Iron polishing at home. What rag is better to polish metal

There are many options for how to polish a knife to a mirror finish. Some of them are aggressive, others are softer and more flavorful. Polishing can be carried out using ordinary natural stones, wet and dry paper. The work is carried out as carefully as possible with the help of special pastes of domestic and foreign production.

Manual polishing

Craftsmen from all over the world in the past did not have specialized equipment, but they did their work with high quality. But how to polish a knife without special equipment? After heat treatment, the craftsmen used natural abrasive materials (such as stone or metal fixtures).

Hand polishing helps to achieve a perfectly flat surface. In this way, you can get the correct shape of the blade. Even using a special polishing and grinding device, it is not always possible to achieve such an effect. It is believed that hand polishing is the final processing of the knife.

How to polish a knife at home correctly using the manual method? Before proceeding to manual processing, it is necessary to polish the knife on a tape, the grit of which should not be less than 320. Using sandpaper, first of all, remove scratches. They can appear on the surface of the product after machining.

Features of emery processing

How to polish a knife to a shine using sandpaper? The first step is to polish at a 90 degree angle. In this case, irregularities may appear on the surface of the knife. This can be due to a build-up of grain on the surface. Sometimes the roughness cannot be removed with slightly abrasive paper. In this case, you need to go back to the coarser material.

To carry out the work as efficiently and carefully as possible, it is necessary to provide high-quality lighting, and the whole process should be carried out under a magnifying glass. When all the shortcomings have been eliminated, you can go back to standard processing.

Various types of sandpaper can be used in the polishing process. The main thing is that the transition between graininess is negligible. First, the processing is carried out with a material with a grain size of 600, then it is increased to 800. You can stop, or you can continue polishing with a material with an indicator of 2000.

Abrasive stones

How to polish a knife blade with a stone? Abrasives of this type have different grain sizes. The most popular indicators are 320, 400 and 600. To properly align the knife, experts recommend using Indian bench stones.

Such a simple device is used to this day, although it was first used in the Stone Age to remove excess material from weapons. At that time, not only stones were used, but also sand and soil.

For polishing, only those stones were used that were harder than a knife in their structure. Some craftsmen prefer a square shape, while others like a round one. The most popular polishing stone is sandstone.

How to use stones correctly?

Coarse and fine stones are used for polishing. Coarse material has a grain size of 80, and a fine one - 15. You can examine the structure of the stone in detail under a microscope. How to polish a knife this way? Rough stone is used to remove scratches that most often appear on the knife after a file. Another type of stone is usually applied before heat treatment. To prevent the surface of the stone from clogging, it must be periodically moistened with water.

To understand how to polish a knife to a mirror finish, you need to pay attention to Arkansas stones. Their grain size can reach 1000. This material is ideal for finishing. If polishing is just beginning, it is better not to use such stones, as they work slowly. To achieve a mirror shine, you can use Japanese wet stones. In addition, on sale you can find not only natural, but also fairly high-quality artificial stones.

Fast manual polishing

You can also polish the knife by hand. Movements should be done along the blade. It is this tactic that helps to get the job done as quickly as possible. Often, a double-sided is used for these purposes.

To polish the blade of a knife is obtained through quick friction. This method has many disadvantages. The surface of the knife turns out to be imperfect, you can see rough waviness and scratches on it.

Such disadvantages can be eliminated, but for this, all scratches must be in the same direction. After rough processing, it is necessary to prepare a small piece of leather and a special polishing compound, with which the finishing is carried out.

Application of dry and wet paper

Polishing work is carried out with both dry and damp paper. The material should be slightly damp so that it does not deteriorate or get greasy during the polishing process. For certain types of work, only dry paper should be used.

How to polish a knife at home using paper? To do this, it is recommended to purchase a whole set, which usually consists of fifty sheets. This option is considered the most economical. It should be borne in mind that waterproof material is more durable than non-waterproof. For polishing metal products, paper treated with crushed silicon carbide is excellent.

To work with the material conveniently, you must proceed as follows:

the paper is folded in half lengthwise;
the material is secured with clamps to a small steel plate;
if you fold the paper in half and place it on the plate, it will not slide off during operation.

Previously, experts recommend making small templates and blanks. If the master needs to process the area near the handle, small strips are not folded, but applied across the entire width. To prevent the tape from tearing during the polishing process, the material is pasted over with masking tape on the back side.

Mirror processing

All types of knives look amazing when they have a perfect mirrored surface. But how to polish a knife blade at home so that it has such an excellent surface? Each craftsman uses his own polishing methods. Whichever method is used, the ideal knife surface speaks of a high level of craftsmanship.

Often, to achieve a perfect surface, the product is first polished by hand to a grain size of 800, and then a special grinding wheel is used. Such processing is necessary in order to remove all irregularities and prepare the knife for the final mirror polish.

Be careful when handling grinding wheels. Too high a speed can damage the product. The grinding wheel should have a soft surface in most cases. For some types of work, solid is used. It is also dangerous to work with unstressed polishing wheels. They have one unpleasant feature - they often grab blades and some other parts of the product.

Security measures

Many people think about how to safely polish a knife at home. The most important condition is not to install the polishing machine directly on the work table. The fact is that in the process of work, the polishing wheel often grabs the blade, which can rebound and harm the master.

Experienced craftsmen, who often polish and grind knives, additionally install special protections on the polishing wheels. In this case, residual material in the form of polishing compound and dust will fly to the floor and not to the technician.

