How to prepare fireclay clay for laying a stove, how to mix the solution

How to make refractory bricks with your own hands (step-by-step instructions)
Refractory (i.e. fireclay) bricks are used for industrial and domestic construction. This material contains up to 70% chamotte, which is a fireproof clay.

The material is used to build buildings that will be exposed to high temperatures. It is suitable for building barbecues, bathhouses, stoves and fireplaces with your own hands.

Fireproof is a material that can operate without loss even at high temperatures.

Pros and cons of fireclay mixtures

Fireclay material has certain advantages that you need to know about if you want to work with it:

clay has a high heat resistance;
good adhesion of the material allows for excellent adhesion to the surface of any material;
the vapor permeability indicator allows the solution to pass wet vapors through its layer, accumulate them inside and, if necessary, return them again, regulating air exchange;
long operational period. Fireclay clay does not crack on its surface for a long time, is resistant to crumbling, and does not change its initial parameters and shape for many years;
This environmentally friendly material does not pose any danger to the human body.

It's fair to say. That with all its advantages, fireclay clay has certain negative qualities:

it is difficult for novice craftsmen to mix a high-quality solution;
the cost of clay is high, which distinguishes it from simple types of clay.

Sometimes it is impossible to complete a particular construction task using traditional materials. There are situations where some designs require a high level of heat resistance. In such cases, they use a special building material - fireclay clay, the uniqueness of which is determined by the technological manufacturing features that give the material resistance to high temperature conditions.

It should be noted that in order to successfully solve construction problems, the preparation of a solution from fireclay clay must be carried out in accordance with the instructions. In addition, it is recommended to adhere to the correct proportions; prepare the fireclay clay solution in small quantities, as it hardens quickly.

When constructing a furnace, it is imperative to use refractory material for both internal and facing work. Among the advantages of chamotte mortar are:

High level of environmental friendliness.
Excellent steam permeability.
Resistant to high temperatures and temperature changes.
Long service life.

However, the masonry mixture is not famous for its advantages alone. It also has certain disadvantages. First of all, it is necessary to address the issue of price. Even if you prepare the solution yourself, its cost will be very high, when drawing an analogy with other materials in this group.

The mixture contains phenolic resin. This element has a high level of toxicity, and accordingly, environmental pollution occurs during production. And the work itself at the enterprise does not benefit anyone, since a lot of harmful dust is generated during the entire work process.

Factory produced mixture

As for efficiency, it is not as high as we would like. For example, if you need to lay only 25 bricks, then you will need to purchase about 20 kg of clay mass, but to lay one cubic meter of structure you will need as much as 100 kg of material.

Types of clay

To create a clay product with your own hands, two types of clay are used: polymer or natural.

The first can be purchased without any problems at a craft store, the second can be obtained independently, which makes the process of creating creations even more interesting, or can also be purchased at the store.

Packaging of varying weights will help you purchase exactly the amount needed to create your creation. For professionals, you can buy large bags weighing up to 15-20 kilograms.

When purchasing a product, you must pay attention to the presence of vacuum packaging. This will mean that the clay was mixed in compliance with all production requirements, and there are no air bubbles in its composition

The presence of air inside the material can lead to destruction of the finished product.

How to dilute fireclay clay for a stove

Preparing a solution from fireclay is considered a difficult task, so it is important to approach this matter carefully, since a properly prepared mixture is the key to a reliable and durable design.

Cooking steps

In order for the resulting chamotte solution to have all the declared positive qualities, it is necessary to strictly follow all the rules for its preparation. To do this, you should adhere to the following algorithm of actions:

The clay is poured into a container in which mixing will be done.
An admixture is laid out on top: fireclay or quartz sand. There should be proportionally more of them than crushed clay by 2–5 times.
The dry mixture is poured with water on top.
Mix everything with a spatula, construction mixer or drill with a special attachment until a homogeneous mass is obtained.
The container is tightly closed and left for three days. It is necessary to close it so that the liquid does not leave the container.
At the end of the soaking period, the mixture is thoroughly mixed again, after which you can begin to work.

If you neglect to properly prepare the solution, you may end up with an indigestible mass that is unlikely to be suitable for any construction work. In order not to waste the material, strictly follow the specified algorithm - this will allow you to get a solution that will last a long time in your furnace masonry.

