The most thoughtful buyer of a sauna stove is a man slightly over 55. He confidently walks along the orderly rows of various stoves and with his gaze selects the mouth of the chimney with the thickest metal. Having discovered such an instance, he taps on it with his finger for a long time and subtly listens to the sound, like a cat to the movement of a mouse. Having “sipped” the stove with both hands, appreciating its fullness, he soon quickly left, shouting loudly at the sales assistant’s suggestions: “don’t teach me how to live.” Such people, as a rule, do not buy a stove at all, but order it from a neighbor in the garage who does welding work. For them, the thickness of the metal is sacred. Probably, products under the loud name Tsar-stoves would satisfy them, after all, a full-weight 8 mm firebox body, or even as much as 10, if you wait.
Pros and cons of metal stoves
To begin with, we can look at the main advantages of the design for private use:
- It is easier to get certified - every device in the house must be checked by a special authority, after which its safety is recognized. Devices that are made according to the drawings of metal furnaces without making mistakes are approved without any questions.
- High thermal conductivity - the materials are non-porous, heat up well and quickly. This point is more about efficiency; for heating a small room, like a bathhouse or utility room - such a stove will be enough.
- Cheap - the low cost is regulated by the fact that such a stove can be created with your own hands without special skills. The main thing is to have blanks of material on hand, as well as a welding machine, which can also be rented or free from friends.
Now about the disadvantages of a metal sauna stove:
- Such stoves do not “breathe” - if a brick, when heated, absorbs the air around it, thereby slowly but effectively heating it, then the metal quickly cools down and requires more resources for heating.
- Risk of fire - the walls become so hot that nearby objects can easily ignite.
- Short service life - as practice shows, the service life is a maximum of 20 years. Much depends on the frequency of use and conditions, the material is susceptible to corrosion, even the thickest walls will be destroyed at high temperatures.
If we are talking about equipping a bathhouse or a small room, then which option is quite suitable. The main thing is to build the structure taking into account the operating rules; the dedicated instructions will help with this.
Furnaces made of boiler steel 09g2s - an improved version of furnaces made of “black” steel at the same price
Steel 09g2s is the same structural steel, but with the addition of alloying elements. In terms of properties, boiler steel 09g2s occupies a middle position between black steel and stainless steel.
Artemenko Vyacheslav Manager of the store on the street. Kollontai, 18
Alloying elements are special additives that increase the heat resistance of steel.
The heat resistance of such material is within 500 degrees Celsius. Accordingly, it also needs to be compensated for by thickness, but less. Fireboxes with a thickness of no more than 3-6 mm are produced from boiler steel, but the service life of such stoves is longer than similar fireboxes made of black steel.
The burnout temperature of a firebox made of steel 09g2s is 500 degrees Celsius. Thickness: 3-6 mm. The service life is from 7 to 10 years.
Let us note another pleasant point for bathhouse attendants - despite the better consumer properties of the material (increased durability), stoves made of 09G2S steel are still the same in price as stoves made of black steel. The key word is “for now” - we won’t guess what will happen in the near future.
Fig 3. Grill'D and Vesuvius Skif sauna stoves are made of 09g2s steel
As for the heating rate of the steam room and the cooling time, boiler steel 09g2s has the same indicators as “black” steel. By the way, if you are interested in the issue of maintaining heat in a steam room, then pay attention to the article “Choosing a stone for a sauna stove.”
Steel 09g2s is not a brittle material, so the main advantage over black steel is durability.
A little history... Manufacturers first began using 09g2s boiler steel only in 2022, and the mass trend for it was picked up only in 2022. Thanks to the advantages of the material, more and more brands are appearing on the market that prefer 09g2s steel. One of these brands is the Grill'D company, which produces all its oven models from this material (except for the PRO models, made of stainless steel). Another popular manufacturer that produces stove models from this material is the Vesuvius company.
How to choose metal for the stove
Technical characteristics depend on the material from which the stove will be made. Therefore, you need to pay special attention to this nuance. Most often, craftsmen make a device from what is already in the utility room or barn.
However, this is not an entirely correct approach; the following options must be taken into account:
- Structural steel - can withstand temperatures up to 400 degrees, it is better to choose sheets of at least 4 mm. It won’t be possible to use it often, as it can easily burn out in one winter. If it is used for a bathhouse that is heated once a week, it will last a long time.
