If you pay attention to how much a cast-iron or steel stove costs for wood, you will quickly understand that buying it for heating a garage or a summer house with a greenhouse is not always justified. A more affordable option is a potbelly stove from a gas cylinder of long burning, made by yourself or welded by the master to order according to your drawings. Our goal is to help with the choice of design, to describe the manufacturing technology of a potbelly stove and its installation, up to the chimney device.
We select the design of the wood stove
Outdated and inefficient heating equipment is gradually becoming a thing of the past, which affects home-made stoves. Nowadays, nobody needs primitive iron boxes with a pipe and doors, devouring firewood without good heat transfer. A modern potbelly stove should be economical and heat the room well. Therefore, advanced craftsmen are constantly working on improving steel furnaces.
In order to achieve the most efficient operation of the wood heater, it is necessary to solve 2 questions: how to increase the efficiency of the stove, stove and burning time from one load, without increasing the quantity and price of the materials used. We present 3 options for homemade products, where these tasks have been successfully solved and implemented:
- three-way furnace of two propane cylinders;
- pyrolysis potbelly stove with an air-fire tube heat exchanger and a secondary chamber;
- A very popular design is the "Bubafonya" with the top burning of firewood from a gas cylinder.
For reference. The first 2 units were developed, made and tested by our expert Vitaly Dashko, who kindly provided his photo and video materials.
If you are friends with the welding machine and have the necessary tools, then technical problems with manufacturing will not arise. Below we will present the drawings and explain the technology of how to make a potbelly stove from a gas cylinder according to all three options. But first, make your choice by reading a review of these furnaces.
Three-way potbelly stove - the principle of operation and pluses with minuses
The master appropriated the playful name “Collider” to this home-made stove because of the unusual appearance and good heat transfer. This wood stove is made of two standard propane cylinders with a capacity of 50 liters, welded to each other at an angle of 90 °, as shown in the drawing. The principle of operation is as follows:
- The first tank, laid horizontally, plays the role of a firebox, respectively, equipped with doors and grates. An impressive portion of firewood is placed in it and set on fire.
- The second vessel is an air heat exchanger with internal partitions that slow down the flow of flue gases and force them to change direction three times and give more heat. At the end, the combustion products leave the heater through the chimney pipe.
- To increase the heating surface, both parts of the housing are equipped with additional ribs.
- Below, a sheet metal ash pan is welded to the firebox, whose door controls the combustion air supply.
Note. With the same success, instead of cylinders, a steel pipe for a potbelly stove with a diameter of 300 mm and thin walls (4-5 mm) can be used.
The estimated power of the “Collider” is 10 kW with an efficiency of about 55%, which allows you to heat a room with an area of up to 100 m² - a cottage, a greenhouse or a large garage (box). Practical tests have shown that in the mode of maintaining heat in a heated room, 1 load of firewood is enough for 1.5-2 hours. If you use a heating unit in a house of a smaller area (25-50 m²), then the duration of combustion will increase up to 3-4 hours.Who understands the topic, he will understand that for a homemade potbelly stove this is a good profitability.
The downside of this long-burning stove is one - a strange appearance. But it is offset by numerous advantages:
- ease of manufacture;
- quick warm-up and decent working time with 1 bookmark solid fuel;
- cheap design, you only have to buy convenient handles and even a pipe for a potbelly stove if there are no propane cylinders;
- due to the size of the firebox, long (80 cm) and massive logs are placed in the stove, which contributes to the duration of combustion;
- the unit can be made with a hob, as shown in the photo.
The “Collider”, like any self-made welded gas cylinder from a gas cylinder, can be supplemented by the installation of a water circuit that regulates the air damper in the ash pan door and external blower fan. The dimensions of the stove are changed in any direction by selecting tanks of a smaller capacity or pipes of a different diameter.
2-chamber pyrolysis furnace overview
This small wood-burning stove, made from a 24-liter gas cylinder, was called Pyaterochka by the number of air heat exchanger tubes. It acts on this principle:
- As in the previous case, the cylinder laid on its side serves as a combustion chamber, and an ash pan is attached to it from below. The role of the grate is played by slots cut into the wall of the vessel.
- An opening was made at the top of the tank, where 5 vertical tubes of the heat exchanger adjoin. Hot flue gases move along them and thus transfer part of the heat to the room.
- From the heat exchanger, the combustion products enter the secondary chamber, where heated air is separately supplied through a separate tube. Due to this, combustible gases formed in the furnace are burned and generate additional heat, and then sent to the chimney.
The results of practical tests of the heater are as follows: a room with an area of 30 m² is heated at 20 ° C for 1 hour, after which one laying of a tree lasts for 1.5–2 hours, depending on the operating mode. Estimated power - 5 kW. As you can see, in this design the burning time is reduced due to the reduction of the firebox, but the stove is very compact and fits in any room. Yes, and it warms pretty well.
Tip. Do you want to increase the burning duration to an average of 4 hours? Then study the drawing of another option, which depicts the same pyrolysis potbelly stove made with your own hands from a 50 liter gas cylinder. The device of the heating units is identical, the difference is only in the volume of tanks used as a firebox.
Thanks to efficient burning of firewood, the Pyaterochka stove is more economical than the Collider, although it is more difficult to assemble. According to the cost of materials, the difference between them is small - in the first 2 cylinders, in the second - 5 pipes with a diameter of 57 mm and a length of 40 cm. A separate advantage of the stove is the ability to burn wet wood and any garbage after heating without losing the intensity of heating. Other advantages are the same - low cost, ease of use and the possibility of modernization.
Another good advice. It is only natural if, after replacing a small cylinder with a standard one (50 l), you want to increase the heater power and add another 2-3 pipes to the heat exchanger. Remember that the flow area and chimney draft should increase accordingly. Otherwise, you will waste materials and time, because due to insufficient traction, the end sections will remain cold and the furnace capacity will not increase.
Top burning stove "Bubafonya"
By and large, “Bubafony” cannot be classified as a bourgeoisie, since it is fundamentally different in principle of work. But to ignore this stove is impossible due to its wide popularity, due to the duration of burning from 1 load of firewood from 6 to 10 hours. At the same time, the heater is famous for its many shortcomings, which we will discuss further.
The operation algorithm of the long-burning stove "Bubafonya", shown in the drawing, is as follows:
- The firebox is a standing upright propane cylinder of 50 liters. Through the hole in the top cover, an air supply pipe enters, ending in a thick metal disc. From below, steel strips are attached to it, distributing air in all directions.
- When the firebox is filled to the top with firewood, a heavy disk presses them down and causes them to sag as they burn. Ignition is also performed from above, and only then the pipe with the load is lowered.
- Combustion air supply is regulated by a flap installed on the upper end of the pipe. The chimney pipe is cut into the side wall of the container under the cap itself.
Note. The place where the pipe passes through the lid is not sealed and secondary air is sucked in, helping to burn combustible gases over the disk when the stove is properly warmed up.
The strengths of Bubafoni are its decent working time, simplicity and the possibility of being converted into a top burning boiler (a stove with a water jacket is made, as described in a separate article). But the weaknesses forced many garage owners to abandon such bourgeoisie:
- the stove cannot be loaded until all the fuel has burned;
- from blocking the damper, the furnace will not go out and will smolder for a long time, because secondary air enters it;
- without good draft, the heater smokes into the room;
- in the mode of slow burning, the stove heats slightly, and the chimney is intensively clogged with soot;
- to return to normal mode, the unit must warm up well, which takes ¼ fuel.
For reference. To burn soot in the chimney, it is necessary to drive the “Bubafony” in maximum mode with each kindling.
Finally, sweeten the pill a little. Despite all the shortcomings, the long-burning furnace from a gas cylinder does not lose popularity, in addition, it successfully operates on sawdust and various combustible waste.
DIY cooking stove instructions
Before you cook a long-burning wood stove, you must prepare all the necessary power tools:
- welding inverter;
- grinder, she is an angle grinder;
- drill with a set of drills.
Note. We will not list hammers with pliers here, since in the house of a good owner there is always a complete set of tools.
Of course, you will need an old propane cylinder, from which you need to twist the valve and be sure to fill it with water before cutting. The fact is that propane is heavier than air and its residues will not leave the tank on their own. To push them out of there, just apply water. The order of further work depends on the chosen design.
We assemble a three-way furnace
In addition to cylinders, for the manufacture of this potbelly stove, it is necessary to prepare the following materials:
- 2 mm thick sheet metal will go to the ash chamber and ribs, 3 mm to the doors;
- a piece of round pipe with a diameter of 100 mm - on a chimney pipe;
- corners or profile pipes for legs;
- asbestos, and better - asbestos-graphite cord on the door seal;
- steel profile 20 x 20 mm or reinforcement of the same section - to reinforce the grate.
Tip. Pens - locks with beautiful ebonite pads are easier to buy than wasting time on homemade ones. To give the stove a modern look, get a heat-resistant paint (sold in aerosol cans).
First of all, cut the metal into workpieces according to the dimensions indicated on the drawing of a long-burning stove, presented in the previous section. The manufacturing technology of the furnace is as follows:
- At the end of the first cylinder, cut an opening under the door and a hole in the wall for the exit of gases. At the second vessel, saw off the bottom, and at the end, make a hole for the 100 mm pipe. Make semicircular cutouts on the walls so that one cylinder fits tightly on the other.
- Cut through the slots of the grate.From the outside, weld 20 mm profile amplifiers to it.
- Make an ash pan and door frames, weld them to the body. Install the legs at the same time.
- Weld the doors and seal the junctions to the frame. Install the sashes and handles.
- Use the cut-off cylinder walls as partitions by welding them inside a vertical tank.
- Connect the two vessels to each other in welding. Install the chimney pipe and scald it.
- Attach heat exchange fins to both housings. On this stove is ready.
A few words about how to make dense doors for a long-burning stove. The technology is simple: a channel is formed from narrow steel strips welded to the inner surface of the leaf, where a graphite-asbestos cord is subsequently stuffed. The main thing is to clearly determine the location of the groove. At the end, all metal must be degreased and painted in 3 layers with interruptions for drying.
Tip. Before painting, it is advisable to melt the welded oven in order to burn out all the old paint.
Making a pyrolysis two-chamber stove
The assembly scheme of this high-efficiency potbelly stove is in many ways similar to the “Collider”, only 1 gas cylinder is used, and pipes with a diameter of 57 and 20 mm are added from the materials (to the heat exchanger and secondary air supply, respectively). The procedure is as follows:
- Cut openings in the tank for the loading door and under the heat exchanger installation. The dimensions of the platform for him are 260 x 200 mm.
- Make an ashpit and set the doors as described above. Weld the legs.
- Make a heat exchanger by cutting pipes in a checkerboard pattern between two sheets of metal. Observe the center distances indicated in the drawing.
- Bend the 20 mm pipe at a 90 ° angle and weld it to the heat exchanger. Attach the latter to the opening cut out in the cylinder.
- Weld the secondary chamber to the chimney. Use a semicircular billet as a cover, which used to be the wall of the cylinder. The heater is ready.
Note. If you use a standard cylinder, the algorithm of work is not changed, only the ash pan needs to be made larger (the size is shown in the drawing).
A little about how to properly supply air to the secondary chamber of a long-burning stove. Before installation, the end of the tube must be plugged, and 5-6 cuts in the form of a Latin V should be made on the sides. Then the pipe is inserted into the hole in the upper area of the heat exchanger and scalded. If you are making a potbelly stove yourself from a pipe taken instead of a cylinder, you will need to weld the back wall and front panel of metal with a thickness of at least 4 mm.
Photo of the assembly process of a potbelly stove
Making a potbelly stove on video
Heater assembly "Bubafonya"
The manufacturing technology of this stove is one of the simplest. Take a 50 liter gas cylinder, cut off the upper part along the factory seam, and then do the following:
- Weld the grate from the fittings of a periodic profile with a diameter of 20-24 mm and install it according to the drawing. Cut out the opening below and place the ash chamber door.
- In the cut off cover, make a hole for the air pipe, and weld a steel strip to the outside of the cylinder for sealing.
- Attach a disc weight with welded air diffusers to one end of the 57 mm pipe by welding, and place an air damper on the other.
- Install the chimney pipe.
- Insert the air pipe into the firebox and put on the cover.
For reference. Many home masters do not put grate and an ash pan door in a “Bubafonya” type stove. This simplifies the work, but complicates the operation: after burning wood, the housing has to be turned over to shake out the ash.
How to install a potbelly stove and a chimney
When placing wood heaters, it is important to comply with fire safety rules. This is especially true of our expert's furnaces, whose upper part can glow red-hot at maximum operating conditions. Here the requirements are:
- In a garage or in a country house built of brick or other non-combustible materials, the minimum distance to the walls of the room is not standardized. But any combustible objects or structures should be no closer than 50 cm from the furnace body.
- In a greenhouse, a potbelly stove should not be placed close to plants and glass outer walls.
- In a wooden house, the floors under the stove are covered with a metal sheet protruding from the fire chamber by 700 mm. The nearest walls are also covered with metal to prevent fire.
A separate question is what to make a chimney for a stove. Aluminum corrugation is definitely not suitable, since the temperature of the gases at the outlet reaches 200-400 ° C, depending on the operating mode. What options are valid:
- ordinary steel pipe with thin walls;
- flue from roofing or stainless steel;
- insulated chimney sandwich.
Tip. It is preferable to take the last version of the chimney - a double-walled pipe with a basalt fiber heater in the middle.
To create good traction, the top of the pipe is placed at a height of 4 m or more, if measured from the grate. The Bubafony potbelly stove is especially demanding for draft; for it, the gas removal should be made higher so that later there are no questions why the stove smokes into the room. Ideally, the vertical section of the chimney should end with a condensate collector, although many home craftsmen do not adhere to this rule.
By the way, the correct chimney allows you to increase the efficiency of the stove-potbelly stove. This is achieved in two ways:
- In a garage or greenhouse, the chimney is lengthened and laid at an angle, and at the other end of the room goes to the roof, as shown above in the photo. So burning products of combustion will give more heat to internal air.
- On the vertical section of the chimney, a heat exchanger is installed, connected to the water heating system of the house or cottage. Minus: from the chimney channel of a long-burning stove, it will be necessary to remove soot more often.
A samovar-type heat exchanger, placed on a chimney stove, should not be directly connected to the water heating network. There is a danger that the coolant may boil and break the piping. It is better to use the connection scheme through a container of water - a heat accumulator, which can also be made with your own hands from a gas cylinder. For a description and drawings of its design, you can go here.