Unfortunately, even a professional layer cannot avoid such incidents, when the solution is of the wrong consistency. The proportions of crushed stone, sand and water are often selected by eye, and when the clay swells for three days, its condition can change in different ways: due to differences in temperature, humidity and similar nuances, which are difficult to influence in non-laboratory conditions.

The ideal consistency of diluted fireclay clay should resemble thick sour cream and not include lumps. If the solution does not satisfy this requirement, then you should analyze the situation and come to an appropriate solution.

If there is a lack of moisture, add water. The presence of a sufficient amount of water directly affects the plasticity of the mixture and its adhesion. If the moisture content is low, the mixture will not apply well and will crack.

If the solution turns out to be too liquid, then sand should be added to it. There is no need to leave the mixture for a few more days.

High-quality clay lies at a depth of 5 meters; higher layers are not suitable for kilns

The quality of the composition is determined by the fat content of the base. According to this criterion, clay is divided into three types.

Fatty is the most flexible. However, when it dries, it cracks and greatly decreases in volume, which is why the stove structures are deformed and destroyed.
Medium fat is the best option. Dries with moderate shrinkage and does not crack. It has good adhesion, strength, heat resistance, and hygroscopicity.
Lean clay has the lowest adhesion rates. It is dry and quickly becomes covered with cracks, which leads to the crumbling of the masonry.

Finding quality material is a great success. Good clay layers are found at a depth of five meters. The upper layers contain a high content of sandy impurities and humus. This type is not suitable for ovens.

How to make fire brick

Although there are many different types of fireclay bricks commercially available, you can make your own.

This is practiced quite often, since in this case it is possible to make a brick of the required size or configuration. for work you need:

Fireproof and extremely flexible clay. It would be a good idea to add kaolin if possible.
To minimize the formation of deformation changes during drying, crushed brick or fireclay from previous firing is used.
Sawdust - they can be taken as waste from furniture production, and sometimes sawdust is combined with charcoal, which has minimal shrinkage.
Wallpaper glue is used to bind wet brittle bricks.
Liquid soap is used to prevent the development of bacteria in the molding compound.

Manufacturing instructions:
Dilute dry clay in an amount of 5 kg with a mixer.
Add to it 1 kg of fireclay, adhesive for gluing wallpaper and 50 grams of soap.
Next, take 4 kg of sawdust and gradually add it to the mixture, stirring constantly.
The resulting mixture should be kept for up to 2 days.

In this case, the freshly prepared mass should not be liquid or dry. The consistency should be such that the mold can be adjusted to the required size. The formation of raw materials should be carried out taking into account the fact that when dried, the brick will decrease in size by up to 15%. The finished raw material is dried on a board for quite a long time, and then fired at a temperature of +1200 degrees for 10 hours, of which the temperature will increase within 7 hours, and the exposure will take 3 hours.

Preparing the necessary materials

First of all, it is necessary to dwell on one point. Thanks to technological progress and the widespread production of building materials, there is currently one technique using which it is not difficult to prepare clay for laying a stove.

The technology is suitable for those people who do not have practical experience in this area, as well as for those who decided to invest once, build a brick structure in their home and never worry about it again.

We are talking about a wide range of ready-made masonry mixtures. They are available for free sale and are packaged in branded bags. All you need to do is purchase the required amount of material and, using the recommendations on the packaging, dilute it correctly.

First of all, it will be necessary to obtain clay of the type that is available in a particular region. It will be most convenient to stock up on it in those places where mining has already been carried out on the ground, in ravines or under the river coastline.

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After the raw materials have been extracted in the required quantity, they should be transported to the place where the structure is supposed to be erected. Fireclay clay is poured into a prepared container and filled with water. Liquids and material should be taken in a ratio of 1:4 according to volume. Soaking lasts for 48 hours.

The hammer drill makes the job much easier

Next, you need to strain the mass through a mesh with cells measuring 3x3 mm, which will make it possible to rid the material of various impurities and stones. Unfortunately, it is almost impossible to obtain sand in the same way. Firstly, it lies deep, and secondly, it can be punishable by administrative liability, so it is better to buy it legally.

A high-quality solution can only be made if you use dry sand, preferably pre-cleaned. Adding wet material is not acceptable, so if it gets wet, it needs to be given time to dry. When the mass is dry, it is also sifted through a mesh with cells of about 1.5 mm.

Once you have figured out what fireclay mortar is, and have also prepared all the components, you can begin the mixing procedure.

Additives and their properties

To improve the quality characteristics of the finished solution, the following components are used:

PVA construction adhesive. Thanks to this additive, the time for preparing the solution can be significantly reduced. Special compositions for instant mixing are available on sale, but their price is quite high.
Cement. This component will also help the solution harden faster. A package of dry fireclay clay will require no more than 2 kg of cement.
Liquid glass. This component, added in an amount of 1-3% of the volume of fireclay mortar, will make the mixture more plastic.
Salt. It is used to increase the strength of joints and plaster. Typically, this ingredient is used in the following proportion: 100-150 g of salt per bucket of mixture.

Main components

Fireclay fireproof kaolin clay is best suited for laying stoves

The clay composition varies depending on the components added:

clay-sand;
clay-cement;
clay-lime.

Stove makers, as a rule, choose the first option. The proportions depend on what clay is used for the oven. If it is oily, the sand ratio will be 2:1, if it is medium oily it will be 1:1. Also, if the clay is of good quality, you can do without additives.

Instructions for use, consumption of solution, how long it takes to dry

Working with fireclay clay is not easy; many beginners have problems: the masonry turns out to be fragile, cracks appear on the plaster and it crumbles. This happens because when fired, kaolin clay almost completely loses its plastic properties, and when mixing the solution, it needs to regain its plasticity. To do this, add special glue or ordinary quartz sand to the solution.

How to use and breed

Dilute fireclay powder with ordinary water. The proportions are taken depending on the further use of the resulting solution.

Cooking instructions for different uses

Many who have worked with fireclay clay often encountered certain difficulties, not knowing how to dilute this material. The strength of the masonry did not always meet the requirements; the plaster cracked and crumbled.

As a rule, this was due to violations made during firing, during which the kaolin clay lost its plasticity. But this problem can be solved by preparing the solution. You should take a special adhesive composition or simple quartz sand and add it to the solution. Before use, the fireclay material is mixed with ordinary water; the ratios are determined taking into account how the solution is planned to be used.

Fireclay clay for laying stoves is prepared as follows. Take a large container in which clay, sand and water are mixed. For ease of use, it is recommended to take a tank of ten to fifteen liters.

The readiness of the solution is determined as follows: take a trowel and scoop out a little mixture. If the solution flows slowly, leaving no traces, then the mixture is ready for use.

Laying the furnace with fireclay clay

Although clay for laying stoves is considered a natural material, safety requirements must be observed when preparing the solution. It is necessary to ensure that drops of the mixture do not fall on exposed areas of facial skin. When working indoors, consider ventilation.

When preparing a plaster mortar, choose the material carefully. The quality of fireclay powder depends on the manufacturing technology and the size of the fractions. To avoid mistakes, you need to check the labeling. If there is o on the packaging container, then kaolin brick material that has defects was used in production.

fireclay sand and kaolin in a ratio of 2 to 1;
the same sand and blue clay at a ratio of 4 to 1.

If simple sand is placed in the solution, cracks will appear because it will expand due to high temperature. You should not use river sand, because it does not contain the components responsible for reliable adhesion.

If Portland cement is added to the mortar mass, its strength increases several times. But the fire-resistant properties of the clay itself are reduced.

How to prepare a solution for plaster? For this you will need a mixing container, PVA, water, kaolin. Powder is poured into the container, water is slowly added until the kaolin is completely covered. You must act carefully so as not to make the solution liquid. After this, you need to wait three days for the mortar mixture to infuse.

The mixture is checked for quality and suitability for use. If the composition is runny, add sand and soak the thick mass with water. As a result, the clay should have a consistency similar to sour cream. PVA is added to the material that meets the requirements to increase ductility and strength. In addition, craftsmen advise adding fine-grained fiberglass.

Since clay does not have good plasticity, a mesh is attached to the surface intended for finishing and treated with a primer.

Fireclay clay material is popular among design specialists for its special textured solutions and beautiful appearance. Figurines, tiles, dishes and other items are made from it. Products made from fireclay clay can be an excellent decoration for any interior design.

This is all due to the fact that fireclay material, if you add certain components to it, acquires good ductility. Many people like it for its environmental safety, because it does not contain harmful toxic substances.

In order to create artistic ceramics, plastic clay of various compositions is used, adding fireclay chips to it, which accounts for about forty percent of the total volume.

When making artistic ceramics, the master creates a sketch, then makes molds and fills them with a clay mixture. Then everything is sent to dry. The process takes a long time, since everything happens naturally so that the geometric shapes of the product are not disturbed.

There are no specific instructions for using fireclay clay. But when you are not confident in your own abilities, and there is no special knowledge on preparing fireclay clay with your own hands, you should entrust the job to an experienced specialist.

It’s worth saying right away that no one can name the exact proportions of the components; accordingly, they will need to be determined independently. The difficulty is that initially the clay already contains sand, hence the distribution of the material. It can be fat (if there is a lot of sand) and skinny (if there is little sand). On average, the proportions range from 1:2 to 1:5 volume.

Preparing the composition

To mix a medium-fat solution with your own hands, do the following:

We take a construction bucket and fill a third of its volume with clay.
Then add sand to the remaining volume until it is completely filled.
Mix thoroughly, adding water if necessary.
We check the thickness of the solution (the mixture should not fall off the spatula if it is turned down, but if placed vertically, it will flow smoothly).

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When the solution is prepared accordingly, this ratio of clay and sand must be remembered in order to know in the future how much and what to use. If the fireclay solution falls off the spatula, you should add more clay and check the density again, and when it does not flow down vertically, then you should add sand.

It is important to mix the correct mortar, because if it is greasy, then when it dries, the structure will become covered with cracks, but if you mix a thin mixture, the masonry will not be strong.

Advantages of modeling clay

You can watch a video on how to make clay with your own hands. This will provide some benefits:

a person clearly sees in what sequence the craft is made;
there is an opportunity to familiarize yourself in detail with each stage of the production process;
in each instruction the number of necessary elements is calculated in advance;
a person gets the opportunity to watch a video of the production process several times and see the final result.

Using video lessons allows you to independently learn how to prepare the desired type of clay and sculpt the desired craft.

A person has the opportunity to familiarize himself in advance with the list of necessary tools and possible pitfalls.

Having studied the technology in detail, you can begin baking your craft and applying appropriate painting to it.

As a result, you get the desired craft, which can be used to decorate your home interior or as a gift. As a bonus, a person gets a lot of pleasure and saves on the family budget!

Methods for removing impurities

From the natural clay stored for oven laying, the first step is to remove foreign impurities. Various methods are used for this.

Dry punching

You can rub the clay through a sieve dry or soaked.

The most primitive way. Use your hands to pick out everything unnecessary - grass, pebbles, garbage, crush large clods. After this, the plastic material must be ground through a metal sieve with cells of approximately 3 mm.

The method can be made a little less labor intensive if the clay is dried. To do this, clay lumps are laid out on a wooden sheet and dried in the sun. In winter, this is done in the cold, laying it under a canopy so as not to be covered with snow. If the volume of material is small, it is placed indoors, on a heated stove or on a heating radiator. The drying speed depends on the size of the lumps: the smaller they are, the faster they dry.

Pour the dried clay into a box with thick walls and crush it with a tamper. After grinding, clay dust is sifted through a sieve with small mesh to remove various inclusions from it: pebbles, splinters, and other debris.

“Dry punching” is a rather labor-intensive task, so it is more advisable to soak the clay for 2-3 days after manual cleaning.

Place the material in a large basin in layers of 12–15 cm, with plenty of wetting.
Pour water in an approximate ratio of one to four with clay.
When the mass softens, mix with a concrete mixer or other means.
Wipe through a grid with 2–2.5 mm mesh.

The bottom layer - sand and stones - is not suitable for holding bricks together

There is also a more ancient method of excruciation:

Several holes are drilled vertically in a wooden container with a small distance between them.
Each of them, before filling the tub with liquid clay mass, is plugged with a wooden stopper.
Grains of sand and various small stones precipitate first due to their greater weight.
Subsequently, after settling, clay particles settle to the bottom.
The top layer of water gradually becomes lighter, but you need to wait until the liquid becomes transparent. As soon as the boundary of the clarified moisture drops slightly below the first hole from above, the plug is removed. The settled water flows out of the container.
After the next level of settled liquid appears, pull out the next plug.

This process is repeated until all clarified water is completely drained. To speed up the precipitation, after loading the solution into the tub, you will need to add bitter Epsom salt - approximately one pinch per bucket. If you don’t have a wooden barrel at hand, it can be successfully replaced by a metal container of suitable height and volume. The principle of operation is the same with one difference - first short pieces of tubes are soldered into the holes, and plugs are installed in them.

When all the settled liquid has been drained, the liquid clay is transferred to a wide box and left in the sun to evaporate excess moisture. After the dried material ceases to be fluid, stir it periodically with a shovel. As soon as the mass becomes similar in texture to thick dough and stops sticking to the palms, it is covered with polyethylene or oilcloth and stored until baking begins.

Best answers

Captain Nemo:

Ideally, clay mortar and brick are almost the same in composition and can withstand heat of more than 1000 degrees. Professional stove makers determine the quality of the clay for the mortar by touch and carry out the laying with a joint thickness of 3-4 mm. With thicker seams, the clay between the bricks does not withstand high temperatures and crumbles, cracks form into which air is sucked in, which means traction worsens, fuel consumption increases and there is a danger of carbon monoxide escaping into the living space.

The golden rule of kiln work is that the less clay in the kiln masonry, the higher its quality.

One of the basic rules of a stove maker, inherited from our ancestors: the less clay, the better the quality of the masonry. And yet, clay is the most noble building material, since it gives the right to make mistakes. If masonry with cement mortar cannot be disassembled without loss, then stove masonry with clay mortar can be disassembled easily and without waste. During renovation work, bricks and facing materials laid on clay mortar can always be preserved.

There is an opinion that the strength of clay mortar can be increased with the help of various additives. For example: for 10 kg of clay - 100-150 g of table salt or 1 kg of cement.

However, our great-grandfathers hardly used cement, and their furnaces stood for a hundred years or more.

If the components are correctly selected, the clay solution does not require any additives, and all kinds of recommendations are just a safety net.

The mortar for masonry should be plastic, moderately greasy, or, as they say, normal. The greasy solution dries, decreases in volume and cracks. Skinny doesn't provide enough strength. Clays for preparing mortar come in different fat contents or plasticity. There are clay deposits from which a solution of normal fat content is prepared without adding sand. Sometimes you have to mix two or three clays taken from different places, and strictly dose them.

First they are mixed dry, then mixed with water. If the clays turn out to be oilier, then sand is added to them, the amount of which can range from 0.5 to 5 parts by volume. The most common ratio of clay and sand in the finished solution is 1:1 or 1:2. The amount of water is approximately 1/4 of the volume of clay. Fatty clays will require more sand, which should be fine-grained and free of foreign impurities. The sand is first sifted through a fine sieve with a mesh size of 1.5×1.5 mm, at least. Very thin clays have to be washed by removing excess sand. sbani /files/pechi_glina

Sergey Kurguzov:

In general, when laying a stove, you need to do everything by eye; clay is not enough; sand needs to be sifted; and when lining, you need to add salt

Sergey Semenov:

Adding cement is optional - for an arch or vault, yes. but it is better to lay the walls without cement. Select the ratio of sand to clay by touch. because clay can be different - the resulting composition should not be too loose (flowing) and not too greasy (viscous and prone to cracks) the criterion is that the furnace seam should be 3-4mm. if you can’t get such a thin seam, the clay is greasy and tediously more sand

What is fireclay clay?

Fireclay clay is essentially burnt kaolin, which is usually called fireclay. Kaolin is one of the types of rocks that has high viscosity and plasticity. In addition to the main element, it may contain impurities in the form of oxides of potassium, calcium, magnesium and sodium, hydroxides of iron and titanium, as well as numerous sulfides.

For use, kaolin is fired at temperatures of about 1500 degrees Celsius, which allows the mineral to be rid of unbound water content. This procedure, in essence, produces finished fireclay. Impurities are removed both during the firing process and during further enrichment.

Heating kaolin to such high temperatures reduces the output ductility of fireclay, but at the same time it acquires its main feature - high fire resistance. Such fireclay is subsequently crushed for further use both to a dispersed state (sand) and to small pieces (crushed stone)

According to processing technology, fireclay is divided into two types:

highly polished;
low annealed.

They differ from each other in the percentage of water absorption: it is lower at higher annealing temperatures.

Scope of use

If we talk about application, fireclay clay is used as an additive to building materials, which reduces plasticity and shrinkage during drying and firing. For example, the addition of fireclay makes it possible to create sculptures whose weight exceeds two hundred and fifty kilograms.

With the help of this material, the ancient era, the art of Ancient Greece, the motifs of Japanese masters, and elements of primitive art are conveyed.

In European countries, fireclay clay is used in facing works to decorate facades, walls, and fireplaces. The industrial sector uses this material to produce refractory bricks, ceramics, various heat-resistant products, and collectible fireclay tiles.

The rough side retains perfect evenness; the effects of abrasions, unevenness and chipping are created on the front surface. The final cost of the tile depends on the severity of heterogeneity and curvilinearity.

With the help of refractory fireclay clay, the natural beauty of nature is conveyed, which is something that many people lack now. This means that products made from such material are still in demand today, in the age of fashionable European-quality renovations and perfectly smooth surfaces.

Fireproof fireclay clay

The material has become popular as a decorative finish in world architecture. Its quality has been tested by time, and we can confidently say that fireclay is reliable.

Proportions and mixing of the solution

You don’t need to add sand to medium-fat clay - it has the correct proportions of components 1:1

In addition to cleaning before mixing, the clay for laying the stove must be prepared. The material is laid out in a metal-lined box or barrel, filled with water so that the liquid covers it entirely. If there are large lumps, they need to be broken into smaller fragments in advance. Everything is mixed thoroughly and left for a couple of days.

The clay composition should have a paste-like consistency, without impurities. If, after 48 hours, small lumps appear in the mass, it must be mixed again, all seals broken and kept for another day.

After preparation, you can begin preparing the solution. If clay and sand are mixed, the latter is poured into a prepared container, then plastic material is laid out, and a sand layer is again poured on top of it. A shovel is used to mix the components. If moisture appears at the top, add a little sand. If the mixture is too dry, add water. The solution can be considered ready if it begins to slowly slide off the shovel and becomes homogeneous.

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If the base is medium fat, you don’t need to add the sand component. Step-by-step instructions for diluting clay without sand for a stove with your own hands:

The material is laid out on a wooden platform in layers, each layer is wetted.
Upon reaching a height of 30–35 cm, the mass is mixed. For this purpose, you need to slap the top layer with the back of the shovel.
The kneading continues until a homogeneous substance is formed.

You can check whether the masonry clay for the stove is prepared correctly: apply a thin layer on the red brick, place another block on top and leave for an hour or two. If, when lifting the top brick, the bottom one does not fall off, you can use the composition to build a stove. The clay takes a long time to set, so you can immediately mix the required volume of the binder composition. Laying out a 50-brick stove for a bathhouse will require approximately 20 liters, and to build a Russian stove it will take 15–20 percent more.

Failure to comply with the proportions of the components of the solution leads to cracking of the structure

How to dilute clay to putty a stove:

The dry base is ground and soaked.
Sand with lime or cement is added. The proportions of medium-fat clay with sand and lime are 1:2:1. When including cement powder, you need to proceed from the amount of sand component in a ratio of 1:3.
To make the plaster layer stronger, you can add asbestos, fiberglass, hemp or straw in a ratio of 1: 2: 0.1 (clay/sand/additives).

When additional ingredients are included in the clay solution, they are first mixed with each other, and only then with the pre-soaked clay.

Self-cooking method

As a masonry mortar I use fireclay clay with the addition of cement.

To make decorative items at home, you don’t need to use refractory clay. In most cases, another material that will be just as flexible and durable will be perfect. But before you make polymer clay, which is what we are talking about, you need to prepare the following ingredients:

PVA glue;
Starch (you can use potato or corn);
Vaseline or hand cream;
Baby oil.

The composition is quite simple, since almost all the elements can be found in any home. You will also need a container of the required size and a plastic spatula, which will be used for mixing.

Bottom of the firebox, grate installed in place

Starch, petroleum jelly and PVA are placed in a container and mixed thoroughly. When the mixture becomes homogeneous, add two tablespoons of oil and mix thoroughly again. After this, the resulting solution must be placed in the microwave for exactly one minute. Then you need to mix the polymer clay again. Next, the surface of the table needs to be lubricated with a cream that does not contain silicone. Place the resulting mass on it and soften it with your hands. After some time, you should get a dough that has the properties of polymer clay. If you do not need to use it right away, the mixture can be wrapped in plastic and stored in the refrigerator.

Checking the quality of the solution

The first testing is carried out before preparing the clay for laying the stove. In order for the solution to be of high quality, you need to accurately determine the fat content of the clay. It will depend on what additional components are required.

How fatty clay is for a stove is determined as follows:

A small amount of clay - approximately 1 kg - is thoroughly cleaned using one of the methods described and soaked for several days.
The resulting mass is divided into five equal parts. Nothing is added to the first, the second is mixed with 25 percent of sifted sand, the third with 50 percent, the fourth with 75 percent and the fifth with 100 percent.
Each part is kneaded separately. If necessary, add a little water until a paste-like structure is achieved. You can determine the readiness of the solution with your hands. If it does not stick, the mixture is considered ready.
The resulting material is tested for plasticity. Each of the five particles is rolled into a small ball and flattened into a flat cake. All resulting samples are marked with labels indicating the proportions of sand and sent to dry. It will take 2-3 days for the fragments to dry.
The resulting samples are tested. The cake should not be cracked or collapse when compressed. If you throw it on the floor, it should remain intact. Based on the results of such testing, the correct proportion of sand and clay components is revealed.

You can test for fat content and plasticity in another way. Roll balls about 3 cm in diameter, place each one between two carefully planed boards. Gently, smoothly press on the top one and check the condition of the ball. If it immediately cracks, the composition lacks fat content. If cracks occur at half compression, the mixture is too oily. With the correct proportion of components, most of the sample will flatten, but will not collapse.

A properly formulated solution will not crack immediately after application.

Additionally, oven clay is tested before use. It is better to redo the solution than to waste time building a stove that will crumble. To check, scoop the composition with your hand and rub it with your fingers. A good binder solution should be slippery and oily. Experienced stove makers determine the readiness of the composition by ear when kneading.

A correctly made mixture “whispers” - makes a kind of rustling sound, and lags behind the shovel. You can also dip the trowel into the mixture, pull it out, and then turn it over. If a thick layer sticks, the composition is too greasy, you need to dilute it with sand. If the mortar layer falls away, there is excess sand, you need to add clean clay.

Application

Refractory types of clay are used to produce molding mixtures, bricks, plaster compositions, and masonry mortars. For the manufacture of each type of product, a specific brand of fireclay clay is selected, taking into account the technical characteristics and price.

Furnace laying

The most popular products are refractory bricks, which are used to lay out the most critical parts of stoves.
Only fireclay types of brick products can withstand maximum furnace temperatures. The remaining kiln layers are usually made from cheaper ordinary bricks. Masonry compositions must have the same coefficient of expansion when heated as the main brick of the firebox. Therefore, mixtures based on refractory clays are used to prepare solutions.

Before starting work, you should make a calculation, taking into account that for one hundred bricks you need to make approximately 3 buckets of masonry mortar

To prepare mixtures that fix bricks, a clay product with a significant concentration of sand is used. When the mass fraction of silicon oxide is equal to 55%, the clay is called a binder; from 19% to a maximum of 48% - smooth. When the sand concentration is less than 21%, the refractory clay is considered depleted.

Features and Benefits

It is better to purchase fireclay clay not from hand or on the market, but from a specialized store. This way, there is less risk of buying low-quality products or those that were stored in inappropriate conditions. The fact is that low air humidity is very important for kaolin, otherwise it loses its unique properties and becomes as unstable to high temperatures as ordinary clay.

The production of fireclay clay is carried out in accordance with the requirements of GOST - 6137−8. According to this document, fireclay must have the following characteristics;

humidity - 5% or lower;
water absorption for low-burnt fireclay is up to 25%, for high-burnt fireclay - up to 10%;
average particle size - 2 mm;
fire resistance limit - 1550−1850 ° C.

The material is sold packaged in bags of 5, 12.5, 20 and 50 kg. To lay 10-15 bricks, 10 kg of burnt kaolin is required, which is equivalent to 1 thousand kg per 1 cubic meter. m. Hardening of the solution occurs at air temperatures from 10 to 25 °C. Strengthening continues for 28 days.

Clay can be stored in its original packaging for 3 years from the date of production. Advantages of calcined kaolin:

Fire resistance, allowing the product to be used for the construction of stoves, chimneys, fireplaces.
Vapor permeability. The material allows excess moisture to pass through, maintaining an optimal microclimate in the room.
Good adhesion. Chamotte-based plaster mortar adheres well to various surfaces.
Safety for humans and the environment due to the fact that the composition contains only natural ingredients.
Long service life. For several years, the clay does not crumble, crumble or crack.

There are only 2 disadvantages: the difficulty of preparing masonry mortar and the high cost compared to ordinary clay.

Fireclay clay for plaster has gained its popularity for a reason. Its advantages:

Durability. When used correctly, fireclay clay does not deteriorate for a relatively long time.
High adhesion. This quality allows the clay to have excellent adhesion to almost any surface it comes into contact with.
Vapor permeability. This material will not become damp over time due to concentrated moisture nearby.
High fire resistance. Can be used in ovens and similar conditions unsuitable for other materials.
Safety and environmental friendliness. The clay is free of toxins and is of natural origin.
Excellent arrangement with fireclay bricks due to the same linear expansion coefficient.
Uniformity during heating. The expansion of the material with increasing temperature occurs gradually, and the appearance of cracks in it is excluded.

It is not without its shortcomings. Like all materials, fireclay is excellent for use in some conditions, and behaves poorly in others. The main negative qualities of fireclay clay usually include:

high cost;
complex preparation of the correct solution.

The first drawback can be rethought by comparing the properties of fireclay clay with other binding materials, and based on the price-quality ratio, a final decision can be reached. The second is simply solved by a clear sequence of actions when mixing the solution.

Tags: clay, knead, masonry, oven, fireclay

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Plastering process

Stoves and fireplaces are structures that are constantly exposed to intense heat, so it is very important to choose the appropriate material. Firebricks made from fireclay clay are excellent for this application.

When buying bricks of this type, you should pay attention to the marking, which should contain the letter “Ш”

To obtain a perfectly flat surface, you should use the rule. It is fixed across the vertical profiles so as to achieve simultaneous contact of all beacons horizontally.

When installing beacons, you should also pay attention to the level of extension of the furnace door and the blower. The level of the profiles and doors must match so that the surface is smooth, without protrusions and depressions. Preparing mortars for laying stoves and fireplaces, plaster for decorating premises is in many ways similar to mixing conventional compositions

Application to the surface is also carried out using the same tools, namely two spatulas: with one tool the solution is placed on the surface and leveled, with the other to remove smudges. Other recipes are used to produce building ceramics and modeling compounds. But the general principle is this:

Preparing mortars for laying stoves and fireplaces, and plaster for decorating premises is in many ways similar to mixing conventional compounds. Application to the surface is also carried out using the same tools, namely two spatulas: with one tool the solution is placed on the surface and leveled, with the other to remove smudges. Other recipes are used to produce building ceramics and modeling compounds. But the general principle is this:

the contents of the package are poured into the container;
the powder is filled with a certain amount of water;
swelling of the powder continues for 3 days;
on the 4th day water is added, in some cases sand, in others additives;
the mixture is stirred until smooth.

Mixing the solution

Before starting work, you need to decide which part of the heating device you will fold at one time. You need to cook a strictly defined portion. Calculations are made as follows. Each brick requires approximately 1 kilogram of mortar. Therefore, to lay 30 bricks you will need to mix the mixture from a standard 2 kg bag.

If 1 cubic meter is used at a time, 5 packages will be required. The work is carried out according to a standard scheme using quartz sand. The proportion of clay and sand for a large oven is one to three, respectively, for a small hearth – one to two. If you are using a ready-made product from a store, quartz filler will not be required. Process Features:

sand and clay or the finished product is poured into a container;
water is also added there, it saturates the powder, when it is completely wet, another liquid is added, its surface should be at a distance of one phalanx of a finger from the wet mixture;
the mixture settles for up to 3 days;
on the 4th, stir the solution with a construction mixer until homemade sour cream becomes thick; if it is dry, add water; if liquid, add powder;
Having achieved the desired density and uniformity, you can begin work.

The technology of laying on fireclay clay does not differ from the usual technique. Experienced masters of masonry heating devices recommend making seams no thicker than 1 centimeter. The structure must dry completely, this will last from 2 days depending on the temperature and humidity. Experienced craftsmen believe that a folded stove contains at least one barrel of water.

To completely evaporate it, after the outer layer has dried, the device needs to be heated little by little 2 times a day with a small armful of firewood. In summer, this procedure lasts from 5 to 10 days, in winter – up to three weeks. Until the stove is completely dry, you cannot heat it to heat the premises. It is also worth understanding that heating structures are not only a source of comfort in the home, but also danger. If the master is not confident in his knowledge, it is better to use the services of professionals.

Construction of furnaces

The production of ceramics from refractory clay can be done in two ways: with firing and without this process. But work begins with preparing the solution:

fireclay and ordinary clay are placed in the container in a ratio of six to four, respectively;
materials are filled with water and left for several days;
the solution is thoroughly mixed with a mixer to a thick consistency - for castings;
the material is poured into molds and dries for several days, depending on the size and geometry; PVA glue can be used to speed it up;
the frozen mass is removed from the mold and modified according to the design.

Garden decor made of fireproof clay