Aluminum alloys have low melting point and good workability details. And there is always a lot of aluminum scrap on the farm.
That's why aluminum is often melted at home to replace non-standard or small parts of mechanisms: a blank is cast, and then processed lathe. Sometimes souvenirs and small interior items are made from aluminum with their own hands.
Melting furnace structure
Homemade furnaces for melting aluminum consist of a body - metal cylinder (2), lined with refractory (clamotte with sand or concrete). Inside the mine is charcoal (8) , serving as fuel. It is installed crucible (3)- a container in which the metal will melt. The crucible can be a thick tin can, a teapot or any container made from of stainless steel.
At the bottom of the shaft (6) made air injection hole (7) through lattice base (4), which allows you to maintain combustion and regulate the temperature in the furnace.
A hair dryer or a vacuum cleaner pipe is used as a blower. Damper (5) necessary to remove excess air.
For ovens with a capacity of several tens of kilograms, you need cover (1) for quick and uniform heating of the metal. In small ovens you can do without it.
Furnace elements should not deform or melt when heated. Therefore, the use of aluminum bodies, tubes and crucibles is unacceptable. It is best to take steel or cast iron details.
Reference. Also used as fuel for smelting aluminum natural gas or electricity.
How to make a furnace for melting metal?
Creating a small unit that can melt several kilograms of aluminum scrap is not a difficult task. To lay out the oven on garden plot will be required following materials :
- red bricks - 20-25 pcs.;
- high tin can - 1 pc.;
- grill grate - 1 pc.;
- drying hair dryer - 1 pc.;
- piece of pipe, with a diameter suitable for the outlet of the hair dryer - 1 PC.;
- roll of electrical tape;
- line segment steel wire length 30-50 cm;
- coal for ignition (the quantity depends on how much aluminum needs to be melted).
The bricks will appear simultaneously and body and fireproof coating oven, a tin can will act as a crucible. At the top of the can are being done two holes opposite each other, and through them the wire is threaded. It will be possible to lift and remove the crucible with the melt from the furnace. The air will be supplied from the hairdryer turned on in cold air mode. Tape or tape to the outlet of the hair dryer attach a piece of pipe- this will be the air duct.
Such simple circuit The furnace is convenient in that no tools are actually required to create it; everything is done by hand.
Important! Do not use oven elements with zinc coating, because when aluminum is melted, toxic zinc fumes will be released.
Brick well installation plan
- Gives his all one row bricks in the form of a rectangular well. The internal dimensions of the hole should be approximately length and width of one brick. On one side two bricks laid out so as to form a corridor for the air duct. The width of the corridor is tube diameter for air supply.
- On the laid out row grating is installed. Instead of a grill grate, you can use any metal lid or plate with holes for air supply.
- Placed on the grill second row bricks, without any gap for the air duct.
Photo 1. Finished brick well for melting furnace. The edges are reinforced with metal strips, the air duct opening is visible.
- Created air duct. Tape or tape to the hairdryer a piece of pipe is wound. To ensure structural strength, the connection point wrapped in thick paper, and then connects duct tape. Electrical tape is a more elastic material compared to adhesive tape, so it is more convenient to work with. The cold air supply button is also secured with tape on the hairdryer. Ready the mechanism is brought to the bottom row bricks.
- In the stove well on the grate coal is poured and melted for ignition. The hair dryer turns on, which activates the combustion process.
Advice. The air supply intensity can be adjusted by changing hair dryer operating mode, and distance between pipe and window for the air duct.
- Tin is installed to the top row bricks for the wire threaded into it. Like a pot over a fire, it hangs over the grate.
- After lighting the furnace and installing the crucible third row are placed two more bricks so that from rectangular hole get square. This will fix the can inside the housing and heat up the oven space faster.
After heating the jar into it scrap can be loaded for remelting. A sign that the jar is warming up is its redness.
The principle of the design and operation of such a furnace is very simple and does not cause difficulties. However, it is always worth remembering safety precautions:
- work in fire-resistant gloves;
- avoid water getting into the melt;
- do not use materials containing toxic substances.
You might also be interested in:
Two-can design
Another variety homemade stove for melting aluminum is a design made of two large cans. One of them serves body, in which a hole is cut for air supply, and bottom of the second jars with holes serves as a divider.
A crucible is installed inside the jars.
Such a device very compact, and small volumes of metal can be melted even in a ventilated garage. However, the design is not resistant or fire resistant, and will only last a few cycles.
Possible problems and their solutions
Carelessly assembled device causes the oven to operate inefficiently and makes it dangerous to use. Here are a few points to pay attention to:
- Slots and gaps in a brick building. They can be caused by chips on bricks or loose fit of refractories to each other. Gaps reduce fuel efficiency and reduce combustion intensity and temperature. Aluminum in a crucible may simply not melt.
Therefore, after laying out each row, a visual check is carried out for the presence of holes. Holes covered with a sand-clay mixture or covered with fire-resistant material.
