How to polish steel at home. Polishing stainless steel to a mirror shine with your own hands

It can be different. After all, it contains several different metals. The basis of stainless steel is iron, titanium, nickel, molybdenum, manganese, and this is not the entire list. Chromium, which is also present in its composition, helps this steel resist corrosion.

What prevents steel from rusting

When chromium interacts with oxygen, a protective film is formed on the surface of stainless steel; it is this film that protects the alloy from exposure to aggressive environments.

The amount of chromium will determine the degree of corrosion resistance of steel.

For example, in the manufacture of refrigerators, an alloy with an average chromium content (10-17%) is used. But if the device is constantly in contact with water or is subjected to temperature loads, then an alloy with a high chromium content, up to 26%, is used. Such appliances include washing machines, dishwashers, sinks, hoods, cookers and kettles.

Where can I polish?

In order for the surface of the alloy to be beautiful and smooth, you need to polish the stainless steel. Nowadays, there are many companies whose specialization is this particular procedure; they put in order various products made from this alloy. But it turns out that you can polish stainless steel at home.

Of course, if you need better quality work, it is better to seek help from specialists. For example, a polished square stainless steel pipe will look much more impressive after factory processing than after home processing.

Any company that specializes in polishing will easily perform this procedure.

How to process steel

How to polish stainless steel to a mirror shine? Here is a list of everything you will need:

polishing paste;
felt or felt circles;
wood glue;
grinding wheels with different grain sizes;
sandpaper or stone;
Bulgarian.

Main stages of the process

The process takes place in several stages. First you need to do some rough cleaning. Next comes a wheel with a fiber base and an angle grinder. But this procedure can be skipped provided that the surface of the product is already quite smooth.

Grinding wheels come next. The surface must be processed several times, and each time the size of the abrasive should decrease.

If such circles are not available, then you can easily make them yourself. To do this, you can use a felt circle or felt. You need to apply wood glue to it with a spatula, and then rub it over the abrasive chips.

This operation will make the steel surface perfectly smooth. Under no circumstances should any roughness remain. After all, after polishing it will be much more difficult to seal them.

The next step is to apply polishing paste and a felt wheel. Here it is better to consult a specialist, since a specific brand of alloy requires a specific paste. Of course, it is best to use diamond, the grit of which is suitable for the metal intended for processing. Final polishing is carried out until there are no visible flaws left. A polished stainless steel pipe should look just perfect.

Stainless steel in everyday life

No kitchen is complete without stainless steel appliances and interior parts. This is not surprising, since this particular alloy is quite strong and durable, especially since it does not require special care. Stainless steel is often used to make dishes, cutlery and stoves, as this metal has a fairly high thermal conductivity.

But there are also some disadvantages to stainless steel: with regular use, it noticeably tarnishes. The kitchen is losing its shine. To prevent this from happening, it is necessary to periodically polish the stainless steel. There are many different ways to solve this problem. An important point in this procedure is the correct selection of polishing agent for stainless steel.

When cleaning steel products, you should never use bleaching agents or use metal sponges or brushes with stiff bristles.

There are several alternative polishing methods.

Olive oil

This method is just for those who are thinking about how to polish stainless steel at home. Tarnished dishes will begin to shine again, like new. All you need is oil and rags, preferably made of soft fabric.

First of all, you need to moisten a rag with oil.
Using this cloth, it is necessary to apply oil to the product so that it is completely covered with an oil film.
Next, you can begin polishing by pressing the oiled rag firmly against the metal.
To prevent the steel from becoming dull again, excess oil is removed using dry towels or napkins. They need to rub the surface until the product is completely dry.

Polishing with flour

You can also use flour to polish metal products. It is good for cleaning flat surfaces, such as a sink or pan.

The product is sprinkled with flour so that there are no gaps left at all.
The flour should be distributed evenly.
Using a dry cloth, polish the surface in a circular motion.
Next, the flour is very easy to remove from the surface.

Mechanical method

Some devices and fixtures have hard-to-reach areas. This is where the question arises, how to polish stainless steel to a shine. There is a way, but you will have to spend a lot of time and make every effort.

You need to purchase a piece of felt and abrasive paste. Apply the paste to the fabric and polish the surface until the metal becomes bright and shiny.

Polishing with chemicals

This method is most often used when you need to clean small items. The main thing is that polishing takes little time and is very simple to do. Below are several recipes for solutions.

Recipe 1

It is important to maintain proportions here. Contains: 230 ml of sulfuric acid, 70 ml of hydrochloric acid, and 40 ml of nitric acid. The rest is water.

For one liter of solution you need another 5 g of sodium chloride, 5 g of acid black dye and 10 grams of wood glue.

The resulting liquid must be heated to 70 degrees Celsius and the part must be lowered there. The product can be left in the solution for a maximum of half an hour.

Recipe 2

You will need orthophosphoric acid, it should make up 20-30 percent of the total volume. Hydrochloric acid (3-4%), nitric acid (4-5%), methyl orange (1%). The rest is water. The solution should be at room temperature, and keep the product in it for no longer than 10 minutes.

