Glass. Getting and using

decorative vases, trays, plates and other glass decorations will give your home original style and charm. You can create them yourself by melting down the accumulated glass bottles. This is lovely way turn old unwanted bottles into something new and elegant. This will take time and some practice. Having mastered the technique of glass melting to perfection, you will find an excellent use for unnecessary glass bottles.

Steps

Part 1

Collect and clean old bottles. Any glass bottle will do. Bottles can be used mineral water, lemonade, beer, wine, condiments, cosmetics and so on. Before melting, they must be properly cleaned and dried. Remove all labels and fingerprints from bottles.

Clean out the oven. Over time, the oven may have become dirty, and dust and debris may have accumulated in it. Dirt has a negative effect on performance heating elements and reduces the life of the furnace. Therefore, before using the oven, thoroughly clean it by following the instruction manual, which will avoid unnecessary costs.

• Cleaning the oven is a great opportunity to re-examine it and check if everything is in order. Tighten the loose screws, remove combustible materials from the oven and check that everything is in order.

1. Test the oven. Check the operation of the oven - run it as planned. Although you should always use test materials and the modes recommended by the instruction manual, you can usually check the operation of the oven using a self-supporting pyrometric cone 04. Place one cone on each shelf at a distance of about 5 centimeters from the oven wall. After that, do the following:

   Prepare the casting mold and shelf. If you do not protect the interior surfaces of the oven, molten glass may stick to them. Coat the shelf and mold with oven cleaner or glass separator to prevent sticking.

   Part 2

   bottle melting

   1. Choose between casting and bending. These are the two main methods of melting glass. As a rule, casting consists in melting glass, followed by filling the casting mold with liquid glass, in which the glass solidifies, acquiring its shape. During bending, the glass is heated to a fluid state and takes a free form, flowing around a supporting surface (for example, a decorative stand or paperweight).

      Set the temperature setting. This mode consists of several intervals with different speed heating and cooling. In each interval, the temperature changes within certain limits and at a certain rate. Temperature regime influences the appearance of the final product and should be chosen according to the type of glass used.

      Place the glass in the oven. Once you have cleaned the bottles and oven, tested the oven, and protected its interior surfaces from glass sticking, you are almost ready to melt the glass. However, the bottle must first be placed securely in the middle of the oven.

      Preheat the oven. The first step is to heat up the bottle and during this step the temperature should not be increased by more than 260°C. For slower heating, you can select a smaller step. This will slow down the process a little, but will prevent the mold from cracking, which can be caused by thermal shock.

      • Upon reaching the temperature provided for in each step, the glass should be kept at this temperature for a certain time. In many cases, a short exposure of 10-12 minutes is sufficient.
      • When working with the oven, it is necessary to use the protective equipment specified in the oven manual. As a rule, these are heat-resistant gloves and goggles.

   2. Reduce speed and continue heating. Upon reaching 560°C, the glass will begin to soften. The thinner walls in the middle of the bottle will start to leak. At this stage, in order to best result it is desirable to equalize the temperature throughout the bottle. For this purpose, it is recommended to increase the temperature in smaller increments, approximately 120°C.

      Melt the bottle. At this stage, you will reach the temperature at which the glass flows. Starting at 704°C, increase the temperature at a rate of 148°C per hour until you reach 776°C.

      Anneal the molten glass. Annealing is carried out below the solidification temperature of glass, which for most types of glass is slightly less than 537°C. To relieve stress in the glass and reduce the chance of cracking, hold it at this temperature for one hour for every 0.64 cm of glass thickness.

Today we will talk about how to make glass with your own hands at home. We will also consider methods and technologies self-manufacturing glass and glass products, namely furnaces, appliances and tools for melting glass

At factories and in chemical laboratories, glasses are obtained from a mixture - a thoroughly mixed dry mixture of powdered salts, oxides and other compounds. When heated in furnaces to very high temperatures, often above 1500 ° C, salts decompose to oxides, which, interacting with each other, form silicates, borates, phosphates and other high temperatures connections. Together they make glass.

We will prepare the so-called fusible glasses, for which a laboratory electric oven with heating temperature up to 1000°C. You will also need crucibles, crucible tongs (so as not to burn yourself) and a small flat plate, steel or cast iron. First we will weld the glass, and then we will find a use for it.

