What can be clay for pottery? Clay treatment Clay from the earth for what it is suitable

28.09.2019

I was on a digger, I was on a topan, I was on a circle, I was on a fire, I was on a fire. When he was young, he fed people, but when he became old, he began to swaddle.

Everyone could guess this riddle in the old days. The hero of the riddle is an ordinary oven pot. Using his example, one can trace the entire path that clay goes through before becoming a ceramic product. Village potters called a pit or quarry where clay was mined "Kopants". From the digger, the clay fell on the "topanets" - a flat place in the yard or hut, where it was trampled underfoot, carefully kneading and picking out the pebbles that got into it. After such processing, the clay came to the "circle", that is, to the potter's wheel, where it took the form of a pot or some other vessel. When the pot finally dried up, it was sent to the “fire”, or rather, to the furnace, where after firing it became hard as a stone. But in order for the pot not to absorb moisture, it had to be “on the burn”. To do this, it was dipped in hot form into leavened thick or liquid flour mash.

The second part of the riddle figuratively and briefly shows the further fate of the finished pottery. It is hardly worth specifically explaining how the stove pot “fed people”, but why it “began to swaddle” in old age is hardly clear to a modern person. The fact is that in the past, housewives were in no hurry to throw away old cracked pots. They were wrapped around with narrow steamed birch bark ribbons, as if they were swaddling. Pots and other earthenware entwined with birch bark could serve for many more years.

living clay

"Living clay" potters called the clay, which is in nature in its natural state.

The clay found in nature is so diverse in composition that in the bowels of the earth you can actually find a ready-made clay mixture suitable for making any kind of ceramics - from sparkling white faience dishes to red oven bricks. Of course, large deposits of valuable types of clay are rare, so factories and factories for the production of ceramics appear near such natural pantries, such as, for example, in Gzhel near Moscow, where white clay was once discovered. Every self-respecting village potter also had, although small, but his treasured deposits, or, more simply, digging pits, where he mined clay suitable for work. Sometimes it was necessary to travel many miles for the required clay, extracting it from deep pits with incredible difficulties. Moreover, one deposit was not always enough, since different products required a different composition of clay. So, for example, greasy ferruginous clay is best suited for black-polished ceramics. It is highly plastic, perfectly molded on the potter's wheel, and after drying it can be ironed to a mirror finish. The ware from such clay does not pass moisture and differs in high durability. One problem: greasy clay cracks easily during drying and subsequent firing. Products made of lean clay containing a significant amount of sand have a rough surface, and besides, they strongly absorb moisture. But when drying and firing, lean clay cracks very rarely. For good clay, the golden mean is preferred when it has an average fat content.

Oily clay is considered to contain less than 5% sand, while lean clay includes up to 30% sand. Medium fat clay contains 15% sand.

Where to find modeling clay

You can find suitable clay for modeling and pottery almost everywhere, there would be a desire. In addition, a small amount of clay can always be “fixed” by elutriation and other methods. Clay can occur immediately under the soil layer at a shallow depth. In garden plots, it can be found during various land works. Layers of clay quite often come to the surface along the banks of rivers and lakes, in the slopes and slopes of ravines. There are areas in the Non-Chernozem region where clay is literally underfoot and in wet weather on country roads it turns into a continuous mess, causing indignation of passers-by. Even from such “dirt” collected on the road, small decorative items can be molded and then fired. But, of course, this should not be done. Even where there is clay soil all around, you need to dig at least a shallow ditch to get to cleaner and more uniform layers.

Clay suitable for modeling can be successfully prepared even in a big city. After all, builders are always digging pits for a new house somewhere nearby, or a water or gas pipeline is being repaired. At the same time, clay layers, lying at great depths, are on the surface.

Determining the suitability of clay for modeling can be done in a fairly simple way. From a small lump of moistened clay taken for a test, roll a tourniquet about the size of your index finger between your palms. Then slowly bend it in half. If at the same time no cracks form at the bend or there are very few of them, then the clay is quite suitable for work and, in all likelihood, it contains 10-15% sand.

clay color

Each type of clay at a certain stage of modeling, drying and firing changes its color. Dried clay differs from raw clay only in a lighter tone, but when fired, most clays dramatically change their color. The only exception is white clay, which, when moistened, acquires only a slight gray tint, and after firing it remains the same white. The color of "living clay", usually in a wet state, is most often deceptive. After firing, it can suddenly change dramatically: green will turn pink, brown - red, and blue and black - white. As you know, craftswomen from the village of Filimonovo, Tula Region, sculpt their toys from black and blue clay. Only after being dried in a kiln, the toys become white with a slightly creamy tint. The miraculous transformation that happened to the clay can be explained very simply: under the influence of high temperature, organic particles burned out, which gave the clay a black color before firing. By the way, similar particles are found in the black soil, where they also determine the color of this soil. The color of clay, both in the raw and in the fired state, is also affected by various mineral impurities and metal salts contained in it.