Concrete mortar It is recommended to use only in the case of a stationary unit that is not planned to be disassembled. But Asbestos sheets and chips should not be used in places where the stove is heated, because this material is a carcinogen.
- Violation of the horizontal level the buildings. Misalignment reduces the stability of the structure and creates conditions for uneven distribution of coal. The result is uneven heating of the crucible and the metal in it.
Laying out each, especially the bottom row of bricks controlled by level. You can also check horizontality placing a jar of water on the grill. On a flat surface, the top edge of the water will be parallel to the edge of the can.
Aluminum is a versatile metal and can be used to make many interesting things, including DIY parts. In addition, it has a relatively low melting point, which allows casting at home.
Of course, to melt aluminum you will need to make a small furnace; it can even be made from coffee cans, as the author demonstrated. It only took him $23 to create the homemade product, not including the cost necessary tools. You can see how this oven is made and make one similar to yours, following the example.
Materials and tools for homemade work:
- two tin cans, one larger, the other smaller (it is highly not recommended to use zinc-coated cans);
- household hair dryer(will pump air);
- a piece of metal pipe (adapter for a hair dryer to supply air to the oven);
- scotch;
- metal scissors (ordinary ones will do, if you don’t mind);
- pliers with long handles (for gripping the crucible);
- gloves;
- coal as fuel, lighter fluid and more.
Mini-stove manufacturing process:
Step one. Making the stove body
The stove body is actually taken ready-made; it is a large tin can of soup, canned food, etc. You need to choose jars with thicker metal. In the lower part, the author made a hole, to which a hair dryer is then connected using a pipe. The hole must be made according to the diameter of the pipe. The easiest way to do it is square shape, but it’s better to tinker a little and do round hole by pipe diameter.
Step two. Supercharging installation
An ordinary household hair dryer is used as an air blower. It must be equipped with an air supply system and have at least two operating speeds. A piece of metal pipe is attached to the hair dryer using tape, and its other end is inserted into the hole previously cut in the bottom of the can. The author secures the cold air supply button with tape; it must be on all the time. Before starting the stove, you need to turn on the hair dryer and make sure that there is no air leakage at the junction of the pipe with the hair dryer. If there is, you still need to wrap it with tape.
You can find a piece as a pipe water pipe, a pipe from a vacuum cleaner will also work, and so on. If the stove is large, you need to take a longer pipe, as it can get very hot and the heat will reach the hairdryer. However, cold air from a hairdryer should cool it well.
Step three. Furnace crucible
The author also has a ready-made crucible for the stove, it is a small tin can from coffee or the same canned food. It is important to remember that such a crucible can only be used once, according to the author, when reuse it inevitably burns out. And this will entail that liquid aluminum will leak into the furnace, which is not very pleasant.
Step four. Furnace tests and conclusions
That's it, the oven is now ready to start. You need to install a crucible in the center and place coal in a circle. Then, after pouring lighter fluid over the coal, you need to wait until it burns completely. After this, you need to turn on the hairdryer at low speed. Tests must be carried out on outdoors, otherwise a spark may fly out of the oven and a fire may occur. In addition, when you first start there will be a lot of smoke from the tin can.
Suitable as a source of aluminum aluminum cans from drinks. But, according to the author, due to the fact that the metal in them is very thin, they do not melt, but burn; in the end, too little aluminum is obtained for casting; in general, such a starting material is not very suitable.
If you decide to melt the cans, you must first crush them.
From 12 cans you can get approximately 150 g of aluminum.
2 cans will give about 300 g, and from 36 cans you can get 450 g of aluminum.
After starting the furnace, the crucible should turn red, this indicates that the furnace is ready and aluminum can be placed in the crucible. When the aluminum is completely melted, it can be poured into molds to form ingots, this is very convenient for further work with metal.
The author recommends warming up the oven before placing aluminum there because an oxide film forms on the tin can, which protects the metal from overheating. If aluminum is placed before the oven heats up, it can burn through the metal and leak out. You should always work with thick gloves that do not burn or melt, since the oven heats up to very high temperatures.
Casting molds should under no circumstances be wet, otherwise during casting the liquid hot metal may explode and fly in different directions.
The author does not insert the hairdryer pipe completely into the oven, since even at low speeds there is too much air supply. By adjusting the distance between the pipe and the oven window, you can achieve the required air supply, and as a result, the temperature.
Important!
When constructing such furnaces, zinc-coated cans cannot be used. The thing is that zinc, when heated, releases toxic fumes that will be harmful to health. If cans with a different coating cannot be found, then you need to work in respiratory protection and do not heat the oven to high temperatures.
Among other things, this furnace can be used as a small forge. When heating steel, a crucible is not installed in it. As a result, it is quite possible to heat a file and then make it from small knife or other product. For example, you can make small souvenir swords from nails.
Having built such a stove, you can melt aluminum and bronze without any problems, and if you try hard, you can even melt steel in it. The whole principle of operation of such a furnace comes down to creating an insulated housing that can withstand temperatures up to 2600 degrees Celsius.