Using GOI paste

This method is well known to craftsmen who are engaged in the manufacture of knives. How to polish a knife with GOI paste? To do this, you must select the appropriate type of polishing material, which depends on the type of metal. In addition, there are a few polishing rules to keep in mind.

GOI paste has been used for over a hundred years. With its help, metal, plastic, ceramic and even glass products are polished. Previously, the paste was presented in green and was made from chromium oxide. However, this substance was found to be poisonous, and at the moment the paste is made from aluminum oxide. The paste is available in red and white.

Types of pasta

Previously, there was only one type on sale. But now specialists have much more choice. The paste is produced with different abrasiveness:

No. 4 - it is used specifically for rough work that is carried out at the initial stage of polishing;
No. 3 - helps to achieve a matte finish;
# 2 and # 1 are used for finishing.

Green paste is sometimes found on the market, but it is difficult to find it. Previously, this polish was produced both in liquid form and in the form of bars. In terms of effectiveness, the two types of paste are identical. Green has one advantage - low cost.

Preparing for polishing

Before you understand how to polish a knife, you need to familiarize yourself with the preparation for this process. It must be remembered that the paste has many particles, thanks to which the polishing is carried out. Sometimes they can accumulate and damage the product. To prevent this from happening, you need to take a small amount of the substance and rub it against an old piece of metal. In this way, large pieces of grain can be broken, otherwise the surface of the knife will not be polished, but will be scratched.

First you need to take a soft cloth and slightly dampen it in gasoline. In this case, the fabric should be as soft as possible. Flannel is great for these purposes. Often times, the paste is applied directly to the polishing wheel. It cannot be applied to the product itself. The knife should be lightly greased with special oil.

How to use the paste?

So how to polish a knife using GOI? When the fabric and paste are ready, you can proceed to the main steps. You just need to rub the product with this composition. Do not apply too much pressure to the surface of the knife. Otherwise, small scratches will appear on it.

For the same reasons, it is not recommended to make very sharp movements. The work is finished when the surface of the product is perfectly smooth. During work, from time to time you need to stop and put a little industrial oil on the knife.

If the surface of the knife has many flaws, in this case, you will need to purchase several types of paste. First, processing is carried out with paste No. 4, thanks to which deep scratches are removed. After that, go to number 3, and then to paste number 2 and 1. The last type of paste helps to finish grinding and achieve a mirror surface.

At the end of the work, you need to rinse the knife in running water. Experts recommend not using water for this, but kerosene, which can be purchased at the pharmacy. Be sure to dry the knife well. Some craftsmen additionally cover the surface of the knife with tsaponlak. This substance helps prevent oxidation of the material. The last stage is the polishing of the product with genuine leather.

Knife handle processing

If everything is clear with the blade, then how to polish the knife handle? In this case, you need to act very carefully. For these purposes, use the finest grit sandpaper. You need to act carefully so as not to damage the handle. This is a rather fragile element.

Now about the material. Which one is better to choose for this operation? GOI paste will be an excellent polishing agent. But which type should you choose for processing the knife handle? In this case, you need to use the paste numbered 1 and 2. For the handle to be shiny, it needs to be polished with a small piece of leather.

If the handle is made of wood, an additional impregnation is required. This will help to preserve its original appearance for a long time. Typically, impregnation is carried out using a regular or special oil, which is sold in an artist store. Alternatively, you can simply cover the handle with a protective varnish.

Conclusion

So, we figured out how to properly polish the knife. As you can see, there are many ways to do this. The main thing is to properly prepare for the procedure and follow the recommendations of specialists. This is the only way to achieve the desired result.

The surfaces of metal products are finished not only to give them a beautiful appearance, but also to protect them from rusting, corroding by acids, alkalis, etc. , in the third - to cover with paints and varnishes, all this can be done by yourself at home.

Rice, 1. Finishing of metal surfaces: A - sanding with sandpaper; B - grinding with a file; B - grinding round products; D - 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 thorough surface treatment 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 the sandpaper around them.

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

METAL POLISHING

Mirror shine is given to metal products by polishing. Without preliminary sanding, only surfaces that have been carefully processed with personal and velvet files can be polished. The file must be chalked. The surface is first processed across the strokes present on it. When the strokes along and across are the same, the direction is changed by 90 ° and so repeated several times. The surface treated in this way, as well as the grinding one, 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 are coarse (dark, almost black), medium (dark green) and thin (light green). First, it is polished with a coarse paste, which makes the surface matte, then medium, and finally, with a fine paste, it is brought to a mirror shine. The paste is applied to a felt swab, woolen or linen cloth and rubbed on the polished surface.

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

Stearin - 32

Beeswax - 6

Technical fat - 5

Lead oxide - 3

Chromium oxide - 80

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

Stearin - 5

Technical fat - 1

Chromium oxide - 14

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

Definition of the concept of "polishing" and its types

Metal polishing with angle grinder

Polishing is a type of metal processing during which shine returns 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:

polishing machine;
sanding machine;
electric grinder;
drills with clamps.

This finishing method has several advantages. Firstly, it allows you to change the frequency of rotation of the 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.

Special grinder - 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 sanded with an ordinary file - a wooden block covered with a cloth, on which a polishing paste is applied.

Metal polishing 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 a rough relief. In this case, a long-term electrolyte-plasma finishing is prescribed, which consists of removing a significant layer of metal.

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

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

Classification of pastes for metal polishing

You can bring a metal surface to a mirror-like state with your own hands without using machines, just pay attention to special tools that are divided into the following groups:

Aquatic. The substance does not contain fats and does an excellent job with its duties;
Organic - contains paraffin and a variety of oils. They are diluted with various oils and fatty acids;
Diamond paste is a revolutionary solution that allows you to instantly achieve the brilliance of any metal surface.

