Stone processing. Methods of processing and refining precious stones

Stone impregnation can help solve many problems with the appearance of stone buildings. Indeed, despite its high strength, durability and reliability, stone can also be susceptible to rust or salt.

The main reason to protect the material is the corrosion of natural stone under the influence of high humidity. Let's look at options for removing stains and protecting the natural appearance of the material.

The stone impregnation agent is used not only to treat facades, but also to remove rust, salt and protect against graffiti. The composition of a particular substance, as well as the principle of its action, depend on the scope of use. All of them create an invisible film on the stone, regardless of whether it is natural or artificial. This film protects stone structures from abrasions and significantly extends their service life.

Principle of operation

The substance promotes the evaporation of moisture from the surface of a stone object and prevents it from getting inside. The water repellent fills the pores of the stone. The molecules of the substance create a special network that prevents the penetration of water.

Do not forget that water-repellent impregnations will not protect against oil stains. Oil particles pass freely through the molecular network and remain in the pores. You can avoid this problem if you use oil-based products.

When to use

Protective equipment can be useful in several cases.

1. Stone is used both inside and outside the building. In both cases, it may be exposed to harmful substances. These can be various solutions with a caustic composition, household chemicals, and even water. They can cause hard-to-remove stains on the surface of, for example, marble.
2. Stone used for exterior decoration, more than others, needs protection. It can be affected, for example, by direct sunlight. Because of this, the same marble can become discolored and faded.
3. Mold, moss, and fungi form on the stone. As these organisms grow, they can destroy the structure of the material and even the entire stone structure.
4. The salt inside the stone, under certain conditions, can come out, crystallize and destroy the material.

Efflorescence on granite

What you need to know about types of drugs

Impregnation allows you to preserve the attractive appearance of stone and decorative stone tiles for a long time. It will not lose its color and will not fade under the influence of direct sun rays. The film on the surface will protect the stone from the appearance of potholes, cracks and chips, making it more durable and dense.

There are compounds that can penetrate deeply into the stone. They close the pores and polymerize it. Such impregnations are called hydrophobic mixtures or water repellents - they play a protective role and protect the stone from moisture. In addition, they make it resistant to petroleum products, reagents and other similar substances.

Types depending on composition

1. Latex impregnations help prepare stone structures for further painting.
2. Impregnations based on chemicals remove rust from stones of natural and artificial origin.
3. Silicone solutions protect stone products from impacts environment, make them resistant to temperature changes.
4. Impregnation without any additional effects. This chemical composition, sometimes silicone-based, which has the ability to penetrate the pores of the stone. Such products do not leave films, stains or smudges. Stone impregnation forms a protective layer inside. After drying, the treated surface will be no different from the uncoated surface. Take granite, for example. When a water repellent is applied to its surface, moisture, oils and other substances will not be able to penetrate inside. They will remain on the surface and can be easily removed.
5. Impregnation with a wet effect. This is a product that takes care of appearance stone, highlights its color and structure. If you cover a surface with this type of impregnation, it will receive a wet shine and rich color, without leaving a film. Impregnation of wet stone is responsible for the decorative component.
6. Protection against graffiti. , can have a destructive effect on the stone. In addition, the process of removing it is fraught with some difficulties. If you cover the surface with this type of impregnation, it will not absorb paint, which, if something happens, can be easily removed with the simplest cleaning agents.

Types depending on the effect

It is noteworthy that absolutely all stones, both natural and artificial, can be treated with hydrophobic impregnations. These are granite (porcelain stoneware), marble, cement stone, sandstone, gypsum. Decorative items made from these materials will only benefit from the use of a water-repellent agent.

Advantages

We can highlight the main advantages of stone impregnations:

1. They make stone surfaces as hydrophobic as possible. Granite, marble, sandstone, gypsum will not change their properties over time. They will become more resistant to weather changes and mechanical stress.
2. Corrosion of cement stone and other similar materials is a serious problem. If they are coated with a special agent, the level of corrosion resistance will increase.
3. Cracks do not form inside stone products.
4. The foundation and plinth become waterproof.
5. Stone surfaces do not change their appearance over a long period of time.
6. Easy to apply without requiring additional preparation.
7. Harmless.