Mix with a spatula on a sheet of paper 10 g of sodium tetraborate (borax), 20 g of lead oxide and 1.5 g of cobalt oxide, sifted through a sieve. This is our burden. Pour it into a small crucible and compact with a spatula so that you get a cone with a top in the center of the crucible. The compacted mixture should occupy no more than three-quarters of the volume in the crucible, then the glass will not spill.

Place the crucible with tongs in an electric furnace (crucible or muffle), heated to 800–900 °C, and wait until the mixture has melted. This is judged by the release of bubbles: as soon as it has stopped, the glass is ready. Remove the crucible from the oven with tongs and immediately pour the melted glass onto a clean steel or cast iron plate. Cooling on the stove, the glass forms a blue-violet ingot.

To obtain glasses of other colors, replace the cobalt oxide with other coloring oxides. Iron(III) oxide (1-1.5 g) will color the glass brown, copper(II) oxide (0.5-1 g) green, a mixture of 0.3 g of copper oxide with 1 g of cobalt oxide and 1 g iron oxide (III) - black. If you take only boric acid and lead oxide, then the glass will remain colorless and transparent. Experiment yourself with other oxides, such as chromium, manganese, nickel, tin.

Crush the glass with a pestle in a porcelain mortar. In order not to injure yourself with fragments, be sure to wrap your hand with a towel, and cover the mortar with a pestle with a clean rag.

Pour fine glass powder onto thick glass, add a little water and grind to a creamy state with a chime - a glass or porcelain disc with a handle. Instead of a chime, you can take a small flat-bottomed mortar or a polished piece of granite - this is what the old masters did when they rubbed paint. The resulting mass is called slip. We will apply it to the aluminum surface in much the same way as they do when making jewelry.

Clean the aluminum surface with sandpaper and degrease by boiling in a soda solution. On a clean surface, trace the outline of the pattern with a scalpel or needle. Cover the surface with a slip with an ordinary brush, dry it over a flame, and then heat it in the same flame until the glass melts onto the metal. You will get enamel.

If the badge is small, it can be covered with a layer of glass and heated in a flame in its entirety. If the product is larger (say, a plate with an inscription), then it is necessary to break it into sections and apply glass to them one by one. To make the color of the enamel more intense, apply the glass again. In this way, you can get not only jewelry, but also reliable enamel coatings for protection of aluminum details in various devices and models. Since in this case the enamel bears an additional load, metal surface after degreasing and washing, it is desirable to cover with a dense oxide film; to do this, it is enough to hold the part for 5-10 minutes in an oven with a temperature slightly below 600 ° C.

Of course, it is more convenient to apply slip on a large part not with a brush, but from a spray gun or simply by watering (but the layer should be thin). Dry the item in drying cabinet at 50-60°C, and then transfer to an electric furnace heated to 700-800°C.

And from low-melting glass, you can prepare painted plates for mosaic work. Pieces of a bat porcelain tableware(they will always be given to you in a china shop) pour a thin layer of slip over it, dry it at room temperature or in an oven and fuse the glass onto the plates, keeping them in an electric furnace at a temperature of at least 700 ° C.

Having mastered the work with glass, you can help your colleagues from the biological circle: they often make stuffed animals there, and stuffed animals need multi-colored eyes ...

In a steel plate about 1.5 cm thick, drill a few recesses different sizes with a conical or spherical bottom. In the same way as before, fuse the multi-colored glasses. Gamma, perhaps, is enough, and to change the intensity, slightly increase or decrease the content of the coloring additive.

Place a small drop of bright molten glass into the recess of the steel plate, then pour in the iris-colored glass. The drop will enter the main mass, but will not mix with it - this is how both the pupil and the iris will be reproduced. Cool products slowly, avoiding sudden temperature changes. To do this, remove the hardened, but still hot "eyes" from the mold with heated tweezers, put them in loose asbestos and cool it in it to room temperature. .

Of course, fusible glasses can be found in other applications. But wouldn't it be better if you look for them yourself?

And at the end of the experiments with glass, using the same electric furnace, we will try to turn ordinary glass into colored glass. The natural question is: is it possible in this way to make sunglasses? It is possible, but it is unlikely that you will succeed the first time, because the process is capricious and requires some skills. Therefore, take the glasses only after you have practiced on the pieces of glass and make sure that the result is as expected.