- Heat-resistant steel - this option can withstand 30 years of operation. The thickness should be at least 1 cm. Many stores sell a ready-made structure that only needs to be assembled; no welding is required, which is very convenient and profitable.
- Cast iron takes a long time to heat up, but retains heat well and heats the room. They have a long service life; such stoves can provide heat every winter for 30-40 years. The material is quite expensive, but fully justifies itself. Self-production is a rather complicated process. Such a device is often used to heat greenhouses and outbuildings. It is advisable to choose thick material, since sheets up to 1 cm will crack at the first temperature change.
Based on these recommendations, you can choose a good material for making a metal stove with your own hands.
What does the manufacturer promise?
As always, the manufacturer promises everything, a lot, and for an incredibly low price.
Let's take the Emelya Premium oven as an example. We present its main characteristics in a summary information table:
| Characteristics of the indicator | Meaning |
| Volume of heated steam room | 9 - 14 cubic meters |
| Time to reach temperature 65 - 85 degrees Celsius | 40 - 50 min. |
| Recommended weight of stone backfill | Up to 70 kg |
| Possibility of installation under a wall | Eat |
| Type and thickness of steel grate | Built-in, 8 mm |
| Furnace roof thickness | 8 mm |
| No deformation of the combustion chamber | For 15 years |
| Overall dimensions, width x height x depth | 450×630×790 mm |
| Possibility of regulating air flow through an adjustable hole in the ash pan area | Eat |
| Length of logs to be laid | Up to 600 mm |
Now let’s look at the above facts with an objective, evaluative look:
- The time to reach operating temperature is indicated “in the range” of 65 - 85 degrees Celsius. As they say in Odessa, 65 degrees and 85 degrees “are completely different things.” Such fundamental things as steam room acceleration need to be indicated more clearly and accurately, without such extended indicators.
- The manufacturer promises the absence of not only burnout, but even deformation of the combustion chamber for 15 years, but the guarantee, however, is only 5 years.
- The practical use of stoves of this type shows that despite the high combustion vault indicated in the design and the non-direct flow of combustion and flue gases, which theoretically should lead to a certain combustion efficiency and increased efficiency, in fact, the consumption of firewood during standard combustion is quite high.
- Low-carbon structural steel has a low scale formation temperature, so thermal corrosion will occur in any case, although not as critical as in the case of lightweight systems. In addition, oxidative processes are accompanied by the participation of atomic oxygen in the internal atmosphere of the steam room, which, with a large array of steel, will require good supply and exhaust ventilation. Otherwise, users may encounter such an unpleasant phenomenon, which is commonly called “oxygen burnout.”
- The massive design of the stove provokes a high threshold of infrared radiation, which in the area of immediate proximity to the sauna shelves can cause extremely uncomfortable sensations. Unpleasant phenomena can be reduced by installing a “brick case” around the body of the furnace, which will cut off infrared wave radiation.
- Finally, such stoves produce hard, sharp steam, which is significantly inferior in terms of conditions to the steam generated by sauna stoves built from mineral building materials.
What is additionally upsetting and alarming
Whatever the manufacturer claims regarding the use of special steels in the production process, the large thickness of the metal during welding requires a very high production culture, which the domestic manufacturer, with rare exceptions, never had. During operation, the most loaded element is the welding seam. Thick metal, especially when special boiler steel is used, is poorly welded and various welding defects are common, the most dangerous of which are hidden cavities.
It is obvious that the thickness of the metal in such areas is significantly less than the nominal one, and the local change in the crystal lattice during the welding process makes the metal very vulnerable. There is no need to wait for the body of the arch to burn out. The result of defective seams can be their burnout in a record short time, and hence the leakage of flue gases into the steam room space, which contain a large proportion of carbon monoxide, the poisoning of which is extremely dangerous.
By the way! Users of such furnaces note the sloppy execution of welds in products, which should, to some extent, be alarming and pay special attention to these areas. It is not for nothing that the offensive but apt nickname “suicide” has been assigned to a number of domestic stoves online.
Famous European brands have long used the following technological methods in the production of products, which elevate their products to the category of reference:
- The use of exclusively nomenclature steels as raw materials, and not what was cheaper, up to the use of second-hand components.
- Cutting is carried out using ion-plasma, laser, and in some cases waterjet systems with numerical control.
- Welding takes place using automated manipulators, so-called “welding robots”, which reduces the negative impact of the human factor to a minimum. It is worth mentioning separately that welding conditions are optimally observed, a protective environment of the weld pool is used, the seams are subjected to subsequent thermal stabilization and complete and deep flaw detection.