Recipe 3

Polishing rules are given below:

The metal must be thoroughly cleaned before polishing. Next, place the product in the solution. It should be remembered that only distilled water can be used here.
During the procedure, the solution must be constantly stirred, only in this case the chemical reaction will take place 100%.
When the required time has passed, the part is removed and washed well with running water. After this, the product must be well rubbed with a napkin soaked in polish.

After this treatment, all roughness is eliminated.

It is not enough to polish stainless steel correctly; it also needs to be cleaned regularly.

Cleaning the sink

Often stains remain on sinks - this is limescale. It is very easy to remove with a vinegar solution. You need to dilute the acid one to five and wipe the surface with it, and then rinse with running water. To give the metal a bright shine, the surface must be rubbed in a circular motion.

Cleaning the stove

Stains from sauces, fat and burnt food remain here. They will have to be removed with a special steel polishing agent. Be sure to remove the heating elements before cleaning. It is best to use the polish while wearing gloves. Otherwise, there is a risk of getting burns on the skin of your hands. After the procedure, it is advisable to rub the surface well with a dry cloth.

Cleaning the hood

This is not an easy task. But quite doable. To prevent dirt and soap from staining the stove, it is better to cover it with newspapers or old towels.

To clean the hood, you can use a specialized product or prepare a solution yourself. You will need bicarbonate of soda, lemon juice and water. The product must be rubbed in carefully so as not to damage the surface. It is enough for the solution to remain on the hood for several minutes, after which it must be washed off with clean running water. Next, you need to polish the surface well with a dry cloth. After this procedure, the hood will shine like new.

Stainless steel is rarely used in household use. Metal is expensive. Difficult to process. Resistant to corrosion. Polished to a mirror finish. Hence the main places of its application: as an interior and household item in kitchens, bathrooms, as well as complex power elements included in the interior of a house or premises. Kitchens, bathrooms, door handles, railings - what is always in sight and catches the eye with sparkling beauty. Proper and timely polishing of such items will preserve the expensive decoration.

Time and moisture vapor affect the structure of the metal. The first sign of corrosion is a slight clouding of the surface. At this stage, restoration of the mirror shine of stainless steel occurs easily.

Polishing methods at home

A small list of interior and household items made of stainless steel, due to the complexity of product shapes, limits the mechanization of the polishing process. At the same time, the high hardness of the alloy due to its high labor intensity does not allow relying solely on manual labor. The best option is a reasonable combination of both methods. Stainless steel stair railings are a good example of the scale of such work. It is impossible to do without small-scale mechanization means. Difficult terrain will not allow cleaning with one tool. There will be many places where this process will have to be completed manually.

An angle grinder can be considered as a tool for polishing stainless steel at home. Better known as "Bulgarian". The procedure goes as follows:

a special fabric circle is installed on the machine;
A thin layer of polishing paste is applied to part of the surface to be treated. During operation of the tool, the polishing agent is evenly distributed on the wheel and transferred to other areas of the workpiece;
As the cleaning properties decrease, paste is added, and the stainless steel polishing process is repeated in a new place.

The dimensions of the grinding machine and equipment limit access to the entire surface of the workpiece. Such places have to be polished manually. A piece of felt and abrasive paste are suitable for this. The cleaning agent is applied to a rag and rubbed onto the treated area until the desired surface mirror finish is obtained. The process is lengthy. You need to be patient.

In 2016, our company introduced a new process for electrochemical polishing of metals. electro or electrochemical polishing, or chemical polishing, is a process that selectively etches roughness to create a mirror-like surface finish.

Thanks to this method, it was possible to weld aesthetic seams, becoming smooth and shiny. For example, about 100-200 microns are removed in about 30 minutes of polishing stainless steel.

On average, stainless steel is shiny in 5-10 minutes, but if preliminary mechanical preparation has been done, you can get a mirror finish within 5 minutes. Electropolishing can also be used for complex parts for which mechanical polishing is practically impossible.
Electrochemical polishing This is an anodic treatment of metal to create a smooth and shiny surface.

The product, which has a micro- and macro-screen, is the anode of the cell. A cathode is a metal that is chemically insoluble in an electrolyte solution.

Polishing metal with glossy glossy hands

Such as electrolytes, solutions using phosphoric acid, chromic acid, sulfuric acid, acetic acid, hydrofluoric acid and others. During the electropolishing process, anodic dissolution of the metal occurs on macro and microcircuits, where the surface becomes smooth and shiny. Hydrogen is released at the cathode. The mechanism of electroporation has not been fully explained.

electropolishing. The effect is usually due to the action of a viscous film formed in the anodic layer, a barrier to dissolution in the metal in the recesses versus dissolution in the protrusions, and alternating activation and passivation of the metal.

Electropolishing of steels is the best type of electrochemical anodic etching. This process combines the operations of removing corrosion, smoothing the surface and giving it shine, passivation, and also increasing the adhesion strength of galvanic coatings to the treated surface.

It should only be taken into account that the initial cleanliness of the treatment must be no lower than grade 7-8 so that, in addition to obtaining shine, a surface smoothing effect is also observed. Carbon and low-alloy steels are electropolished with alternating current of industrial frequency in an electrolyte of the composition, % (by weight): 96.5 orthophosphoric acid (p = 1.54 g/cm3), 2.0 technical oxalic acid, 1.5 wood glue in tiles.

Operating temperature 15-30°C current density 15-20 A/dm2. The dwell time, depending on the surface condition, is 1-5 minutes. Before preparing the electrolyte, glue and oxalic acid are dissolved separately. The electrodes are the parts themselves, hung on rods of three-phase or two-phase alternating current with a voltage of 12-15 V...

For anodic polishing of carbon steels with direct current, an electrolyte of the composition is used, % (by weight): 65 orthophosphoric acid (p = 1.67 g/cm3), 20 sulfuric acid (p = 1.84 g/cm3) and 15 water (total content ). The PB-5 inhibitor is administered in an amount of 5% of the volume of the acid mixture; it dissolves slowly with stirring (within two days). Working temperature<15-25°С, корпус ванны имеет рубашку для водяного охлаждения.

Anodic current density >20 A/dm2, exposure time up to 20 min. at voltages up to 30 V. Lead cathodes are periodically cleaned.

Electrolytic polishing and etching

For most alloys, the normal process of sanding, wet polishing and dip or wet etching will give quite satisfactory results. However, in some cases, preference should be given to electropolishing, especially if there is a danger that the hardening obtained during the polishing process will affect the surface structure.

Jacquet was apparently the first to use electropolishing for metallographic work. His method involves the usual first stage of mechanical processing of the sample to obtain a sufficiently smooth surface.

Then a circuit is formed in which the sample is made the anode; The electrolyte is selected so that the sample metal is only slightly soluble in it. Under these conditions, the metal ion concentration at the surface quickly saturates, after which the current mainly depends on the metal ion concentration gradient perpendicular to the surface. Protrusions on the surface are associated with a large concentration gradient and tend to dissolve faster than depressions.

Thus, electrolysis results in smoothing and, under appropriate conditions, a fine polished surface can be obtained without plastic deformation. The process is regulated mainly by the concentration of polarized ions, and this determines the characteristic relationship between the current density and the applied voltage (Fig. 132). As the voltage increases, the current density first increases to a certain maximum, then decreases slightly and remains constant until a new process begins in the electrolyte (usually the release of oxygen).

The most satisfactory results are usually obtained at a voltage that corresponds to the right edge of the horizontal portion of the given curve, as shown by the arrow in Fig. 132.

The apparatus for electrolytic polishing is relatively simple; One of the possible options is shown in Fig. 133. The apparatus is an inverted jar, through the neck of which a sample holder 3 and a positive input are inserted; The holder and parts of the sample that are not subject to polishing are protected with varnish.

The top of the vessel is closed with a wide rubber or cork lid through which cathode 1 is inserted; Depending on the electrolyte used, the cathode can be copper or stainless steel.

The released hydrogen exits through a wide tube; the same tube is used to remove the electrolyte from the apparatus.

Electropolishing is most suitable for single-phase alloys, for which it is usually sufficient to prepare the surface on 00 or

132. Relationship between current density and applied voltage in an electropolishing bath

Rice. 133. Device for electropolishing: 1 - cathode; 2 - outlet tube for evolved hydrogen; 3 - sample

Multiphase alloys are more difficult to polish in this way; for them, light mechanical polishing with water and aluminum or magnesium oxide powder can give the best results.

Before electropolishing, the sample surface in all cases must be completely free of grease; It is advisable to wash it in carbon tetrachloride.

Electrolytic polishing and etching processes require voltage variations over a wide range. According to the literature, the most commonly used intervals are 50-110 v. The current density also varies widely - from 1 to 500 A/cm2, so it is recommended to make a stationary control panel that operates with

adjustable voltage transformer and current rectifier.

Relatively little is known about good electrolytic polishing reagents. Most of the early work was done with mixtures of perchloric acid and acetic anhydride. This reagent, however, is explosive.

Polishing stainless steel – a mirror in 5 minutes is real!

For many metals, solutions of orthophosphoric or pyrophosphoric acids were also used.

The electrolytic method, in addition to polishing, can be used for etching metals and alloys; in some cases both processes can be carried out in the same electrolyte.

A relatively higher voltage is used for polishing, and at the end of this process the voltage is reduced to a certain value and etching is carried out. Electrolytic etching can also be used for samples whose surface has been mechanically polished.

This method should always be used when conventional polishing does not produce satisfactory results. Apparatus suitable for this purpose has been shown in Fig.

133. The literature provides a lot of data on samples electrolytically etched in aqueous or alcoholic solutions.

Stainless steel items have become a part of our lives. These are interior elements for the street and at home, various dishes at home and much more. Stainless steel is an alloy of iron and carbon mixed with special elements. Steel acquires high resistance to negative environmental factors thanks to these elements. But under the influence of various factors, even such a durable metal can lose its original appearance. How to polish to a mirror shine? If such a need arises, then you have two options:

Contact a specialized company that provides this type of service.
Do it yourself at home.

Let's look at how to polish metal to a mirror shine with your own hands in different ways at home.

Polishing at home

You can also get a shiny and smooth stainless steel surface at home. There are several ways that will help us with this.

Preparation for polishing

First you need to clean the product properly. You can use dishwashing liquid for this:

Dilute the detergent in water.
Clean the stainless steel surface with soapy water.
Rinse and dry the product thoroughly.

Olive oil polishing

This method is suitable for polishing tarnished items. All you need is a little olive oil and a soft cloth or napkin:

Apply a little oil to the fabric and spread it so that the entire surface is covered with an oil film.
Press the fabric firmly onto the surface and polish the stainless steel product with smooth movements.

Important! Continue until you see a noticeable change in structure.

Now you need to remove the remaining oil. Napkins or a dry towel are suitable for this. Wipe the surface until it is completely dry.

Polishing with flour

How else can you polish metal at home? For these purposes, you can use flour, however, this method is more suitable for flat surfaces, for example, for pots, knives or a sink:

Sprinkle flour over the entire surface and spread it evenly over the metal.
Polish using a soft cloth in a circular motion.

Important! For greater effect, you can use an old toothbrush.

Shake off any remaining flour.

Chemical method

You can polish metal at home using a chemical method. To do this you need to prepare a special liquid. There are several ways to do this:

For such a solution you will need 230 ml of sulfuric acid, 70 ml of hydrochloric acid, 40 ml of nitric acid. To 1 liter of solution you need to add 6 g of acid black dye, 10 g of wood glue and 6 g of sodium chloride. Bring this mixture to a temperature of 65-70 degrees and place your stainless steel items in there for 5 to 30 minutes.
The solution is prepared in the following ratios: phosphoric acid 20-30%, hydrochloric acid - 3-4%, nitric acid - 4-5%, methyl orange - 1-1.5%. Place the product for 5-10 minutes at a temperature of 18-25 degrees.
Per liter of composition there are 660 g of hydrochloric acid, 230 g of sulfuric acid and 25 g of orange acid dye. Heat the solution to a temperature of 70-75 degrees and place a stainless steel object there for 2-3 minutes.

Important! All these components are very aggressive, so it is necessary to ensure complete eye protection. hands, face and respiratory organs.

The stages of polishing using chemical solutions are as follows:

Immerse the pre-cleaned stainless steel item in a container with a chemical solution.

Important! Adhere to a strict dosage of substances included in the solution to obtain the desired concentration.

The liquid must be stirred constantly.
After the expiration date, the product must be removed and the remaining reagents washed off with clean water.
Wipe the part with a cloth containing polish.

Under the influence of chemicals, all roughness will be eliminated and the product will acquire its original shine and radiant appearance.

Mechanical polishing methods

These polishing methods involve the use of tools and devices such as:

polishing machine;
Sander;
electric sharpener;
drill with lock.

Important! The method has a number of advantages. This is fast, efficient, you can change the rotation frequency of circles and belts, use additional attachments made of leather, fabric, wool and other materials.

The product for polishing metal to a mirror shine with your own hands depends on the brand of stainless steel:

Diamond paste performed best, but it has one significant drawback - a rather high price.
If you don’t have one, then you can use GOI paste. It comes in four types, depending on the grain size.

Important! For manual grinding, you can use the same diamond paste or GOI paste. Its effectiveness depends on the quality of consumables.

This is done as follows:

Apply a little product to the felt disc and add a few drops of machine oil to dilute the paste.

Important! For metal, it is best to use a coarse grit paste.

Polish the surface in a circular motion, being careful not to rub too hard.
Do this until you are satisfied with the result.

Important! How can you polish a knife to a mirror shine at home? Such smooth metal surfaces are polished with an ordinary file - a wooden block covered with a cloth, onto which polishing paste is applied.

Stainless steel care

Polished stainless steel looks very beautiful. To maintain it in this condition, special polishes are used. They are available in the form of concentrates and liquid emulsions. The polish is applied immediately after the polishing process is completed. Then you need to periodically apply polish to ensure that your stainless steel product looks nice for a long time.

Polishing metal using an angle grinder

Polishing is a type of metal processing that returns shine to the metal surface. At the present stage, the following grinding methods are distinguished:

What tools and machines are used? Mechanical methods involve the use of the following tools and devices:

The action must be prolonged to be effective. Finally, a thorough rinsing and drying will return the copper to its shine. Even if you use specific and safe products, we recommend washing copper items with soapy water. Copper varnish will ensure durability. Corrosion stains can always be removed with a mixture of vinegar and salt or, conversely, with lemon juice. If there are burns on the bottom of the pot, a fine abrasive powder is ideal.

Brass is an alloy of copper and zinc that has always been widely used. It is found in handles, locks, handrails and more. If the brass is painted, it can be cleaned using very warm soapy water and then polished. An even simpler system, useful for small areas or areas that are difficult to reach, is to rub in a piece of lemon that has been soaked in salty hot vinegar. Cleaning will be great, but you will have to use other methods for polishing.

polishing machine;
Grinder;
electric sharpener;
drills with clamps.

This finishing method has several advantages. Firstly, it allows you to change the rotation frequency of circles and belts, which has a positive effect on the quality of processing of the metal plane; secondly, additional attachments made of fabric, leather, wool, etc. can be installed on the polishing machine.

Just take care to use the products that are available in the market. There are many types and are suitable for this purpose. If the brass is painted, we recommend simply dusting and washing with warm, soapy water. You don't need to do this often, but be sure to dry thoroughly each time. If the paint gets damaged, you will need to use acetone and remove it completely. Then it would be wise to contact an expert for the necessary repainting. Also for silver and metal we will use procedures similar to those we have encountered so far.

Special grinding machine - angle grinder

Manual grinding differs from automated grinding in that its effectiveness depends on the quality of consumable polishing materials. In manual finishing, diamond paste and additives based on chromium or iron oxide are used. Smooth metal surfaces are polished with an ordinary file - a wooden block covered with a cloth, onto which polishing paste is applied.

Creamy liquids are great to spread evenly on the surface to be buffed with a cotton ball. Then allow the treated surface to dry and wipe with a soft cloth until all residue is removed. Then wash the object with soap and water and rinse under running water for each product.

Unfortunately, silver is a metal that oxidizes very easily, so some care is required to protect it more effectively. Especially if the object has engraved or carved parts, it is recommended to apply a special protective paint, which is available in a canteen or specialty store. Unusual objects can also be protected with a black cloth wrapped around the objects themselves to eliminate contact with air and lightweight or aluminum foil for home use.

Polishing metal with a special device

Combined processing methods

Metal polishing can be carried out using combined methods, in the case of an unprepared and rough surface with rough relief. In this case, a long-term electrolyte-plasma finishing is prescribed, which consists of removing a significant layer of metal.

Brass is often used as a material for jewelry, accessories, architectural features and home decor. With vintage and vintage styles taking over fashion trends lately, brass has made a comeback—both in the wardrobe and in our homes.

This metal alloy has a beautiful and soft shine, but due to the copper content it darkens, and if objects are exposed to too much moisture, a light darkness can appear. In some brass products this is a sought after effect, but in others the darkening makes it even worse.

This processing method is used in extreme cases when quick restoration of the shine of a metal product is required. Among the disadvantages of the technology, one should highlight the high energy intensity, especially at the initial stage of processing, when 100% more energy is used than usual.

An electrolytic plasma polishing machine processes the part in two stages. At the first, the surface is degreased, and at the second, the grinding itself occurs, which, in turn, also consists of two cycles: cutting off the rough layer and grinding the metal. Cleaning from grease is mandatory, since a viscous surface leads to oxidation of the metal and deterioration in the quality of its finish.

If you want your jewelry and accessories to regain their beautiful shine, try some of these simple recipes to clean brass at home. Before testing any of the following recipes, make sure you are dealing with real copper. Take a magnet and touch it to a metal surface - if it sticks, you are most likely holding a copper-plated metal object in your hand. In this case, we advise you not to use acids such as vinegar and baking soda, but prepare a soapy solution and use a toothbrush to gently scrub the item.

Classification of metal polishing pastes

You can bring a metal surface to a mirror state with your own hands without the use of machines; just pay attention to special tools, divided into the following groups:

Aquatic. The substance does not contain fat and does its job perfectly;
Organic products - contain paraffin and various oils. They are diluted with various oils and fatty acids;
Diamond paste is a revolutionary solution that allows you to instantly achieve shine on any metal surface.

Let's take a closer look at the last version of grinding. Diamond paste is so effective that it completely replaces a polishing machine. Diamond Substance is available in two types: ASN and ASM brands (expensive).

Rinse and dry well with a cloth. However, if the magnet does not stick, you are dealing with real copper. In this case, you can use one of the other cleaning suggestions. In many cases, you don't need anything more than a little soap and water to clean brass jewelry or accessories. Wipe them well with a sponge or brush, dry them and polish them with jewelry cloth. If you don't have one, a simple household microfiber cloth will also do a great job. Roll the metal in a circular motion and restore its shine.

Diamond paste has the following advantages:

Accuracy. Synthetic diamonds allow you to polish any metal product to a shine as accurately as possible;
Wide range of grain sizes. There are more than 12 grit types available on the market today;
Simple operation allows you to carry out cleaning procedures yourself without the use of special tools;
Diamond paste requires minimal tools: a rag, water and rubber gloves.

The main disadvantage of the cleaning product in question is its high price. On average, diamond paste on the consumables market costs more than 500 rubles per 35 grams of the substance.

Salt is an excellent assistant in environmental cleaning. We've already mentioned salt as a great tool for cleaning brass and other copper items in this article. In a small bowl, mix a couple of tablespoons of salt and 1 tablespoon of water. Mix well until you get a thick paste. Brush the surface of the brass with the mixture, for small curves, corners and details you can use an old toothbrush. Wipe the surface with a cloth soaked in vinegar.

We present several specialized tools that are required in their field of application. This is a surface treatment of various metal products aimed at eliminating impacts and burrs, leveling welds, cleaning rust and old paint coatings, stains from metal oxidation and others. They are used where they are intended to clean and grind metal surfaces to obtain varying degrees of smoothness and be polished to a metallic luster.

Working principle of diamond paste

Diamond paste acts on a metal product mechanically and chemically, forming dispersed films. The composition of the cleaning agent includes substances that promote the occurrence of adsorbing processes, which facilitates grinding of the material.

Diamond paste is applied to different types of fabrics (felt, microfiber or jeans), paper, rubber, plastic and other types of non-metallic materials. It is worth noting that diamond paste can also be applied to polishing wheels to increase the efficiency of metal surface processing. In this way you can achieve a mirror effect. Circles made of felt, felt or leather are installed on the polishing machine.

It also allows you to treat areas where a classic tool cannot reach. Because it works to a degree of polishing, it is most often done on metal surfaces that are left exposed and their special "metal" beauty will not be hidden under the paint finish. In short, it is usually stainless steel. It is obvious that alienation leading to the loss of national identity is not only a typical Bulgarian phenomenon. Stainless steel products are widely used in the chemical industry, for all types of liquid storage containers and pipelines for the production of medical equipment, the food industry - in general, anywhere important is steel that does not interact or corrode when exposed to chemical aggressive substances.

Description of the polishing process

To grind a metal surface you will need: laps and several tubes of diamond mixture with different grits. Diamond paste is evenly distributed over the working surface of a rag or other material. Experts have noticed an interesting pattern that makes it possible to improve the quality of metal processing.

Besides its practical side, so that stainless steel products are widely used in home cooking, cut and polished to a high-gloss surface giving an exceptional decorative effect, which is why some of the most luxurious and timeless, bathroom and kitchen cabinets, railings and others. Elements of home and home furniture are made of stainless steel.

This type of steel also has its own mechanical characteristics. They are well welded by argon arc welding, which is difficult to ream with a drill due to their high viscosity. In terms of their surface treatment, another important feature is that they have significantly lower thermal conductivity than conventional steel. Therefore, for example, for a more intense carbohydrate disk, the material can easily overheat and a characteristic blue surface color appears. This requires processing at low disk speed or moderate tape speed.

It turns out that you need to add castor or olive oil to the polishing substance. The ideal ratio is considered to be a mixture consisting of 40% diamond dust and 60% oil. After dilution, the mixture is immediately applied to the metal surface.

This, however, should not affect the power of the electric motor or the amount of torque that is transmitted to the grinding wheel or shaft driving the belt. This gives a truly magnificent six, each machine, for processing stainless steel surfaces, with the same success and for the same purpose, except it can be used for processing products made of ordinary steel or non-ferrous metals. It is also important to emphasize that while machines are by far the most important element in this program, they will be useless without a wide range of grinding and polishing discs, sheets, strips, washers, felts, abrasive pastes, wire brushes, etc. this is what Metabo offers them.

Experts recommend starting work only with large grains, gradually moving to abrasives. During processing, make sure that no unnecessary elements - dust, sawdust, hair or pieces of rags - get into the mixture. The presence of foreign objects greatly impairs the polishing to a shine. It is also recommended to wash your hands after changing from one grit to another.

Additionally, flat, concave or convex surfaces, including the outside surface of pipes, can be machined in otherwise inaccessible areas. This is a small and powerful electric motor with a working disk diameter of 125 mm. Also a characteristic feature of this machine is its high torque - 4.2 Nm, whereas in conventional models with the same power it is 3.3 Nm. The characteristic of this angle grinder is also.

A special rotating grille that protects the motor windings from solid metal particles sucked in by the cooling air flow. The protective screen rotates and locks manually without tools. The working disk is fastened with a special nut and without tools.

Types of Diamond Dust

On the modern market you can find products not only for polishing metal, but also other materials, for example, wood, glass, stone, etc. They can be classified by color, for example:

Huge range of diamond paste

Yellow packaging indicates that the substance is intended for grinding ceramic materials and glass products. It is worth noting that this dust can also be used for finishing metal;
Blue packaging. This type of product is used for finishing glass. The grinding agent has a fairly wide selection of abrasive elements - from 60 to 10 levels;
The red packaging is suitable exclusively for treating metal surfaces.

As for the packaging itself, diamond paste is sold in compact plastic jars with a volume of 35–45 grams. The average cost of a jar depends on the size and quality of abrasive materials. The finer and higher quality the polishing material, the cheaper the paste costs. The average price is 450–600 rubles.

Highly wear-resistant self-extinguishing brushes with improved dust and greater particle protection. The machine works with various discs and washers for coarse fine polishing, metal brushes, etc. Particularly useful in combination with lamellar discs with refined corundum abrasive grains of different sizes, suitable for coarse and fine medium surface treatment of plain and stainless steel, non-ferrous and light metals, titanium alloys and the like.

At first glance, it is obvious that this is a tool designed to treat very hard-to-reach places, including corners where it is still possible to reach. The elongated narrow sanding arm, around which the endless belt is stretched and moved, causes the machine to be called a "band saw". The arm can rotate 270° to achieve the most comfortable position.

Paste GOI

GOI chrome paste is a universal product used for polishing metal and non-metallic surfaces. Although it was invented in the early 1930s, it is still used to polish metals today.

Polishing paste GOI

This grinder is the most unusual and highly specialized tool in the group of six. Its unusual shape is due to its purpose - grinding pipes and other oval-shaped objects. The fixed arm contains the drive shaft and one guide roller. The second belt pulley is located at the end of the movable arm. Under the influence of a strong spring, this shoulder supports the stretched belt. The maximum segment that the tape can wrap is 270°. It can process pipes with a diameter of up to 180 mm.

The GOI product comes in different grain sizes (classified according to the size of the abrasive materials). There are different types of grain size: fine, medium, and coarse. Fine dust is used for polishing soft and non-ferrous metals, coarse grains are used for rough finishing of ferrous metals and steel.

Features of use. Initially, the polishing agent has a solid structure, which can be diluted with a few drops of machine oil. If you need to polish an uneven metal surface with bends, it is recommended to apply the paste diluted on a rag.

It can be changed easily and quickly by hand without tools. It is specially designed for grinding and polishing stainless steel surfaces. Groups of raw non-woven fabric used for cleaning, sanding and finishing - to remove scratches, surface stains and oxidation of the metal surface.

Felt for polishing with polishing paste. He specializes in welding and grinding welds located in corners and other hard-to-reach areas, such as creating safety bars on stairs and other areas. In practice it is an angle grinder with a grinding disc attached to the end of an extended arm. This design allows the discs to reach places where a conventional sander cannot reach. To avoid leaving traces of corrosive metal on the treated stainless steel surface, the extended arm is made of aluminum alloy, and the metal washers for attaching the working disk are made of stainless steel.

The second polishing method is intended for processing smooth metal surfaces. Its peculiarity is that a small amount of abrasive material is applied to a wooden block. Then it is recommended to make methodical movements back and forth along the surface being treated.

Video: Polishing aluminum

The surfaces of metal products are finished not only to give them a beautiful appearance, but also to protect them from rusting, corrosion by acids, alkalis, etc. In one case, it is enough to file the product, in another, it is necessary to bring the surface to a shine by grinding and polishing , in the third - cover with paints and varnishes; all this can be done yourself at home.

Fig. 1. Finishing of metal surfaces: A - sanding; B - grinding with a file; B - grinding of round products; G - polishing with paste.

After processing metals with a file, more or less deep marks from the notch teeth always remain on them. To make the surface cleaner, smoother and even shiny, it is sanded and polished.

METAL GRINDING

At home, metals are polished with emery cloths after carefully treating the surface with a personal file. To make the skin comfortable to hold, it is wrapped around a wooden block (Fig. 1, A) or a wide file; The ends of the skin are held with the thumb and forefinger of both hands. Convex cylindrical surfaces can be sanded by wrapping sandpaper around them.

First, the surface is processed in different directions, with coarser, coarse-grained skins, then with finer ones. The final grinding is carried out in one - longitudinal - direction using sandpaper with the finest grain. When grinding, the product must be fixed motionless.

METAL POLISHING

A mirror-like shine is imparted to metal products by polishing. Without preliminary grinding, only surfaces that have been carefully processed with personal and velvet files can be polished. The file should be rubbed with chalk. The surface is first processed across the strokes on it. When the strokes along and across are the same, the direction is changed by 90° and this is repeated several times. The surface treated in this way, as well as the grinding surface, is polished with special polishing pastes.

The industry produces polishing pastes under the GOI brand. They consist of fine abrasive powders (chromium oxide, iron oxide, etc.), soft plastic substances composed of wax, stearin, kerosene and other materials. GOI pastes come in coarse (dark, almost black), medium (dark green) and fine (light green). First, they polish with a coarse paste, which makes the surface matte, then with a medium and, finally, a fine paste, bringing it to a mirror shine. The paste is applied to a felt swab, cloth or linen cloth and rubbed onto the surface to be polished.

You can make your own polishing pastes. For polishing steel products, the following composition is recommended (in parts by weight):

Stearine - 32

Beeswax - 6

Technical lard - 5

Lead oxide - 3

Chromium oxide - 80

For polishing and glossing brass and nickel-plated surfaces, use pastes of the following composition (in parts by weight):

Stearine - 5

Technical lard - 1

Chromium oxide - 14

The polished surface is wiped with a rag soaked in kerosene, and then dry with a clean rag.

In skillful hands, metal grinding turns into an entire art. It may seem that this type of processing is not at all difficult - just grind it. But this opinion disappears for everyone who gets acquainted with a huge number of different tools and abrasives for metal processing.

1 Abrasives and grinding – what you need to know?

The term “grinding” itself, according to some history experts, came into the Russian language from Polish. In essence, this type of processing is nothing more than cutting, only the material is cut off with abrasive wheels. The latter are porous bodies, the structure of which consists of a huge mass of small mineral formations - grains. The grains are connected to each other by a so-called ligament. When interacting with the metal surface, the abrasive wheel with the sharp edges of individual grains removes a thin layer and, due to uniform action, leaves behind a smooth and even surface.

Grinding features and patterns should be taken into account. The first feature is the high chip removal rate. With standard processing with grinding wheels, the rotation speed of the wheel reaches almost 2000 meters per minute, with high-speed processing - all 3000 meters. When turning, the speed is 30 times lower. The grains interact with the surface at a speed of 0.0001 seconds or even 0.00005!

There are many grains on the surface of the grinding wheel, which are randomly placed and have different cutting edge shapes. This is why, when interacting, the chips turn out to be so crushed. The operation of a grinding machine requires five times more electricity than when operating a milling unit and 10 times more than when processing a part on a lathe.

It is important to remember that due to the arbitrary shape of the grains, their large number and the strong crushing of the chips, a lot of thermal energy is generated at the interface between the surface and the grinding wheel. The part can heat up significantly; for example, metal grinding is accompanied by heating up to 1000 °C at the contact points. At this temperature, the properties of the metal can change significantly, for example, steel can become more brittle. Therefore, it is important to provide for the cooling of the metal and the wheel itself, as well as to correctly calculate the grinding allowance.

During interaction with the part, some of the grains and chips are crushed and fall between the remaining grains, while the other part is dulled and more and more machine power is needed for operation. When the force exceeds the strength of the abrasive material or the bond that holds the material together, the grain is partially or completely chipped.

2 Grinding modes - how not to miscalculate the speed?

The choice of mode is influenced by several factors: the surface roughness after processing, the specified accuracy, the characteristics of the grinding wheel (number of grains, bond, cutting depth) and the power of the main drive of the grinder.

When processing the periphery of a grinding wheel, the following indicators of the cutting mode are taken into account: wheel speed, depth of cut, speed of movement of the part itself, cross-feed capabilities. The speed of the circle is a parameter that depends only on the capabilities of the machine and the diameter of the circle itself, measured in meters per second. During processing, the wheel speed remains stable. As a rule, a circle of the maximum possible diameter allowed for the unit is installed on the machine, and the maximum number of spindle revolutions is also set.

Low strength and rigidity of the machine or individual parts leads to speed restrictions, since at high speeds strong vibrations occur, along with this, accuracy decreases, wear of consumables increases, and productivity decreases.

It is advantageous to perform roughing at the maximum cutting depth allowed by the grain parameters of the wheel, part and unit. In this case, it is important to maintain the cutting depth no more than five hundredths of the transverse grain size. That is, with a 100-grit wheel it should be less than 0.05 mm. If you exceed the recommended cutting depth for such a wheel, its pores will quickly fill with waste and the wheel will become unusable.

When working with non-rigid parts and materials, as well as when burns occur, the grinding depth should be reduced. If we are talking about finishing processing (the so-called “fine grinding”), small depth values are selected - in this case, the accuracy and class of processing are significantly increased. The harder and more durable the materials, the less depth is set when processing them, since as this parameter increases, the power consumed also increases.

When feeding longitudinally, to establish the optimal grinding mode, they start from fractions of the wheel width. Roughing involves contact with 0.4–0.85 wheel widths per revolution of the part. More than 0.9 is not used for longitudinal feed, since in this case a spiral strip of unpolished material remains on the surface.

3 Grinding methods – metal grinding in detail

Grinding methods largely depend on the degree of complexity of the surfaces. Simple surfaces include an internal and external cylindrical plane; complex surfaces can have a helical and involute shape. To process these shapes, the most commonly used types of grinding are flat, round internal and round external. If we delve into the details, external cylindrical grinding has subtypes:

Grinding with longitudinal feed - consists of a combination of rotation of the abrasive, rotation of the workpiece surface (part) around its axis, as well as reciprocating rectilinear movement of the workpiece (or abrasive) along the axis of the workpiece. At the end of each double stroke the workpiece is fed to the grinding depth.

Plunge grinding differs from the previous version in that the work uses a grinding wheel whose height is equal to the grinding length or even greater, so that there is no need to feed to depth. Cross feed is performed continuously until grinding is completed.
In centerless grinding, the part is fixed on a support rod between the working and feed wheels. For processing, the circles rotate, as well as the circular and longitudinal feed of the part itself. The feed wheel sets the part rotation and longitudinal feed. Shaft grinding is a well-known example of centerless machining.
Cylindrical internal grinding also has several varieties: grinding with longitudinal feed, centerless plunge grinding, centerless with longitudinal feed, and plunge grinding. Internal round machining with longitudinal feed is no different from external round machining, just like plunge grinding. Centerless internal machining is also achieved by support rollers.
Surface grinding is a type of processing carried out both by the periphery of the grinding wheel and its end. For flat machining, a combination of the following movements is required: cutting movements, workpiece feed, cross-feed of the workpiece to the grinding depth and straight-line movement of the workpiece. Surface grinding machines are equipped with tables that are capable of performing rotational or reciprocating movements; accordingly, the feed of the part becomes linear or rotary.