Let's dwell in more detail on the last version of grinding. The diamond paste is so effective that it completely replaces the polishing machine. Diamond Substance is produced in two types: ASN and ASM brands (expensive).

Diamond paste has the following advantages:

Accuracy. Synthetic diamonds allow you to polish any metal product with maximum precision to a shine;
Wide range of grit sizes. More than 12 types of grit can be found on the market today;
Simple operation allows you to carry out cleaning procedures with your own hands without the use of a special tool;
Diamond paste requires minimal tools: a rag, water, and rubber gloves.

The main disadvantage of the considered cleaning agent is its high price. On average, diamond paste on the market for consumables costs more than 500 rubles for 35 grams of substance.

Working principle of diamond paste

Diamond paste acts on a metal product mechanically and chemically, forming dispersed films. The composition of the cleaning agent contains active substances that promote adsorption processes, which makes it easier to sand 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 should be noted that diamond paste can also be applied to polishing wheels to improve the efficiency of metal surface treatment. In this way, you can achieve a mirror effect. Wheels made of felt, felt or leather are installed on the polishing machine.

Description of the polishing process

To grind a metal surface, you will need: laps and several tubes of diamond mixture with different grain sizes. The diamond paste is evenly spread over the working surface of a rag or other material. Experts have noticed an interesting pattern that improves the quality of metal processing.

It turns out that castor oil or olive oil must be added to the polishing agent. The ideal ratio is a mixture of 40% diamond dust and 60% oil. After dilution, the mixture is immediately applied to the metal surface.

Experts recommend starting work only with coarse grains, gradually switching to abrasive products. During processing, make sure that unnecessary elements do not get into the mixture - dust, sawdust, hair or pieces of rags. The presence of third-party objects will greatly impair the polish to a shine. It is also recommended to wash your hands after changing from one grain to another.

Types of diamond dust

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

Huge assortment of diamond paste

The yellow packaging indicates that the substance is intended for grinding ceramic materials and glass products. It should be noted 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 only suitable for 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 the abrasive materials. The finer and better the polishing material, the cheaper the paste costs. The average price is 450-600 rubles.

Paste GOI

GOI chrome paste is a universal tool for polishing metal and non-metallic surfaces. Despite the fact that the tool was invented in the early 1930s, it is used to polish metals even today.

GOI polishing paste

The GOI tool can be of different grain sizes (classified by the size of abrasive materials). There are such types of granularity: small, medium, and large. Fine dust is used for polishing soft and non-ferrous metals, coarse grains - for rough finishing of ferrous metals and steel.

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

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

Video: Aluminum polishing

The rolled bundle retains its shape with force. Prepared 5 nozzles marked P400, P500, P800, P1000, P1200. Large transverse scratches are present. Shaft torque is highly dependent on speed.

Up to 12,000 rpm, the speed drops when pressed, and above 20,000 rpm, the skin quickly wears out. Grind perpendicular to scratches until they disappear. This nozzle is quickly renewed and provides the required surface pressure.

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The worn and greasy part is cut off. The direction of grinding is periodically changed to perpendicular. This way the material is removed more efficiently and chaotic scratches are better removed. We increase the number of the paper. In the process of grinding, the paper wears out, its aggressiveness decreases, and the coarse abrasive crumbles. Therefore, less pressure should be applied to the new paper so as not to get deep scratches. Coarse paste for fine sanding. 320 is all that was indicated on the package.

Before switching to a thinner paste, the polishing site should be cleaned of its remnants. Another no name paste. The dye is indicated in the composition. The type of abrasive is anyone's guess. This is not necessary, the paste is applied only to the nozzle. Haste grinding is noticeable. Better grinding.

Metal polishing is more than fine sanding. There are also chemical processes (dissolution of oxide films by substances that make up pastes) and thermal (thermal softening of the material and smearing it over the metal). Before polishing, the surface must be cleaned from scratches, gradually reducing the size of the abrasive. Before moving on to finer sandpaper, make sure that all scratches are removed. Depending on the depth of the scratches, the number of sanding paper is selected, from which sanding will begin. In the presence of medium paste GOI No. 3, sandpaper with a number greater than P1200 can not be used because their grain size is comparable, and sandpaper itself with a small grain size quickly becomes greasy.

For steel polishing, the optimal nozzle pressure is 1–2 kg / cm ^ 2 and the peripheral speed is 30–35 m / s. Peripheral speed formula. V = (3.14 * D * n) / 60 (m / s); D-nozzle diameter (m); n-speed (rpm). In the case shown, V = (3.14 * 0.01 * 15000) / 60 = 7.8 m / s. This is 4 times less than the recommended one. Those. you can increase the diameter to 4 cm without loss of quality. At the same time, it will quickly crumble from cotton wool, but leather or cotton threads will withstand.

Polishing at a higher speed and pressure than recommended reduces the surface quality but increases the amount of metal removed, so this can be used in the initial polishing phase. To obtain a better polish, the speed and pressure are reduced to values lower than the recommended ones.

In the process of polishing, the binders included in the paste melt and act as a lubricant in the process of cutting the material with an abrasive, and also remove heat from the surface. At the same time, the polishing head itself heats up and the binder begins to penetrate deep into it, leaving the abrasive grains without lubrication and heat dissipation. After that, the grains, having lost their binder, fall off and leave scratches on the metal being processed. For the same reason, the paste should not be applied to metal. The nozzle passing through the metal cannot capture all the material, and the captured abrasive grains are not held well enough, moreover, the grains themselves are not evenly distributed over it. An excess of pasta also does nothing good. It simply slides over the binder layer between the metal and the nozzle, and the abrasive grains float in the layer without coming into close contact with the surfaces.

Since the binder must melt for the normal operation of the paste, then such pastes will work only in a certain temperature range, when the binder has already melted, but is still thick enough to hold the abrasive grains on the nozzle. For most pastes, the range starts at 70 degrees Celsius. And it is for this reason that hand polishing is extremely ineffective. For normal operation, you need to melt this, add any liquid oil and mix. Conventional softeners are not suitable for softening. evaporate quickly and the product thickens.

Well, I will continue in the same spirit, I will share my ordeals for polishing steel. What is written below is just my private experience, if I am wrong - correct it, I will not be offended. I made myself a katana not so long ago, or rather - tachi with variations. The idea was to make an elongated katana and feel what medieval undersized Japanese felt. Those. approximately for them katana, that for us, Europeans, tachi, and wakizashi for them, that for us katana. I think that if someone went in for sports, they will understand how problematic the mechanical transfer of oriental martial arts, designed for short and strong Asians to Europeans, is. In general, I did something with a long blade of 85cm, with a thickness at the thickest point of 8mm and a blade width of 29mm at the border with the handle. To facilitate the design, the butt had to be made very, very sharp, but in the end something turned out with a completely classic center of gravity at 1/3 of the beginning of the blade and weighing 1.05 kg (hand-held spring scales). After all, the question arose about polishing; the main tool is a grinder with 8500 RPM. Tried almost every consumable, right down to the bronze end brushes. Of course, I used Velcro emery wheels. For me personally, it was important not to kill the edges on the katana, because the grinder cuts them off too easily. Before the grinder, I used a new small and relatively soft whetstone moistened with water so that a paste is formed from the abrasive. With the help of it, I finished the edges and refined the tip. Then I used the following grinding wheels: 80-> 120-> 180-> 400. The smaller the particle size of the circle, the faster it deteriorates. 80, 120 - it took 2 laps; It took three or four 180s. The 400s are another story. They took exactly 10 pieces. How to polish them? First, with each circle you need to walk over the 400th surface that has not yet been polished. The circle wears out very quickly, a large abrasive flies off it, but the remaining particles give a real mirror. Therefore, when the circle begins to leave a mirror surface, it must be postponed "for later" and a new one should be placed. When the entire surface is polished with the 400th, we put the old circles on the grinder and we get a real mirror, albeit with individual scratches. The last stage is GOI paste. As for the name - the paste was developed by the State Optical Institute, and not by a Spanish artist of modern times (not Goy's or Goy's paste); it is not made by Jews for non-Jews (goyim; this is not "goyim paste", although google knows such a request :). For her, I bought a felt circle, but such a circle is heavy and there is no point in putting it on the grinder - the vibration is so strong that either you will not feel good, or the grinder will fail. I put this circle on a drill, especially since it was with a speed regulator. We rub the circle with GOI paste, if it has hardened (long storage), then drip a few drops of kerosene onto the circle of paste and wait. while it is absorbed, then the paste is easily rubbed into the circle. Put a few drops of kerosene on the polished surface, for example, using a glass tube (if any) or an eye dropper (sold in pharmacies). Which kerosene to take? Roughly speaking, there are two types of kerosene on sale - one light and the other heavy. The first is a lighter-boiling fraction of oil, it smells more like gasoline and boils at a lower temperature. It won't suit us. The second is the heavier fraction, boiling at a higher temperature; it is similar to the old "aviation" kerosene - it has a characteristic smell. He is what we need, tk. it evaporates much more difficult. drip kerosene onto the surface of the polished part and start polishing. A lot of GOI paste is not needed, kerosene sometimes needs to be added, but without fanaticism. With kerosene, the procedure is absolutely not dusty, but if someone does not like kerosene, get ready for its smell. In the end, we get a completely mirrored surface, but do not forget to wipe it with a clean cloth, because it is hidden under a layer of polishing products. Specularity is similar to that of chrome-plated surfaces, but small scratches are still present. Unlike chrome or nickel plating, the color is not white, but gray. To remove black plaque after polishing, I advise Kalosha gasoline - a cheap analogue of petroleum ether (yeah, who needs it for something, use this gasoline), which evaporates quickly. Eventually can be washed with soap and warm water, wiped dry and rubbed with alcohol, which dries perfectly.
By the way, does someone not know a household item with a hardness of 60 HRC? I checked the hardness of the tip - it scratches two types of glass i.e. more than 70 HRC (someone will say that I overheated it, but IMHO - exactly what is needed for the point), but the blade, of course, is not. But I don't know about an object with a hardness of 60. I think that for all fans of the manufacture of cold steel it would be good to compile a table of household items in the hardness range of 45-75 HRC in increments of 5, so that one could immediately say that the hardness of the blade is such and such.

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CLEANING OF METALS

1. CLEANING GOLD

a) Gold rings can be cleaned of iodine stains by immersing the ring for a quarter of an hour in a solution of 1 teaspoon of hyposulfite in a glass of water.

b) Cleaning matte gold. Take 80 bleach, 70 bicarbonate salt and 20 sodium chloride. Pouring the mixture with 3 circles. distiller. water, it is stored in sealed bottles. The blackened objects are placed in a cup and poured over with a pre-shaken liquid and left alone for a while. Sometimes the mixture is warmed up. After taking out the items, wipe it, rinse it with alcohol and put it in sawdust to dry.

c) Gold objects are cleaned with a powder consisting of 16 chalk, 6 1/2 clay, 4 lead white, 1 1/2 magnesia and 1/2 bloodstone, or 80 iron oxide (kolkotar) and 30 ammonia.

2. CLEANING SILVER

a) Silver items can be cleaned by putting them in a hot water solution of tartar (cremortartar) for a few minutes and then wiping thoroughly with chamois leather.

b) Silver spoons will always be clean and shiny if, immediately after use, they are washed in boiling water, to which a small amount of soda has been added, and poured over with clean hot water, then wiped dry with a soft towel. Spoons should be washed once a week in soapy water with a little ammonia. Thanks to this, even a completely tarnished spoon gains a shine and looks just like new. Dark spots of silver spoons originating from eggs are removed by rubbing them with ash. Damp stains come off from washing in warm vinegar, then rinsing in clean water and wiping dry.

c) It is known that both silver and silver-plated items fade relatively quickly in the air and acquire a very ugly appearance. To eliminate such tarnishing, a trace is recommended. means: a liquid solution of collodium is prepared and this solution is smeared with a thin and possibly even layer of silver or silver-plated objects: alcohol evaporates quickly and a thin film of collodium, completely invisible to the eyes, remains on the metal surface, perfectly protecting silver from tarnishing under the influence of air or gases in it ... Experiments carried out in foreign museums have shown that silver coated with a thin layer of collodium retains its color, shine and polish for a long time. If necessary, this thin protective layer can be easily removed with hot water or even better with alcohol.

d) Silver items are first cleaned with water and soap, and while still warm, they are lubricated with a solution of 1 sulphurous soda (hyposulfite) in 3 water, after which they are wiped off with a rag.

3. CLEANING OF COPPER.

a) Objects made of polished copper are wiped first with a soft cloth dipped in kerosene, then cleaned with a woolen cloth with chalk or Viennese lime powder. Severely neglected copper objects are restored to their shine by wiping the object with a cloth soaked in dilute hydrochloric acid. Then they clean it, as indicated above, or dissolve 30 g of oxalic acid in 1 liter of water, add 4 tablespoons of alcohol 3 tablespoons of turpentine. After that, the liquid is shaken well and poured into bottles for storage. When used, the object to be cleaned is lightly wiped with this liquid, and then wiped with a dry linen rag: the copper is quickly cleaned out and becomes shiny. b) Mix 1 oxalic acid, 25 red iron oxide, 20 tripoli, 60 palm oil, 4 paraffins. It turns out a paste, which is perfect for cleaning things made of copper and brass.

c) Red iron oxide (Caput mortuum) in the form of a delicate red powder for cleaning objects made of copper and brass is obtained by heating ferrous sulfate until it disintegrates into a white powder. This latter is then heated in a crucible, and a delicate red powder of iron oxide is obtained.

d) Mix transparent powder of ferrous sulfate with the same solution of potassium oxalate. The resulting yellow precipitate is washed, dried and heated as above.

e) Mix 9 crude oleic acid with 1 kerosene, which can be colored with alkanine or infusion with an alkane root.

f) You can refresh the surface of small copper products by boiling them for 30 minutes in a solution of soda ash (40 g / l).

g) Products made of copper and brass retain their luster when thoroughly waxed.

h) Darkened copper peels well with raw potatoes.

4. CLEANING GOLDEN BRONZE,

a) Take 5 glasses of water and dissolve alum in it until saturation, then boil the solution over a fire while it is hot, rub the darkened place with a cloth until the stain disappears. b) Boil yellow peas, grind it until a thick dough is obtained and, while still warm, stick it around a bronze thing. A few hours later, when the pea dough is compressed, the bronze is washed clean with boiling water and wiped dry with a clean cloth. All rust and all stains come off.

b) Bronze parts can be cleaned with raw potatoes or a stiff hair brush dipped in hot vinegar. After that, the part must be wiped with a soft cloth,

5. CLEANING NICKEL.

Nickel items to be cleaned are moistened first 2-3 times with a mixture of 50 alcohol (or vodka) and 1 sulfuric acid, then they are rinsed with water and, rinsed with alcohol (or vodka), wiped with a thin linen cloth.

Nickel-plated surfaces of various objects can be cleaned with cigarette ash by sprinkling it on a damp cloth.

Rust on nickel is removed as follows: smear the object with some kind of grease and leave it there for several days, then wipe thoroughly with ammonia. If the rust has penetrated deeply, you can take diluted hydrochloric acid instead of ammonia, which, however, is left on the metal for no more than a minute. Then the item is washed with water and polished with chalk and crocus.

If the nickel layer is covered with a bluish bloom, then it is washed with a mixture of alcohol and sulfuric acid in equal parts by volume. Rinsing lasts only a few seconds, then the item is washed with water and alcohol and wiped dry.

6. CLEANING OF ZINC.

Zinc items are cleaned perfectly with a solution of 1 hydrochloric acid in 2 water. This solution is rubbed with a brush on the object to be cleaned until the dirt falls away. Then, when the object is still not dry, lightly grease it with wood oil and rub it with finely crushed chalk with a cloth until it shines.

7. CLEANING OF STEEL.

A simple and good composition for this purpose is a mixture of paraffin and oil. Add 1 paraffin to a bottle of 20 oil, shake thoroughly until the paraffin is completely dissolved and, after wiping off the object to be cleaned, cover it with a brush with the indicated mixture; then leave for 10-12 hours. in place, protecting it from dust, after which the item is wiped with a dry woolen cloth. If a steel tool or any other object requires careful cleaning, due to its significant rust, etc., then use the following composition: prepare a mixture of 5 turpentine and 25 stearic oil. This mixture is diluted with alcohol until a thick liquid is obtained, with which the object is coated, and when the alcohol evaporates, the metal surface is wiped with a mixture of 45 animal charcoal and 25 kolkotar (mummy) in powder.

8. CLEANING OF METAL PARTS OF MACHINES.

Moniteur Industriel points out the next best practice in France. 10% of paraffin is added to one liter of kerosene and, having properly corked the vessel, set it aside for a day, shaking it from time to time, after which the mixture is ready for use. Then, with the help of a cloth, all metal parts of the machines to be cleaned are moistened with it. After wetting, they leave in this form overnight (or even better for a day) and only the next day they wipe dry with a clean cloth.

With this method of cleaning, rust, oily resinous dirt, etc. disappear, and the metal parts of the cars seem to be polished again. There is no other way to clean them so well, not to mention the extreme cheapness of this method, which makes it quite suitable for cleaning all kinds of machines, tools and, in general, products made of steel and polished iron.

METAL POLISHING

METAL POLISHING ASSOCIATED WITH CHEMICAL CLEANING

1. IRON POLISHING.

The iron products to be polished are immersed for some time in a mixture of 1 sulfuric acid to 20 by volume of water, then the object is removed, thoroughly rinsed with water and dried in sawdust. After drying, it is immediately immersed in nitric acid for one or two seconds, after which it is rinsed again with water, again dried in sawdust and then thoroughly wiped off. In this case, the surface of the object becomes shiny, like glass. According to "Cosmos" a "there is no other way to achieve such a perfect polish as above.

2. POLISHING STEEL.

Steel products are polished by means of a leather mug covered with a mixture of 16 tin and 1 zinc. Crocus or bloodstone moistened with alcohol is applied to the flat side of the mug and, after moderate drying, is polished with agate.

3. POLISHING BRASS.

Equal parts of water and bovine bile, boiled together, give a good polish. The liquid, after cooling, is bottled and stored in them. When used, it is applied to brass and bronze objects with a brush or polished objects are immersed in it.

4. POLISHING NICKEL.

The mixture consists of 8 stearin, 32 lard, 2 stearic oil and 48 finely ground Viennese lime. Objects are polished with this paste using a circle covered with cloth (according to Hildebrand).

5. POLISHING ALUMINUM.

a) Aluminum is immersed first in a strong solution of caustic potassium or sodium, and then in a mixture of 2 nitric acid and 1 sulfuric acid. After that, it is placed in pure nitric acid and, finally, in vinegar diluted with water. After rinsing thoroughly in running water, dry in hot sawdust and polish with a polish. Aluminum treated in this way acquires its natural pure white color.

b) 1 each stearic acid and clay, 6 tripoli. When it comes to polishing smooth surfaces, then the paste is applied to a leather circle. After this treatment, the item is polished with a crocus using a leather mug, which makes the shine even more beautiful.

c) If polished by hand, then the most suitable is a mixture of petroleum jelly and ceresin or a solution of borax in hot water, to which a few drops of ammonia are added.

6. POLISHES FOR METALS.

a) 90 g of finely sifted tripoli and 90 gvinnokamic acid are ground with 450 g of liquid paraffin. After vigorous shaking, rub in with a woolen cloth and polish with suede.

b) 60 Parisian paint (pure iron oxide), 10 wax, 30 oleic acid and 2 rosin. From the addition of gasoline, iron oxide is mechanically distributed in the liquid, and large grains of varnish sink to the bottom, and when drained, an elutriated mass is obtained, which does not form scratches on the metal at all.

c) Equal parts of ferrous sulfate and sodium chloride are ground thoroughly in a mortar and the mixture is heated in a flat crucible or other vessel until red hot. Various chemical glassware at affordable prices can be ordered on the moslabo.ru website. In this case, vapors are formed, and the mass turns into a liquid. When the vapors no longer rise, the vessel is removed from the fire and allowed to cool. The resulting brown mass is washed with water to remove all undecomposed ferrous sulfate particles. The remainder is an excellent polishing powder.

7. POLISHING AGENTS FOR ALUMINUM.

According to Morny, shaking in a bottle mixes equal parts of olive oil and vodka until the liquid resembles an emulsion. The polishing stone is dipped in the emulsion and the aluminum is polished like silver, without applying too much pressure. The black streaks that sometimes form from the polishing stone are not harmful, but they can be removed from time to time with a soft cloth.

8. POINTING THE MAT ON ALUMINUM.

First, aluminum objects are launched for 20 seconds. in a hot 10% solution of caustic soda, which is previously saturated with table salt in a cold state. Then the objects are rinsed with water and wiped with a brush, after which they are immersed again for 30 seconds in the above solution. After a second rinse and rinsing in hot water, the items are dried in sawdust.

9. POWDER FOR POINTING THE MAT ON JEWELRY.

Consists of 40 g of saltpeter, 25 g of table salt and 35 g of alum. Mix into a homogeneous mass and heat in an enamel vessel, with constant stirring with a glass stick, until water vapor leaves. Then cool the mass by placing the vessel in cold water, turn into powder and store in well-sealed glass vessels until use.

If the objects are to be only partially made dull, the parts that are supposed to remain shiny are covered before matting with a layer of the following mixture: 50 g of powdered carbon dioxide, 5 g of sugar and 5 g of gum arabic are ground with water into a gruel, which is applied with a brush to remaining shiny places.