The basis of paint for glass will be rosin. From resinates, acid salts that make up rosin, you previously prepared driers for oil paints. Let us turn again to resinates, because they are able to form a thin, even film on glass and serve as carriers of the coloring matter,

In a solution of caustic soda with a concentration of about 20%, dissolve with stirring and remembering, of course, caution, pieces of rosin until the liquid becomes dark yellow. After filtering, add a little solution of ferric chloride FeCl3 or other ferric salt. Keep in mind that the concentration of the solution should be small, salt should not be taken in excess - the precipitate of iron hydroxide, which in this case forms, will interfere with us. If the salt concentration is low, then a red precipitate of iron resinate is formed - it is there that is needed.

Filter off the red precipitate and dry it in air, and then dissolve to saturation in pure gasoline (not automobile, but solvent gasoline), it would be even better to use hexane or petroleum ether. Paint the glass surface with a thin layer with a brush or spray gun, let it dry and place it in an oven heated to about 600 ° C for 5-10 minutes.

But rosin belongs to organic substances, and they cannot withstand such a temperature! That's right, but that's exactly what you need - let organic base burn out. Then the thinnest film of iron oxide will remain on the glass, well adhered to the surface. And although the oxide is generally opaque, in such thin layer it transmits part of the light rays, i.e., it can serve as a light filter.
Perhaps the light protection layer will seem too dark or, on the contrary, too light. In this case, vary the conditions of the experiment - slightly increase or decrease the concentration of the rosin solution, change the firing time and temperature. If you are not satisfied with the color in which the glass is painted, replace the iron chloride with another metal chloride, but certainly one whose oxide is brightly colored, such as copper or cobalt chloride.

And when the technology is carefully worked out on pieces of glass, it is possible to make the transformation of ordinary glasses into sunglasses without much risk. Just remember to remove the glass from the frame - the plastic frame will not withstand the heat in the oven in the same way as the rosin base ...
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To get glass, sand must be melted. You must have walked on hot sand on a sunny day, so you can guess that for this it needs to be heated to very high temperatures. An ice cube melts at a temperature of about 0 C. Sand begins to melt at a temperature of at least 1710 C, which exceeds maximum temperature our usual oven almost seven times.
Heating any substance to this temperature requires high costs energy and hence money. For this reason, in the production of glass for everyday use, glassmakers add a substance to the sand that helps the sand melt at a higher temperature. low temperatures- about 815 C. Usually this substance is soda ash.
However, if only sand and soda ash are used in the melt, an amazing type of glass can be obtained - glass that dissolves in water (frankly, not the best choice for glasses).

The glass commonly used to make windows, mirrors, glasses, bottles, and light bulbs is called soda-lime silicate. Such glass is very durable, and in molten form it is easy to give it the desired shape. In addition to sand, soda ash and limestone, this mixture (experts say "mixture") includes a little magnesium oxide, aluminum oxide, boric acid, as well as substances that prevent the formation of air bubbles in this mixture.

All these ingredients are combined and the mixture (the mixture is placed in a giant furnace (the largest of these furnaces can hold almost 1,110,000 kg of liquid glass). .

The strong fire of the furnace heats the mixture until it begins to melt and turns from a solid to a viscous liquid. Liquid glass continues to be heated at high temperatures until all bubbles and veins disappear from it, since the thing made from it must be absolutely transparent. When the mass of glass becomes homogeneous and clean, the fire is reduced and the glass is waited until the glass turns into a viscous viscous mass - like a hot toffee. The glass is then poured from the furnace into a casting machine where it is poured into molds and shaped.
However, in the production of hollow things, such as bottles, glass must be blown, as balloon. Previously, glass blowing could be seen during fairs and carnivals, now this process is often shown on TV. You've probably seen glassblowers blowing a piece of hot glass hanging from the end of a tube to create amazing figurines. But you can also blow glass with the help of machines. The basic principle of glassblowers is to blow into a glass drop until an air bubble forms in the middle, which becomes a cavity in the finished thing.

After the glass has been given the necessary shape, a new danger lies in wait for it - it can crack when cooled to room temperature. To avoid this, craftsmen try to control the cooling process by subjecting the hardening glass to heat treatment. The last stage of processing is removing excess glass droplets from the handles of cups or polishing plates with special chemicals that make them perfectly smooth.