- At the forefront are an excellent design school, many years of experience and business reputation, which in the current market is far from an empty phrase.
Classification of metal furnaces
There are several types of stoves, which also differ from each other in performance characteristics. Briefly about three options for everyday life:
- Chamber ones are popularly known as “potbelly stoves”. The chimney is shortened to 2 meters; when the fuel burns out, the remaining flue gases contribute to combustion. Efficiency is 60%; such a device is cleaned 1-2 times a year. The main advantage is that there is no condensation, because the chimney heats up to 100 degrees and any liquid simply evaporates.
- Duct - inside there is a labyrinth of gas tubes. Operates on the principle of a burner. The efficiency is higher than in the previous version and is 80%. Can be used in several modes - flame and “afterburning”.
- Bell-type - when properly designed, gives an efficiency of 80%. It can run on coal due to the combustion of fuel in the bell. You can even heat a house of 60 square meters.
Each person decides which option to choose for household needs individually. Any type can be built with your own hands.
Making a sauna stove
A good option for heating a bathhouse would be a simple steel stove; the device is lined with bricks for safety. The only negative is that it is not mobile, so it is better to immediately choose dense and high-quality sheets for arrangement. Tools that will be useful:
- Welding equipment;
- Bulgarian;
- 3 mm diodes.
Sheets must be at least 4 mm wide, and reinforcement - 10 mm.
Important! Such a metal stove will ensure safety due to the fact that it will heat up quickly and will not emit carbon monoxide.
How to build a metal stove with bricks:
- First you need to make a foundation. To do this, you can make a wooden formwork of 20 cm, an area of 1 * 1 m.
- Next, install the reinforcing mesh; it must be done in such a way that it does not touch the ground or floor.
- Next, you need to mix the cement and fill everything with mortar. The M400 is suitable for these purposes.
- The foundation takes at least 4 weeks to dry.
- During this time, you can assemble a metal stove according to any drawing.
- Next, they make a brick rim on top of the structure, which is placed on the foundation.
- Everything sets within another 2 weeks. During this time, you can equip the chimney structure, as it plays an important role in safety.
It doesn’t matter here whether the owner of the site will design and assemble the stove himself or purchase a ready-made kit. Since the preparation itself takes most of the time. If all the rules are followed, the stove will last a long time and will delight you with warmth for 20 years.
Stainless steel stoves - the best performance
Today, stainless steel fireboxes are rightfully considered one of the best on the market. Judge for yourself: the heat resistance of such sauna stoves is as much as 800 degrees! This is 200-300 degrees higher than the maximum temperature inside the sauna stove. It follows from this that scale will not form in such furnaces.
The burnout temperature of stainless steel stoves is 800 degrees Celsius. Thickness - 2-6 mm.
The high temperature resistance also determines that the stove will serve faithfully for a very long time - more than 20 years! Durability is not the only advantage of such stoves: they are not fragile, quickly heat the steam room, and are available in various design solutions.
Fig. 4. Grill'D PRO series sauna stoves are made of stainless steel 4 mm thick.
The only disadvantage of stainless steel stoves is the price. It is 2-3 times higher than the price of stoves made of structural steel or 09g2s. In order to level out the difference, stoves are produced from stainless steel with a thickness of 2 mm. The price becomes comparable to stoves made of black steel (from 15 thousand rubles), but 4-6 mm models still remain on sale. thick (from 40 thousand rubles).
By the way, we did not stipulate at the very beginning that the article will focus specifically on stoves for baths, and not for saunas. If you have not delved into this issue yet, we recommend that you read our article: “What is the difference between sauna stoves and sauna stoves.”
Simple heater for a summer house
Such a heating metal stove is well suited for quickly providing heat to a small bathhouse or even a sauna.
The main advantages are that it is mobile and easy to manufacture.
Preparing for vaping takes 1.5 hours, the walls heat up quickly. One caveat - you need to attach 2 chimneys to the stove. The first will participate in heating the room itself, the second will remove carbon monoxide.
What does the oven consist of:
- Steel - iron sheets of at least 3 mm.
- It is better to make the firebox from thicker steel -6 mm.
- The kit also includes latches and a metal grill.
This structure can be assembled using a welding machine. Such sets are purchased in a disassembled state, the instructions are already included. Designing a metal stove will not be difficult, as it will fully comply with fire safety rules.