Operating rules

The application of hydrophobic agents follows some basic rules.

1. Processing marble, granite, gypsum and gypsum products begins with cleaning their surface. They need to remove stains from oils, tar, bitumen, salt, and mold. Removal can be done using special cleaning products.
2. Depending on the type of impregnation used, the working surface should be dry or wet. For example, silicone-based solutions require moisture for the reaction to begin.
3. Corrosion of cement stone, as well as other types of stones, leads to the formation of cracks. They need to be sealed before covering the surface with a water repellent. For small cracks, it is enough to mix cement and sand. For larger ones, epoxy resin is suitable.
4. Concrete products (this also applies to repaired cracks) must be cured for 4 weeks before coating.
5. It is important to determine whether the materials and impregnation are compatible. For example, products for limestone, gypsum, granite or marble may differ in composition and principle of action. If there are any doubts regarding the use of a particular composition, a test application should be carried out.
6. Under no circumstances should the impregnation be diluted or modified in any way. It must be applied from the container in which it is supplied by the manufacturer.
7. Water repellents are applied with a roller or brush, or they can be sprayed.
8. Apply impregnation in a thin layer. If there is any excess left, remove it immediately.
9. It is important that the room in which work is carried out is well ventilated.

How to Remove Rust Stains

Sometimes rust may appear on the stone surface. How to deal with it? Using special cleaners. They come in two types:

• liquid,
• pasty.

Both rust removers are made on the basis of inorganic acids and anti-corrosion additives. Such cleaners are not suitable for stones that are damaged by acids, such as plaster and gypsum structures.

Marble materials

Marble processing is a separate issue. This natural stone has a heterogeneous structure, veins, inclusions, and cracks. Unlike granite, it is soft and easy to work with. These properties affect the durability of marble products.

To correct the situation, impregnation for marble is suitable. It is easily absorbed without leaving stains or streaks and without changing the appearance of the products. Such substances make marble more durable, moisture-resistant, and resistant to destructive factors.

Help chemicals

Both natural and fake diamond. It often develops salt stains or rust stains. Removing them is difficult, but there is a way out. Granite, porcelain stoneware, gypsum and gypsum products can be coated with a special hydrophobic impregnation, sometimes with a silicone base. It will protect surfaces from moisture, rapid destruction and staining.

If stains have already appeared, you can use rust removers. All these substances have a protective and decorative function. For example, treating marble with impregnation makes marble products strong, reliable and durable, and also protects against rust and other stains.

The use of stone in the design of apartments and houses has long become a classic of the genre. However, processing this material, unlike wood, is impossible without the use of special tools and equipment.

Manipulations require patience, physical effort and knowledge of the basics of processing technology. The surface of the natural type of stone is quite hard. If you use modern equipment for processing and know technological secrets, you can cope with the task quite simply.

Processing depth

When processing stone, you can give the surface a certain texture, which can be achieved by grinding and multi-transition processing. Today there are four known design options for the treated surface, among them the following should be highlighted:

• chopped;
• impaled;
• rough grinding;
• polished or matte;
• polished.

The first looks like a natural chip that is formed when splitting an array. Stone slabs with such a plane they are more often used for finishing basement parts and creating fences.

Stone processing may involve the creation of a rough grinding surface that has a smooth geometric shape combined with a rough base. When using rough grinding, the material is used for the production of building blocks, paving stones, the construction of fences and fences, as well as the formation of porch steps and borders.

Stone processing may involve the creation of a matte or polished surface, which can be achieved by polishing without removing the mirror. The stone turns out smooth, but not shiny. It is used for finishing and facing work.

For monuments, sculptures and when decorating façade elements, a polished surface is used. If you resort to manual processing, the implementation of the idea may take several weeks or months of monotonous hard work. It would be more advisable to use power tools and available materials.

You can make a rough tabletop or simple paving stones yourself if you are familiar with the characteristics of the rock and its structure. The easiest to process are:

• calcite;
• silicates;
• sandstones.

