Lime Mortar for the Kiln
Clay mortar does not have sufficient strength for masonry foundations, and under the influence of condensation in the area of the chimney at all can crack, so for these parts of the furnace use lime mortar. To prepare it, you will need:
Slaked lime is not suitable for this work. you must take burnt lime and quench it yourself to obtain the known dough. At home, this process is not recommended: it is difficult and dangerous. It is better to buy ready-made lime mortar in a construction store.
Preparing lime mortar is dozens of times easier than clay mortar. The required amount of self-digging sand is sifted through a sieve with a mesh of 1 mm, purchase select a fraction of 0.7-0.9 mm. The presence of organics in the sand will not be a problem in this case, especially since lime has biocidal properties. You can take regular tap water: its hardness requirements are not stringent.
The ratio of dough to sand is 1:3, and water is added to the consistency of a fat sour cream. It may be necessary to adjust this ratio. Knead the lime dough well and begin to add sand to it, beginning with 1/2 part. After kneading, look at the paddle: ideally, it should adhere with a layer of 2-3 cm, and it is to obtain such an effect that sand is added. Usually it is about 3 parts, but may be up to 5.
The last step is the flow test. We put 3 mm mortar on the brick, put the second brick on top, tap and observe the behavior of the mortar. Ideally, a little mortar should appear at the edges, which will not trickle down. If it does not squeeze out, you need to add a little water, dripping. add lime dough, as the amount of sand required to ensure proper plasticity is determined in the previous step.
Lime and cement mortar for the furnace
This mixture for masonry furnace is widely used in the construction process with their own hands. It consists of cement, sand and water. This composition is used in the manufacture of foundations (especially in places with high humidity). It is used in masonry chimneys over the roof of the structure. This composition has the property to harden in the air and in water. It takes 30 minutes for the mixture to set, and to completely dry after 12 hours. The mixture for the furnace is easy to prepare with their own hands, by mixing sand and cement in the proportion from 1:1 to 1:6. It should be used within one hour, in which case the quality of strength is preserved. You can buy ready-made dry mixes to perform the above work.
The lime compound is simple to make and easy to prepare with your own hands. The quality of a mixture depends on how the lime is put out. In a container for the preparation of lime is poured with water, then wait until it ceases to boil (this passes the process of quenching). Preparation of the mortar with your own hands includes several steps:
- Determine the required volume of product, excess is not stored for long.
- Sift the lime thoroughly. Take out all the stones, you should get a fine fraction. The work is done with rubber gloves on (it corrodes the hands).
Note: The lime must be completely fine. Do not allow large particles in the mixture. In the process of drying, it will start to “shoot” and thus spoil all the work done.
- Mix the mixture with a trowel or drill with an attachment until it is a thick sour cream. If the mortar turns out too viscous, add dry mass.
- When plastering stoves, you can add a little gypsum or cement, this will increase the strength of the attachment. The same mixture is used for stove plastering.
- Prepared masonry mixes for the furnace should be stirred in the process, otherwise they will quickly harden.
Dry mixes for furnaces are used at all stages of the work, from the initial stage to the facing of the furnace.
Composition of mortar for masonry stoves
To prepare quality clay mortar for the furnace, it is necessary to choose the clay itself. It should not be greasy, otherwise when drying the joint between the bricks will crack. And it is quite possible that small cracks will appear. If there are a lot of such micro-slots, the chimney draught will be significantly weakened. The stove will not heat well, and the smoke will “leak” into the room.
If the mortar is too thin, the brickwork will be brittle and not strong. The mortar will crumble over time, and cracks can also appear. The consequences. smoke, carbon monoxide in the room, and again, a bad draft. Only one conclusion: the clay must not be too greasy or too thin. As always, the golden mean is above all.
It happens that nature herself creates clay, already completely ready for masonry furnace. But it is rarely encountered, so we have to prepare it properly. The first thing to do is to determine the proportions of the components (sand and clay). The easiest option. to establish the consistency of clay by experience.
For this purpose, the clay is cleaned of impurities (stones, twigs, grass) and soaked in water. The volume of the experiment is not large (one kilogram is enough). All the clay is divided into 5 parts. Do not add anything to the first part and make a small “flatbread. In the second part of the sand is added, in the volume of ¼ of the clay and also a “doughnut” is made. In the third part, ½ of clay sand is poured. The fourth part is filled with sand in equal proportions, and the fifth is filled with sand and a half. All five “patches” are dried well, and only after that is it possible to determine the workability of the solution. In order not to mix up the experimental samples, it is necessary to clearly remember where and which sample is.
If the dried “stucco” easily crumbles, then it has an excess of sand (lean clay). If cracks appear, conclude that the clay is greasy. The one with the highest density and strength, and which does not crumble is the best mortar for oven masonry. These are the proportions that should be used to prepare the “brick glue”.
Now about the sand. If you buy it in the store, then everything is clear here. It is already completely ready for use. If, on the other hand, you are making it yourself, then this loose mixture simply needs to be sifted. To do this, use a construction sieve. Sifted sand is best washed. In its clean, washed form, it will have excellent bonding properties.
In nature there are two types of sand: this river (sea) and mountain sand. In our case, the best option would be the mountain component. The explanation is simple: river sand is always smooth, polished with water. And the mountain has a rough, irregular structure. It makes the mortar and bricks stick together better.
Using clay for masonry stoves
On average, three buckets of clay mortar for 100 bricks are needed to put the stove in the bath. Mortar made of clay is used because its chemical composition is not very different from red brick and together they are well tolerated by high temperatures above 1000 degrees. Clay mortar creates joints that are no more than 4 mm thick.
This is an essential point, as too thick joints between bricks can not withstand very high temperatures and gradually begin to crumble. At best the joints will get covered with cracks, through which the air will start to get inside the sauna causing decrease in draught and increase fuel consumption. In addition, there is an increased risk of carbon monoxide entering the chimney and not inside the room.
In the process of masonry furnace must adhere to the main rule. the less clay will be used in its construction, the better the quality of the future structure. In addition, clay is considered the most noble building material, as it gives the worker the right to make a mistake. For example, masonry made of cement mortar can not be dismantled without loss, but the stove, laid with a solution of clay, is dismantled easily and without waste.
Stages of preparation of clay
For home makers it is very important to know how to prepare chamotte clay for masonry stoves. To do this, you can use the following scheme:
- Take a package of powder and pour it into a pre-prepared container.
- Pour the powder with water and leave it to swell for three days.
- After this time again add water and at the same time stir the clay. The process continues until a homogeneous mass is obtained.
- In some cases it is allowed to add sand.
In the process of working with clay it is necessary to constantly stir the solution, the quality of the work depends on it. In addition, it is important to pay attention to the consistency of the solution, it is recommended to add water to a too thick composition, to a liquid one. powder. It is especially important to meet this condition when masonry furnaces using refractory clay.
The amount of water in the solution plays an important role: dry composition crumbles and crumbles, liquid. flows on the working surface. Therefore, it is very important to know how to dilute chamotte clay for masonry stoves. When calculating the water used, note that the solution of normal consistency resembles a thick sour cream.
If in the process will be used clay for instant work, you need to pay attention to its peculiarity. When preparing the mortar there is no need to leave the powder to swell for three days, so the entire process will take much less time.
What kind of mortar is needed for masonry brick oven
Properly selected mortar for masonry furnace brick, features heat resistance, the ability to withstand temperature fluctuations (heating / cooling) without cracking and loss of strength. The type of masonry mortar, selected depending on the row and the thermal and strength loads experienced by the laying row.
For masonry use different types of mortars made from clay, cement, self-made. There are ready-to-use mixtures.
Optimal fatness of clay
To check the level of fatness of this main component of the masonry mortar, there is an elementary way. You need to take 0.5 liters of clay, mix with water, so that by consistency it became similar to steep dough. Then the resulting mass should be carefully kneaded and form a ball with a diameter of 4-5 cm. When it dries, you need to put it between two planks and squeeze them.
Building the Vortex Masonry Stove
If, as a result, the ball cracks when squeezed halfway, its fatness is high, which means that the mixture lacks sand. If it decays almost immediately, you need to add clay. In the case where the cracks went in the compression of the ball by a third, the composition of the stove mixture is matched perfectly.
The obvious advantage of the solution, the ingredients of which are carefully selected and dosed, is that the masonry will have a neat appearance due to the thin joint. In addition, the furnace mixture of normal fatness will ensure sufficient reliability and durability of the structure. However, such a mixture does have one disadvantage: such mortar is not resistant to the humidity of the environment.
Preparation of the mixture with your own hands. all options
Having understood the principle of determining the plasticity of the mortar for masonry, you can start mixing it. With their own hands this operation can be performed using different methods. A very simple methodology, which we, in fact, have already considered. You need to soak the clay in a small amount of water 24 hours before the scheduled masonry procedure. Then (in a day) add the liquid to the soaked material and mix the mixture with a shovel until it resembles a sour cream. After that, you need to strain the resulting mixture and add sand to it (remember the proportions mentioned above).
If there are no liquid puddles on the surface of the clay mortar, you have done everything correctly. If the clay protruded in liquid form on the surface of the masonry mixture, you need to add more sand to it.
In cases where perfectly pure clay is used (without foreign inclusions and small stones), the mixture for the stoves can be prepared by your own hands according to the second method. The essence of it is as follows. Add fine sifted sand to the clean clay and fill the resulting composition with water (a quarter of the total volume of the mixture). Thoroughly mix the mixture until it reaches a sour cream-like consistency. At the output it should easily slide off the shovel, but in no case spread. The next step is to add cement and salt to the resulting composition. These components will increase the strength of the clay oven solution. Use 750 mg of cement per 10 liters of mixture and about 200 g of salt.
The third method involves the use of refractory clay and sand-chamotte. These components should be mixed in the same proportion. Then add water to the mixture made. Its amount is 25% of the clay. You mix it up. That’s all. This is, probably, the most elementary way of preparation of mortar for masonry stoves. There is also another method of preparing the mixture we are interested in with our own hands. It is made from loam. You will have to knead 10 small portions of different mortars. The first mixture has the proportions. part cement part sand 10 parts loam, the second. 2 parts sand 1 part cement 9 parts clay, and so on. The last composition will thus contain 1 part cement, 10 parts sand and 1 part loam.
All kneaded mortars should be placed in small boxes and left to dry out in the fresh air (for 6-7 days). After a week, proceed to inspect the resulting mixes. For masonry choose the composition, which has the maximum amount of clay and there is no cracking phenomenon. Believe me, it will be perfect. will be able to withstand furnace heating temperatures up to 500-600 ° C without deforming and crumbling. Choose your own version of making clay mortar!
Types of lime mortars for stoves
It is undesirable to use the clay mixture for the chimney in the part that rises above the roof. Because of the formation of condensation, the clay gives cracks and breaks down. In this case, the mortar for masonry stoves is prepared on the basis of lime dough. The same mixes are used for laying the foundation for the stove.
Lime dough is obtained by combining 3 parts water and 1 part quicklime. It has a plastic consistency, similar to softened greasy clay. The density of a properly prepared lime dough is 1400 kg/m3. For masonry furnace chimneys and foundations, it is bought in ready-made form in construction stores.
Lime is quickened in the lime detergents plant in the lime detergents machines. It is not recommended to make the dough yourself, as lime leads to burns of the skin and respiratory tract. To stay healthy, you must apply strict safety measures: wear gloves, goggles, respirator, dustproof clothing.
The fatness of the lime dough affects the amount of sand to be added. Too greasy will require up to 5 parts of sand to achieve a normal consistency of the mortar. Before combining the components, the dough should be strained through a sieve with 1×1 cm meshes. Water is added to achieve the necessary consistency.
The strength can be improved by adding cement. The resulting lime-cement mixture with two binders and aggregate also has a high resistance to moisture. The following proportions of mortar for masonry furnace, foundation and chimney allow for better quality:
The sequence of work is as follows: mix cement and sand separately. Lime dough is diluted to a viscous state with water. Then the mixed dry ingredients are added and stirred. Water is added again in small portions to make it viscous.