Brick ovens eventually need repair. Cracks can occur during long-term operation, or due to errors in its construction. It is not always possible to do a complete reconstruction, and often it is not necessary. Timely repair of a brick oven solves the problem for several heating seasons ahead.
You can invite a specialist or close the cracks in the furnace yourself.
What composition close up cracks in the furnace
Thermal expansion in brick kilns often results in cracks at the junctions with steel structures. Contribute to their appearance and local overheating, and sometimes - errors in the construction of the furnace. It happens that the solution does not spill out, the smoke does not come out, but you still need to close the gaps. No one can guarantee that at some point smoke cannot come out of them. And when the stove smokes, being in the room is not only unpleasant, but also unsafe. The current repair of brick ovens with your own hands will save money for a large-scale reconstruction of the heating facility in the future.
The easiest way to close up small defects, up to 0.5 cm. cement.
On sale there are many options for ready-made solutions. They are accompanied by detailed instructions and manufacturer's recommendations. Experienced stove-makers solve the question of how to cover up the cracks in a brick oven simply: you need to use the same mortar for repairs as for laying. But most often the composition is unknown, since usually old structures have to be repaired.
If the splits are deeper and wider, then crushed fireclay and alumina (aluminate) cement are added to the solution for repairing a brick oven. This cement hardens very quickly, the raw materials for its production are limestone and rocks containing aluminum oxides. Crushed chamotte will give the solution thermal and chemical resistance. A finely ground additive for laying kiln structures will solve the problem if it is not possible to find alumina cement, and Portland cement is used instead. The ground chamotte plays the role of a "reinforcing mesh", thereby preventing the appearance of fresh cracks.
How to cover up cracks: stages of work
When the solution is ready, you can begin to cover up the defects.
The repair steps are as follows:
- preheat the oven (to a warm, not hot state);
- cracks expand;
- thoroughly cleaned from dust and dirt;
- be sure to moisten with plenty of water;
- smeared with prepared solution.
Further heating is possible only after the solution has completely dried. But this should be done at a maximum of half of the fuel bookmark. After the fuel burns out in the “light” mode, you can heat the stove as usual.
Attention: it is better not just to cover the cracks in the brickwork with a mortar, but after laying them with an asbestos cord. When working with asbestos, you need to use a protective mask.
Thus, in order to learn how to repair a brick oven with your own hands, you must definitely study the procedure and composition of the solution.
Features when repairing a firebox
Most often, the firebox is damaged when it is lined with ordinary red brick, and not fireclay. The brick is stratified and falls off with plates. How to repair a brick oven in this case? It makes no sense to cover up and reinforce red brick, it still crumbles from high temperatures. Since it is impossible to reduce the temperature level in the firebox, additional lining must be made to reduce the effect of temperature on the walls.
The inner lining of the firebox is made using the following materials:
- Cast iron. It will be enough for a long time. But there is one trick: you need to leave a gap between the wall and the cast iron. For this, corrugated cardboard is laid, which will burn out immediately at the first firebox, and the gap will remain.
- Steel. For. To repair with steel. It is also necessary to make a gap. But steel will still burn out quickly enough, especially if repairs are made in a bath furnace.
- Chamotte brick SHA-6 ("bream"). It is able to serve without splitting under prolonged loads of extreme temperatures. A gap of 1 cm is left between this brick and the wall with the help of embedded basalt cardboard. The solution is taken the same as when laying fireclay. After repairing the stove with the help of the furnace lining, the heating rate of the room will be reduced, but the temperature inside the furnace will be higher. Combustible gases burn out completely.
- fireclay brick. You can repair a destroyed firebox with ordinary fireclay bricks placed on edge. True, it will reduce the furnace space, the gap between it and the wall will also have to be maintained.
- Vermiculite boards. Such plates are environmentally friendly, do not emit harmful fumes, are made entirely of natural material, and are highly fire resistant.
- Superizol (calcium silicate). When the question arises of how to repair the furnace with your own hands, it is worth considering this safe material of mineral nature. It can easily warm up to 1000 degrees.
Attention: vermiculite plates and superisol are not often used. But they justify themselves in cases where you do not want to reduce the size of the firebox. The only task that will have to be solved when repairing the furnace furnace is to organize the fastening of these fire-resistant panels.
How to repair cracks around steel elements
Metal and brick have different expansion when heated, and this leads to cracks. To prevent this from happening, stove-makers make special recesses in the bricks during the construction of the stove. Steel or cast iron elements are laid with heat-insulating materials (asbestos cord, asbestos cardboard, or mineral wool cardboard). The heat insulator must be resistant to temperatures from 800 degrees.
How to repair a brick oven with your own hands if these requirements were not met and cracks appeared? Such gaps are sealed with a solution with the addition of fireclay. In case of large damage, the structure is disassembled, the fixing wire is tightened and the metal is wrapped with a heat insulator.
How to prevent cracks in the hob
In heating and cooking stove structures, the “sore” place is the cast-iron hob. By themselves, cracks in the panel do not interfere with the operation of the furnace. If it is folded correctly, it has good traction, cracks do not cause inconvenience. But - for the time being. If the design of the furnace is broken or there are errors in the masonry, then carbon monoxide can seep through these cracks. And this is a big threat to the lives of people who are in the room.
As a rule, high-quality cast-iron panels almost never crack. But it's better to be safe.
In order to prevent the appearance of cracks on the panel, the first heating of the oven with a new hob is done carefully, it is heated slowly, without loading the entire furnace. To distribute heat evenly over the panel, a thick layer of sand is poured on it, or a brick is laid out. The sand is removed or the brick is removed from the panel only after it has completely cooled. A uniformly loaded panel will “sit down” without distortions, which means that there will be no “stress” cracks in it.
In order not to crack the stove in the house, it is necessary to take a responsible attitude to the performance of work during the construction of the building. The main causes of the malfunction are laid at this stage. But if the problem has already arisen, it is important to quickly eliminate it. How and how to do this, you will learn about this in the article.
Collapse
First you need to understand why the cracks are spreading along the wall of the stove.
Reasons for the appearance
Before you properly and reliably cover the oven, in order to prevent repeated malfunctions, you need to know what can affect the integrity of the oven coating:
- with a long break in the heating of the house and sudden changes in temperature;
- the laying of the furnace was carried out on a poor-quality mortar;
- perhaps the reason is the settlement of the building or foundation. In this case, it will be necessary to carry out a major overhaul of the foundation, increasing its size and strength;
- after laying the furnace, the process of normal drying of the surfaces was disrupted;
- when plastering the oven, a low-quality mortar was used or a thick or very thin layer was applied;
- perhaps the reason is faulty ventilation and condensate settling on the walls of the furnace.
Can a cracked stove be used?
The answer to this question is unequivocal - it will be necessary to cover up a faulty, fuming stove immediately, it is not recommended to use it. Such requirements are explained not by a violation of the appearance of the walls, but by cracks that let carbon monoxide into the room. Poisoning by combustion waste can lead to sad consequences.
The statistics of firefighters say that most people die in a fire because of gas, and not from fire.
Damage diagnostics
Therefore, at the first sign of smoke in the house, you will need to do:
- diagnose the surfaces of the furnace and find a malfunction;
- after that, immediately prepare a solution or buy ready-made material to fill the gaps;
- plaster the walls and re-plaster them.
But first of all, it is the diagnostics that will help determine the size of the damaged surfaces and the approximate amount of materials to be eliminated. If the solution just cracked from high temperatures, you just need to beat off a layer of plaster and apply a new layer of quality materials.
It is worse if the cracks are through and continue to expand after the work has been done. In this case, it may be necessary to call specialists to find the causes and lay a new stove. Stone stoves are a complex structure, so you should not try to lay it out according to the book, it is better to entrust this work to an experienced stove-maker.
Such cracks can no longer be simply covered up.
In this example, too, do not gloss over. The brick was badly cracked.
If the cracks are small and their size does not increase, you can proceed to fix the problem yourself. To do this, it is important to prepare a quality solution and properly apply it to the wall. How to cover up cracks in the furnace so that it does not crack from heat - knowledge of the basic materials for making the solution will help in this matter.
Examples of small cracks:
How to cover cracks?
For these purposes, you can use several options that will reliably seal cracks in the walls and prevent gas from escaping into the room. Let's analyze each method in more detail.
Chamotte clay
Before you cover the cracks on the stove with fireclay clay, you need to know its advantages: 
- the material is resistant to the effects of temperature during fuel combustion;
- high level of vapor permeability;
- resistant to moisture when heated;
- environmentally friendly material, safe for humans and animals, so it can be used in residential areas.
To make a solution, you need to mix several ingredients:
- 1 part cement brand 500;
- 2 parts fireclay clay"
- 7 parts river sand.
The solution is well mixed and water is added. The consistency depends on the skill and type of work, but you should not make it very liquid or thick. To get rid of stones and lumps, the clay can first be soaked in water for several hours and knead the lumps of material, and sift the cement and sand. Such a solution will be plastic, laid on the surface in an even layer.
Plastering walls with a certain skill is easy. To do this, it is important to install beacons and distribute the solution, level the layer on the wall. You will need to prepare a trowel, a spatula, the size of which depends on the surface area.
clay and sand
This is the most democratic inexpensive solution for plastering surfaces. Such a solution for the furnace has sufficient plasticity and is not subject to destruction under the influence of high temperatures.
Preparing the solution for work is simple, for this you will need:
- prepare a large trough in advance, fill in the required amount of clay and completely fill the layer with water. For 1 bucket of clay, pour 3 buckets of water. Clay should soak within 24 hours;
- then mix the solution, and add more water to it. We pass the liquid through a sieve, get rid of lumps and let the solution settle;
- we drain the protruding water, extracting the density of the solution like homemade sour cream;
- in a ratio of 1 to 1, add river sand and mix the solution.
Expert opinion
Pavel Kruglov
Baker with 25 years of experience
Important! At this time, the quality of the solution can be determined. Having lowered the handle from the shovel into it, and seeing the adhered clay - in this case, you will need to add a little sand. Only after seeing small clots of a solution of sand and clay on the holder, you can start plastering the walls of the stove.
With this solution, it is necessary to repair all the cracks that have appeared, after wetting the surfaces and then plastering the stove in several layers. In villages, the old method is still used, adding horse manure to the finished solution. Such a solution is obtained with enhanced thermal insulation properties. Hay plays the role of air layers that prevent the free passage of heat.
Grout
Such a putty for the oven is sold ready-made, but it is easy to make it yourself. The main advantage of this material is the ability to maintain properties even when heated to 10,000. Industrial materials are used to equip and repair stoves and fireplaces, but the price of such a grout is high, so home craftsmen make it with their own hands.
The mixture for coating the oven is done in several stages:
- knead large lumps of clay and pour it into the trough;
- fill it with water and leave for 10-12 hours;
- we pour part of the sand into the soaked clay, maintaining a ratio of 1 to 4, knead the solution well, adding 5 parts of chopped straw in small portions;
- add 1 kg of coarse salt to the finished putty and finally mix the solution.
Ready grout can fill gaps between bricks, cracks, cracks and make the first draft layer of plaster.
oven glue
In order to repair the stove from a crack, you can buy heat-resistant special glue at a hardware store. Due to its properties, it is not exposed to high temperatures for a long time. In its composition, the addition of fireclay clay and cements with high refractory properties is used.
A plastic and solid mixture of glue is produced. With the help of solid materials, the surfaces of furnaces are plastered. Cracks and seams between bricks are filled with plastic glue.
When using this material, follow the instructions for dilution and use of the heat-resistant substance. It should not be done in large portions, it dries quickly and becomes unsuitable for work.
How to coat the oven correctly?
In order to reliably cover the cracks in a brick oven, work is carried out in several stages:
How long to wait for drying?
It is not recommended to use the oven until the solution is completely dry. When using different materials, this period may vary. Using a heat-resistant adhesive as a putty, the mortar layer will dry within a few hours.
More time will be required for drying and becoming a solution of clay and sand. In this case, it will be possible to use the stove only after a day. Then the brick oven, protected from cracks by mortar, will remain crack-free for a long time.
Therefore, we do not advise you to rush, immediately flooding your Russian stove with a stove bench. Sealing cracks in the furnace is a simple but responsible job. The choice of material for the solution is a purely individual matter. The main thing is to do the work carefully and responsibly. Then your house will always be light and clean, without the smell of burning and smoke penetrating through the cracks in the walls of the furnace.
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The brick oven is designed for a long service life. But sometimes it can fail for one reason or another. In order to less often face the problem of serious destruction of a brick oven, it is necessary to carry out preventive and repair work in time.
To fix minor problems, you do not need to call the wizard. You can solve such issues on your own, having little skills in construction.
A standard brick oven consists of:
- grounds
- prefurnace sheet
- ash pan and furnace
- grate
- chimney and pipes
All repairs of a conventional design are divided into:
- current
- average
- capital
Main problems and how to fix them
Minor Issues
- Scuffs that appeared on the pre-furnace sheet. They can lead to serious problems and even fire. To solve the problem, the wiped sheet is replaced with a new one. To do this, we dismantle the deteriorated metal, protect the flooring with an asbestos sheet and fasten a new sheet of metal of the desired size on top.
- Replacement grate from the grate.
- Lack of traction. If the draft is gone, most likely you are faced with a clogged chimney or lack of air flow. Once a year, inspect the chimney for dirt, debris, and foreign objects. Chemical preparations are used to clean the channels.
To clean the chimney from soot, you will need to prepare:
- Firewood
- Trowel with sharp edges
- Soot scraper
- Clay mortar for masonry
- Lime and plaster for whitewashing
The whole working process comes down to heating the stove with wood. It is better to use alder or aspen firewood, as they quickly burn out, form good traction, and burn out soot. Sprinkling salt on the wood can clean the chimney and chimney of soot. This procedure is recommended every three months.
Replacing the grate comes down to:
- Taking out old grates
- Carrying out repair work on masonry and blowing, if necessary
- Laying a new grate, not forgetting to leave gaps of 5 mm
- Filling gaps with sand or ash
Attention: the new grate from the grate must strictly match the old one in size. It must be laid in its original place without the use of a solution.
Problems of medium complexity
- Shattered furnace door
- Damaged chimney
- Firebox repair and relocation
Medium repair work also includes the renewal of masonry joints. They not only spoil the appearance of the structure, but also let harmful gases into the room. To detect problem areas, it is recommended to heat it. To solve the problem, you need:
- Clear the seams.
- Rinse the walls with water using a brush.
- Noticeable cracks and defects in the brickwork should be filled with a new clay mortar.
So that after drying the clay does not crack, it is worth adding a little table salt to it. For one bucket of clay, it will be enough to add 300 grams of salt. If the cracks in the masonry are large and deep, they should be sealed with a refractory cord.
A shattered furnace door can be strengthened. If you notice that gaps have formed around the doors, and it wobbles a lot, it's time to repair it:
- We clean the repair site to the brick and rinse it with water
- We prime the surface
- We put a sealant in all the cracks
- We close it with a solution
To prepare the solution, we need to take:
- Chamotte clay
- Heat Resistant Adhesive
- Portland cement
- Sand
The prepared composition should be similar in consistency to sour cream.
After strengthening the furnace door, after 24 hours, the structure should be heated with a small amount of firewood.
Capital works
- Complete lining replacement
- Alteration of the furnace from one type of fuel to another
- Repair and re-laying of brickwork
Repair without dismantling the oven
If you need to replace burned-out bricks without dismantling the stove, prepare the following materials and tools:
- Brick
- A hammer
- Masonry mortar
- Scraper and trowel
Instead of old burnt bricks, it is necessary to lay new material, having previously moistened them with water. Next, apply the solution to the masonry.
Attention: with the prepared solution, carefully lubricate the place of the fallen brick. The new material is placed in its original place, pressed and sealed.
How to shift the firebox
It also happens that the refractory brick from which the masonry is laid is destroyed and becomes unusable. In this case, it is necessary to repair it through the furnace door. If the damage is small, clay mortar will help to cope with them. If only a few bricks are destroyed, it is recommended to replace them by removing the old mortar.
To complete the work, you will need to prepare:
- Spatula, hammer and chisel
- Solution
- Refractory brick
The old mortar is removed with a construction tool, this place is wetted with water, and new bricks are laid on top.
When repairing the firebox, it is advisable to use the same solution that was used during construction. After repairing the furnace, it will be possible to use the stove only after a week.
How to restore an oven
If you want to restore an old brick stove and restore its aesthetic appearance, you should stock up on the following materials:
- Heat resistant tiles
- paint
- Whitewash or lime
When decorating the oven with tiles, it must be laid on a prepared and even surface. Be sure to use bas-relief edges and frescoes. The advantages of this material include:
- Ease of care
- Presentable appearance
- Durability
If you want to cover the oven with paint, pay attention to the material that can withstand temperature changes. To give the product originality, apply drawings and ornaments with paints using a stencil.
Whitewashing the oven is the most common option. To give a snow-white sheen, add salt to the composition of lime.
Oven Repair Safety
Before you start repairing a brick oven, be sure to take care of safety:
- To prevent heating and ignition of wooden surfaces, use insulating materials adjacent to the heated part.
- Choose your consumables carefully. They must be of high quality and without visible defects.
- To prepare the solution, it is recommended to use oily clay and heat-resistant glue.
- Before starting work, place a steel sheet in front of the vent.
Summing up, it is worth noting that timely preventive work and repair of minor problems will significantly extend the life of a brick oven. Keep in mind that repair work must be carried out with full responsibility, since not only the performance of the structure and its appearance, but also the safety of your home depends on this.
If your brick oven is broken and you need to repair it, then in this article you will find practical tips for repairing ovens with your own hands and the features of their implementation.
You can and should repair the stove yourself with your own improvised means.
There are different types of ovens. Usually they consist of a foundation, a pre-furnace sheet, a furnace and an ash pan.
An ordinary brick oven consists of a foundation, a pre-furnace sheet, a firebox and an ash pan (in the common people - a blower). A grate is necessarily attached inside the stove. The outer part is a chimney and a pipe. Often the oven is equipped with a cast-iron stove. In some versions, the stoves are tiled.
Consider the most common types of brick slab breakdowns and options for fixing them with your own efforts. Repair is conditionally divided into 3 types: current repair, medium and capital.
Current (minor) repairs
A special door is provided for cleaning the oven.
It is impossible to melt the furnace - there is no draft. Occurs for some reason. This, for example, after a long break in the use of the stove, the accumulation of cold air in the chimney, the lack of air flow that would support combustion, a strong wind outside; chimney clogged with soot.
We do this: we use not paper for ignition, but a piece of rubber or dry fuel; kerosene and other flammable liquids are not recommended.
If the chimney is clogged with soot, this can be determined by how long it has been “blown out”. It is recommended to do this at least once a year, preferably in the summer. It is necessary to take a number of measures to eliminate this problem. First, you need to try to burn out the soot in an improvised way. To begin with, we pour a handful of coarse salt into a burning stove and quickly close the barrier, because it will crack a lot, pieces of soot will fly out through the chimney. If it does not help, then you need to clean it manually through a door specially provided for this.
If the stove smokes heavily, the brickwork may have “leaked out” and, as a result, cracks have formed that need to be covered with hands.
If the brickwork is “leaky”, then the seams are covered with a solution of clay and sand with the addition of crushed asbestos fiber and salt.
For coating, we prepare a solution of clay with sand with the addition of crushed asbestos fiber (for elasticity) and salt, 100 g per 3 l of solution. The solution should be of medium viscosity (this is important, since fatty, drying, it will crack, thin - it will not give strength, and then the masonry will crumble). You can buy oven mixture in the store and do everything according to the instructions that are attached. Make repairs with the finished mixture faster.
The problem of replacing a burned-out brick arises in the event that the old one falls out or burns out.
We clean the place of the old brick with our hands from clay and dust, moisten it with water, put a pre-prepared clay cake there. Before laying a new brick, we dip it into water and coat it with a clay solution on the sides and top - to secure all the seams. Next, carefully lay it in place of the fallen or burnt brick. The mortar for brickwork is the same as for sealing cracks.
Medium repair work
When replacing the grate, it is necessary to provide a 5 mm expansion joint between the grate and the brickwork.
This is the repair and strengthening of furnace parts with your own hands.
You can strengthen the loose furnace door by first dismantling the brickwork near it and re-securing the door with steel wire.
When replacing the grate, it must be borne in mind that they should not lie close to the brickwork, but with a gap of 5 mm, fill the gap with sand.
Pre-furnace sheets should be changed if they are perforated or rusted, they should not be repaired. They removed the old sheet, took out the nails, put a piece of felt soaked in a liquid solution of clay under the bottom, and nailed a new sheet on top.
The stove must be periodically whitewashed with a solution of lime. Lime is known for its antibacterial properties.
When replacing the lining, the old and new masonry are made of homogeneous bricks, since there must be the same coefficient of thermal expansion.
A furnace needs a more serious repair, in which the lining of the firebox has broken, the chimney has been damaged, or there is a need to re-lay the brick "under". When changing the lining, it is necessary to take into account the fact that the old and new masonry are made of homogeneous bricks, since there must be the same coefficient of thermal expansion. In the same way, change the brick in the chimney.
Repair of a tiled stove deserves special attention. A very carefully damaged tile is taken out, the place where it was cleaned, placed on a solution previously made of clay with the addition of brick rubble, a new tile is placed, which is preliminarily adjusted to fit the size of the place. The masonry should be even, we rub the irregularities with our hands.
Capital reconstruction
The overhaul of a brick stove includes the restoration of full working capacity, the replacement or improvement of broken parts. You can also do this on your own.
When repairing the chimney, the destroyed masonry is sorted out. The outside of the chimney can be plastered.
Chimney repair. Outside, we simply plaster the masonry. If the masonry is destroyed, you need to sort it out.
Lining. If you need to change it completely, it is not recommended to touch the main masonry of the furnace. We disassemble the wall of the furnace from the ash pan to the height of the firebox, do not touch the ribs of the furnace, remove the rubble from the analysis of the old lining, lay out a new one without tying it with the brickwork of the walls. Seams should be no more than 2 mm thick.
Converting a furnace from one type of fuel to another is a crucial moment. Each stove-maker has his own methods of reworking. Let's consider one of them. We lay out the walls of the firebox with refractory bricks, always on. We make small slopes around the sides of the firebox so that the coal rolls down during the furnace and the grate is closed with hot coals. We pay attention to the quality of the bricks used.
A few words about the operation of the sauna stove. You can repair it, like a regular one, with the only difference being that we carry out preventive measures more often, since the temperature of the sauna stove is much higher than usual. In this case, the fire resistance of bricks and mortar is very important. In no case do not use the oven with a broken stove, it is better to replace it.
Useful information
The tools that will be needed in the process of repairing the furnace are your hands and desire, a sufficient amount of bricks, a double-sided stove-maker's hammer (on the one hand, it is like ordinary milk, and on the other, in the form of a pick for breaking and breaking bricks), a trowel, a plumb line, level, tape measure, bucket for mixing the solution.
In conclusion, it should be said that by repairing minor problems in a timely manner, you will prevent the occurrence of serious breakdowns and your stove will serve you faithfully for a long time. Repairs must be done conscientiously, because the safety of your own home is at stake.
Sooner or later, the owners of summer cottages and private houses have to solve the problem - how to cover up the stove? A failed heating device poses a threat to the life and health of the inhabitants of the house. It is no coincidence that fire safety rules prohibit the operation of a faulty furnace. The work of a master stove-maker is not cheap. However, if necessary, you can repair the "heart of the house" yourself.
Why is it forbidden to operate a faulty furnace?
The oven can fail for various reasons. Sometimes it is easier not to cover up emerging defects, but to re-shift the furnace. However, such drastic measures are rarely required. As a rule, the main causes of an emergency condition are shrinkage, poor-quality materials and mistakes made when laying out the hearth.
Heating systems require regular maintenance. According to the norms of SNiP, heating devices in the country should be examined twice a year. And in a private house at least once a quarter. Unfortunately, most homeowners neglect these requirements.
The main danger for the residents of the house is not a collapsed hearth, but the cracks that have appeared in it. The explanation is simple - obviously no one will heat the emergency furnace, but cracks can not always be noticed in time. Carbon monoxide seeping through them is a serious danger to the inhabitants of the house. According to statistics provided by the Ministry of Emergency Situations, in a fire, 70% of people die from smoke, and of those who survived, 42% end up in the hospital with carbon monoxide poisoning.
Therefore, timely repairs are the key to the safety of your family. Most stove masters, when asked: “how to cover the stove so that it does not crack from the heat?”, Will advise using clay. However, there is a nuance here. There are several types of mixtures and almost all of them use clay.
Clay - the basis of kiln masonry mortars
Clay is the main component in the manufacture of masonry kiln mixtures. This is due to its unique quality - when heated, it turns into stone. Clay mortar withstands high temperatures and ensures the reliability of the entire structure. But other ingredients are also used to make it. Clay is divided into two types: dry and oily. When heated, the first crumbles, and the second cracks and dries out.
Note that the ratio of the components of the solution will always be different. Each time the proportions are determined by experimentation. After all, in nature there are never two absolutely identical breeds. For each solution, depending on the fat content of the clay, the ideal combination of ingredients will change.
The quality of the breed is determined as follows. It is necessary to roll up a clay cord 1 cm thick and 20 cm long, and then wrap a wooden blank with a diameter of 5 cm around it. A normal clay cord gradually stretches and when its thickness decreases by more than 70% of the initial volume, it breaks.
The most common is a mixture of clay and sand. It is in demand when laying, finishing and repairing the hearth.
The name "clay-sand mortar" speaks for itself. It consists of sand, clay and water. Oddly enough, problems can arise even with water - it should not contain mineral salts and silt. Otherwise, even whitewashing will not save you from protruding salt stains. At the beginning of the 20th century, craftsmen used rainwater to mix the mortar. However, not only water needs to be cleaned.
Sand, which is used to prepare the solution, is pre-sifted through a sieve. This allows you to clean it of gravel, grass and roots, which makes the masonry joint thin and neat. Before starting to mix the solution, the clay must be soaked in warm water for 12 hours.
The step-by-step preparation of the mixture is as follows:
- 1. Stir the wet clay mortar - there should be no lumps in it.
- 2. Add the sifted sand to the prepared mixture. The combination of 4 parts of clay and 2 sand is considered optimal. Although the amount of sand depends on the clay, more precisely, its fat content.
- 3. Sometimes, if whitewashing the hearth is not planned, lime is added to the solution. After mixing the solution to a creamy state, cover the container with plastic wrap and forget about it for 12 hours.