10. FINAL FINISH OF LOCKSTER'S PRODUCTS.

To give the locksmiths a beautiful look, they resort to various means, depending on the nature of the work. Small artistic forgings acquire a beautiful appearance if, at the end, they are supplied with an intense black color. But for such works, the paint is not applied by smearing, but the following operations are performed: they light a fire in the furnace that corresponds to the size of the object being processed. The fire should not smoke (it is best to use coke for this). Then they grease the object with ordinary linseed oil and expose it to fire, but only for such a time until the oil evaporates and the rest of it burns to the iron. After cooling, rub the object firmly with a cloth slightly soaked in linseed oil.

The smoother the surface of the iron during processing, the more beautiful the deep black color will look. This color is extremely durable and perfectly protects against atmospheric influences.

To etch iron parts black, they must be clean, brilliantly straightened and polished. Then they are smeared with liquid oil and sprinkled with wood ash, then they are held over hot coals until they turn out a shabby black color. After cooling, the items are rinsed in water, to which a few drops of sulfuric acid have been added, and immediately thoroughly wiped off with a coarse, clean cloth.

Rubbing with oil protects the product from exposure to air.

Fly marks on scales, panels and other parts are very difficult to remove with gasoline, alcohol and other solvents. At the same time, these spots disappear without a trace if you wipe the dirty areas with a cloth or cotton wool soaked in saliva.

To make the iron especially soft, it is heated red-hot, quickly cooled in soap, heated again until red-hot and, after placing the viscous powder, allowed to cool slowly. When processed in this way, the iron becomes very stringy and soft.

CLEANING GOLD.

Cleaning gilding, especially on wood, requires very careful handling. All dust should be wiped off the gilding first, then the gilding is carefully wiped off with a soft sponge, even better with a piece of cotton wool slightly moistened with wine alcohol or turpentine.

Instead of these liquids, good strong beer, a solution of the so-called Marseilles soap, or a mixture of 10 parts of ammonia and 40 parts of soap alcohol are also used.

Egg whites are also considered a good cleaning agent for gilding, with which you gently wipe the item with a piece of flannel.

You can use a mixture of proteins (2-3 eggs) with 18 g of jelly water; With this liquid mixture, using a soft brush, wipe off slightly gilding, especially the most tarnished places.

Finally, the same purpose can be served with pure wine vinegar, which is used to cover the gilding with a soft brush, sponge, or a piece of pata. After 5 minutes, the vinegar is carefully washed off with clean water, without wiping anything.

For cleaning gilded bronze, in addition to ammonia diluted with water, the following method also gives good results: the gilding is wiped off, first of all, with a brush moistened with water. Then cover with a soft brush with a mixture of 60 parts of water, 15 parts of nitric acid and 2 parts of alum, after which the liquid is allowed to dry without wiping it off.

CLEANING OF METAL PARTS OF MACHINES.

Here is the best method, now practiced in France, for cleaning metal parts of various kinds of machines: Add 10% paraffin to one liter of kerosene and, after sealing the vessel well, leave it for a day, shaking it from time to time, after which the mixture is ready for use. Then, with the help of a cloth, all metal parts of the machines to be cleaned are moistened with it. After wetting, they leave in this form overnight (or even better for a day) and only the next day they wipe dry with a clean cloth.

This cleaning method removes rust, oily resinous dirt, etc. and the metal parts of the cars seem to be refinished. There is no other way to clean them so well, not to mention the extreme cheapness of the method itself, which makes it quite suitable for the indicated purpose in relation to all kinds of machines, tools and, in general, products made of steel and polished iron.

Metal polishing: features of the preparatory and main processes. Metal polishing classes in accordance with GOST. Various methods, tools and machines for polishing and grinding metal to a mirror finish.

Metal polishing is the final stage in the manufacture of metal and alloy products, which consists in removing the thinnest layer of material from the surface of the part. There are many ways in which you can polish a product to a high shine both at home and in industrial production. They are described in detail in this article.

GOST 9.301-86 regulates the quality requirements for processing metal products as a result of polishing. There are no special indications regarding the gloss of surfaces after grinding, however, after polishing, various defects, grooves, scratches, burrs, corrosion, etc. should be excluded.

In a word, polishing measures are designed to give the product an attractive appearance and consumer qualities.

In production, there is such a thing as "polishing class". The level of surface roughness of a particular part is determined by means of special equipment (microscopes and profilographs) up to 1 micrometer (μm, 1 mm = 1000 μm). If metal grinding is carried out at home, then the depth of irregularities is determined by eye.

There are 14 roughness classes, which are indicated in special drawings in accordance with GOST 2789-59.

The polish classes and requirements for them are presented in the table below.

Description of the surface	Roughness size (up to microns)	Polishing class	Mechanical processing method
Processing marks are very noticeable	320	1	Planing, sharpening and milling
	160	2
	80	3
Processing traces are very faint	40	4	Soft abrasive blasting, semi-finishing
	20	5
	10	6
Processing traces are not visible at all	6,3	7	Fine flow, grinding
	3,2	8
	1,3	9
The surface of the metal product is perfectly smooth and has a characteristic mirror-like shine.	0,8	10	Finish polishing, soft polishing
	0,4	11
	0,2	12
	0,1	13
	0,05	14

Preparatory stages

Industrial enterprises that deal with various types of metal processing check the condition of surfaces before grinding. Before using various chemical reagents and polishing machines, the part must be prepared for further polishing stages; for this, the product is affected by one of the mechanical methods:

processing the part with compressed air in conjunction with special coarse abrasive elements that remove large build-ups of corrosion and rust from the surface;
cleaning the surface of the product with brushes with stiff bristles to remove signs of oxidation and sludge (dust formed as a result of cleaning with a coarse abrasive);
degreasing surfaces from traces of previous polishing agents by processing with warm organic solvents;
the use of alkaline solutions to remove residues of minerals with oil content;
electrochemical degreasing (immersion of a metal product in an electrolyte).