If, for example, clay contains iron oxides, then after firing it becomes red, orange or purple. According to the color that the clay acquires after firing, they distinguish between white-burning clay (white), light-burning (light gray, light yellow, light pink), dark-burning (red, red-brown, brown, brown-purple). To determine what kind of clay you have to deal with, mold a plate from a small piece or roll a ball, which, after thorough drying, fire in an oven. Put the prepared clay in a wooden box and fill it with water so that its individual lumps protrude slightly above the surface. It is advisable to immediately prepare as much clay as possible. With an abundance of clay, only a small part of it is consumed, and the rest will be constantly aged.

The more wet the clay is, the better. Previously, potters kept clay in the open air in the so-called clay pit - a special pit, the walls of which were made of logs, planks or thick boards. The clay had to lie in the clay pit for at least three months, but sometimes it was in open storage for several years. In the spring and summer, the sun's rays burned it, in the autumn the winds blew and the rains poured, in the winter it froze in the cold and thawed during the thaw, then melt water penetrated into it. But all this was only beneficial for the clay, since it was loosened from numerous microcracks, while harmful organic impurities were oxidized and soluble salts were washed out.

The centuries-old practice of folk masters has shown that the longer the clay is aged, the better its quality.

Urza 05-12-2009 22:12

Greetings. Through the search, nothing but a divorce about "golden and silver clay" was found.

Where, living in Moscow, you can find free or cheap to buy a lot of clay (red, blue, what the hell with it)? I knew one place in Butovo, but everything has already been dug up there and the people do not allow them to dig in peace, yelling, waving their hands and what it is. In any case, it was like that a few months ago and I moved out of there right now ...

Literally today I walked with a shovel, dug "clay" from the banks in the Losino-Ostrovsky forest park, but came home, began to wash and was horrified to find that 50 kg of this guan that I brought home are not clay ... At the same time, it is generally difficult to identify what the hell is this...

In stores I met blue clay for modeling, but expensive. Rather, it is cheap, but there is so little of it in the package that you need to buy a dozen of such packages, and this will cost a pretty penny.

In short, some bullshit
No one will tell you where you can dig up pure red (or blue, green, purple, yellow, blue, black) clay in Moscow and Moscow Region? And \ Or where can I buy it cheaply? or who can sell?

Until recently, I was spending reserves "from Butovo", but alas, today they are over, and I don't know how to replenish them.

Urza 05-12-2009 22:17

P.S.: I'm sorry if it's in the wrong section... If it's in the wrong section, please move it

Marik 05-12-2009 23:08

Contact those who dig wells - they have this clay like mud... (no laughing).
Only choose the direction from Moscow. In the east, sand is for sure, but in the South - clay. I cleaned a well in my country house a couple of months ago (the rings moved), took out half a cube of clay. The bakers took everything. Clay like butter, not a grain of sand...

sergeant 05-12-2009 23:20

quote: Where, living in Moscow, you can find a lot of clay for free or cheap

metrostroy..
oddly enough, the builders go to a meeting and allow them to dig up a bag.
look for a place where these miners crawl out to the surface and take out the soil.

Urza 05-12-2009 23:51

Thank you ... Then if someone has clay in their dacha or maybe someone has it lying around from the well, tell me, I would drive up!
As for the metro construction - what stations are currently under construction? I would also go

VVH 06-12-2009 12:18

in Mitino. Mitino station and Volokolamskaya, Volokolamskaya right at the Moscow Ring Road from Mitino.

Urza 06-12-2009 02:35

Thanks a lot! Unfortunately, I don’t have a car .... I feel like I’ll have to carry these tens of kilograms of clay

Urza 06-12-2009 02:58

Is it sold in the construction markets?

VVH 06-12-2009 12:47

fireproof for sale. Furnace. I don't remember bags of 20 or 25 kg.

Urza 06-12-2009 12:49

Thanks, I don't think that's what I need...

lindwurm 07-12-2009 19:36

Bitsevsky park. there is gray clay in the streams. pretty greasy.

Urza 07-12-2009 19:48

Thanks, I'm learning.

Mini-report - today I went to the metro station under construction, as it were ... I ruined 4 hours in traffic jams. They have clay, but as an evil, all dirty, with sand and stones ... Well, so that it was not in vain, I scored myself ~ 45 kg such as it was.
Now I wash, but she is really skinny.

Still, today, sorting out on the balcony, I found a large shovel ... the thought came to my mind - what if I stupidly take it, go out into the "open field" and dig deep? What is the probability of hitting clay?

I have a forest park across the road from my house, there are fields, glades, etc. where, in general, you can dig deep without running into the roots.
I just thought like this - instead of this trip, I could dig deep into the depths for 4 hours. I think it would turn out pretty good. And there would be a place to which 5 minutes walk from home and take as much as you want ... But is there a high probability of success?

lindwurm 07-12-2009 19:58

all dirty, with sand and stones...

clay from Bitsa - only with small roots.
if you look for yourself, then look at the streams and small rivers - you don’t have to dig for 4 hours.

Urza 07-12-2009 20:00

Thank you!
I think tomorrow I'll try to dig near the river.

lindwurm 07-12-2009 20:03

quote: Originally posted by Urza:

near the river.

before you dig, look at the water's edge. you will probably find clay zhevlak already washed with water.

Urza 07-12-2009 20:07

Where I will dig everything is so overgrown and dirty... Yes, and last time I was digging just from the shore, but I dug out... not clay O_o... some kind of G...

lindwurm 07-12-2009 20:13

what is clay for?

Urza 07-12-2009 20:28

I make primitive non-circular pottery like this

High-quality clay for laying stoves is one of the most important conditions for the reliability and durability of a future heating structure. Clay can be purchased at a specialized store or mined with your own hands. But in any case, it is necessary not only to be able to choose it correctly, but also to properly prepare for

There are a considerable number of different varieties of clay, and not every one of them is suitable for laying a stove. Therefore, it is worth understanding what this substance consists of, what qualities it must have so that it can be used for this kind of construction work.

It would seem a ridiculous question - each of us has known this natural fossil since childhood. However, not everyone knows the component composition of clay and its specific properties used in construction practice.

Clay composition

The mineral components of clay can vary significantly in their percentage composition, but all its types necessarily contain substances from such groups as montmorillonites and kaolinites or other layered aluminosilicates. This type of natural material contains various impurities in the form of sand and carbonate particles, but its main composition is aluminum oxide - up to 39%, kaolinite - about 47% and water 14%.

In many ways, the composition of clay depends on the method and place of its formation. Thus, residual and sedimentary clays stand out.

Residual clays are formed during the weathering of non-plastic rocks and their transformation into plastic kaolins.
Sedimentary clays are formed as a result of the transfer of weathered natural products and their settling in a certain place. These can be clays formed on the ocean, sea or river bottom, as well as on the continental part. Marine rocks are divided, in turn, into coastal, lagoonal and shelf.

Clay is not a rare mineral substance, and is quite widespread throughout the planet. You can find it almost everywhere, so clay can not be called an expensive material.

Basic properties of clay

Clay is a micro-granular substance, and regardless of the place of its formation, it differs in its characteristics from other natural resources. Due to its properties, it can be used not only in construction, but also in other areas of human life.

Clay quickly absorbs moisture and swells under its influence, while acquiring water resistance, that is, the ability to keep water out.
The second, no less important positive quality of the mineral is its plasticity, due to which it can take any form.
When dry, the clay acquires high strength. Due to this quality and water resistance, it is often used for flooring in basements or building "locks" around, for example, wells or the foundation of a house.
In addition, very important qualities of this material are the high adhesion of the solution and its gas density.

Depending on the proportions of the ingredients in the composition of the clay, it may have a different degree of fat content. Or rather, it can be skinny, normal fat and very oily.

Clay for kiln masonry

Clay for oven masonry, already cleaned and crushed, can be purchased at a specialized store and used to prepare a mortar. It should be borne in mind that for laying only one hundred bricks, having a standard size of 250 × 120 × 65 mm and laid flat or on a “bed”, 20 liters of mortar will be needed, which is placed in two buckets.

For the construction of the entire furnace, depending on its size and model, it may take from 550 to 2500 pieces of bricks, not taking into account masonry and foundations. Therefore, having calculated the costs of the required amount of all materials, it is quite possible to think about how to save at least on clay and sand for mortar, especially since they can be found literally under your feet, leaving the countryside.

If you decide to carry out this simple process of preparing such materials yourself, then some questions will certainly arise:

Where can you dig up clay and find sand, thereby saving a fairly significant amount?
How can the quality of the material and its suitability for furnace mortar be determined?
How to make a solution correctly, based on the fat content of the clay that you managed to find?
How to prepare the ingredients for the solution?
How to make the right kneading?
What components are needed for the solution, besides clay?

It is possible to find simple answers to these questions. And start in order.

How to find and pick up clay?

Clay is usually easy to find near any suburban area. The layers of this mineral are not too deep, but each of them may have a different composition. Such layers can be clearly seen on the steep banks of rivers or the sea, as well as in quarrying. It is there that you can notice that numerous layers have different shades and densities.

It should be noted that even in one place, each of the layers, depending on the composition, may have a different fat content, therefore, when choosing the right material, it is recommended to take samples from several layers. In this case, it should be taken into account that the higher the layer lies to the surface, the fatter the clay. Therefore, it makes sense to immediately check the middle layers, since in them the mineral should have the most optimal fat content.

Skinny clay usually lies in the lower layers, and if you dig it up, then the solution will have to be “greasy”, adding very oily clay to it. It is much easier to correct a very greasy composition - it can be brought to a normal state by adding sand.

Solutions using clay with a normal fat content have good plasticity, since the balance of its constituent substances is observed in it. When the masonry dries, these mixtures practically do not crack and do not shrink. Well, and what is also very important - they are much easier to work with.

Fatty solutions when wet are very plastic, and it is also convenient to work with them, but when moisture evaporates from them, they begin to crack and crumble into large fragments. Therefore, such clay will not give the masonry reliability and durability.

It is not recommended to use lean rocks of clay for furnace mortars, they are not plastic and do not give strength to the masonry.

Video: An experienced stove-maker shares the secrets of producing quality clay

Determination of the fat content of clay empirically

If the clay is mined independently, then its fat content can be determined immediately at the site of the excavation. To do this, you need to take a handful of the mineral in your hand, moisten it a little with water and knead until smooth. Organoleptically, you can feel to the touch how high the fat content of the clay is. If it becomes sticky and plastic, like plasticine, then this is a fatty breed. Skinny clay, crumpled into a ball and moistened with water, will still crumble. This version of the material will have to be "fat".

There are a number of more accurate oil content screening tests for this material, and these should be used to select the best clay option.

First way

It is necessary to take about 0.5 kg of clay, which is diluted with 100 ÷ 130 ml. water. The mass is mixed until homogeneous. It is better to carry out this procedure manually in order, as they say, to feel the homogeneity of the composition, which, at the end of kneading, should not stick to your hands and have the consistency of plasticine.

From the resulting mass, you need to roll two balls having a diameter of 40 ÷ 50 mm. One of them remains intact, the other is crushed into a cake. These prototypes are left to dry for two to three days at room temperature.

If, after drying, cracks appear on the prepared parts, this indicates that the clay is very oily, and it is necessary to add a little more sand to it when mixing the solution than indicated in the recipe.

If the cracks are insignificant, and the ball thrown onto the table from a height of 800 ÷ 1000 mm does not break into pieces, then the clay has a normal fat content, this grade is excellent for masonry mortar.

Second way

To test the clay in the second way, you will need 2 ÷ 2.5 kg of clay, which is kneaded with a paddle, adding water. You need to bring the mass to the consistency of plasticine, and if it still continues to stick to the wooden paddle, then the clay is very oily. When mixing the solution, more sand is added to it than required according to the recipe.

Clay, which has a normal fat content, remains on the paddle in separate clots, but does not stick to it completely.

Third way

This method of checking clay for fat content is considered the most accurate. To conduct the test, 0.5 kg of clay is taken, which is kneaded with water to a thick dough. Further, a ball rolls from the resulting mass, with a diameter of 40 ÷ 50 mm. Then, the ball is compressed between two smooth boards until cracks appear on the clay. In this case, the fat content is determined by the thickness of the cake and the type of cracks that have appeared.

If the clay is low fat or lean, then even with a slight compression, the ball will crumble into pieces.
If the clay is very oily, then when compressed to half the original diameter, narrow cracks form.
If, when the ball is compressed ⅓ of its original diameter, cracks appear on the clay, then it has a normal fat content, and is well suited for masonry work.

In this figure, you can see how to check clay for fat content:

1 — Determination of the plasticity of a mineral:

a) lean clay with low plasticity;

b) normal clay has medium plasticity;

c) oily clay, plasticity is high.

2 — Determination of plasticity using the "ball" method:

a) a ball of lean clay is compressed 1/5 ÷ 1/4 of the diameter;

b) a ball of clay of normal fat content shrinks to ½ of its original size.

3 — Determination of fat content using the "flagellum" method:

on the left, the stretch-to-break method -

b) normal;

c) fat.

4 - On the right - a way to bend around the rolling pin:

b) normal;

c) fat.

During the tests, you can immediately adjust the resulting mass by adding greasy clay to the lean solution, and sand to the greasy mixture. If the adjustment will take place on small portions, then the proportions should be recorded immediately, and then, choosing the best option, use the data to knead a large amount of material for

Clay cleaning

After carrying out experimental measures and leaving the clay elements to dry, you can proceed to cleaning the clay from pebbles, plant roots and other inclusions that will interfere with normal operation and reduce the quality of the masonry joints.

Clay cleaning can take place in two ways:

1. Grinding and sifting clay through a metal sieve, which should have cells no larger than 3 mm. Dry clay does not grind well, so the whole process will take a lot of time.

2. If another cleaning method is chosen - “wet”, then before carrying it out, the clay must be soaked and wait until it swells and becomes soft. Then, the resulting solution is rubbed through a sieve with a volume mesh-netting with cells of 3 mm, through which it is convenient to wipe a clay solution of medium density.

clay soaking

Before proceeding with the “wet” method of cleaning, the clay must be soaked. It should be immediately noted that dry-cleaned clay is soaked in exactly the same way before mixing the solution.

Dry cleaned or uncleaned clay is poured into a container. Usually, old bathtubs are used for this or wooden boxes are made, then upholstered with metal roofing sheets. In order for the clay to get wet well, and it was easier to mix it, it is covered with layers of 120 ÷ 150 mm, each of which is spilled with water and mixed. The top layer is filled with water so that it covers the mixed clay.

The soaked clay is left in this form to swell for a period of 14 hours to a day. During this time, it can be periodically mixed with a shovel, adding water if necessary.

Then, the whole mass is mixed, water is added to it, and it is again left for 14 ÷ 24 hours. After this period, the composition is mixed again, and if it is prepared from rubbed clay, it can be immediately used to prepare a masonry mortar. If the crude clay was soaked, it is passed through a sieve into a container prepared for this.

