Classification of muffle ovens
According to the type of heating elements muffle furnaces are divided into:
There are also industrial and homemade muffle furnaces.
Industrial muffle furnace with automation
But it is impossible to make gas-fired ovens at home, although gas is cheaper than electricity, as such experiments are forbidden by law. Electric control of the furnace provides the convenience of temperature control.
According to their design type, muffle furnaces are divided into:
Heating can be done in air, in a vacuum or in a gas environment. At home, it is only possible to design a furnace with heat treatment of products in an air environment.
When you make your own muffle furnace it is possible to give it the desired shape and volume, to decorate it in a style suitable for the interior.
Main parts of the construction
- The external part of the furnace, the shell (housing).As the body for the future muffle furnace is convenient to use a used gas stove, or rather an oven from it, or an electric stove. To use them, dismantle all plastic parts. In the case where there is no possibility of using such versions of the body, it is welded from sheet metal (thickness of at least two millimeters).
- Thermal Insulation Layer. This part of the construction is extremely important. Its quality determines the efficiency of the furnace and the heat loss it incurs. The inner layer of thermal insulation is a refractory (fireclay) brick, capable of withstanding temperatures up to one thousand degrees.
- The outer layer, which reduces heat loss to the surrounding space, is laid with perlite or basalt wool. Asbestos is not safe to use, because when heated, it is emitted into the atmosphere of carcinogenic substances.
- Elements that directly heat the work space. Heating elements inside the muffle furnace are spirals made of nichrome or flecril wire. Thickness 1 mm. Nichrome (nickel-chromium) wire is very plastic and corrosion resistant.
- Fechral (aluminum, chromium, iron) wire is slightly cheaper because it does not contain aluminum and also has the necessary properties for its use in a muffle furnace.
The list of materials and tools for assembling the construction
- angle grinder (a machine for grinding and cutting materials) with metal cutting discs;
- welding machine;
- Sheet steel with a thickness of 2 mm;
- metal corners;
- fireclay fireproof brick;
- refractory mix;
- heat-resistant silicone;
- Basalt thermal insulator (wool, density 200 kg/m3) or perlite;
- safety glasses and a respirator;
- nichrome (fechral) wire with a cross-section of 1 mm;
- wire cutters or metal scissors.
Making a device
In this case, we will tell you how to make a vertical muffle kiln for firing ceramics with your own hands.
For this you will need the following tools:
- Angle grinder (angle grinder) and 1-2 wheels;
- electric arc welding and electrodes;
- Locksmithing tools, including wire cutters;
- 2 mm nichrome wire.
- 2.5 mm steel plate or a used oven casing;
- angle
- fittings;
- basalt wool
- Fireclay bricks;
- refractory mortar;
- silicone sealant.
Materials and elements for work
Muffle furnace for melting aluminum with their own hands or hardening steel parts. for the production we prepare a complete set of materials. We will need:
- chamotte brick;
- heat insulation;
- Sheet metal or any improvised material. If there is an old safe with an inner layer of sand, then you are in luck. Such a furnace will last a long time and will save on the outer layer of insulation;
- refractory clay, sand, or ready-mixed masonry. For sealing cracks and voids, you can buy a fire-resistant sealant or use a mortar;
- electrical cable, ceramic insulators, circuit breaker for connection in the switchboard.
Materials and tools for assembling the construction
Before you start making a muffle furnace with your own hands, you need to acquire a set of tools. For the work will come in handy:
- welding and electrodes
- angle grinder;
- wire cutters and scissors;
- respirator, goggles;
- steel or an oven casing;
- metal corner;
- galvanized mesh with a mesh of 2 x 2 cm;
- door. ready-made or homemade
- fireclay brick;
- refractory mixture;
- heat-resistant silicone;
- perlite or basalt board (roof insulation 1. 2 cm thick);
- 1 mm nichrome wire.
The thickness of the metal for the body should be 2. 2.5 mm, as the final construction will be very heavy. For the same reason, if thin-walled appliances are used, they should be reinforced with a steel angle.
Those who are going to engage in firing ceramics, do not need the temperature above 800 ° C, so they can make a muffle of any porcelain or faience crockery, or an old flush tank.
How to make a muffle kiln for ceramic firing with your own hands
A muffle furnace is a heating device designed to perform work at very high temperatures. The unit is used by jewelers and ceramists to melt metals in it, work with glass or firing clay products. The price of the finished device is very high, so many believe that the muffle kiln for firing ceramics and clay with their own hands is a very profitable product, especially for small workshops.
Types of muffle furnaces
Gas muffle furnace Heating devices differ in several ways, which is not particularly reflected in their performance.
Among specialists, there is a classification according to certain categories.
There is a gradation according to the structural, refractory and conductive materials used in the manufacture of stoves.
Muffle furnace with their own hands: the secrets of making
Surprisingly enough, but in our pragmatic time, there are people who are interested in doing amateur ceramics firing, jewelry homemade or physics experiments. For this, enthusiasts need a high-temperature gas or electric muffle furnace. But in the store, a ready-made oven is not cheap. So it is possible to make a muffle furnace with your own hands. Those home craftsmen who are used to making repairs and assembling equipment themselves, doing this work with their own hands will not prove too difficult.
Classification of muffle ovens
According to the type of heating elements muffle furnaces are divided into:
There are also industrial and homemade muffle furnaces.
Industrial muffle furnace with automatic control
But it is impossible to make gas furnaces at home, although gas is cheaper than electricity, as such experiments are forbidden by law. Electric control of the furnace provides the convenience of temperature control.
According to the structural type muffle furnaces are divided into:
It can be heated in air, in a vacuum or in a gas environment. At home, it is only possible to design a furnace with heat treatment of products in an air environment.
When you make your own muffle furnace, you can give it the desired shape and volume, to decorate it in a suitable style for the interior.
Main parts of the construction
- The outer part of the furnace, the shell (housing).As the body for the future muffle furnace, it is convenient to use a used gas stove, or rather an oven from it, or an electric stove. To use them, remove all plastic parts. In cases where there is no possibility of using such variants of the body, it is welded from sheet metal (thickness of at least two millimeters).
- Thermal insulation layer. This part of the design is extremely important. On its quality depends on the efficiency of the furnace and the heat loss it incurs. The inner layer of thermal insulation is a refractory (fireclay) brick that can withstand temperatures up to one thousand degrees.
Fireclay bricks for the internal finishing of the muffle furnace
Spirals made of nichrome or flecrale wire
List of materials and tools for assembling the structure
- angle grinder (a machine for grinding and cutting materials) with cutting discs for metal;
- welding machine;
- 2 mm thick sheet steel;
- metal corners;
- fireclay fireproof brick;
- Refractory mixture;
- Heat-resistant silicone;
- Basalt thermal insulator (wool, density 200 kg/m 3) or perlite;
- safety goggles and respirator;
- Nichrome (fechral) wire with a cross-section of 1 mm;
- Pliers or metal scissors.
Materials and tools for assembling the structure
Before you start making a muffle kiln with your own hands, you need to acquire a set of tools. For work will come in handy:
- welding and electrodes;
- angle grinder;
- wire cutters and scissors;
- Respirator, goggles;
- steel or a case from the oven;
- metal corner;
- Galvanized wire mesh with a mesh size of 2 x 2 cm;
- The door. ready-made or homemade;
- fireclay brick;
- Refractory mix;
- heat-resistant silicone;
- Perlite or basalt board (roof insulation 1. 2 cm thick);
- Nichrome wire 1 mm.
The thickness of metal for the body should be 2. 2,5 mm, as the final construction will be very heavy. For the same reason, if thin-walled appliances are used, they must be reinforced with a steel angle.
Those who are going to do the firing of ceramics, do not need temperatures above 800 ° C, so they can make a muffle from any faora or faience dishes or an old flush tank.
Masonry refractory
For a homemade muffle, it is not recommended to use clay, even fireclay. It does not conduct heat well enough, and to properly burn it, you need a temperature of 1900 ° C, which in the home conditions can not be achieved.
The brickwork will be much more reliable, but it should be taken into account that the spiral located inside the furnace will slowly evaporate, and these vapors will enter the product.
The process of making a refractory chamber
So it is better not to use homemade units to work with precious metals.
So, a fireclay brick and a mixture for the mortar, which is not afraid of heat, is purchased.
Fitting and marking
This action is necessary to perform in order to be able to cut a groove in the muffle wall for the heater spiral before the start of masonry.
- The future lateral and back wall of the refractory are laid out on a flat surface.
- The bricks are fitted, trimmed (it is important not to forget about the thickness of the seams, 3. 5 mm, they can be imitated by a wire).
- After adjustment, the bricks are numbered and the surface of the bricks is marked with the marks of where the spiral will run (at this stage, the spiral should be made with your own hands).
- In goggles and a respirator make a cut grooves angle grinder.
Finishing the furnace with tiles is an expensive pleasure, but such decor brings a unique sophistication to the design of the room. To save money you can try to make them yourself. Tiles for the furnace: the technology of production with their own hands, read carefully.
Step-by-step instructions for assembling the Bubafonja stove can be found here.
The Russian stove is still relevant, and its construction is quite labor-intensive. But if you are not afraid of difficulties and you want to build your own oven, step-by-step construction instructions will help you: https://microklimat.pro/otopitelnoe-oborudovanie/pechi/russkie-svoimi-rukami.html. Consider the rules and stages of masonry furnace.
Making a spiral for the muffle furnace
We need a rod-base, on which the wire will be coiled. Its diameter should be about 5-6 mm and the surface should be smooth. When the coil is ready, it is attached to the brick workpiece and the resulting dimensions are marked.
Later, when the masonry is ready, the coil will need to be carefully placed in the grooves and secured with “staples” from the same wire. The staple ends are embedded in the joints.
The coil outlets are located in the side or rear wall. It is more convenient to fix them on a ceramic plate. A switch is installed on the body, and the coil wires are connected to it. On one side it will have two contacts (” and “-“). If you make two separate circuits, you will get three stages of power of the device:
RCD and grounding are mandatory. To avoid burning the coil the first time you connect it, you must wait until the masonry mortar is completely dry.
Chamber
The heat-resistant mixture is diluted (you can read the instructions on the package). Filling the bucket with water. The brick will be dipped in it for 20 seconds before it is laid.
First the bottom of the muffle is laid out, then the walls are built. The ceiling is vaulted, with lock bricks.
Another option, when the chamber is made of bricks, placed vertically and in a circle. Should turn out something like a pipe.
Also, grooves are made, and on the sides, with the help of an angle grinder a bevel is made.
When using the finished oven case, the angle bracing is made, then basalt insulation is glued to the inner walls (with heat-resistant silicone or spets. glue). Then, from the bottom up, the already fitted, numbered bricks with a groove are placed. They should be laid very tightly (the thickness of the joints should not be more than 5 mm).
Thermocouple
It is necessary to control the degree of heating in a closed muffle, but it is much more difficult to do than, for example, in the smith’s furnace.
At high temperatures, only one kind of sensor can work. a thermocouple (dissimilar conductive parts, which are connected together).
Two ceramic tubes are made, from which two wires are led out: one of aluminum, the other of the chromel alloy (or nickel and iron).
One end of the wires is twisted together. It is not necessary to weld, as the ends will soon burn anyway. They will need to “bite off” and twist the ends again. The other ends are connected to a regular household tester.
Door
On the door, there is also a layer of fire brick. To secure it, a steel angle is welded, which will support the masonry.
The door is removed, put on a flat surface. On it mounts the mesh.
Cement is added to the mortar, and bricks are laid.
Liem at home. Homemade. melting furnace
The door must be reliably locked during the melting work. It can be fitted with a screw or wedge mechanism.
Hinges from appliances may not be able to withstand the load of a brick-lined door. It is better to replace it with a more powerful one.
Seal
It is unacceptable that the door does not adhere loosely to the body of the oven. It requires additional sealing.
You can use a heat-resistant rubber band (used on ovens). And you can still the same silicone. The door in the adjoining places is degreased, and on the stove itself is applied a substance that is not sticky silicone (any grease).
Silicone is applied thickly to the edges of the door, it closes. As a result, the sealant will stick to the door, but the edge of the oven will remain clean.
The sealant will burn out over time, so silicone should always be on hand to replace it.
Drying the kiln
The stove is placed in a dry, ventilated room with positive temperatures.
To check the readiness of the furnace, you can turn the spirals on the weakest power mode. A dried unit will not emit steam.
Tips for DIY
When created from chamotte bricks, any pottery hardening will need to use a heating element. And if there is a need to place an appropriate solution, it is necessary to make notches and technical cavities in the ceramic material. It is best to pre-mark all the location of the element and only then resort to making incisions. All this can be done at home, using simple power tools.
It is worth starting with sawing the seams, using a cutting machine, with a special diamond wheel. And then it is necessary to remove the resulting ceramic areas. And here it is best to use a drill. To avoid cracking and damage to the material and each of the elements. You should not use a hammer and chisel, because when you hit it, cracks may form, which will subsequently lead to the uselessness of each of the elements.
Selected and created homemade furnaces should be obtained with an understanding of the technical processes in which they will be involved. And here arises a natural question, whether to create a more voluminous furnace or to make a more miniature solution. In the case of remelting jewelry, a minimal amount of interior space will be sufficient. This will allow more practical use of the products and will not require additional room.
But in the case of blacksmithing, it will be necessary to create more weighty structural solutions that will allow the melting and hardening of metal.
Watch a video in which the user demonstrates in detail the construction of a muffle furnace made with his own hands:
