Plastering a furnace is not such a simple task as it might seem at first glance. An improperly applied finish due to constant temperature changes will necessarily crack or completely disappear in pieces. In order to plaster the stove correctly, you should first knead a suitable solution. Actually, the finishing procedure itself must be done in compliance with a certain technology. How to plaster the oven so that it does not crack - we will talk about this later.
What is it for
Furnaces and fireplaces can be decorated using a variety of materials: tiles, artificial stone, heat-resistant drywall, etc. However, it was plaster that was always considered optimal in terms of price / quality ratio. This finish looks very neat. In addition, if the application technology is strictly adhered to, it can last for a very long time. Plaster for the furnace allows you to:
In addition, plaster also closes the joints in the masonry. And this, in turn, prevents the accumulation of household dust in them.
How to plaster the oven so that it does not crack: a traditional solution
Most often, for the decoration of fireplaces and stoves, it is not a cement-sand mixture, but clay. This material is able to maintain its properties at temperatures above 100 ° C. Like cement, clay for furnishing furnaces is mixed with sand. The latter is previously carefully sieved through a fine lattice. The amount of sand needed to prepare a high-quality mixture of sand depends primarily on the clay content. The higher this indicator, the more plastic the mixture. Therefore, the more sand should be added to it. If it is deficient, the mixture will crack after drying.
Typically, the ratio of oily clay to sand in a stucco mortar for stoves is 1: 3 or 1: 4. To strengthen the composition, you need to add straw or hemp to it. Qualitatively, the stucco of the clay furnace can also be done if a little fiberglass (0.2%) is mixed into the solution. In any case, dilute the mixture in such a way that it turns out to be as homogeneous as possible. The clay itself must first be soaked for at least 3 days.
Other types of solutions
Answering the question of how to plaster the stove correctly so that it does not crack, it is worth considering the use of other options of heat-resistant mixtures. The above method of preparing a solution is far from the only one. There are many recipes for such plasters. If desired, a heat-resistant solution can be made, for example, by mixing:
clay, sand and cement in the proportions of 1: 2: 1 with the addition of 1% asbestos;
gypsum, lime and sand in a ratio of 1: 2: 1 plus 2% fiberglass;
clay, sand and lime in a ratio of 1: 2: 1 with the addition of 2% asbestos.
Purchased Heat Resistant Blends
Also, finished plaster for the stove can be used for decoration. There are many varieties of such mixtures. But the most popular are Pechnik and Terracott. The advantage of such plasters in comparison with self-made ones is a high degree of heat resistance. "Pechnik" and "Terracotta" are able to withstand temperatures up to 200 degrees.
Whatever mixture is used for plastering the furnace, purchased or home-made, it is not necessary to cook large quantities immediately. The volume of a single serving should not exceed 8-10 liters. In any case, you need to develop a solution in a maximum of 2-2.5 hours.
Plaster fiberglass mesh as additional reinforcement
In order to ensure that the solution on the furnace subsequently holds as solid as possible, it is not enough to use reinforcing additives in the form of straw or tow. When finishing, a special fiberglass mesh should also be used. This material can now be purchased at almost any construction supermarket.
There is a fiberglass stucco mesh very inexpensive - about 30 rubles per 1 m 2 . Finishing, when used on a stove, lasts much longer. Instead of fiberglass to reinforce the solution, you can take a metal mesh.
Preparatory Activities
Before proceeding with the actual plastering of the furnace, its surface should be thoroughly cleaned. Do not apply mortar on smoked or dusty bricks. Otherwise, for a long time thereafter he will not hold out. After cleaning, bake the oven. But there is no need to lay too much firewood or coal in the furnace. Plaster for stoves and fireplaces is applied only on a warm surface.
Finishing the furnace immediately after the end of its laying is impossible. You need to wait at least two weeks. The masonry should be well hardened before plastering.
Before you start applying the solution, among other things, you should choose the joints between the bricks by 10 mm. In this case, the heat-resistant mixture for plastering stoves will stick to the surface better. Also, in the masonry, you need to drive in small carnations, on which the reinforcing mesh will subsequently be stretched .
What tools will be needed
Before proceeding with the plastering of the furnace, among other things, you should prepare:
capacity for solution;
trowel;
sandpaper for grouting;
broom or brush;
bucket with water;
construction level.
Plastering technology
Well, the preparations have been completed, and the tools have been prepared. Now let's see how to plaster a stove. So that the applied mixture does not crack and does not crumble, this work must be done correctly. Plastering is usually carried out in several stages. Preliminarily, the furnace surface is wetted with clean warm water. You can moisturize it with a conventional broom. Then are executed:
spray of solution;
padding;
nakryvka.
Mixture spray
The first plaster layer is necessary in order to level the surface of the furnace. Spray, as can already be judged by the name, is performed using the same broom or brush. The thickness of this layer should ultimately be 3-5 mm. After the spray is leveled, it is necessary to stretch the previously cut fiberglass mesh on the surface of the furnace by slightly pressing it into the solution.
Padding
The second layer of plaster can be applied after drying the first. Its thickness should also be 3-5 mm. The primer should be smoothed and smoothed in the most thorough manner. In this case, since it will dry quickly on a hot stove, it is necessary to moisten it periodically. The solution for the primer should be used slightly more liquid than for the first.
Nakryvka
The last layer of plaster is necessary in order to smooth the surface of the furnace completely. The primer must be moistened quite liberally before application. The solution in this case should be used even less thick than for the first two layers. The mixture should fill absolutely all cracks and irregularities remaining on the surface. The thickness of the coating layer can be from 2 to 5 mm. It is impossible to level the stove with plaster in planes. Ultimately, the total thickness of the finishing layer should be no more than 1-1.5 cm. When laying out brick ovens for the house with your own hands, this should be borne in mind. When performing this work, the walls should be tried to be made as even as possible initially.
How to plaster corners correctly
To make the stove look neat, carefully leveling the surface of the plaster is not enough. In addition, it will be necessary to beautifully draw the corners. In order to make them as neat as possible, it is worth using leveling rails. After the solution has dried, they should simply be removed. Instead of rails, you can also take an aluminum profile, designed for attaching drywall. It is fixed on the furnace with a mortar and plastered flush. Of course, both the slats and the profile should be set using the building level.
Oven coloring
So, now you know how to plaster the stove so that it does not crack. Of course, after the applied solution dries, its surface must also be whitened. To use for this purpose the best milk-chalk mixture. This whitewash tolerates temperature extremes and also does not get dirty. In order to cook it, you just need to mix 1 kg of crushed chalk with 2 liters of milk. You can paint the oven with ordinary lime. This finish will also not deteriorate due to the high temperature. In order to keep lime better on a hot surface, a little salt can be added to it (35 g per 1 kg).
Do not paint stoves and fireplaces using oil paint. The linseed oil contained in such a paint will begin to evaporate at high temperatures, and an unpleasant smell will appear in the room.
Instead of a conclusion
Today, many people build brick stoves for the house with their own hands. A description of the assembly technology of such structures, as well as their drawings and diagrams can be easily found in the specialized literature. However, putting the stove or fireplace correctly is only half the story. Plaster on the surface of the heating equipment of this variety must also be applied, adhering to the proper technology. Otherwise, the stove or fireplace will not perform its functions effectively. And in the interior of even a modest country house they are unlikely to fit harmoniously.