Their low hardness makes it possible to simply give the material the required geometric shape. But such rocks are rarely subjected to further processing; they are usually polished in a semi-rough manner. The cladding for a fence or the base of a building is easier to make from calcined sandstone, which is quite common and is also called shepherd stone.

The material received its name for its ability to split into even, identical tiles, the size of which is several tens of centimeters. The tiles can be sanded with river sand to smooth out unevenness. This allows you to use the resulting products for laying the courtyard of a house or improving the basement.

Processing methods and techniques

Stone processing remains unchanged for many years. The standard set of technological techniques involves cutting and disassembling the massif, layers, boulders and large blocks into light and small parts that can be transported and then processed. This stage is complex, and competent processing allows you to reduce cutting costs and eliminate splitting along non-designed trajectories.

Processing natural stone at the next stage involves leveling the surface and trimming the plane. The process uses stone-cutting hand tools or special machines. Wet or rough grinding is carried out with homemade sanding boards or heavy cast iron plates, the former of which are made of bog oak or soft stones.

Once this operation is completed, a finished product with a closed or unpolished surface is obtained. Stone processing at home may include polishing with further grinding as an artistic treatment. At this stage, you can get a mirror and see the pattern, as well as the design on the surface.

For DIY processing, you can use power tools, but sawing and grinding work is carried out under a hood, since the resulting dust can affect the respiratory system. To confirm this, it should also be said that crumbs will accumulate on brushes, transmission mechanisms and open gearboxes. The same principle is used to process artificial stone.

Sawing and piercing

The most common methods of dividing an array into smaller layers is pricking. For further processing, defect-free and flat layers are used, the thickness of which reaches 10 cm. In order to obtain such a piece, holes are drilled in the array, located sequentially. Their depth should be equal to the thickness of the piece being broken off. Then you need to use a hammer and a hardened chisel to break through the cut line.

After some time, the material will crack. Additionally, you can use a diamond tool. The broken layers are cut using cast iron discs coated with diamond. Using a grinder with a cutting diamond blade, the material should be cut along the splitting line to a depth of 20 mm.

The slab is laid on two oak beam supports so that the groove is above the far support. A pine strip is laid on the cut, and then the division line should be hit with a hammer. When choosing a tool for stone processing, you may prefer a construction hammer with a pobedit tip. It allows the stone to be split into separate blocks, from which paving stones or cladding are made.

Grinding Methods

After the array has been divided into blocks and slabs, it is possible to carry out artistic treatment stone It involves rough grinding. In order to make the surface flat and remove bumps and protrusions, the stone is ground with a cast-iron plate, onto which a thin layer of abrasive material is applied.

Methodology

First you need to apply a layer of coarse sand moistened with water. A cast iron slab is laid on top, which will allow the sand layer to grind on the base. In order to make the labor-intensive process of grinding and roughening more productive, you can use homemade machine for processing stone, which is a heavy steel table. A rotating cast iron circle with a diameter of about 70 cm is installed on it. The surface must be periodically moistened with water and abrasive, then the slab or paving stones being processed are laid face down.

Choice of abrasive and abrasive

For quartzites, limestones, marble-like materials and sandstones, basalt or fine granite dust can act as an abrasive during roughing. When you have to work with heavy and hard rocks, you should grind them with a special tool. In industrial processing, crushed cast iron shot is used to grind granite. This processing depth will be sufficient for paving stones, step slabs and paving slabs. For façade finishing elements, finishing grinding must be performed.

Final stage

Finish grinding is carried out using grinding powders with different sizes grains More often these are calibrated powders of sintered silicon carbide or aluminum oxide. Processing is carried out with electric grinders, which are equipped with plastic or thick rubber attachments. It is applied to the surface. The nozzles rotate at high speed, which requires uniform and dosed pressing of the angle grinder to the surface. Otherwise, the plane may be pressed through, and local overheating will occur.

Finally

Finish grinding is accompanied by the formation of a large amount of dust, so the surface must be regularly moistened with water. Open areas Face and hands should be covered with gloves and a mask. In order to give the leveled surface a shine, you should use felt cloth circles with polishing pastes.

How to manually prepare a stone for polishing.
Jet grinding.
I will show you a way to process stone that is accessible at home, using jet as an example. This method is very ancient and primitive, so even a teenager can do it. In the old days, people even cut minerals in a similar way.
First of all, we need the stone itself - jet. I specifically show in the photo two cut pieces, they were once one whole. The one on the right has already been sanded.

I left two planes of natural origin untouched, I like it better this way.
The most important component in stone processing is abrasives. I have been using sanding tape for a long time, the markings are in the photo below. This sandpaper can be used to process glass and hard minerals - chalcedony, jasper, quartz...

For the work I used a small piece of sandpaper measuring 10*9.5 cm.

You will also need a small, hard, flat surface. A hand plane blade or a metal plate of suitable size will do. It is important that it does not bend, size 3.3*50*160 mm.

It remains to talk about the container with water, I use a photo bath, size 4.5*17*22 cm.
Water is necessary when working with jet to prevent dust from spreading around the work area. Coal dust is harmful to health and is very difficult to remove from surfaces. Water also helps remove sludge from abrasive and stone surfaces. During intensive grinding, it cools materials.

Let's get to work. Pour water into the container, no more than half, so as not to splash. Place the plate in the container at an angle and secure the sandpaper. With your free hand, begin to grind the surfaces of the stone, dipping the mineral a little into the water to wet the surfaces of the workpiece and the abrasive.

Continuing the stone processing topic, which we touched on in the previous article “Extraction methods.” Dimensions and fractions,” I would like to talk separately about the methods and methods of texture processing of the surface of natural stone. It is worth mentioning right away that not all stones can be processed in all ways. Since all rocks differ in structure and texture, there are suitable and inappropriate processing methods for each of them. There are more than a dozen types of processing in total, and we would like to characterize the most popular of them in a brief, abstract form. So:

Sawing- achieved by sawing the workpiece. The cut surface remains unevenly rough, with so-called grooves up to 2 mm high. Sawing with steel shot gives additional relief, while special reinforced plates made of hard alloys, on the contrary, smooth it out. It is both the primary processing, followed by the final one, and the final one. Sawn slabs find their application in landscape design(for designing walking garden paths and adjacent areas, artificial reservoirs), in finishing works for cladding plinths, interior cladding of premises, and is also used as a decorative element (fireplaces, entrance lobbies, walls).

Grinding - the process of leveling a solid material using abrasives to a uniformly rough surface (traces of processing are visible). It is performed in several stages (from 3 to 7). At each stage, different grinding attachments are used with a gradual reduction in abrasive grains. The maximum permissible unevenness is up to 0.5 mm. The quality of grinding is influenced by such characteristics as workability (see article Qualitative characteristics of natural stone). Polished slabs are used where it is necessary to increase friction, thereby reducing slipping, and these are flights of stairs, floors, pedestrian areas

Polishing(fine grinding) - maximum smoothing of the plane with a grinding tool sprayed with micro-grinding powders. In other words - improved, smooth sanding or polishing without shine. Tool marks are not visible, the surface is matte with a slight velvety shimmer, the natural pattern is clearly visible. Polishing is widely used for the manufacture of floor slabs and slabs for external/facade cladding of buildings.

Polishing- maximum smoothing of the surface to a mirror shine and clear reflection of the details of objects (without traces of previous processing). There is chemical polishing and mechanical polishing. For chemical polishing, special compounds are used - GOI paste (chromium oxide) or tin nitrate, and for mechanical polishing - felt or felt circles. Each stone has its own maximum gloss level, beyond which the polishing quality does not improve. The standard is considered to be the maximum gloss of glass, which is 200 units. Polishability can be:

• Excellent- 170-200 units. - full-crystalline marbles, fine-grained granites, quartzites.
• good- 140-170 units. - granites, marbled limestones.
• Average- 70-140 units. - basalts, limestones, dolomites.
• Bad- less than 70 units. - tuffs, loose limestones. (see article Qualitative characteristics of natural stone)

Polishing reveals the natural texture of the stone - color and pattern. The most common type of treatment, suitable for both interior and exterior decoration.