- 4. Do not forget to mix the settled mixture, and then make a ball out of it and squeeze it - if cracks appear, add more water.
- 5. Straw is added to the clay as a reinforcing layer. However, today there are more reliable materials. When restoring the stove, cover it with plaster mesh, this will allow you to forget about the repair for a long time.
Despite the low cost of the components, such a clay-sand mortar competes confidently with modern building grouts and adhesives.
Features of repairing furnaces using fireclay clay
Chamotte clay is often used in the construction and repair of brick ovens. After heat treatment, this breed receives additional properties. Kaolin clay is used to make fireclay. In the process of heat treatment (+1500 degrees), it turned into a stone. The resulting stone powder is added to the composition of the solution during the repair or construction of the furnace.
Chamotte clay differs from similar materials in the following advantages:
- resistance to high temperatures,
- vapor permeability,
- high adhesive properties.
In addition, fireclay clay is safe for human health and will ensure a long service life of the hearth. Unfortunately, there were some negatives as well.
Fireclay does not occur in nature, and kaolin clay, which is its basis, is a rather rare material. It is not surprising that the main disadvantage of such material is the price. The second caveat - fireclay does not tolerate a humid atmosphere. Therefore, in order to qualitatively cover the furnace, it is necessary to use other materials (cement, quarry sand).
The finishing mixture of fireclay for repairing the hearth is created in the following proportions: 7 parts of sand, 1 cement and 2 clay. The amount of water is selected individually. The proportions may vary slightly, but this combination is considered the best.
A solution of fireclay will be more reliable if certain regulations are observed during its manufacture: first of all, dilute the cement to a state of thick milk, then add the remaining components.
Previously, refractory clay was soaked in water for three days before work - this gave it plasticity. Products of modern manufacturers do not require such a long preparation. The solution can be kneaded immediately after the last component is poured into the container. Rough kneading is done with the help of improvised tools (shovel, chopper, etc.). But it is better to complete the mixing of the mixture manually. The solution in this case will turn out to be of better quality - after all, with your hands you will feel even the smallest lumps.
Heat-resistant glue - prompt repair of furnace equipment
Of course, it is foolish to deny the merits of traditional solutions, but sometimes the furnace needs prompt repairs. For example, a planned celebration at a winter cottage may be in jeopardy due to a faulty stove. It will be difficult to get clay in this case. Of course, shops sell fireclay mixtures all year round, but they cannot be used immediately after purchase. And how can you cover up a home or country hearth other than clay-based solutions?
One option is a heat resistant adhesive designed to work with fireplaces and stoves. Such glue is sold in the form of a dry mixture or immediately ready for use. However, if there is a large front of work to be done, it is better to use dry glue, since the liquid mixture dries quickly.
The main components of heat-resistant mixtures are the same chamotte, cement, sand, synthetic and mineral additives. Depending on the type of glue, one or another element predominates in it. After all, each of them is responsible for a certain characteristic. For example, cement is responsible for strength, synthetic additives increase plasticity and moisture resistance, and fireclay heat resistance. Therefore, when planning a furnace repair using heat-resistant glue, pay attention to its composition.
The procedure for carrying out repair work
In fact, after making the solution yourself, the repair itself is unlikely to cause many difficulties:
- 1. The surface is cleaned of plaster and finishing material residues.
- 2. The oven needs to be slightly melted, after which the cracks that appear are poured with water. This will prevent the oven brick from absorbing moisture from the solution.
- 3. The mixture is smeared into the cracks, and its remains are laid in an even layer on the surface of the furnace.
- 4. At the final stage, the entire surface is plastered.
The oven will be ready for use only after the solution has dried. By the way, in this home-made solutions lose to heat-resistant glue - it dries in 30 minutes, after which you can start kindling.
The very work with heat-resistant mixtures almost completely repeats the work with clay solutions. The only difference is that after sealing the cracks, the oven is not plastered, but is finished with solid adhesive heat-resistant mixtures.
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