Scientists are still arguing about what glass should be considered - solid or a very viscous (syrup-like) liquid. Since the windows of old houses are thicker at the bottom and thinner at the top, some claim that the glass runs down over time. However, one can object to this that earlier window panes were not made perfectly even and people simply inserted them into the frames with a thicker edge down. Even the glassware of times ancient rome do not show any signs of "fluidity". So the example with the old window glass does not help resolve the question of whether glass is in fact a highly viscous liquid.

Composition (raw materials) for glass production at home:
Quartz sand;
soda ash;
Talamit;
Limestone;
Nepheline syenite;
Sodium sulfate.

How glass is made at home (production process)

Usually scrap glass is used as ingredients ( broken glass) plus the above components.

1) Elements The future glass is fed into the furnace, where it all melts at a temperature of 1500 degrees, forming a homogeneous liquid mass.

2) Liquid glass enters the homogenizer (an apparatus for creating stable mixtures), where it is mixed to a mass with a uniform temperature.

3) The hot mass is allowed to settle for several hours.

This is how glass is made!

Almost every material and compound in the world has three possible states: solid, liquid, and gaseous. Under normal conditions, materials are in a different state, which depends on their chemical properties.

To bring them out of balance, it is necessary to raise or lower the temperature to the specified value. For example, the melting point of glass starts at about 750 degrees Celsius. The material has so-called amorphous properties, so it has no specific meaning.

It all depends on the amount and quality composition impurities in the compound. So you can set a specific value for the selected item only experimentally. This will require a set measuring instruments, which is available only in specialized laboratories. You can, of course, take household analogues, but they will have too large an error.

Calculation principles

Calculating the melting temperature of glass at home is a very difficult task. It will be associated with many difficulties, among which it is worth highlighting:

• 1. The need to ensure a gradual increase in the temperature of the melted body strictly by one degree. Otherwise, it will be impossible to reliably establish at what particular indicator the process of transition from a solid to a liquid state begins, that is, the experiment will fail.
• 2. You need to find a very accurate thermometer that can measure temperatures up to 2 thousand degrees Celsius with a minimum error. Best fit electronic device, which will be too expensive for domestic experiments.
• 3. Conducting an experiment at home is, in principle, not the most good idea, because you have to look for dishes in which you can melt glass, get a stable fire source that can provide the desired level of heating, and buy expensive equipment.

melting process

In laboratories, scientists find out the desired value with the help of multiple experiments. Then the melting point of the glass is entered in a table that also contains the chemical composition of the compound. This is necessary in order to understand which elements affect melting the most, so that in the future this indicator can be brought to more or less standard characteristics.

The absence of a clear number makes it irrational to use production resources. For example, in glass factories, furnaces are maintained at a temperature of about 1600 degrees Celsius, despite the fact that many types could melt without problems even at one thousand. Energy savings would significantly reduce the cost finished products, which would have a positive effect on economic efficiency activities of glass factories.

The melting temperature of glass in degrees starts from 750 (some sources give a figure from 1000) and continues right up to 2500. At the same time, if we take acrylic glass, which in fact is not glass, but simply has such a name, then it melts at only 160 degrees, and at 200 degrees it already begins to boil. But it consists of an organic resin and does not contain silicon and other chemical elements.

But other brands, on the contrary, can often boast of a motley variety of composition. The sand used in the production is often insufficiently cleaned, resulting in finished goods contains a lot of unnecessary stuff. Outwardly, this does not affect the operational properties in any way, but leads to amorphous chemical characteristics.

Lowering the melting point of glass can be achieved by adding appropriate elements to the melt. In domestic experiments, the most accessible are lead oxide and boric acid. Mass fraction will need to be calculated using known formulas, since it will depend on the amount of molten glass. After solidification, it will be possible to repeat your experiment and make sure that now the material melts at a much lower temperature.

But it is worth considering that the resulting glass does not have practical value and is suitable only for experiments. This is due to the fact that the addition of impurities also changes its operating parameters, so that the substance will not be able to fully cope with the functions assigned to it. That's why no one changes technological process by adding the specified components.

Basic values

Approximate glass transition values liquid state for some species:

Melting temperature bottle glass- 1200-1400 degrees Celsius;
- the melting point of quartz glass is about 1665 degrees Celsius;
- melting point of ampoule glass - 1550-1800 degrees Celsius;
- liquid glass melting point - 1088 degrees Celsius.

For the latter substance, an exact figure can be indicated, because it does not exhibit amorphous properties, since it is an aqueous alkaline solution of sodium and potassium silicates. It is also worth considering that the glass does not melt immediately, but first passes into a viscous caramel-like state. This property is used by glassblowers to create various products and souvenirs.

You can do this kind of craft at home. There will be no shortage of raw materials, since you can find a lot glass bottles right on the street. And as a device for softening the material, the usual gas lamp. Own products handmade You can then sell for souvenirs and earn good money.

What is currently impossible to do with your own hands? Whether ordinary craft, wardrobe item, furniture and more. How to make glass at home? - It would seem that it is unrealistic. Nothing is impossible in today's world. The main thing in this business is desire. And in this article you will find detailed step by step algorithm such a fun and interesting activity.

What is known about glassmaking?

It is known from history that glassmaking is a very ancient process. According to the time frame, it refers approximately to the period before 2500 BC. Previously, such a rare and valuable occupation in our time has been replaced by the widespread production of this material.

Glass products are found everywhere. They are used as containers, household and decorative elements, insulators, reinforcing fiber and other things. Glasses differ only in the constituent material that is used for manufacturing. But the process itself is almost the same.

The main materials you will need:

1. the main element is quartz sand (silicon dioxide);
2. sodium carbonate or soda;
3. calcium oxide, she is lime;
4. furnace for melting glass;
5. other salts and oxides that can be used additionally on an individual basis (oxides of aluminum, iron, magnesium, lead and calcium or sodium salts);
6. protective clothing;
7. grill;
8. charcoal;
9. forms and other elements for shaping;
10. refractory crucible.

Methods for making glass using a furnace

The first way to solder glass at home is to use an oven.

Acquisition of quartz sand:

• This material is the basis for the production of glass. Glass, in which there are no impurities of iron, has its advantages - it is light. What can not be said about the glass in which it is present. It will give off greenery.
• It is important to wear a mask before starting work. Quartz sand is fine-grained and easily enters the nasal cavity and further into the lungs. This, in turn, will irritate the throat.
• You can easily buy quartz sand in a specialized online store. Its cost is low.

Important! The cost of the approximate amount that will be needed will be around $ 20. e. In the future, you can buy it up to a ton, the approximate cost of which will be 100 c.u. e. This is if you plan to work on an industrial scale.

• It happens that finding high-quality sand is not so easy, and it contains more than the amount of impurities. Dont be upset. In this case, manganese dioxide will come to the rescue. It should be added to a small amount. If in your idea it is glass with a greenish tint, then absolutely nothing needs to be done. Leave everything as it is.

Addition of carbonate and calcium oxide:

• The carbonate in this case lowers the production temperature of industrial glasses. At the same time, it causes glass corrosion with the participation of water. To avoid this, it is necessary to additionally introduce lime or calcium oxide into the glass.
• Magnesium or aluminum oxides are used for glass durability. As a rule, these inclusions occupy a small percentage in the glass composition. The figure is approximately 26-30 percent.

Addition of other chemical elements:

• This method to make decorative glass at home requires the use of lead oxide. It gives shine to crystal, its low hardness, makes it accessible to cutting, and gives a low temperature of melt formation.
• Lanthanum oxide can be found in eyeglass lenses. It has a refractive property.
• With regards to lead crystal, it can contain up to 33 percent lead oxide.

Important! The more lead, the more dexterity is needed to shape the molten glass. Based on this, many glassblowers prefer a smaller amount of it.

• Iron impurities in quartz glass give it green tint. In this case, iron oxide is added to increase the greenish tint. This also applies to copper oxide.
• Yellow, amber, and even black can be obtained with a sulfur compound. It all depends on the amount of carbon or iron added to the glass charge.

The main stages of glass production:

• Place the mixture in a temperature-resistant crucible. The latter should be as resistant as possible to the temperature that will be in the oven. It can vary from 1500 to 2500 degrees. It depends on the additives.

Important! There is one more important requirement for the crucible - it must be such that it can be easily fixed with the help of metal tongs.

• Melt the mixture to a liquid consistency. For industrial silicate glass, this can be done in a gas-fired furnace.

Important! There are also electric, muffle and pot furnaces. They can perform special glass. Please note that quartz and sand, which do not contain additional impurities, go into a glassy state when the temperature in the furnace is 2500 degrees Celsius. If sodium carbonate is added to the contents, this is ordinary soda, then the temperature will drop to 1500 degrees.

• Carefully monitor the consistency of the glass. It is important to remove all bubbles from it in a timely manner. This can be achieved with regular stirring to a uniform density. It is also necessary to add one of the elements - sodium chloride, sodium sulfate or antimony oxide.
• Shape the glass. To do this, use one of the following methods.
• The simplest thing is to pour the melted glass into a mold and wait until it cools down. With this method, many optical lenses are created. Previously, this method was used by the Egyptians.
• Place the finished molten glass in a bath containing molten tin. The latter acts as a substrate. Next, you need to blow it with compressed nitrogen for shaping or polishing. Another way is to collect at the end of a hollow pipe required amount glass and, turning the pipe, blow it out.

Important! Glass made using this method is called float glass. It has been produced since the early 1950s.

• Leave the glass to cool down. It is important to place it in a place where it will not be damaged, water, dust or, for example, leaves will not spoil it. Keep in mind that when in contact with cold objects, it will crack.
• The final step of this method to make glass at home will be glass annealing. This method of heat treatment will give strength to the material. When using it, all point sources of stress that can be encountered during the glass cooling process will be removed.

Important! Upon completion of this work, additional coatings can be applied to the glass to increase durability and strength. Also can be laminated.

1. Unannealed glass is less durable.
2. As for the temperature for finishing work, it depends on the exact composition of the glass - from 400 to 550 degrees Celsius.
3. The cooling rate of the glass depends on the size. Large glass items must be cooled slowly. Smaller things go faster.

Method for making glass using a brazier

The second way to make glass at home is a charcoal roaster. Let's take a look at everything step by step in this case.

Equipment for work

First you need to make an oven. A barbecue grill is perfect for this. It is important that it is heated with charcoal. In this case, in order to melt quartz sand into glass, the heat that coal generates when burned is used. Again, the cost of this material is not too high. They are widely available.

Important! Grill Use standard size. Better if it is in the form of a dome. The main qualities that he should have are the presence of thick walls and good strength. If the grill has a ventilation hole, usually located at the bottom, it must be opened.

However, there may be small obstacles in this method. Even if there are very high temperatures, it is not always possible to melt it with ease. To do this, before starting the process, you need to add lime, borax or washing soda. The amount of additives should not exceed ⅓-¼ of the volume of sand.

Important! Remember that these additives significantly lower the melting point of the sand.

Glass Formatting

For blowing glass, prepare a long hollow metal tube. In order to pour glass, a mold is needed. It should be dense and should not melt from hot glass. Use, for example, graphite.

Important! Using this method it must be remembered that the heating of the grill is much higher than its normal heating. It is possible that the grill itself may melt. Therefore, in the manufacture of glass in this way, you need to carefully and responsibly perform all actions. Negligence can result in serious injury or even death.

Security measures:

1. Near working area place a large amount of sand and a fire extinguisher.
2. All work must be done outdoors.
3. The floor must be concrete, for example.
4. Stay away from the grill when cooking glass to protect yourself and your clothes from high temperatures.
5. Remember to wear protective clothing. These are fire-resistant clothing, oven gloves, a high-strength apron over clothing, and a mandatory welding mask.
6. also in this method you will need a vacuum cleaner. It will act as a coal blower. We have it in the following way: we carry the body to a sufficient distance. We fix the hose to the ventilation hole, which is located below. It may need to be bent to give the desired shape. You can fix it to one of the legs of the grill. The hose must be fixed firmly and not move.

Important! If the opposite happened, then in no case do not approach him, because he is very hot. Next, you need to turn off the vacuum cleaner and look at the position of the hose. It must be aimed exactly at the vent hole.

Operating procedure:

• On the inner surface grill lay out charcoal. It is necessary to put it in two or even three times more than for roasting meat. Well, if it is filled almost to the brim.

Important! Use hardwood charcoal. It burns faster and better than briquetted.

• In the middle of the bowl, place a cast-iron container or a crucible with sand.
• Carefully study the packaging of the coal used. Fire it up in a suitable way. There is coal that ignites directly by itself, and there is material for which ignition fluid is used. Wait for the flame to spread evenly.
• Wait until the coal is ready for further work. The readiness of coals can be determined by color. They will be orange.
• The next step is to turn on the vacuum cleaner. This is necessary so that the coal is blown.

Important! Coal exposed to air flow can be heated to very high temperatures. Up to about 1100 degrees Celsius. This must be taken into account when near the stove. Ascending flashes may appear from it.

Glass is a material that clearly stands out from the rest made by man. First of all, this is due to the properties of this material. Although one type of glass is mined as a mineral, this product is usually the result of human life.

glass properties

In addition to the fact that glass has a melting point and that a wide variety of products can be made from this material, it has many other properties. The density of glass depends largely on its chemical composition, this indicator characterizes the ratio of volume to weight of the material. So, this indicator is the lowest for quartz glass.

Crystal, on the contrary, has the highest, which can exceed 3 g / cm 3. The strength of this material also depends on the chemical composition, that is, how glass can maintain its integrity in products under the influence of external loads. In tension and compression, the influence of the chemical composition is almost the same. The hardness of the material is affected by the presence or absence of impurities and their quantitative index in a given instance. The hardest is the one that contains a large number of silica, namely quartz, as well as borosilicate. In turn, the presence of lead oxides in the composition reduces the strength characteristics. As you know, the high melting point of glass allows you to change it appearance and if necessary, get a completely different shape. But at low temperatures, which are considered normal for human life, glass under the influence of loads is destroyed, not deformed.

The brittleness of glass products depends on the thickness of the material as well as the shape. The easiest way to break into fragments is glass flat shape. In order to increase this indicator, magnesium oxides and boric anhydride are added to the composition during the production of the material. The more inhomogeneous the glass, the more likely it is to break under mechanical stress.

Temperature effect

The melting temperature of glass is worth special attention. Despite the fragility of the material, in order to convert it into a liquid state, it will be necessary to heat it to high temperatures. Concerning ordinary glass, then its melting point ranges from 425 to 600 o C, for quartz this figure reaches 1000 o C. Due to its fragility and, accordingly, the complexity of the work, it is really big parts glass, there was a need to create a material that could be more durable, while maintaining other properties. And in 1936 organic glass goes on sale. The melting point of plexiglass is low, it is only 160 o C, and at 200 o C the material comes to a boil. Plexiglas is used literally everywhere, since its transparency is the same as that of others, but in terms of impact resistance it is an order of magnitude higher.

Glass types

If we temporarily do not consider plexiglass, but remember other types of this material, then there are four of them: ordinary, quartz, borosilicate and crystal. Each species has its own special features that distinguish it from the rest.

Ordinary glass

This type of glass includes soda, potash, and also lime-sodium-potassium. The first type is used for the production of window glass, dishes, various glass containers. Potash has a higher melting point. Glasses of this type are used to create high-quality tableware. This type of ordinary glass has a pronounced glare and transparency. The latter type is also actively used for the production of dishes.

quartz glass

This type of glass is obtained by melting raw materials of high purity. Therefore, the answer to the question of at what temperature quartz glass melts is 1000 ° C. This demonstrates the fact that given type material is also the most heat-resistant, therefore, if you lower it in a hot form in cold water, it will not crack. Due to this, quartz glass can be used at very high temperatures, because in order to bring it to a liquid state, the temperature must reach 1500 ° C.

There are two varieties of this glass - transparent and milky-opaque quartz. In terms of their performance, they are almost the same, but differ in optical properties. The surface of quartz glass has a high adsorption capacity not only for moisture, but also for certain gases. It is also worth remembering that quartz must be protected from all kinds of contaminants, including greasy marks from hands, such stains can be removed with ethanol, as an option, acetone is used.

Borosilicate glass

This type of glass contains a large amount of boron oxide, which explains its name. Thanks to the introduction of this substance into the composition, it can be much stronger than other types. The thermal shock resistance of borosilicate glass can be up to 5 times that of lime glass. Other indicators are related to the chemical resistance of glass, allowing it to be actively used in electrical engineering. To soften this type of described material, it is necessary to heat it to a temperature of 585 ° C.

crystal glass

Everyone is familiar with crystal, it is this material that is considered the highest grade among various glasses, it not only has a unique brilliance, but also has the ability to strongly refract light. Crystal glass can be lead-containing and lead-free. The former have more weight and demonstrate beautiful game light, they make dishes or souvenirs. Lead-free glass is more commonly used in optical instruments and are of high quality.