Heat treatment/ Burning / Melting - Stone surface treatment (mostly granite) with a high temperature flame (2300 -2700ºС) until a rough surface with traces of peeling is achieved. When exposed to fire, some of the minerals melt and burn out, resulting in the formation of small depressions and mounds. The graininess of the resulting texture depends on the size of the granite crystals and the duration of exposure of the flame to the surface.
Heat-treated stone is more often used in road construction, arrangement of local areas in landscape design, as well as for the design of entrance groups and flights of stairs, that is, where it is necessary to reduce slip.

Skol(“Rock” texture) - chipping of the top layer of the surface with special wedges to imitate roughly processed stone or even unprocessed natural chipping with chaotic depressions and bulges. More often, chipped texture is found in the external cladding of buildings (effectively emphasizes the monumentality large buildings), as well as when solving various problems of landscape design, it fits harmoniously into the natural landscape.

Bush hammering- a processing method to impart a uniformly rough surface with a maximum permissible relief unevenness of up to 5 mm. Processing is carried out on impact machines and using special attachments - bush hammers (historically, a bush hammer was a hammer with a working surface in the form of teeth, designed for impact chipping of the surface of natural stone; today, a bush hammer is a special attachment for a stone-processing machine, repeating the essence of a historical hammer). This processing method is used when it is necessary to remove the top worn layer of stone for renewal, as well as in finishing work in the form of flooring, where it is necessary to reduce slipping.

Brushing- the essence of the treatment is the same as with bush hammering - giving a uniformly rough surface and an aging effect, but is achieved with the help of special brushes, not bush hammers.

Galtovka- the process of stone processing in special tumbling drums or tumbling vibrating machines. The stones, together with the filler (arbaziv), are placed in machines, where, when exposed to sharp corners and edges, they are chipped and smoothed. The result is a smooth surface with smoothed edges - the effect of a stone that has been in moving water for a long time. The result of natural tumbling is pebbles.

Sandblasting and waterblasting- abrasive methods in which sand or other fine abrasive material is sprayed either with a high-pressure air stream or with a stream of water, cleaning the surface and giving it a uniform roughness.

Split- the oldest method of interaction with stone and its processing, based on pinching/separation of a slab-like piece of rock from the main mass along natural fibers, as well as splitting stone raw materials into thinner and more convenient tiles for further work (flagstone). It is not suitable for all rocks, but rather only for a number of certain ones that have a layered texture. Flagstone is very popular in landscape design when decorating paths, gazebos, ponds, cladding fences and other home buildings; in the design of building facades, as well as in interiors - they frame entrance lobbies, fireplaces, and decorative panels.

Etching- exposure of the stone surface to chemical reagents. It is used to remove the top layer of rock, clean it, and give a rough surface.

Hydrophobization- treatment chemical solutions, as a result of which the surface becomes non-wettable.

Fluting- treatment with chemical solutions, as a result of which the pores and capillaries are compacted and, as a result, water absorption is reduced, strength and frost resistance are increased.

We hope that we were able to convey the nuances of surface treatment methods, characterizing them from the technical side of execution and from the point of view of the achieved result.
Please note that not every method is suitable for every type of rock or suitable for every product or use.

A homemade machine for polishing stones, rings, cufflinks and other jewelry - in each of these products stones play the role of sculptural, artistic and building material, and also serve as the main detail of an applied artistic composition.

Do you think we are talking about precious stones? No, the simplest ones.

The stone will not reveal its beauty to everyone - it reveals it only to those who are patient. But how much effort must be put in to correctly cut the stone, grind and polish and process it to get the intended shape.

For this work, the stones give a picture of thousands of years, it comes to life and delights with magical shades and tints. If a person can at least once achieve such a result himself through manual stone processing with your own hands, he will fall in love with this business completely and irrevocably.

It all starts with searching for a stone. These can be both minerals and ore rocks. Special attention jasper, agate, crystal brushes and flint were awarded. But this is just the beginning. Next comes processing, during which the stone is cut with cutting discs, which can be found in any diamond tool store. Hobbyists prefer discs with a diameter of 125 to 200 mm and use them on a motor with a power of 150-200 watts via a belt drive. After cutting, it is important to cool the blade on both sides.

Making a machine for processing stones at home

Stone cutting machine simple conditions It's not difficult to do. If you look at the design, you can easily understand where the cooling is supplied and where which parts will be located.

Grinding rules

Grinding stones to create flat plates can be done even on simple glass using abrasive powders. You should spray the glass and apply a little powder and you are ready to start. When grinding, the powder is added little by little as the abrasive wears out, and water is needed to maintain the creamy mass.

When, when grinding, you move from a coarser powder to a fine one (by fraction), the glass and hands should be washed well with soap and a brush: if even a little powder of a larger fraction gets into the powder of a smaller fraction, everything will be ruined.

When the stone is ground, it should be polished on a felt/felt mechanical wheel, the diameter of which should be between 140 and 200 mm. During the polishing process, chromium oxide powder and water should be used. The rotation of the circle should reach a speed of 410 to 700 rpm.

This is just one way of processing, although in reality there are many more. For those who have fallen in love with manual processing of stones at home, we would like to offer an excellent design of a machine for processing small stones. Since the scheme is extremely simple, we will only give recommendations.

1. We propose to use electric motors as a motor for washing machine– they are usually single-phase, power ranges from 190 to 240 watts and they can reach up to 1300 rpm. With such engine characteristics, two-stage pulleys with gear ratios of 1:1 and 1:0.35 can be used.
2. The first gear is ideal for processing on faceplates with fixed abrasive material, but the second will be used for processing with loose abrasive.
3. Use the V-belt from the Zaporozhets car as a gear shifter. You can make the mounting thread both left and right, the main thing is that the faceplate does not move off the axis when working with a load.
4. The trough for collecting slag should be at least 2 times larger than the diameter of the faceplate, the same applies to the height of the sides. You can attach rubber to the sides of the trough so that if the stone falls out of your hands, it will not break.
5. Since all processing is carried out using water, we will need a dropper. The problem is that it is only used when working on a faceplate with a fixed abrasive. When using bulk abrasive, it is better to wet the stone in a separate bath, the availability of which should be taken care of in advance.
6. And, of course, you should have not just one faceplate, but a whole set: wooden, cast iron, metal with felt and felt attached. This is required for various stages of processing and polishing.

Dry cleaning

Dry cleaning can be used to remove surface deposits. Its advantages are that the samples practically do not suffer from chips and scratches. When processing stone at home, you can use a 5-15% solution of oxalic/hydrochloric acid.

Important: Before using these acids, make sure that the minerals being treated are not soluble in it. Aragonite and azurite cannot be treated with acid.

When processing lapis lazuli and turquoise, you should be careful, since they, although slowly, also dissolve. To soften organic residues, stones are soaked in acetic acid. Fat compounds are easily removed with acetone and gasoline.

Some household chemicals are highly effective for dry cleaning, for example, Antikipin, which perfectly removes carbonate limescale shells from minerals. For hard-to-reach areas, use Progress detergent. In the final stages of processing, chemical minerals can be cleaned with glass and crystal cleaners.

The effect will also be from a “chemical bath”, i.e. you boil the mineral in a pressure cooker. Thanks to this technique, steam will penetrate even into places inaccessible to humans. After processing, the stones should be rinsed well under running water.

Cutting and splitting

Stones that have already been washed and cleaned should be sorted. Some people only collect beautiful specimens or fossils, rare species. Most subjects all the found material to polishing, which helps to reveal the beauty of the stones, and people experienced in this matter sometimes find planes in the sand that, when cut, reveal a picture of the play of colors, bizarre landscapes and even portraits.

As a result, some people simply collect stones, while others use them for crafts, combining them with wood and metal.

But before you start, you should split the stone and remove the excess. For this process (preparation), we will make a special device that will help in working with large samples. We will need a clamp with two teeth made of hardened metal (alternatively, use a vice in which 2 corners with teeth made of pobedit will be mounted).

The stone should be cut with diamond wheels or saws

The grinding and cutting machine can be made on the basis of an electric drilling device or an EZS-1 sharpener. In this case we will have 2 shaft outputs, one of which will have a 6 chuck and the other an emery wheel or a diamond coated wheel. The power of such a device will be 250 watts, and the rotation speed will be ~ 2750 rpm.

To process stones for jewelry at home, you can use other electric motors, the power of which will be in the range from 250 to 500 watts and the rotation speed from 1400 to 3000 rpm. Use a box with a hinged lid as a stand for the machine. The machine itself should be bolted to the cover. This modification of the working tool will allow you to install the machine at an angle.

A side table is attached to the box on the chuck side. Its height can be adjusted so that you can work with circles of different diameters. We place a 2.5*2.5 cm duralumin corner bar on the side table. A protective guard from the cutting wheel should be installed on the side. We draw a middle line along the protective fence and table, which will help when positioning the stone for cutting.

The stands and supports of the side table should be covered with felt or rubber to insulate the machine

You will also need a tray of water to cool the cutting wheel, which we will place under the side table. To reduce friction when cooling, use a soap solution. Place another pan of water under the faceplate.

When cutting stone, it is fed along a panka guide, which can be adjusted to the thickness of the plate that will be cut. The stone is fed only towards the cutting wheel. Cooling with water can be done in the form of a moistened piece of foam rubber, which should be held in the left hand on the side of the cutting wheel, since the right hand will feed the stone.

If the stone is large, it is better to hold it with both hands, and press the foam rubber and pebble against it. For additional stability, the edge of the stone is cut off, resulting in a supporting platform. If this option does not suit you, the stone can be installed in cardboard box according to size, fill with cement mortar and after hardening, cut the stone with. When the cutting is finished, carefully remove the cement. It can be difficult to cut a large stone, so you should first cut it and insert three blades made of thin steel plates into these grooves. Thanks to this, you will be able to cut stones whose dimensions are slightly larger than the diameter of the cutting tools.

If there is a need to cut cracked stone

Before the process, it should be glued with epoxy glue. On a wet surface, outline the cracks with a pencil - this will make them easier to see. Before gluing, the stone is dried so that there is no water in the crack. To do this, heat the stone on an electric stove, and then cool it to 60 degrees Celsius. Apply glue to the stone that has not yet cooled down with a stick or brush so that it penetrates deeper and hardens. After this, the stone will be strong enough that it can be safely cut even into thin slices.

Grinding

For more bright color The cut of the stone should be carefully polished. It is fashionable to perform it on a machine, which we proposed to make for splitting and cutting. To make sanding easier, place the stand cover at an angle. Use diamond-coated faceplates for this process, but abrasive wheels (rubberized) will also work.

The last option is good because you can make grooves in them - this will make it easier to grind round stones. In addition, they are much safer to operate. But there are also disadvantages: during operation, they produce a lot of dirt due to rapid wear, and sometimes even scatter into small particles during operation. It is for this reason that, while observing safety precautions, they should be covered with dense steel casings. To do this, you can use an unnecessary aluminum bowl, in which you must first remove the bottom.

The first stage of stone processing by grinding is carried out on a wheel with a large abrasive/diamond grain from 350 to 60 microns, and the second on a wheel with a grain from 60 to 37 microns, and the last - from 37 to 10 microns.

When sanding, you will also need a continuous supply of water, so as in the case of cutting, you can use a piece of damp foam. Ideally, a tank with a tap and a rubber hose will be installed above the machine, through which water will flow drop by drop into the pan. To prevent splashing, use a bowl guard.

Polishing

The main tools for the final stage of “Polishing” are laps, polished circles made of fabric and felt, and brushes made of plant materials (can be made of jute). Lappings are the most important tool that brings the surface of the stone to perfect look. They come in manual and planchet form. The material for stone processing can be any: tin, cast iron, wood, lead, hematite, fluoroplastic, chalcedony.

As a rule, they are needed for fine grinding, and when polishing, GOI paste or moistened chromium oxide is added. Instead of the latter, you can use green paint with the same name, since oxide is the main component in its composition. Polishing using it is carried out with a leather swab. But GOI paste and oxide have their drawbacks - they eat into the cracks of stones and are very difficult to remove even with gasoline. Aluminum oxide powder can be used for polishing.

Other DIY stone processing technologies

As we have already understood, achieving different stone textures gives different effects.

Let's look at several popular types: