Fire-resistant finishing mixtures are durable and do not deform when exposed to high temperatures. Cracks worsen the appearance of the hearth and let carbon monoxide into the room, so a heat-resistant stove putty is used. The composition is bought ready-made or prepared according to the technology with his own hand using heat-resistant materials.
Composition of materials and mixtures for the furnace
The walls of the stove get hot during operation, so the usual mixture will crack and crumble after a few months. The raw materials for kneading refractory putty for the furnace are sand, cement, gypsum, lime and clay.
Recommendations for preparing a solution:
- it is preferable to use lime or clay in the composition, but it is imperative to add asbestos;
- complex mixtures based on cement can be used, but asbestos or other fibers remain an additional component;
- straw or hemp can replace asbestos.
Store dry putties are mixed with water in accordance with the instructions on the package. Ready mixtures are pre-mixed in buckets. The amount of solution is prepared, which is used before hardening and loss of plasticity.
The composition is independently prepared in order to coat small foci; for large furnaces it is better to purchase high-temperature mixtures prepared at the factory.
Materials (edit)
Sand is a loose sedimentary rock, almost entirely composed of silicon dioxide. For the solution, river, sea and quarry types can be used. The grains of sand formed in water bodies are characterized by a rounded shape with a smooth surface.
Clay is a sedimentary rock that includes kaolinite, when dry, it is dust, becomes plastic when moisture is added. The porous and waterproofing material is characterized by sinterability, refractoriness, viscosity, and shrinkage.
Lime is obtained artificially by burning carbonate rocks and includes a large amount of calcium, magnesium, dolomite. Lime dough or slaked variety (boiling pot) is used.
Asbestos refers to mineral filaments from the silicate group, which naturally form flexible fibers. Refers to carcinogens, has high heat resistance, does not dissolve, but fluffs up in water. In stove putty it serves as a binder and dispersed component.
Cement is an artificial inorganic binder. When moistened, it forms a plastic mixture, which subsequently hardens and gains strength not only in air, but also in water.
Refractory mixtures
Factory refractory compositions are versatile and designed for high quality work. Manufacturers abandoned the use of asbestos due to its carcinogenic effect and replaced it with harmless components.
Common ready-made formulations:
- Plitonite. The line of Russian-German manufacturers includes materials of the Super-Fireplace brand for household and industrial hearths. The scope varies depending on the composition.
- Mastic Titan. The solution is prepared on the basis of stone flour with polymer additives.Heat-resistant stove putty firmly adheres to the surface and withstands up to + 1300 ° C.
- Terracotta. Gray plaster sets quickly, breaks down at + 400 ° C, can be applied with a layer of up to 8 mm. Prepared on the basis of kaolin fireclay clay.
- Thermo +999 PRO brand. The composition is suitable for top application and for refurbishment of the fuel compartment. The reinforced mortar withstands + 1000 ° C, sets in 1 hour, but fully gains strength during the day.
The coating for Emelya's stoves and fireplaces is made on the basis of white heat-resistant clay and kaolin. The dry mixture is diluted with water, after hardening it prevents cracks and shedding of the layer.
The Pechnik brand is a competitor to the well-known Terracott brand, withstands surface heating up to + 300 ° C, is applied with a layer of up to 10 mm. The line includes starting and finishing mixes.
Advantages and disadvantages
Heat resistant fillers offer advantages over traditional mortars. They are distinguished by high strength at high temperatures due to the presence of binder fibers and the use of refractory materials.
Positive aspects of application:
- The solution consists of safe components; when the surface is heated, no harmful air impurities are released.
- The putty, prepared in compliance with the technology and application rules, serves for a long time.
- The mixtures adhere well to the surface of the stove, made of various materials, there are varieties that are used for metal finishing.
The disadvantages include a higher cost than standard ready-mixed mixtures. Such compounds are rarely used as a finishing layer - they need to be painted or tiled.
Self-preparation of putty for the oven
A solution prepared with your own hands saves money and differs little from factory mixtures. For cooking, natural materials are taken, which are available in all localities.
Compositions are being prepared:
- gypsum-sand-limestone (0.3: 2: 2);
- clay-sand-limestone (1: 2: 2);
- clay-sand-cement (1: 2: 0.3).
If the clay is skinny, the solution is mixed in skim milk. The addition of slaked lime brightens the putty, the final white color is given by a mixture of chalk and milk. Fiber is added to the mass in an amount of 1/10 of the total volume. Gypsum additives speed up the setting, so less mortar needs to be mixed.
You will need chamotte or other fatty clay, sand, lime, gypsum (alabaster). The volume of sand depends on the fat content of the main component, but for the first time it is difficult to determine the required proportions. The advice of an experienced specialist will help.
Purpose of the oven solution
The stove surface treatment improves the appearance and helps the fireplace blend in with the interior. Regardless of the construction material, the putty evens out the surface. It is important to strengthen the strength of the walls, on which the plaster remains for a long time in its original form.
If the masonry cracks, combustion products pass through the cracks and lead to carbon monoxide poisoning. Conventional putties do not withstand high temperatures, break down and tend to crack. The uneven surface of the masonry accumulates dust, soot and is difficult to clean from dirt. On the layer of putty, painting with heat-resistant paints is carried out.
The technology of finishing the furnace with plaster
For work, standard tools are used. Surface preparation is required for a good adhesion of the mortar. The thickness of the plaster is determined before starting the process using a level, a plumb line and a straight batten.
Work order:
- Old and peeling coatings, if any, are removed. Use a metal brush or hammer and chisel.Cleaning is carried out before the initial masonry.
- Notches are made and the seams deepen by about 0.7 cm.
- The surface is primed with a deep penetration compound. The degree of adhesion depends on this.
- A reinforcing metal mesh is nailed. Nails or self-tapping screws with dowels are used.
- The spray is done in the first layer and hardly evens out. The second layer is applied to determine the texture on the treated area.
The surface is smoothed with a trowel with the addition of a certain amount of solution to the pits. The mixture should dry completely and set before finishing decoration.
Decorative finishing
The finishing coat is chosen depending on the preferences of the owner and the surrounding interior. The filling of the plasterboard of the fireplace for painting is carried out with mixtures that can withstand high temperatures.
The hearth in the room is finished:
- improved putty with painting;
- decorative plaster;
- natural stone, marble;
- artificial material for a stone;
- metal, heat-resistant glass;
- ceramic tiles, porcelain stoneware;
- decorative brick (bassoon).
For any kind, materials with refractory properties are used. Natural stone does not crack when heated, but the quality of the glue matters. The ceramics can withstand temperature fluctuations, but the tiles are laid with seams, the seamless method is not applied. Tile crosses are used to keep the same gaps.
