DIY forge: video, drawings, photos

Well, how much we love wild abstruse definitions: special heating devices for the purpose of increasing the plastic characteristics of the metal. Let's try to translate all this disgrace into human language.

A forge is essentially a stove. It is clear that it has its own characteristics, varieties and technological nuances, but it is still a stove. It is needed to heat metal parts to a temperature so that they can be forged, that is, subjected to deformation.

This is the main and general fact for all kinds of forges - from primitive country crafts on bricks to industrial furnaces with many technological features of application and purpose.

On a different fuel

This is how the ancient coal forge works.
Initially it was heated with charcoal, then with coke. Both are almost pure carbon. In principle, the forge can also be heated with wood, allowing it to first burn down to coals, i.e. to charcoal; Let's see how further. The design of the forge is greatly simplified if you use purified monogas, propane or butane as fuel. They consist of carbon and hydrogen, which is also an excellent reducing agent and, when combined with oxygen, produces even more heat. Moreover, the gas can be mixed with oxygen in advance, while still in the burner. We will also look further into how gas burners for a forge are constructed, but for now let us state a fact: a brick gas forge can be assembled in a hurry, as long as there is a burner, see fig. (You can also watch the video at the end of the section on how to make a gas forge yourself).

However, this applies only to pure monogases for industrial use. Household natural gas, firstly, consists of a mixture of saturated and unsaturated hydrocarbons, which have different oxygen requirements and different heat release for complete combustion. That is, it is fundamentally impossible to set up the optimal air supply for heating the metal for high-quality hardening or cementation.

Secondly, natural gas contains sulfur, silicon, and phosphorus in negligible quantities. At least in the form of an “odorant” – mercaptan – artificially introduced into household gas for immediate leak detection. If phosphorus and silicon, with precise dosage, can still be useful (the first - for surface phosphating; the second - for improving magnetic properties), then sulfur is the worst enemy of steel, completely killing its operational value, and irreversibly; restoration requires complete remelting.

Therefore, household gas can be used as fuel for the furnace, firstly, only after purification from sulfur-containing compounds. The simplest, but by no means free, method is to pass gas from a cylinder through a container with mothballs before feeding it into the burner. It desires sulfur no less than carbon desires oxygen. Secondly, heat in a gas furnace only parts that are not critical and will not be loaded in the future; say, decorative elements of artistic metalwork.

Conclusions and useful video on the topic

The injection burner developed by Alexander Kuznetsov is especially popular. In this video, he explains what the structure consists of and how to assemble it:

Example of an injection burner operation:

Properly designed and made with your own hands exactly according to the requirements, the injection burner will become a reliable assistant for a long time. This device will replace expensive factory-made tools. With its help, you can solve many everyday problems without resorting to the help of professionals.

Would you like to tell us about how you assembled an injection torch for blacksmithing with your own hands? Do you have useful information on the topic of the article? Please leave comments in the block form below, ask questions, post photographs.

Firebox rules

The optimal fuel is fine coke, which, although more expensive than regular coal, is consumed in minimal quantities for work. Since high temperature is required to ignite it, a homemade forge for a forge must first be heated with wood. Only after the main fuel has burned out is the preparation introduced into the hearth for ripening, reducing the blast.

In order for the forge to work correctly on ordinary coal, it must first be fried to completely evaporate the coke oven gas, which will become clear by the change in color of the flame. Such fuel is usually used for the manufacture of large original products.

To forge figures from Damascus at home, it is necessary to use charcoal for the firebox, but this fuel requires jewelry work, since it instantly responds to blowing and quickly burns out.

You can also use ordinary hardwood firewood for the firebox, but first burn it in the shell to completely prevent unburned wood chips from getting on the metal. This method of producing heat is considered the most economical.

A few words about the air supply itself

Of course, something must force delicious oxygen into this pipe, which will heat the coals in the chamber to hellish temperatures. You can use blacksmith bellows. The kind our ancestors used in their forges. But this is not the best option, you need at least a couple of bellows to get the required temperature, and it would be nice to have an assistant who will tirelessly press the bellows. It is much more productive to use electric leaf blowers. For example, a turbine for inflating mattresses. I used an old Soviet vacuum cleaner. You can even twist the hose from blowing in to blowing out, but it broke. I had to tape the bag on the side where the air is blown out.

Open forges

An open forge gas forge consists of vertical stands on both sides of a metal container, which is installed on a fire-resistant base. The role of the base can be performed by:

concrete floor (platform);
several refractory bricks laid in a row, etc.

A gas burner is installed on the racks, with the nozzle pointing down. In most cases, forges are installed on a metal stand, which has a tray at the bottom for placing the workpieces to be processed.

Classification of forges

Before making a forge, you need to familiarize yourself with their classification in order to select the most suitable design option. Classification is carried out according to the following criteria:

by type of fuel used;
by type of construction;
according to hearth size.

Types of forges by type of fuel used

According to the type of fuel used, forges are divided into the following types:

gas;
solid fuel;
on liquid fuel.

Solid fuel forge

Gas furnaces have the simplest design and are cheap to repair and maintain. They are characterized by minimal weight, which allows them to be made portable or compact.

Solid fuel furnaces are distinguished by the ability to obtain the highest possible heating temperatures, the relatively low cost of building materials for construction and ease of operation. For their kindling, it is permissible to use the following types of fuel:

carbon or coke, characterized by high cost and increased efficiency (consumption is up to 5 times less than coal), it does not contain foreign impurities, ignites at temperatures above +450°C;
Coal, the most common and efficient fuel, emits coke gas when burned, so when lighting it is necessary to wait until it has completely evaporated; it is suitable for forging various decorative elements or parts of medium quality;
charcoal has a minimum ignition temperature compared to other types of fuel, but it burns out quickly and is characterized by increased consumption, so it is effectively used for kindling.

It is permissible to use diesel fuel, fuel oil or waste oil as liquid fuel.

At the same time, it is important to pre-clean it, since the presence of impurities will cause an unstable flame and release of harmful compounds into the atmosphere

This also makes it difficult to maintain equipment due to frequent blockages.

Classification by design features

A homemade forge can be classified according to its design features as follows:

by installation method: portable or stationary;
according to the design of the combustion chamber: closed or open type;
according to the placement of the boost: with a side or central nozzle.

Types of forges by hearth size

There are different sizes of hearth forges: small, medium and large. They are determined by the operating efficiency of the installation and completely depend on the intensity of fuel consumption and operating modes of the fuel chamber. The optimal efficiency of fuel flow rate is from 1 to 1.5 m/s.

The productivity of the forge is directly proportional to the amount of tension and hearth area. In this case, the minimum tension is considered to be in the range from 100 to 150 kg/m2 h. Values outside this range are not economically viable.

Features of working with a forge

After making a forge, you need to learn how to use it. To do this, it is recommended to adhere to the following rules:

The beginning of working with the device is to load fuel onto the grate. Some blacksmiths recommend placing a workpiece on a heated layer of coal, and pouring another layer of coal on top of it. In this way, it is possible to achieve the highest possible temperature in the chamber.
If wood is used as fuel, an additional ring (21 cm in diameter) must be placed on the grate.
To ensure good traction over a homemade forge, it is necessary to install a special hood. You can also do it yourself.
In order to heat the workpiece to the temperature required for forging, it must be kept in the middle of hot coal. It is important not to overcook the workpiece. This can deteriorate the properties of the metal, which will complicate the process of working with the workpiece or make the metal very brittle.
For forging, it is recommended to use a special hammer whose weight does not exceed 1 kg. During work, eyes must be protected with goggles. This will help prevent hot metal from getting into your eyes.
A large metal thing can be used as an anvil. This could be a rail or a sledgehammer.

A homemade forge has significant advantages over a purchased one. It is much cheaper, easier to use and maintain.

Solid fuel device for forge

The simplest model of a solid fuel device for a private forge is an outdoor open stove, which does not require the installation of a ventilation system. The construction of the structure involves pouring a reinforced concrete base; wall bricks must be laid at the base of the structure. The table is installed at a convenient height; a hole is left in one wall for the blower.

The mountain pit is laid out of fireclay bricks supported on steel corners; a cavity for the grate is left in the middle part of the structure. A chimney or probe will help ensure sufficient draft in the fireplace; the air supply system is installed at the final stage of construction work. Installing an electric fan in the chimney or installing blacksmith bellows will help increase the draft.

In a home forge, a container for hardening parts and a gas-air chamber are not mandatory elements. They can be useful in cases where thermal or shock hardening is required when working with damask steel. In the gas-air chamber the following is carried out:

drying and heating oxygen;
filtering oxygen from condensate and foreign impurities;
mixing air with additives for alloying steel.

To melt precious metals and create an alloy of non-ferrous metals, it is necessary to make a crucible from a heat-resistant material. The device, made in the form of a cap, allows you to increase the operating temperature in the furnace without the risk of overheating the workpiece and the formation of soot.

Making a forge from a potbelly stove

Essentially, this is the same potbelly stove, only without the grate. The appearance of blacksmiths can be in the form of a cube, parallelepiped and cylinder. After cleaning the grate, the air does not come from the space below, but is blown through a side channel, which can be adjusted. As a result, the oven heats up better. It retains gases longer, which also increases the heat.

The manufacturing procedure is as follows:

From a pipe with a diameter of up to 300 mm, a ring 100 mm wide is cut. This part is called a collar.
A sheet 4 mm thick is taken and a circle equal to the diameter of the collar is cut out of it. This will be the door.
A piece of pipe for air supply is cut off. It can be from 76 to 102 mm.
The damper is inserted into it using a handle, a spring and a nut.
A strip 30 mm wide and length equal to the perimeter of the door is cut out of a 3 mm sheet.
The strip fits around the door and gets scalded.
A hole is drilled in the side of the door and a pipe for air supply is welded there.
Using a locking device, the door is attached to the collar.
This unit is installed on the firebox with a distance of 100 mm from the bottom.
In the back part, at the top, a hole is cut and a chimney is installed.

The disadvantages of such a stove include the absence of an ash pan. However, longer combustion results in improved combustion of solid waste. Ash removal can be done less frequently.

Some useful tips

For the mechanism for blowing air into the forge, an old vacuum cleaner with speed controllers is most often used.

Now you can clearly see how you can complement your home blacksmith’s forge. In the meantime, you need to acquire a simple anvil and blacksmith pliers, without which it is impossible to work.

Charcoal and stone coal, firewood and coke can be used as fuel. Coke is more expensive than coal, but its consumption is 5 times less. Combustion of coke produces less slag and soot. It's better to use coke. This is what professionals call coke of fine fractions, which does not need to be pre-cracked, wasting time on this.
You can use mains or bottled gas as fuel. This fuel will allow us to eliminate the need for grate bars. The heating temperature can be adjusted. Fuel is quite cheap and available.
It is recommended to install an exhaust hood made of sheet metal 4 mm thick on top. The joints of the parts are well welded to ensure the tightness of its internal volume.
It is necessary to make a hole in the side wall of the forge for a gas burner. A smoke removal system is also needed. This is a pipeline with a cross-section of approximately 30x30 cm. Its height is about 5 m.
Instead of a vacuum cleaner, you can use a fan from a car heater.
A hole cut in the back wall of a homemade forge will significantly improve the ventilation of the installation. Using this hole, it will be possible to heat longer workpieces.

You can make a homemade forge for blacksmithing yourself in a small room at your summer cottage. This device will make it possible to produce unique forged parts to create canopies, fences, gates and other things to decorate the interior of the site and the house.

How to make an anvil from an old rail

The experience of a portal user with the nickname DIMDIM is interesting. He tells you what can be achieved when making homemade products if you apply your ingenuity to the matter.

DIMDIM FORUMHOUSE Member

I decided to take up forging. I watched a lot of videos online and came to the conclusion that I could make the entire instrument myself. First of all, I need an anvil, a forge, and various accessories. To save money, I will make everything from what I have in my “bins”, i.e. from scrap materials.

From the Internet, the user learned that most often a homemade anvil is made from a railway rail.

Because there was no rail in the “bins”, DIMDIM involved all friends, relatives and acquaintances in the search for the “donor”. Soon the search was crowned with success, and the user became the owner of an old but strong rail.

All that remains is to cut off everything unnecessary from the workpiece and give it the desired shape. Having uncovered the metal cutting machine, the user began to work.

According to DIMDIM, it took four hours to cut the rail, made from high-carbon heat-treated steel, into two pieces and trim it, with regular stops for the cutter to allow it to cool.

Then came the turn of making the so-called. “horns” of the future anvil. Because The sawn-off part of the rail did not fit at the required angle on the cutting machine bed, so we had to disassemble the clamping device and connect the bed to an additional table.

The user had difficulty cutting the rail into a triangle, then the tedious work of giving the anvil “horn” the desired shape began.

The work was carried out alternately using an angle grinder, a cutting machine and various fasteners and pads.

This work took another 5 hours.

DIMDIM

Having made the blanks, I started assembling the anvil and tried to connect all the parts together. Because the rail was crooked and the parts could not be connected. My friend and user of the Movik portal helped me out.

A member of FORUMHOUSE suggested DIMDIM to assemble an anvil on a frame, which was used as a steel counterweight from an elevator. As the author of the idea, Movik welded all the parts into a single structure.

The next stage is the production of a square hole in the “tail” of the anvil, which is necessary for fastening various devices - mandrels, staples, bending forks and cones, the shank of which has the same cross-section as the “receiving” hole.

When making an anvil on their own, craftsmen make the “square” in different ways. The hole is burned with a welding machine, drilled and then finished with a file. The user simplified his task - taking a grinder, he cut a groove in the rail, and then welded a corner made from a T-shaped guide from an elevator to the end.

When assembled, the anvil took on the following appearance.

The user also made a set of attachments for the anvil.

Manufacturing and installation of a burner in a closed gas furnace

Let's consider two options - make a burner from scratch, using the recommendations of experienced home craftsmen, or use a ready-made design, adapting/modifying some of its characteristics. It should be noted that in the first case you should have very high qualifications, as well as have experience in setting up and, at a minimum, repairing such devices. Otherwise, the matter may end in an explosion, burns, and other troubles.

Confusion bell made of heat-resistant steel type X18N9T.
Steel tubular body shaped like a double truncated cone.
Gas supply head.
Air supply head.
Mouths.
Regulators for the amount of gas-air mixture.

To make such a burner you need: 1.5-inch pipes, a sheet blank with a thickness of at least 1.2 mm for the confuser, two fittings and three flanges for connecting the elements. It is better to make a welded structure from heat-resistant steel, and welding must be done under submerged arc or using inert gas. High-pressure hoses can be used as air and gas supply pipes, the diameters of which will correspond to the connecting dimensions of the housing. Fixing clamps and high-quality seals made of gasoline-oil-resistant high-temperature rubber are also required. All other elements are connected using threads.

Horn with a homemade gas burner

On some websites there are recommendations for making a burner body by rolling a tubular blank. But at high jet pressures, plastic hardening of the material can lead to the emergence of zones of internal stress, which, when starting the burner, often cause cracking in the body metal.

The option of installing a burner from a used gas stove is much simpler. You will first need to determine the fuel costs required to quickly heat the metal for forging. When selecting a finished design, the power of the main unit (boiler, stove, etc.) for which the device was used is established. The product of this value by the efficiency (for gas it is 0.89...0.93) gives the desired power value W. It is a little more difficult to establish the gas consumption T. The calculation algorithm is as follows:

The calorific value of the fuel Q is determined (for propane, 3600 kJ/m3 can be taken);
Using the formula T = 3.6W/Q, the flow rate is determined.
Based on the calculation results, all the necessary shut-off and control valves are selected: valves, tees, o-rings, etc.

Installing a burner in a forge for forging with your own hands is done as follows. First, a confuser is inserted into the prepared lining hole, and the burner mouth is attached to it through a sheet gasket made of heat-resistant steel. The product itself is attached to it, and tubes for supplying air and gas are screwed in. They check the effectiveness of the regulators, after which they carry out a test run of gas from a cylinder or a stationary network. All work must be carried out in a well-ventilated area. At the slightest smell of gas, installation work is stopped and the source of possible leaks is determined.

If you find an error, please select a piece of text and press Ctrl+Enter.

Mobile

Here in Fig. - drawings of a deservedly popular design: a fully functional mobile forge intended for outdoor use. This is the kind of device that was in mind when thinking about cavalry and sewing machines.

Pay attention to the node marked with number 1. This is a drainage for fine adjustment of the blowing. The drainage tube extends and retracts, and at the bottom there is a longitudinal row of small holes, 1-2 mm in diameter, drilled into it. By bypassing air into the drainage, the boost can be very precisely controlled.

The nuances of self-production

How can you make a homemade blacksmith's forge? To do this, you will need drawings of a heating device model that suits you and the room where the equipment will be located.

Forges differ in the types of heating chambers.

Closed heating chambers. They are the most efficient because they minimize fuel consumption while providing excellent heating of workpieces. But the blanks themselves are limited in size, since they depend on the dimensions of the chamber.
Open heating chambers. This design provides that fuel is poured onto the grate, and air is supplied from below. The metal blank is placed on the fuel. Although fuel consumption is slightly higher, larger workpieces can be used.

How to make a blacksmith's forge in order to be able to forge iron at home? Let's consider each stage of construction of the structure.

Photo of a handmade forge

Table. The table is the basis of a homemade forge. The drawings show that building this element is quite simple. Typically the table height is up to 80 centimeters, and 5 millimeter thick metal is used for the lid. The working surface can have different sizes. It all depends on what kind of metal workpieces you are going to work with. Another option for building a table is to use angle iron to create a frame. Bricks and a grate are laid inside it. The grill should be positioned in the center.
The grid is mounted in a hole made in the table. Then the fire brick is closed on all sides. Select the height of the table directly to your height so that the structure is at waist level.
Blowing For the forge to work effectively, it requires high-quality air supply. Due to oxygen, the temperature rises and the metal begins to melt. Traditional forge designs used a foot-driven blower. But now everyone has the opportunity to use electricity, so the optimal solution is an electric fan or an old vacuum cleaner. The vacuum cleaner supplies air with the required force. If you have a speed controller, you will get a chic homemade horn.
Now all the structural elements are assembled into a single system - a homemade metalworking forge.
Pour the required amount of fuel onto the grate. First use wood chips and medium wood, after which comes the turn of coke. Turn on the blower and place your workpiece over the fuel. A small amount of coke may be added on top of the iron. If there is no coke or there are large reserves of wood waste, you can use them.

This is a model of a simple blacksmith's forge. If you have the desire or opportunity, you can significantly improve your own equipment for blacksmithing, bringing it closer to the features of an industrial forge.

What does an industrial forge have?

Professional blacksmiths use industrial forges, which are characterized by increased efficiency and high reliability. It is almost impossible to make an industrial forge yourself. But somehow bringing a homemade model closer to the ideal is quite possible.

What is different about an industrial forge, and what components are included in its design?

Air supply nozzle. Homemade forges use the hose of an old vacuum cleaner to supply air instead of a nozzle;
Fire brick. There is a complete analogy between home and industrial devices;
Grate. Most homemade forges involve the use of a grate. Many people make it from old frying pans with thick walls;
Solid fuel socket. This slot allows you to conveniently load the required amount of solid fuel. Equipping a homemade forge with such an element will not be a problem;
Frame bricks. These are already stationary devices that are laid with bricks. For a simple forge, such elements are already superfluous;
Air supply fan. We looked at an example with a conventional vacuum cleaner, which does a good job of pumping air. If you want, you can use fans or other similar devices;
Metal carcass. The table is supported on its basis;
Air chamber. Homemade forges do not have it, but if you need professional equipment, equipping the device with a camera will not be a bad idea;
Ash pit. If you are going to regularly use your forge at home, we recommend equipping it with an ash pan. This will make it easier to care for the device;
Forge casing.

Stationary

Stationary forges are made by experienced craftsmen according to their anthropometric data. A piece of orange-hot iron weighing several kilos in pincers is an extremely traumatic object, so the ergonomics of a stationary forge must be ideal.

Note: in the novel “Peter the Great” by A. N. Tolstoy, a case is colorfully described in which the still young tsar-craftsman received a fair beating from a forced blacksmith for clumsiness when welding an anchor’s claw. Only Peter’s enormous physical strength prevented a production emergency at that time.

Take the sizes

The approximate dimensions of a stationary forge are shown in Fig.

These are approximate, but the height of the table and its dimensions must be determined precisely:

We stand straight, feet shoulder-width apart. Bend the right freely lowered arm at the elbow.
An assistant measures the distance from the elbow to the floor. Add 5-7 cm to it, this will be the height of the table.
Now we take the largest pliers in the same hand, the assistant measures the distance from the stomach to the ends of their lips.
We add 10-12 cm to it, we get half the length of the table diagonal.
We take the length of the side of a square table equal to 1.4 of the length of the half-diagonal (0.707 of the full diagonal).

Note: there is no need to make the table round, because... You will have to take different parts with pliers. But rectangular is possible if you work together with a helper.

Design

The sequence of manufacturing a stationary forge is visible from Fig. It is better to lower the tuyere vent with supercharging from a vacuum cleaner or car stove snail lower, and at the same time make the air drainage flap (points 4 and 5) retractable forward. The result is an air receiver with a sufficiently large capacity, and the damper can be pulled out and pushed in with the toe of your shoe.

Also pay attention to the solid grate, pos. 2. In this case, it is special for forges. The secret is in the intersecting hollows that divide the slab into squares. Soot accumulates in them. If you drill holes in a smooth slab, you will have to clean them with a steel rod after each forging.

But why can’t the grate be made from slats, like in a stove? Because the mass of fuel is not sintered uniformly. In the cracks between the slats, the air flow will jump to where it is more free for it to exit. In that place the temperature will be higher, and the entire workpiece may become over-dried in spots. An amateur craftsman will not notice this by eye, but under load the local fragility will affect it. And passing air through a two-dimensional regular structure (the stove grate is one-dimensional) reduces the unevenness of air distribution by an order of magnitude. If the grate is three-dimensional, as shown in Fig. with the installation of the forge at the beginning, the uneven distribution of air has practically no effect.

But what if there is nowhere to get a special grate? Then an acceptable solution is a completely homemade tuyere with a concentric arrangement of holes with a diameter of 8-10 mm; such a system does not clog so quickly and the blast ensures more or less uniform blowing over the area. The principle of operation is similar to a shower diffuser.

You cannot inflate the air shower with a vacuum cleaner; it will blow out the fuel.

You need to take a snail from a car stove or something similar. In this case, it is also undesirable to regulate the blowing by drainage; the optimal boost for uniform blowing is rather weak. It is necessary to build a throttle valve into the air duct, and make the lower cover of the lance removable only for cleaning.

Self-production

Mini horn

The smallest forge you can think of is a mini forge. For a novice blacksmith, this is the best option, intended for use only outdoors. The principles of construction are as follows:

Mini-forge drawing

6–8 bricks can be used as the main building material. Having built a stand from them, you can move on.
The construction of a grate can be done using scraps of metal pipes and a fragment of a steel strip, the thickness of which should be at least 4–6 mm.
Such a forge can be heated with either coal or coke. For ignition and blowing I use a regular blowtorch. It provides both heat supply and process continuity.

The use of a mini-forge indoors is prohibited due to the lack of a chimney in the structure.

Portable forge

The construction of a mobile forge can be carried out using kitchen utensils such as a goose pan. As a boost system, you can use a fan from a hand siren or any other suitable device.

A portable forge has certain disadvantages:

its design is non-separable, so it is difficult to get rid of carbon deposits;
does not allow creating very high temperatures, the maximum possible value is 900 °C;
operation is quite expensive: only coke or charcoal can be used as fuel.

Despite this, this type of coal forge has many more possibilities than the homemade brick construction described above. This is due to the fact that the work space of a portable structure is open at the top and is much larger.

Stationary forge

This design is the most complex from a construction point of view. Experienced craftsmen manufacture the forge independently, taking into account their own anthropometric data. Its ergonomics must be honed to the smallest detail: the work performed here is often very dangerous.

So, when building a stationary forge, it is necessary to proceed from your own physical data. To do this you need to measure:

Table height. Stand up straight with your feet shoulder-width apart. The right arm must first be lowered and then bent at the elbow. This will be the height of the table, to which you need to add 5–7 cm.
Half the diagonal of the table. You need to take large pliers in the same hand and measure the distance from their lips to the stomach. By adding 10–12 cm to the result obtained, you can get the desired result.
The length of the side of a square table. To do this, the result obtained in step 2 should be multiplied by 1.4.

A forge is an open or closed furnace used in blacksmithing to heat metal
. To make a stationary forge with your own hands, you will need the following materials:

heat-resistant steel with a sheet thickness of at least 4 mm;
fireclay brick;
rolled metal, from which the forge frame should subsequently be assembled;
steel chimney for carrying out the process of removing gases generated during the combustion process;
fireproof putty, which must be used to seal cracks;
steel for lining on the outside.

Materials for making a forge

Rules for the manufacture of a stationary structure

Since the forge is a stationary unit, its location must be clearly defined. Access to one of the walls is necessary because the forge should not be independent. The presence of a wall will allow you to more securely arrange chimneys and install a fan. This design can use a homemade lance.

Support frame for forge

The construction of the forge should begin with the manufacture of a support frame. It is brewed from a metal pipe. The upper part is constructed using refractory bricks. This will make the structure durable and allow you to use the stove more intensively.

The channels provided for ventilation and chimney should be lined with steel corners around the perimeter. The metal is also used in the construction of the lining and damper of the furnace. Sheets used in finishing must have a stiffener.

The forge table must have a forge nest, the optimal depth of which is 10 cm. Below it is an ash chamber into which air is supplied. The size of the table is not regulated, but it is better if it is designed taking into account the master’s data.

A square-shaped pipe should be rolled out of 2 mm thick steel. This will be the ash receptacle. A hole should be made in one of the walls into which a pipe for air supply will later be inserted. This can be done using a vacuum cleaner.

Portable

The next design is a portable forge made from... goose horn. The design is clear from Fig. The lining is fireclay marl mixed with fireclay sand (ground fireclay bricks, commercially available). Firing the lining after drying - as work progresses.

The capabilities of a goose forge are wider than those of a 6-brick one, because The workspace is larger and open at the top. But there are also significant disadvantages:

Non-separable design: when cleaning the tuyere (see below about the stationary furnace), carbon deposits fall down and clog the perforation of the air duct, even if its holes are oriented sideways or downwards. To clean you have to break the lining.
Works only on coke or charcoal, because... There is no table with space for burning.
Expensive to operate: carbon consumption is comparable to that of coal in real furnaces.
Low operating temperature, up to 900 degrees, because A lining that is not properly fired will crack.

What kind of fan is needed?

Below we will move on to designs that are already quite functional, which require full blowing. And electricity for the fan can be found everywhere. But what kind of fan is needed for a forge? Once upon a time, forges were blown with bellows; For those who are curious about how blacksmith's bellows work, see Fig. on right.

Note: it was from the remains of blacksmith bellows of ancient times that archaeologists established that metallurgy among primitive peoples had a mystical and sexual meaning - from Scandinavia to South Africa, the clay fitting of the forge was made in the form of male genitalia, and the nest for it in the forge was female.

As for productivity, 200-250 l/min is quite enough for a stationary coke furnace. That is, the fan motor power is sufficient from 80-100 W.

Much more important is that we need to push air through a fairly dense mass of sintered fuel. Therefore, when choosing a fan, first of all you need to pay attention to the pressure it creates at zero performance , the so-called. maximum pressure. The meaning of this parameter is simple: the fan will create the maximum pressure by forcing air into a closed cavity.

For the forge you need a maximum pressure of 220-230 mm. Hg Art., which corresponds to approximately 0.3 ati. Axial fans (impellers) of this type are created only by industrial ones, such as VN-2 or its analogues. Household exhaust and industrial cooling systems are not standardized in terms of maximum pressure at all and, as a rule, do not create what is needed.

In addition, they bring the air up to maximum pressure slowly, in minutes, and during delicate forging work, the blast needs to be changed in seconds. It is useless to install a receiver: when the valve is opened, the air in it will expand adiabatically, which at 0.3 ati will only produce zilch.

Overall conclusion: to pressurize the forge you need a centrifugal fan-scroll . You don’t need to look at the specification; any centrifugal fan will provide the required maximum pressure based on the very principle of its operation. It is best to take snails from radiation protection systems of military equipment; they also have high productivity. True, the power supply is 12, 24 or 27 V DC, so you will need a transformer and a rectifier of appropriate power.

Any old household vacuum cleaner will work perfectly, but you need to take into account that its power will almost always be excessive.

You should not reduce it with an LATR or a thyristor regulator: the motor will work in a difficult mode of excessive rotor slip and the service life of an already worn-out old man will be short. It is best to make a wide air drainage in the tuyere, as in the stationary forge described below.

Characteristics and types of injection burners

The design of the forge burner determines the degree of waste of the metal when it is heated for forging, the intensity of scale formation on the surface, and the total gas consumption. In closed forges, short-flame burners are used.

Their design guarantees rapid mixing of the combustible mixture, which ensures high efficiency. Combustion products are removed from the furnace working space evenly and as efficiently as possible.

Operating principle of burners

In burners of this type, propane coming from a gas pipeline or cylinder is burned. Here, a mixture of gas and air is formed due to ejection, i.e. the latter being sucked into the burner under the influence of the energy of a gas jet under pressure.

In the area where air is taken in, a vacuum appears, due to which the air itself moves in a given direction. Mixing in the burner body, the working mixture escapes from it under pressure, creating the desired temperature.

The quality of operation of a gas burner depends on the constancy of the ratio of the volume of gas and air. Changes in gas density affect the burner's ability to suck in air.

The fuel combustion device or burner is the main component of the gas furnace. Its operation depends entirely on the correct manufacture of this key element

All changes in combustion temperature must be accompanied by similar changes in the air supply required for combustion.

If the indicators are unbalanced, the injection coefficient must be adjusted to achieve its stability. This is achieved by changing the gas pressure or adjusting the air damper.

Classification of burners according to main characteristics

They are classified according to different criteria. Based on the volume of primary air sucked in, a distinction is made between partial-mix and full-mix burners. The main characteristics of the former are the injection coefficient and the multiplicity.

The injection coefficient is determined by the ratio of the volumes of air injected and those required for 100 percent combustion of gas. The expression “injection ratio” refers to the relationship between the volume of primary air and the gas consumption of the burner.

Combustion of gas mixed with air in an injection burner occurs in a special nozzle - a tunnel made of refractory material

Injection burners used in home forges come in low (up to 5 kPa) gas pressure and medium - from 5 kPa to 0.3 MPa. When the gas in the burner is under a pressure of 20-90 kPa, the power of air suction remains practically unchanged, even when the gas pressure and vacuum in the furnace undergo changes.

When the pressure drops below this level, the injection coefficient increases, the pressure drops, and the vacuum in the forge increases. Depending on the presence of the distribution manifold, there are single- and multi-flame burners.

There is a division according to the number of nozzles: with one nozzle - single-nozzle, with several - multi-nozzle. These elements are placed in the center or scattered. According to this feature, there are burners with a central nozzle and a peripheral one.

Burner hole

Determine the location where the burner will go. Many people like it when the entrance is located at the top and the flame is directed downward. And some people prefer to have multiple burners. I choose an economical approach, and I also love when what I do looks good. That's why I like the single burner at the back of the forge with the flame pointing upward. Place bricks on the bottom and draw a circle where you have chosen the location of the burner. Using a concrete drill, make many holes around the perimeter of the drawn circle. Drill the holes partially at first and, having made a circle, continue again, adding side-to-side movements to punch through the brick and merge adjacent holes. If you take your time, the cutout can turn out relatively smooth. Trace a hole on the metal bottom and cut it out using a gas (plasma) cutter.

Design of the gas supply channel in the burner

The gas supply channel is a copper or brass tube of the following sizes:

outer diameter 6 mm;
wall thickness not less than 1 mm.

This tube is equipped with:

on one side there is a gas valve with a hose that goes to the gas source (main pipeline, cylinder, etc.);
on the other hand, the nipple from the kerosene stove is mounted. In this case, it is necessary to do the following: sharpen the working part of the nipple to a cone;
cut an M5 thread inside the pipe and screw the nipple into it (it already has a standard M5 external thread).

Fuel

Their composition includes hydrogen and carbon, which, when combined with oxygen, release a lot of heat. Moreover, such mixing can occur in advance, for example, in a burner.

Coal for forge

However, it must be understood that it will be almost impossible to manage natural gas for such purposes, since it consists of different hydrocarbons that require different amounts of oxygen. Therefore, it will not be possible to organize optimal air supply. In addition, natural gas contains sulfur, which negatively affects the properties of the metal. Therefore, the mixture requires pre-cleaning or can be used to process non-critical parts.

Heating the workpiece in a forge

A forge furnace requires two main and only properties: it can produce very high temperatures, up to 1200 - 1500°C, and the ability to maintain the desired temperature for a certain time. In other words, we need strong and even heat.

At what temperature do metals become forgeable, that is, begin to be ductile? This is different for all metals and alloys. But the visual sign that the metal part has heated up to the required temperature is also common - this is the orange color of the part.

All metals respond to heat by changing color from dark red to piercing white. So the orange color is a signal that you can start real blacksmithing work on metal.

Drawing of a blacksmith's forge.

The only metal that behaves quite meanly and does not change its color when heated is aluminum. It is not the easiest metal to forge and weld in principle; with aluminum you need to know and apply many special requirements.

So, the absence of an orange color while it has already warmed up for forging is a significant factor that makes it difficult to work with this capricious metal and its alloys. After all, you can’t overheat. Underheating is also no good.

Gas-powered devices

A distinctive feature of this type of forge is that it is much easier to prepare them for work than forges that run on solid fuel.

If we talk about the design of gas-type forges, it consists of the following elements:

Camera. For its manufacture, a material with fire-resistant properties is used. The outside of the chamber is lined with steel with heat-resistant properties.
Front flap. Its opening is ensured by using a counterweight or hinges. In order to be able to observe what is happening inside the chamber, a small viewing window is mounted in one of its walls.
Under. For its manufacture, fireclay bricks are used, which have heat-resistant properties.
Burner. Several types of burners can be used. When determining the type of burner, the main factor is the type of gas that is used. For example, if a propane-butane mixture is used as fuel, a diffuse type burner is used. Burners of this type guarantee uniform heating of the workpiece, as well as the formation of a minimum amount of waste.
Mixing reducer. Air enters the gas mixture, which is located in the cylinder.
Nozzle. Its shape is directly dependent on the shape of the workpieces that will be used in the work process.
Grate grate. Its purpose is to increase the traction rate, as well as to ensure the collection of scale.
Fan. With its help, air is forced into the burner.

The use of gas forges is possible subject to the following safety rules:

The blacksmith's room must be periodically ventilated to prevent gas accumulation;
It is not allowed to place devices containing oxygen or mixtures containing it near the forge;
By using a gas analyzer, it is necessary to check the final combustion of gas before starting the furnace again.

Design and purpose of the device

The first do-it-yourself blacksmith's forge was invented by the ancient Khalibs. Nowadays, there are several design options for this device. When classifying them, they are guided by the following forge factors:

Fuel used for ignition (coal, gas, coke, fuel oil).
Forge design.
Device dimensions.
The purpose for which it is intended to be used (heating for forging, heat treatment of the workpiece).

The fuel can be fuel oil, gas or coal. As a rule, coal is most often used. This fuel option is safe and low cost. As for fuel oil or coke, these types of fuel are expensive and also polluting.

The use of gas provides a high level of efficiency, but at the same time requires more careful maintenance of the installation.