The modern chemical industry offers a wide selection of specialized abrasive compounds for polishing and grinding any materials. However, all modern products are united by a narrow specialization (by type of surface being treated and by grain size), as well as the serious cost of branded polishes. As a universal analogue that adequately copes with the finishing of metal, plastic or glass, we can name the long-known GOI paste.
Composition and properties of GOI paste
The abrasive paste produced by the State Optical Institute was developed in the 30s of the last century as a means for high-precision finishing of the surfaces of metal, ceramic and glass parts. The original composition of the paste contained chromium oxide powder, which provided a memorable dark green tint to the composition.
Currently, chromium oxide is prohibited for use as it is a toxic compound. Therefore, modern GOI pastes are made on the basis of aluminum oxide and are red or white in color.
The red paste provides intense polishing, while the white paste is designed to create a smooth, glossy surface.
The paste also contains plasticizing and binding substances, such as stearin, silica gel and kerosene, and auxiliary additives.
Depending on the size of the abrasive fraction, GOI paste is divided into the following types:
- No. 4 is intended for primary processing (removable layer from 20 to 40 microns);
- No. 3 to form a matte surface without marks from abrasive particles;
- No. 2 and No. 1 for final fine polishing (removable layer no more than 0.1 microns).
According to the release form, GOI paste comes in bars, tubes and containers, and there are also polishing wheels for grinders impregnated with the composition.
Car enthusiasts and service stations successfully use GOI paste for grinding and polishing car glass (especially windshield glass), mirrors, as well as headlights and other lighting fixtures.
Headlights
Car headlights are an important element of traffic safety. They must provide the intensity and dispersion of the light flux sufficient for confident movement at night and in conditions of poor visibility. The vast majority of traffic accidents at night occur due to insufficient lighting or malfunctioning lighting devices.
Most modern cars are equipped with plastic headlights, but there are headlights and fog lights with glass lenses.
When using a car for a long time, the glass of the headlights becomes cloudy under the influence of the external environment. Solid dust particles and small stones leave scratches and microchips on the outer surface of the headlights. Plastic headlights also often become cloudy from exposure to tar, motor oil and aggressive auto chemicals. You can restore the transparency of headlights using GOI paste. To assess damage to the outer surface of the headlights, they should be thoroughly cleaned of dirt and dust using specialized detergents. Contaminant particles that are not removed from the headlight glass will lead to additional scratches during subsequent grinding.
Polishing headlights with GOI paste is done manually or using a felt attachment on a drill. To achieve the desired effect, you need to treat the damaged surface for at least 3-4 minutes. Periodically, you should clean the headlight from dust and excess paste using a dry cotton cloth, and evaluate the result achieved. Grinding is carried out until the headlight glass becomes absolutely smooth.
If the transparency of the headlight could not be restored by grinding the outside, it means that the defect is on its inner surface. This problem is typical for plastic lighting fixtures: Under the influence of high temperatures from halogen or xenon lamps, the inside of the headlight becomes cloudy. To restore transparency, it is necessary to disassemble the headlight and polish the inside of the lens. Glass headlights, as a rule, do not need to be polished from the inside; it is enough to wash the light-transmitting surface well with a glass cleaner.
In a similar way, using GOI paste, you can restore the appearance of faded or worn out rear lights.
Attention! During manufacturing, a protective coating is applied to the surface of plastic headlights, which is removed during the grinding process. Therefore, after polishing with GOI paste, it is necessary to re-coat the treated area with a special varnish in several layers. The protective film dries after at least 24 hours.
The sequence of steps for polishing headlights with your own hands can be seen in the following video:
Glass
When the car moves, grains of dust and debris carried by the oncoming air flow intensively damage the outer surface of the interior glazing with sharp edges. Additional damage to the windshield in the form of chips and cracks is caused by small stones flying out from under the wheels of oncoming traffic, as well as grains of sand that fall on the windshield wiper blades. When the window lifters are repeatedly activated, the door windows are scratched by solid dust particles deposited on the inside of the seals - velvet. Excessive efforts when cleaning glass from adhering ice and snow with a hard scraper or wiping with a dry, rough cloth also add mechanical damage.
As a result, the glass becomes dull, cracks, scratches and abrasions impair visibility, and at night they distort the headlights of oncoming cars, blinding the driver.
Shallow glass damage (up to 300 microns), microcracks, chips and local abrasions from wipers can be eliminated by grinding and polishing the glass using GOI paste.
In the presence of deep scratches, extended cracks and chips, grinding can lead to loss of transparency and curvature of the glass surface. In this case, it is advisable to replace the glass with a new one.
Before polishing car windows with GOI paste, they must be thoroughly washed and dried. It is recommended to highlight defective areas with a marker on the inside of the glass. Adjacent parts of the roof, pillars and hood must be protected from accidental damage with masking tape or other material. When polishing (especially using power tools), be careful not to damage the glass.
To polish the windshield, you should use only GOI finishing paste with a minimum size of abrasive particles (No. 1).
How to dilute
Before use, GOI polishing paste requires pre-softening. In its initial state, the paste can be quite dry, which will make it difficult to apply to a polishing cloth, and hard lumps will lead to the formation of unnecessary scratches on the glass during processing.
The list of liquids used to soften the material is quite extensive: from distilled water, industrial and motor oils to white spirit and purified gasoline for lighters.
It is not recommended to dissolve GOI paste with gasoline or white spirit. due to their flammability, and then it is difficult to neutralize the specific pungent odor of these liquids. The following method is more practical:
- Apply a small amount of motor oil to a block of GOI solid paste using a syringe or pipette;
- the liquid is rubbed into the block using flannel or cotton cloth until the paste has a consistency similar to plasticine;
- With the resulting plastic mass, you can polish defective areas of glass or headlights without the risk of damage.
For greater homogeneity, the mixture of GOI paste with motor oil can be heated before use (for example, in the microwave) and mixed thoroughly.
Advice! Prepare the polishing mixture in batches. Over time, the liquid evaporates and the paste becomes solid again.
The glass or plastic surface to be treated must also be moistened with water and lubricated with industrial or motor oil. If you apply GOI paste on dry glass, there is a high probability that the outer layer will become dull.
How to use
The principle of processing with GOI paste is that the small particles contained in the paste remove a thin layer of glass along with microcracks and scratches.
The pre-prepared paste should be applied to a cloth or polishing wheel and lightly wiped on a hard surface to remove excess and solid particles. After this, the defect areas are ground first with reciprocating movements with partial overlap of the strips, and then in a tapering spiral from the edge to the center of the damage.
Important! The paste should be applied only to the working surface of the instrument, and not to the glass itself.
Periodically you should wipe the element being treated with a damp cloth and monitor the condition of the polished surface.
Polishing with GOI paste using a grinder should be performed at medium speed (no more than 1000 revolutions), with smooth movements without stopping the working tool in one place. The grinding wheel should be positioned at an angle of no more than 5 degrees and have the maximum possible contact area with the workpiece. Should be constantly check the degree of heating of the polished surface(especially for plastic headlights) and, if necessary, stop grinding until the part has cooled.
Upon completion of polishing, the remaining paste and abrasive dust should be rinsed off with plenty of water, and then wipe the glass dry with a microfiber cloth.
To maintain the effect, it is recommended to repeat the polishing procedure approximately once every 1.5-2 years, depending on the operating conditions of the machine.
The modern chemical market offers motorists a wide range of abrasives for grinding and polishing. Many compounds have a very narrow specialization, that is, they are intended to treat only a certain type of surface, and branded polishes are also very expensive. Today we will tell you about GOI paste - a universal product that can be used for polishing various materials.
1 Composition and technical characteristics of GOI paste
The GOI (State Optical Institute) abrasive paste was developed back in the 30s of the 20th century and has since been used for high-precision finishing of the surfaces of glass, ceramic and metal products. In those years, the paste included chromium oxide powder, which provided it with a recognizable dark green tint.
Today, chromium oxide is not used in the production of abrasives, as it is recognized as overly toxic. Instead, aluminum oxide is used to make GOI paste, which gives the composition a white or red color. It is better to use red paste for polishing, and white paste to create the smoothest glossy surfaces.
GOI paste is usually spoken of as a universal product that can be used for polishing various materials. In addition to aluminum oxide, modern GOI paste for polishing windshields includes special binders and plasticizing substances, in particular, stearin, kerosene and silica gel. Depending on the size of the abrasive fraction, there are several types of polishing paste:
- No. 4. Designed for initial surface treatment. Capable of removing a layer with a thickness of 20 to 40 microns.
- No. 3. Used to create matte surfaces without traces of abrasive particles.
- No. 2 and No. 1. Designed for fine, final polishing of surfaces. Provides removal of a layer less than 0.1 microns thick.
On the market, GOI paste can be found in different packaging: bars, tubes, containers. Special polishing wheels made from paste are also produced for grinding machines. Car enthusiasts and specialized service centers use this composition for polishing and grinding car mirrors, glass, headlights and other lighting devices.
2 Rules for using paste for polishing car headlights
Headlights are one of the important elements of the car, affecting the safety of using the vehicle at night. They must create an intense luminous flux, powerful enough to ensure good visibility. A significant portion of road accidents that occur at night occur due to poor lighting or problems with lighting devices.
Modern cars are usually equipped with headlights made of plastic, but there are fog lights and other light sources made of glass.
During the operation of the car, the glass of its headlights becomes cloudy due to constant exposure to the environment. Microchips, scratches and cracks appear on lighting devices due to small stones and dust getting into them. Plastic headlights often become cloudy due to exposure to motor oil, automotive chemicals and tar. To restore the original transparency and functionality of headlights, you can use GOI paste.
Periodically, you need to clean the headlight from excess abrasive substances and dust with a dry cotton cloth in order to evaluate the results of polishing. Before starting polishing, it is necessary to assess the extent of damage to the lighting fixtures. To do this, the surface of plastic or glass headlights is thoroughly cleaned of dust and dirt with special detergents. If dirt particles are not removed, they can cause further damage to the surface of the headlights during sanding. In order not to damage parts of the body adjacent to the lighting fixtures with abrasive compounds, it is recommended to dismantle the headlights before processing.
There are several ways to polish headlights with paste. Processing can be done manually or with a drill with a special felt attachment. Damaged surfaces must be treated for 3–5 minutes to achieve the maximum positive effect. Periodically you need to clean the headlight of excess abrasive substances and dust with a dry cotton cloth to evaluate the results of polishing. Processing continues until the headlight becomes completely smooth.
If grinding did not restore the original transparency of the headlight, it means that it also has defects on the inside. They occur under the influence of elevated temperatures when using xenon or halogen lamps, causing the inside of the headlamp to become cloudy. To restore the transparency of the device, you will have to completely disassemble the headlight and polish it from the inside. Glass headlights do not require polishing from the inside; they simply need to be treated on the outside and then washed with glass washing liquid.
It is important to note that the surface of modern plastic headlights often has a special protective coating that is erased during grinding. Therefore, immediately after processing and cleaning the lighting devices, they need to be re-coated with a special transparent varnish in several layers. Complete drying of such varnish occurs no earlier than a day after application.
3 Is it possible to use Goya paste to treat car windows?
While the car is moving, dust, particles of dirt and debris, carried by oncoming air currents, constantly fall onto the outer surface of the interior glazing. They can damage glass and negatively affect its smoothness and transparency. The windshield receives more serious damage when colliding with small stones flying out from under the wheels of oncoming vehicles.
Glass also gets scratched when using power windows due to dust and sand particles getting stuck on the inside of the seals. And the windshield is scratched by grains of sand deposited on the windshield wipers. You can damage the glass surface with your own hands if you use excessive force when cleaning the glass with a scraper of snow and ice.
GOI glass polishing paste should be used only if you are confident in your abilities and will not allow scratches to appear during use. All this leads to cracks, scratches and dulling of the glass, which impairs the visibility and appearance of the car. Minor damage to glass (up to 300 microns) can be effectively eliminated using GOI polishing paste. However, grinding cannot be carried out if there is significant damage; such work can lead to curvature of the glass surface and an even greater loss of transparency.
Before processing, glass must be thoroughly washed and dried. It is best to mark areas with damage on the inside with markers, and adjacent parts of the body, hood and roof should first be protected with masking tape. Polishing glass manually and especially using electric tools should be done very carefully and carefully. Any sudden movements can damage the glass or other parts of the car.
4 How to properly dilute and use abrasive paste?
Before polishing the car with the purchased paste, the abrasive agent must be softened. In its original state, this material is too dry, which makes it very difficult to apply to a polishing cloth, and hard lumps of paste can damage glass and other vehicle parts.
To soften the paste, you can use different liquids, from motor oil and distilled water to refined gasoline and white spirit. We do not recommend using flammable chemicals to dissolve the paste. With them, you not only expose yourself to danger, but also endow the treated machine parts with a pungent odor that will be difficult to get rid of.
In its normal state, GOI paste is very dry, which prevents it from being easily applied to a polishing cloth. The easiest way is to dilute the paste with motor oil, a few drops of which should be applied to a hard abrasive block using a pipette or syringe. Use a cotton or flannel cloth to rub the liquid into the block until the paste becomes similar in consistency to plasticine. In this form, the product no longer poses a danger to the surfaces being treated.
To increase the homogeneity of the resulting paste, the mixture of GOI with motor oil can be slightly heated in the microwave and mixed thoroughly.
The principle of polishing surfaces with a paste is that the small particles contained in it remove the thinnest layer of plastic or glass along with the microcracks present on them. The prepared paste is applied to a cloth or polishing wheel and rubbed a little on hard surfaces to remove solid particles. Then the surface with existing damage is processed with reciprocating movements with the next strip partially overlapping the previous one. After this, it is allowed to treat the surface with a cloth or in a circle in a spiral direction from the edge to the center.
The surface to be treated must be damp, and during processing it must be periodically wiped with a wet cloth. Cleaning from dust will also allow you to monitor the condition of the processed part. To polish with a grinder, use a power tool at medium speed - less than 1000 rpm. Glass and other materials should be processed with smooth movements, without stopping in one place. The abrasive wheel should be positioned at an angle of less than 5 degrees to the surface being treated in order to have maximum contact with the workpiece. If the part becomes very hot, processing should be stopped. It is better to repeat polishing every year or two so that important elements of the car remain operational.
– this is a special abrasive material in the form of a dense granular paste intended for grinding and final finishing of metal surfaces. GOI paste has been used in metalworking, technology, arts and crafts and other fields of activity. The abbreviation GOI means State Optical Institute, the enterprise where this material was developed.
Types and composition of GOI paste
The basis of GOI paste is chromium oxide with the addition of stearin, fat, silica gel and kerosene. The more chromium oxide in the composition, the more granular the material is - the larger the grain size and the rougher the processing. Therefore, pay attention to the composition of the GOI paste you have chosen - the possibility of solving a particular problem depends on this. The coarsest has 81 parts of chromium oxide, the medium has 76, the finest has 74 and, among other things, contains bicarbonate of soda.
In general, the grain size of the paste is determined by its designation - fine, medium and coarse, or by number - from 1 to 4:
- No. 1 - for final polishing and adding shine.
- No. 2 is almost identical to No. 1.
- No. 3 - medium grain, gives the metal a matte shine, removes small irregularities.
- No. 4 – the largest grains, a high abrasive sufficient to remove small scratches. Not suitable for precision grinding.
Features of using GOI paste
A frequent question from users of GOI paste is how to use it in this or that case. The answer to this depends on the specifics of the problem being solved. Let's look at the basic rules of polishing.
So, the answer to the question: how to polish metal with GOI paste, let's start with the main rule - you cannot apply the paste to the surface itself. It is applied to a cloth or, if we are talking about grinding knives, to a wooden block. Before use, the paste must be rubbed on an unusable piece of metal to get rid of large pieces that can damage the surface. This is equally important for successful application.
Let us draw your attention to the following important tips:
- Sufficient density and hardness of the paste requires it to be liquefied before use. To do this, you can use spindle oil, stirring it with the broken fragment until a homogeneous consistency. After this, you can apply it to a rag.
- To polish knives, the paste is applied to a wooden block or board. Then you can move the knife back and forth at the angle required for editing.
- To work on a grinding machine, the paste is applied to a felt wheel. To do this, you also need to dilute the paste with machine oil.
An important role when polishing is played by the choice of rags - soft or harder. To polish plastic, you need the softest flannel or cotton cloth. Fine polishing of metal can be done with denim, canvas or felt. Old felt boots are also suitable for these purposes.
In general, GOI paste is an important tool in metalworking for precision surface processing, high-quality grinding at minimal cost and without the use of special equipment.
Affordable and effective remedy
GOI paste is a polishing agent for products made from various metals. And for each there is its own variety. It is important not only to choose it correctly, but also to know how to use GOI paste correctly.
Varieties of Green Polish
Three types of polishing paste have been known since Soviet times:
- No. 4. The first rough processing was carried out with it.
- No. 3. The surface becomes matte, without streaks.
- No. 2 and No. 1. Used for finishing, adding gloss to surfaces.
These varieties differ in the size of the abrasive particles included in the paste.
This drug was produced:
- in a solid block;
- in a box in the form of a viscous liquid mass.
This product is popular due to its excellent properties and inexpensive price.
Getting ready for polishing
The use of GOI paste has a number of specific features. It turns out that the remedy needs to be prepared. How to do this?
- glasses of water;
- two teaspoons of ammonia;
- 50 grams of soap cut into strips;
- 50 grams of washing powder.
Take a soft cloth. Flannel is best suited for this procedure.
Soak a cloth in gasoline. The one that is poured into lighters is also suitable.
Apply a thin layer of paste to the moistened cut.
Wipe the unnecessary piece of metal to remove excessively large pieces that will lead to scratches.
It is strictly prohibited to smear the product itself with the product!
Let's start the process
The preparation was successful: a flannel cloth was moistened with paste and gasoline, all unnecessary large grains were removed. Let's start polishing.
Important: do not press on the product, make smooth movements with your hand and simply rub the surface.
When you notice that the product has become smooth, stop. It's polished.
Please note: it is necessary to apply industrial oil of liquid consistency to the item being processed from time to time.
We remove gross defects on products
There are several types of pasta To polish products with severe defects, processing is carried out with all types of paste. The sequence of their application is as follows: No. 4 → No. 3 → No. 2 → No. 1.
Rinse the polished product in kerosene. It can be freely purchased at pharmacy chains. After drying it, apply tsaponlac, which fights the oxidation process. Products coated with this preparation will not require re-polishing for a long time.
We clean glass, plastic, silverware
Need to tidy up your cell phone's display glass and body? GOI paste will come to the rescue. Plastic is a fragile material and should be handled with care, so take the softest product of all - No. 2. Otherwise, there will be countless scratches on the lid.
How to polish plastic? There are no special additions: like any other item. The procedure is similar to that described above.
First, wipe the glass with rubber pads, and then polish it with a cloth soaked in paste.
Please note: do not use gasoline or oil when processing your phone!
Silver can also be treated with this reliable product. Lighten spoons, forks and cups. Just first boil it in a solution mixed from:
After this treatment, polish with paste and let your silver items shine with renewed vigor.
Car enthusiasts use GOI paste to polish their windshield. Watch the video on how to polish an IZh wing with GOI paste:
Stop! Do not polish!
But it’s a miracle that not all objects without exception can be polished. There are also those that are prohibited:
Gilded items. Under the influence of the paste, the top layer, which is of the main value, will be erased.
Steel (except for knives, which are polished with a whetstone with stretched leather) and nickel. They are processed with a special device, and not by hand.
Metal watch. But: You can polish it if you remove the mechanism from them.
Sapphire crystals on the watch. Not affected by paste. Polishing will not bring the desired effect.
Only when used correctly will a unique polishing product bring results.
GOI paste, developed back in the distant 1930s in the bowels of the State Optical Institute, has not lost its former popularity even now. You can hardly find an owner who doesn’t have a piece of this green (and sometimes other colors) product hidden somewhere. Let us remind you how to use GOI paste and give some tips on the safe use of this “greetings from the past.”
Today there are four types of GOI paste on the market:
- No. 4 is used for primary processing of the material, if it has not been processed before;
- No. 3 gives the surface a matte appearance, eliminating all remaining strokes;
- No. 2 and No. 1 finish what their “older relatives” started, making the surface glossy and finishing the polishing.
The type of GOI paste depends on the size of the abrasive used in its manufacture. The paste was produced in a hard (bar) or softer (box) version. Why do we talk about GOI paste in the past tense? The fact is that at the moment, not a single Russian plant has the right to produce this product due to the presence of chromium oxide in its composition, which is hazardous to health - this compound is a carcinogen, i.e. it accelerates the development of cancer cells.
Preparation for polishing
The action of GOI paste consists of the work of small abrasive particles, which, through friction, erase irregularities from the surface. Before you start polishing, you need to prepare a small piece of soft cloth and soak it in gasoline (it is not necessary to use car fuel, gasoline for lighters will be enough). A small amount of paste is applied to the material. Using the prepared tool, you should first wipe the unnecessary metal surface to remove excessively large abrasive particles, otherwise the desired surface will not be polished, but damaged. You don't want to see a scratch on the surface after polishing, right?
Polishing
After preparing the polishing tool, you can begin the process. To properly polish a surface, you need to carefully, without sudden movements or strong pressure, rub the desired area with polish until the surface becomes smooth. If necessary, you should return to the previous stage (if the surface requiring polishing has a large area, the GOI paste will quickly run out).
If the product has many flaws, you should use not just one type of paste, but several. So, for initial treatment, GOI paste No. 4 is applied to the rag, as the number of flaws decreases - No. 3, and so on, until the surface takes the desired form.
The treated element should be washed with kerosene in order to remove any remaining abrasive from it. In the absence of kerosene, ordinary running water can be used, but this is not recommended, since under improper conditions there is a high risk of rust. Considering that many polish the necessary surfaces in the garage, where there is often high humidity, this point should not be discounted.
Carry out polishing work outside residential premises. The ideal place would be a garage, workshop with good ventilation, or some open space. Polishing with GOI paste requires rinsing with kerosene, and inhaling its vapors is dangerous to health.
Polishing soft metal products
GOI paste can be used to polish items made of any metals, including soft ones such as silver and gold. This procedure will help restore the former shine of your favorite utensils. But polishing such objects requires a special approach.
Let's look at the polishing process using silver spoons as an example.
- Before carrying out the procedure, you should thoroughly wash the spoons and clean them with a stiff brush (an ordinary toothbrush is ideal) with tooth powder applied to it.
- Then a solution is prepared containing ammonia, tooth powder and soap shavings. All this is mixed until completely dissolved.
- Spoons are soaked in the resulting solution.
- Then the mixture should be put on fire and brought to a boil.
- The spoons are removed, washed in running water and then wiped with GOI paste.
It would be better to use types of paste No. 1 or No. 2, since the other two can leave scratches on expensive utensils.
Polishing plastic and glass products
It’s amazing but true: GOI paste can be used to restore old equipment to its former beauty! To polish plastic products, you should use GOI paste type No. 2, since more abrasive types can damage soft plastic.
It is worth noting that when polishing equipment, kerosene, gasoline and running water are not used. Only abrasive is applied to the rag, without the use of auxiliary products. The process itself is no different from polishing other materials and objects.
Where should you not use GOI paste?
It would seem that GOI paste is a universal remedy. But no, there are surfaces that should not be touched with this polish due to the fact that such a procedure will either make no sense or cause harm.
Firstly, you should not polish mechanical watches with GOI paste. Types No. 1 and No. 2 will only enhance the visibility of small scratches and emphasize them, and pastes No. 3 and No. 4 can simply erase the top layer of metal, causing the watch to lose its former luster.
You should also not use this product to polish sapphire crystals on watches - there will simply be no effect, since sapphire crystal is very durable.
Precautionary measures
At the beginning, we mentioned that GOI paste is not currently produced in Russia due to its toxicity. However, it is sold freely in stores whose owners were able to supply the well-known polish. And if a person purchases this remedy, he should know some precautions in order to avoid tragedy.
- You need to use GOI paste extremely carefully, avoiding contact of its particles with the mucous membranes of the eyes and nose. If you are unable to protect yourself from this, immediately rinse the affected surface with running water and call an ambulance.
- Use a respirator or at least a medical mask when working with polish, especially when polishing metals using a cloth soaked in gasoline. You should not expose your body to the risk of poisoning from vapors of chemically complex substances.
- Keep children away from polish storage areas.
- Work with the product while wearing gloves to protect the skin of your hands.
So, GOI paste is an effective, but unsafe remedy. Even if you have used it for polishing many times, you should always be on guard when working. If the situation allows, it is better to use more gentle methods.