All of these methods are most often used in industrial production. At home, to prepare a metal product for polishing, it is enough to treat the surface with sandpaper of various hardness.

Methods for polishing metal

To polish metal to a mirror shine at home, a special paste is most often used, for example GOI or diamond, popular among home craftsmen, as well as a polishing machine with an abrasive wheel.

The following types of polishing are used in metal processing enterprises:

mechanical;
chemical;
electrochemical;
using plasma;
laser;
ultrasonic.

Mechanical method

One of the most effective ways to self-polish metal is to polish the surface of the product with a polishing machine.

The grinding machine is an indispensable tool for high-quality polishing of metal until the initial shine appears. The polishing machine has a so-called abrasive wheel, the coating of which will depend on the nature of the work and the material.

The very process of metal processing using a grinder will proceed as follows:

The wheels for polishing and the area of metal to be processed are wetted with water. To process metal, the disc must rotate at 1400 rpm. It must be foreseen that at such a speed of rotation the spray will spread 1–1.5 meters, therefore it is necessary to take care of the appropriate protection of the face and clothing.
The surface to be machined will begin to heat up as a result of friction, and the water will evaporate. As a result of this interaction, irregularities and roughness will be removed, forming blockages of metal particles and water on the basis of the abrasive wheel. Switch off the machine every few minutes and rinse the disc under running water. Particles of metal should be removed not only from the tool, but also from the surface of the product.
To achieve a mirror finish, it is recommended to use a felt material. Such a nozzle is put on the grinding disc so that the edges protrude 1–1.5 cm beyond the border of the wheel. The felt and the surface of the metal part must be moistened with water, after which the metal is finished polishing.

If a special machine is not available, you can use a polishing agent such as sandpaper. First, you need to sand the surface with a coarse abrasive, and then a softer one. After the transition from one grain to another, you can proceed to the finishing stage of processing.

At the final stage, a polish is used. For metal products, as well as for stone surfaces, diamond paste is excellent, which can return surfaces to a perfect smoothness and mirror shine. The surface of the metal product is carefully processed with the cloth on which the polishing paste is applied.

Chemical polishing is the most effective solution for metal and alloy products that have a decorative function.

The essence of the chemical method for cleaning metal is that all the work to restore the surface of the product is performed by special solutions of chemicals and acids. The solution must be heated to a certain temperature, which depends on the constituents of the metal alloy, after which the metal product is immersed in the solution for several minutes. A reaction occurs between the metal and the chemical solution, as a result of which the defective layer of the product is destroyed.

In order to immerse the part in the solution, special holders are used. There is no need to use manual labor, and the metal is processed evenly over the entire surface.

However, this method has a drawback: after the procedure, the surface of the product is matte rather than shiny. In addition, this method requires compliance with a number of safety rules.

Electrochemical metal polishing

At first glance, electrochemical metal polishing is the same as chemical polishing. The part must be lowered to the bottom of the tank with the solution, but at the same time it is necessary to ensure the passage of electric current through the product. The current accelerates the destruction of the oxide layer even in subtle depressions on the metal surface.

As a result, the product acquires perfect smoothness. This method is perfect for those who are looking for an answer to the question of how to polish metal to a mirror finish.

The disadvantages of this method are high energy costs and the need for regular replacement of the chemical solution.

Plasma polishing

Plasma polishing of metal is similar to electrochemical cleaning: the product is also immersed in a chemical solution, followed by an electric discharge through it. However, the plasma electrolyte method does not involve the use of a mixture of chemical reagents and acids, but a harmless solution obtained from ammonium salts.

The result of electroplasma polishing will be not only a mirror-like shine and perfect smoothness, but also additional protection against corrosion.

Laser polishing of metal

The metal polishing process using a laser system eliminates the need for various polishes, solvents and abrasive particles.

The laser device acts on the surface of metal products by sending pulses of light. Energy, in contact with a metal, is converted into plasma, its particles disintegrate, which leads to the appearance of a shock wave. The light pulse is not long enough to damage the product, but it breaks down the damaged metal particles. In view of this feature of the laser beam, if the product requires deep cleaning, the same area of the metal surface will have to be affected several times.

The laser machine, made of steel, has the feature of self-limiting. The device itself reduces the intensity of exposure and the power of the beam, as soon as the laser reaches the metal layer that does not need polishing.

Ultrasonic metal polishing

Metal polishing by ultrasound is one of the types of processing of various surfaces by crushing, that is, the destruction of the defective surface layer is carried out after applying a load to the material. Vibrations of the ultrasonic wave form chips and cracks, as a result of which the top layer of metal leaves by itself, like an eggshell.

This method helps if the material is not a conductor of electric current and cannot act as an anode during electrochemical cleaning. It is also great for grinding thin and delicate items, including precious stones and metals.

Ultrasonic metal processing technology is as follows:

A composition of abrasive elements is placed in a special working sector of the device.
The device is located in the immediate vicinity of the treated surface.
The vibrating device causes the abrasive elements to vibrate, affecting the top layer of the article.
The defective layer cracks and collapses under the influence of vibrations.

Silicon or boron particles on a carbide basis can act as abrasive elements, and fresh water supply can act as a vibrating factor.

If you have experience in polishing metal using industrial and improvised methods, share it in the comments.