Chamotte clay

For some sections of the furnace, which will be discussed below, fireclay clay is used for masonry. This clay in its finished form is unlikely to be found on its own, since it is produced using a special technology consisting of several stages:

Ordinary soaked clay, enriched with various additives, is molded into briquettes and dried.
Next, there is the firing stage - this process takes place at a temperature of 1200÷1500˚С.
Burnt briquettes are crushed to the state of flour to obtain fireclay clay, and to a coarse-grained fraction - to obtain sand.

Due to the fact that fireclay material is subjected to high-temperature firing, it is refractory and able to withstand temperatures above 1800 ° C.

Chamotte clay contains highly dispersed hydroaluminosilicates. During the manufacturing process, this material, due to sintering and firing, acquires the following characteristics:

Hygroscopicity averages no more than 7.8% of the total volume of clay.
Moisture content - not higher than 5%.
Fire resistance reaches 1530÷1830˚С.
Fraction size from 0.005÷0.01 mm.

The special qualities of fireclay clay give the solution based on it high plasticity, and when dried, it acquires the strength of a stone.

Making a solution from this material will not cause difficulties, since in a dry state it is, in fact, ordinary clay, but already crushed and purified. Therefore, it is pleasant to work with such clay, and the kneading process consists of the following steps:

Clay powder is poured into a prepared container, for example, a 10-liter bucket. Then a small amount of water is poured into the clay and mixed well until smooth. If necessary, a little more water can be added to the solution, and then it should be left for 2.5 ÷ 3 days to swell.
After this period, water is still added to the solution, and it mixes well, the mass should have the consistency of thick sour cream. It should be noted that when making this solution, it is not scary to pour water into it, since this is easily corrected by pouring a small amount of dry clay into the resulting mass.

In addition to ordinary chamotte clay, in specialized stores you can find ready-made instant compositions that are kneaded immediately before laying. Using such building mixtures, you do not have to wait for three whole days until the clay swells.

What solutions are needed for the oven?

Not all novice stove-makers know that not one, but several solutions are used for laying the stove, since different departments have different heating temperatures.

The attached scheme defines separate zones of the furnace structure, in which different clay mortar can be used for masonry.

1 - The foundation of the furnace is arranged on the basis of a cement-sand mortar, but around it a waterproofing layer can be made, a kind of "castle" 100 ÷ 150 mm wide from clay, which must be well tamped.

2 - Waterproofing from sheets of roofing material is laid on the foundation.

3 - The first two rows of bricks are usually laid on a cement-sand mortar. Sometimes a little lime is added to it for greater plasticity.

5 - The heat storage zone of the furnace is laid out on a clay-sand mortar that can withstand temperatures of 500 ÷ 600 degrees - this is how this zone can be heated.

6 - The furnace chamber of the furnace is made of fireclay bricks, and a solution of fireclay clay is used for its masonry, since the temperature in this area of \u200b\u200bthe heating structure can reach 1 thousand degrees.

7 - Laying the source of the chimney is carried out on a clay-sand mortar. In this area, the furnace heats up to 300÷400 degrees.

8 - The chimney fluff, located under the ceiling of the room, is laid out on a clay-sand mortar.

9 - A metal box arranged for fire safety around the pipe can be filled with sand, expanded clay, vermiculite or the same clay-sand mortar.

10 - The neck of the chimney is laid out on a cement-sand mortar with the addition of clay.

11 - The pipe head, exposed to atmospheric precipitation, is usually laid out on a cement-sand mortar.

If the solutions are made independently, and used in combination, then you can save up to 12 ÷ 15% on their purchase.

Making solutions using clay

In addition to the fact that it will be necessary to find, dig up and clean the clay from impurities, you should also know how to properly make furnace solutions.

This table presents the materials that are used for and the proportions of making solutions.

Mortar types	clay mortar	Mortar	cement mortar
Materials used	Consumption of ingredients in volume parts
Sand	4	2,5	3-4
Chamotte clay	1	-	-
regular clay	1	-	-
Lime	-	1	-
Cement M400	-	0,5	1

We will not dwell on cement-sand and lime mortar - they are not included in the content of this publication. We are only interested in clay-based compositions.

Clay-sand mortar

As is already clear from the above diagram, the "lion's share" of the areas of the heating structure is laid out on a clay-sand mortar, which is why it can be called the main one in the construction of the furnace. The materials from which this mixture is made have a fairly affordable price in specialized stores, but they can also be obtained independently - in this case they will cost almost free.

The most "running" when laying the furnace - clay-sand mortar

Despite the low cost, the clay-sand mortar has amazing properties that are ideal for the construction of furnaces:

The average density, which is very important for its expansion when heated.
Heat resistance up to 400 degrees.
Maximum gas tightness.
High fire resistance.
Clay mortar can be reused if it was not used for laying the combustion chamber.
The mixture can be prepared with a margin, since its shelf life is unlimited. If moisture evaporates from the solution over time, it only needs to be diluted with water and mixed well.
Ecological purity of the material, which is important for indoor use.

The disadvantages of the clay-sand mortar include its hygroscopicity, which means that it cannot be used for pouring the foundation and laying the upper part, located on the street.

As mentioned above, in order for the solution to be plastic, serve for a long time, and it was comfortable to work with it, you need to choose the right proportions of its components, which will depend on the fat content of the clay.

In order for the mass to be homogeneous, without lumps and inclusions, the clay swollen after soaking is well mixed with a construction mixer, a shovel, or by trampling.
While mixing the clay solution, sifted sand is introduced into it, in previously determined proportions, and also, if necessary, water is added.
The readiness and plasticity of the solution is checked with a clean metal spatula, along which the captured mass should slide easily.
It is also very important to ensure that the mixture has maximum adhesion. To check this quality, the solution, with a layer of 7 ÷ 8 mm, is applied to the brick, on which the second brick is placed and pressed on top. In this case, the excess solution is squeezed out, which is immediately removed, and the seam should be about 5 mm.

The bricks are left to dry for 30-40 minutes, after which it will be possible to check the quality of their adhesion. To do this, you need to take the resulting “construction2” by the upper brick and raise it, that is, create conditions for the lower brick to be suspended. If the lower brick is held on the mortar, then the adhesion of the materials is considered optimal, that is, the mortar turned out to be of high quality and suitable for laying the furnace.

The correctness of the consistency of the finished solution can be checked by carrying out the following manipulations:

In the prepared mass of the solution, you need to lower the spatula or trowel soaked in water. If the solution sticks to it, then the mixture turned out to be very oily, and it should be “thinned” by adding a small amount of sand. After that, all the components are mixed again, and the test is carried out again. This is done until the desired consistency of the solution is reached.
If water appears on the surface of the finished solution, made in an ideal consistency and standing for some time without stirring, this means that the clay used in it has insufficient fat content. In this case, a small amount of clay with a high degree of fat content should be added to the solution, and the resulting mixture should be mixed well again. In this case, the proportions of the ingredients used in the composition change, that is, the amount of sand decreases, and the solution becomes fatter.
If a spatula is lowered into a solution of normal fat content, and the mixture does not stick to it at all, this indicates that it lacks plasticity, which means that some more oily clay needs to be added to the mass.

Video: an example of the preparation of a clay furnace solution

Clay-chamotte mortar

As mentioned above, fireclay material has an increased resistance to high temperatures, reaching up to 1800 degrees, therefore, solutions made with its use are used for laying a firebox, where it is in constant contact with an open flame. In a solution mixed with fireclay sand, clay is still the main component, so its shelf life is also unlimited. Even a completely dry solution will “come to life” with the addition of water to it, and will be ready for use.

To mix the solution on which the walls of the combustion chamber will be laid out, the following materials can be used:

It can be fireclay clay, used in its pure form or with a small addition of sand.
Ordinary white or gray clay of normal fat content.
Too oily ordinary clay can be “thinned” by adding chamotte or quartz sand to it in proportions of 1: 1, or by selecting fractional parts of the ingredients.
If a model of a heating structure with a moderate heat load is chosen for construction, such as, for example, an ordinary cooking stove, a “Dutch” or a Russian stove, then it is quite possible to use an ordinary clay-sand mortar with a small addition of fireclay sand for laying the firebox.
For a furnace with an increased heat load, the solution is made up of two components. It uses 70÷75% fireclay sand and 25÷30% ordinary clay. Such a mixture is kneaded in the same way as a regular clay-sand mortar:

- Ordinary clay is cleaned and soaked for 2.5 ÷ 3 days.

- After that, the mixture is thoroughly mixed.

- Sand is gradually added to the mixed clay, and the mixture is brought to a homogeneous state and the desired consistency.

- When moisture evaporates from any clay solution, it is renewed by adding water.

Entirely from fireclay refractory bricks, the best mortar for its laying will be a mixture of fireclay sand and clay, or completely made from fireclay clay.

From the foregoing, we can conclude that with a "modest" budget, you can find the opportunity to save on the ingredients of the solution for the construction of the furnace. Of course, it will be easier to go to the store and buy everything you need ready-made, but if you want to refrain from extra costs, you can always find such an opportunity.

We continue to move into the cosmic unknown. The world is looking more and more like futuristic fiction. Therefore, the essentially unnatural return to simple, natural materials seems so natural.

Another source of the modern desire for naturalness is the permanent fear of ecological collapse. Environmentally friendly design is in demand today more than ever. It is today that clay is beginning to be associated with value, despite the stable, directly opposite historical connotations. Contemporary design embraces clay, enthusiastically discovering its incredible decorative and practical potential.

Clay in construction

Clay as a material in a modern interior has a very wide application due to its plasticity. What other material can be equally used both in bulky construction and in the manufacture of the finest handicrafts?

Clay, different in composition and properties, can be used almost everywhere today. So, along with the traditional clay one! - brick, adobe blocks are very popular as a building material. Consisting of clay, sand and organic fillers, they have both extremely low cost and excellent technical characteristics.

Although the modern technology for making adobe blocks differs from the traditional one: as a rule, sawdust is used instead of straw, and the blocks themselves are not made manually, but mechanically, nevertheless, this material continues to retain the charm of ancient times.

Adobe blocks are actively used in construction today, and houses made from them show themselves in the best way, both in terms of technical criteria and aesthetically.

What you need to know to use clay

It is useful to know that in order to use clay independently, as a building or decorative material, to obtain a satisfactory, high-quality result, it is extremely important to be able to select the composition of the clay. This becomes more obvious if you know, for example, that the building mixtures themselves sometimes contain several types of clay at once, which tells them their qualities.

The amazing possibilities of clay

Clay as a material has a truly inexhaustible application possibilities. Known to man since ancient times of his formation, it still remains relevant. Like thousands of years ago, clay serves our most diverse needs, albeit in a different form than before: instead of unfired dishes, today we have at our disposal both universal faience and the finest porcelain; instead of adobe floors - a myriad of slabs and tiles - and so on.

Today, clay-based plasters for walls, building mixtures, roofing and cladding materials, stucco, sculptures, dishes, decorative items and much more are made. Despite the spread of innovative materials, clay firmly holds its traditional positions, and even penetrates into the camp of a competitor, constantly discovering new opportunities for its actualization.

Walls

Clay plasters are gaining more and more popularity today. The living surface of walls plastered using this material is not only very attractive, but also has many useful properties due to its naturalness and environmental friendliness.
Clay plaster is a hypoallergenic material that acts like a filter. It is able to absorb excess moisture, which contributes to the regulation of the microclimate inside the house. It is more than affordable. It is easy to apply. It has excellent protective characteristics and is resistant to microcracks, which prevents its destruction.

Floor

To date, there are a number of technologically different ways of arranging clay. At the same time, the composition and basic properties of these floors are almost identical.

The clay floor is poured or lined with a mixture of clay, sand, straw, gravel or other additives. As a result, the floor acquires a smooth, wear-resistant surface that is unique in its properties and appearance. Such floors have antiseptic and antistatic properties. They help maintain an optimal moisture balance, are able to contain and even neutralize unpleasant odors. In addition, they have the ability to retain heat: heating up during the day, they gradually release it at night.

It is also important that the surface of the clay floor does not require special maintenance and is easily repaired if necessary.

Facing

Facing exterior walls with clay is not an easy task: clay absorbs and releases water well when wet and heated, which results in cracking. This requires the use of special technologies in the processing of the finished coating and the production of facing materials. As such, clay can be used in the form of ceramic outdoor tiles and plaster mixes.

Walls made of adobe are also not very moisture resistant, so they need additional plastering. For this purpose, lime is traditionally used, which compensates for the natural lack of clay blocks and imparts a special charm to the building.

Roof

Traditional ceramic tiles are made by simply firing clay. Despite the simple technology, which has not changed since ancient times, such tiles can serve for many decades, sometimes without even needing repair. Manufacturers, as a rule, give a guarantee for their products up to 30 years.

Such tiles are not afraid of temperature changes, overdrying from direct sunlight, and even open fire and acid rain. The clay roof cools and heats up very slowly, which provides a special comfortable climate inside.

When choosing a tile, it is recommended to pay attention to the fact that the pores on its surface must be closed: the more “porous” the tile, the higher its ability to retain and absorb moisture, which can eventually lead to its destruction. In addition, the tendency to absorb a large amount of moisture significantly reduces the frost resistance of clay tiles.

Pottery

Despite the huge number of newfangled materials for making dishes, clay does not lose its position. Products made of ceramics, porcelain, terracotta and faience are still common and in demand.

Ceramic cookware does not emit harmful substances when heated. There is no scale in it. It is chemically inert - in a word, ceramics is almost an ideal version of dishes used in our everyday life. Terracotta is made from special red varieties of clay. After firing, it acquires a characteristic texture, while it can be both coarse-grained and fine. The color of terracotta varies from red-brown to creamy flesh.

Today, terracotta is used to make dishes, which was not done before: there was an idea that terracotta did not like water. The development of terracotta production technology has changed the situation, and now many manufacturers have turned to this material in search of new interesting solutions.

home spa

Clay has a very unusual use in modern life. Since the same ancient times, clay has established itself not only as a building or decorative material, but also as a cosmetic product.

Clay well tones, disinfects, whitens the skin. Great for making hair masks, as it contains a large amount of silicon, which promotes the growth and strengthening of the hair follicle.

Although today clay, by a strange coincidence, as a building or decorative material is perceived by us with a slight touch of exoticism or even social disorder, nevertheless, the global craze is changing this state of affairs more and more actively.

Every year projects and ways of using clay become bolder and more interesting. So it is quite possible to expect that after some time the appearance of our dwellings and cities can change significantly, including thanks to clay.

12 reasons to choose clay:

Clay heals.
Regulates air humidity (keeps a healthy microclimate).
Has antiseptic properties.
Absorbs odors.
Attenuates high frequency radiation.
Preserves and protects the wooden structures of buildings.
Accumulates thermal energy (excellent material for low-temperature wall heating).
Clay is pleasant to the touch and in its natural form gives a feeling of warmth.
Clay materials (compared to other materials) have better soundproofing properties.
Clay is easy to work with, hypoallergenic and 100% recyclable.
Clay plasters, thanks to various natural additives, can have different interesting designs.
Housewives note that in houses with clay plasters, windows do not “sweat” and mold does not form on the walls.

Clay plasters

Where do we use clay plasters?

Plasters can be applied to almost any hard and rigid surface (walls and ceiling):
- walls insulated with straw blocks or reeds;
- concrete, fired and unfired brick, foam block, silicate brick, gypsum;
- board, OSB, shingles, timber (with a base of reeds).

Plasters are most often applied to interior walls, because slanting rains can damage clay outside. However, there are exceptions when the house is well planned. Clay plasters will organically look in private houses, apartments, office buildings, restaurants, etc.

What is in clay plaster?

We use plasters that contain clay and sand, as well as sometimes finely chopped straw and mineral pigments. Burlap or serpyanka are suitable as reinforcement.
In decorative plasters (for example, AURO firms) there are materials of natural origin.

For clay plasters, you can use clay (after testing for viscosity and foreign particles content), which you get, for example, by digging a well or a trench under the foundation of a new house. This clay must be properly prepared and mixed with other necessary natural materials (sand, straw, etc.). In this way, you can independently achieve almost minimal material costs. The clay will most likely have a brown tint, so if you want to change the color of the top coat of plaster (walls or ceiling), you can look for clay near the river, purchase from a brick factory, or from some clay flour sellers. To date, clay is sold in ready-made powder form and in different colors.

You can achieve lighter shades of clay plaster by painting it with lime or casein paints. The main thing is not to use classic paints that leave the surface of the clay plaster closed to the penetration of steam. The advantage of unfired clay is that its surface can not be completely painted over: if you leave some parts in their natural color, then the sensations from touching the clay material are much more pleasant.

For design, you can use various shades of clay, as well as natural additives (grass, sand, small gravel, pebbles, shells, etc.), which will change the surface relief and add a pleasant smell.

It is easy to protect the surface from abrasion with a breathable casein primer, while the color of the plaster does not change.

We most often work with ready-made dry powdered clay, since the extraction and processing of local clay requires a lot of time and labor, which not everyone can afford.

How thick is clay plaster?
Regulates the humidity in the room (that is, maintains a healthy microclimate) a layer of plaster with a thickness of at least 1.5–2 cm. Decorative plasters are applied in a layer of 2 to 5 mm.

Clay partitions

Clay partitions in apartments and offices

In order to improve the microclimate (in particular humidity control), we recommend building non-load-bearing partitions in apartments, as well as inside reinforced concrete and brick buildings, from unbaked bricks (raw) or from rammed clay. These partitions are a kind of thick plaster and take any, even a curved shape. Thanks to this interesting aesthetic element, the image of the company can be favorably emphasized.

Clay partitions in frame houses and log cabins

In modern frame houses and log cabins, there is not enough heavy mass that could accumulate thermal energy (heat-cold). Previously, a massive Russian stove was installed in log cabins, which also served as a heat accumulator. Today, instead of it, partitions made of heavy adobe (rammed clay) or unbaked bricks (it can be facing or laid out under the finishing plaster) can serve as the necessary mass. As a result of slight temperature fluctuations in the room, thermal comfort increases. Such partitions can be heated due to radiators, wall heating, radiation from brick ovens, as well as from direct sunlight falling directly on the wall.

In addition, clay partitions are a good option if you want to complement the monotonous walls of your log house with some other material. Firstly, clay takes moisture from the air just as well as wood, but gives it back faster. For example, if moisture is adsorbed into wood in bathrooms, it can become too saturated over time. Therefore, we advise planning clay elements in log houses, which not only externally blend perfectly with wood, but also give it additional protection. Secondly, many housewives note that in houses with clay plasters, windows practically do not “sweat” and mold does not form on the walls.

Answers to frequently asked questions

The plaster does not fall off and does not chip off?

Clay plaster will not fall off when applied to a secure hard surface by an experienced craftsman. But, as experience shows, it can chip off, like any other plaster (cement, gypsum). The possibility of chipping corners is reduced when they are rounded, by the way, now this is a very popular element of decoration.

How can dust be removed from the surface of the plaster? Can plaster be wiped off?

The plaster surface (natural, primed with casein primer or painted with casein paint) is cleaned in the same way as wallpaper or wall surfaces with standard paints, most often with a broom or a vacuum cleaner with a soft nozzle. Where it is necessary to wipe or wash the surface of the plaster (bathrooms, toilets, kitchens), we recommend choosing Tadelakt Moroccan plaster.

Does plaster crack after drying?

Clay plaster itself does not crack. For complete confidence, we use fittings: linen or jute burlap. Cracks can occur if, for example, an apartment building has not yet fully shrunk (which happens within a few years after the house is built).

How is chipped or cracked plaster repaired?

Chipped or cracked plaster is easy to repair after wetting the wall with a felt trowel.

Is it an expensive pleasure - clay plaster?

The cost of applying clay plaster for painting together with materials is approximately the same as gypsum plaster with putty for painting.