no point in polishing for another reason - this glass is so hard that it cannot be polished with a paste.

Outcomes

When using this polish, especially green, you need to follow the safety precautions very carefully. Be sure to use a respirator, especially when polishing metal and using gasoline. Avoid inhalation of vapors and particles. The shavings can cause severe irritation of the mucous membranes and even get into the lungs. If this happens to you, contact your health care provider.

Pasta history
This polishing agent was developed in our country and a very long time ago - in the 30s of the twentieth century. It was invented by specialists from the State Optical Institute. Hence the name of the paste (in the first letters) - GOI.

For nearly a century, this product has been used to polish steel, other metals, ceramics, plastics, stone and even glass. Our grandfathers knew how to use GOI paste. It was originally made from chromium oxide and auxiliary substances and had a green color. Today, such a remedy can also be found in stores and on the market.
However, the production of green pasta is currently prohibited and discontinued. The fact is that chromium oxide is a poisonous carcinogen. Modern GOI pastes are white or red and are made from aluminum oxide. With the second type, polishing is faster. With the use of a white paste, you can get a better and smoother surface.

Varieties of green pasta
We will talk about how to use GOI paste correctly below. Now let's see what varieties of this material exist. Once there were three types of GOI green paste. And today, even in a store or on the Internet, you can buy a product with different sizes of abrasive particles: No. 4 - intended for initial rough polishing of surfaces; No. 3 - gives the surface a matte look, while strokes are not visible on it; # 2 and # 1 are used for finishing and give a glossy finish. A green variety was produced both in solid bars and in the form of a more liquid pasty mass (in boxes). The popularity of both types is due not only to the high quality of polishing, but also to the more than affordable price.

What you need to do before polishing So, let's start to understand how to use GOI paste. Small particles in it, when rubbing the surface, remove a thin layer along with scratches and microcracks. Polishing is usually done with a soft cloth dipped in gasoline (you can use a lighter). A small layer of paste is applied to it and rubbed a little against an unnecessary piece of metal. This is necessary so that all too large pieces are broken in the paste. If they remain, the surface may not be polished, but rather scratched. The cloth should be really soft. Take flannel, for example. Sometimes the paste is applied to the polishing wheel as well. It cannot be smeared directly on the surface of the workpiece. The product is preliminarily slightly coated with liquid industrial oil ("spindle").

How to use GOI paste on glass and plastic.
Very often this tool is used to make cell phones "divine". In this case, it will be necessary to polish, firstly, the case itself, and secondly, the display glass. Since plastic is a rather soft material, you should use a gentle paste from jars No. 2 to process it. Otherwise, the case may be scratched even more. The answer to the question of how to use GOI paste for plastic is simple: just like when processing any other materials. The glass is pre-polished with special rubber wheels. Further, the actual GOI paste is used. The procedure in this case is carried out in the same way, that is, using a rag. Oil and gasoline are not used when processing phones.

How to use GOI paste for cleaning silver items
As already mentioned, this tool, both green and red or white, can be used to process absolutely any metals. This also applies to silver. Feel free to use GOI paste to lighten your spoons, cups and forks. How to use GOI paste for cleaning silver? Before starting polishing, the product should first be thoroughly brushed with a toothbrush coated with tooth powder. Then pour a little ammonia into a glass of water, adjust the soap and add a little powder. All this must be thoroughly mixed until completely dissolved. Next, the liquid is poured into an enamel saucepan. After that, silver cutlery is lowered into it. Then put the saucepan on the fire and bring the liquid to a boil. After that, the silver should be removed and rinsed in cold water... Then you can start processing it with GOI paste according to the method described above.

What cannot be polished
Next, let's see in what cases GOI paste cannot be applied. You now know how to use it. However, in no case should this tool be used for processing gilded items. Otherwise, the top valuable layer will be very quickly erased to the bottom metal. Steel (except for knives) and nickel are usually processed not by hand, but using a special machine. Metal watches are also polished with a cloth. However, they must first be disassembled and the mechanism removed. Do not start polishing too badly scratched surfaces with option no. 2 or 1. In this case, the defects will become even more noticeable. You cannot polish sapphire glasses on watches with GOI paste. She simply does not take them. Where is the tool used? We figured out how to polish with GOI paste. Now let's see where exactly this tool is used. GOI paste is used not only at home for polishing, silver, watches, dangerous blades and razors, etc., but also in production. In the latter case, it is used most often in electroplating shops for the processing of products from non-ferrous and ferrous metals. Polishing is carried out using special polishing machines with felt wheels.