As for the dimensions, it is not necessary to strictly observe them; the author made it for himself so that he could melt at least 2 kilograms of aluminum at a time.
The design of the oven is very simple, it consists of a container, a lid, a hole for gas supply, and also has a drain. The insulation here is designed to withstand high temperatures, and special attention is paid to the creation of the cladding, because it must withstand the temperature of the burner flame.
To create the body, you will need either sheet steel thick enough to be welded, or a piece steel pipe. Galvanized steel cannot be used for such purposes, since zinc burns and emits gases that are very harmful to health.
Materials and tools for creating a furnace:
- refractory clay;
- sawdust;
- refractory cement;
- materials for creating the furnace body, lid, etc.;
- welding;
- Bulgarian;
- corner;
- gas supply pipe and burner.
Furnace manufacturing process:
Step one. Making insulation
The author's insulation consists of several layers. One part is designed to retain heat from the oven, and the second part is located inside the oven and can withstand high temperatures from the burner (ceramics).
For such purposes, you will need fireproof clay; it can be purchased in stores specializing in creating ceramics; it is sold in powder form. When purchasing, it is important to ask what temperature this clay can withstand. You will also need sawdust; they are mixed with clay and form a single mass. When the kiln first warms up, the sawdust inside the clay burns out and air chambers form there. Thanks to these chambers, the temperature inside the oven is well maintained.
The components are measured by volume; for such purposes, you can take a coffee jar. First, a dry mixture is made at the rate of one part clay and three parts sawdust. The mixture must be mixed very carefully so that the sawdust is evenly mixed with the clay. Then you can add one part of water to the mixture and mix everything thoroughly again. The mixture should sit for at least 12 hours. During this time, the clay will absorb water well and become plastic, making it very convenient to work with.
Step two. Making the furnace cover
The oven lid is very easy to make. First, a frame is created; in appearance it resembles a motorcycle wheel. Such a frame can be made from a steel plate and a couple of steel rods. The whole thing is bent, cut, and then welded. The author makes a ventilation hole in the center of the lid; for these purposes you will need a can of coffee or other product, it is installed in the center. To prevent the jar from sticking to the clay, you can lubricate it with vegetable oil.
Well, now the frame is installed on a flat surface and the insulating material is evenly placed into it. It is important here that the clay completely fills the entire mold, then the lid will be strong and will not burn out. When the clay begins to dry, you can carefully remove the jar from the center, although it is better to wait for the clay to dry completely so as not to damage the lid. It will take a week or ten days to dry.
Step three. Manufacturing the main part of the furnace
At this stage, the author fills the previously made oven frame insulating material from clay and sawdust. In the process of forming the inner part, you must remember to leave space for the drain, and also make a hole for the gas supply. There are several options for how to make the inside of the oven. For example, you can fill the mold completely and then insert it in the center metal pipe and use it to carefully remove the core. Holes for gas supply and drainage can be made in a similar way.
You can also pre-install a mold in the center of the oven, and then fill the resulting space with insulating material. In both cases, it is important to remember to step back from the bottom so that the kiln has a floor. After shaping, you need to let the clay dry for at least one week.
Step four. Vent Covers
To completely close the oven if necessary, you can make a couple of covers like the author did. These covers are also made from an insulating compound. For molding, you can use coffee cans, canned food, etc.
Step five. External protective layer
To protect the furnace insulation from overheating, you will need to apply a protective layer to it; it must withstand high temperature. For such purposes, the author used refractory cement. Well, then everything is simple, the mixture needs to be mixed with water and then applied evenly by hand to all areas with open insulation. Of course, such cement is quite expensive, but fortunately you need very little of it.
Step six. Drying the oven
If the clay is already dry by eye, this does not mean that it is 100% moisture free. There is quite a lot of water there, but it is a serious enemy. If there is water in the clay when the oven is heating, the resulting steam will lead to the formation of cracks and so on. To completely dry the oven, the author took a number of measures. First, you need to drill a series of holes in the insulator; for these purposes you may need a concrete drill.
Next, the outside of the stove is wrapped with glass wool or other insulation, and an incandescent lamp is lowered into the center. As a result, the walls warm up well and moisture comes out of them. The bulb must be used at least 100W.
Step seven. Attach the lid and apply gas
A mixture of gas and air must enter the oven. You can make the burner yourself or buy a ready-made one.
To attach the cover you will need a corner, an axis, and a piece of pipe. The essence of the design is that, if necessary, the heavy and hot lid can be easily turned to its side. For these purposes, a gap of a couple of millimeters must be maintained between the lid and the top of the oven.
Step eight. Casting Accessories
For casting, you first need a crucible. The author made it from a piece of thick steel pipe. She will need to weld the bottom and also attach long steel handles. Everything here must be very reliable, otherwise if the handle, God forbid, comes off, contact with liquid metal will be very deplorable.
You will also need to make a pair of blacksmith tongs, a ladle and other accessories. It won't be difficult.
As is known, the melting point of aluminum is over 660°C. Using home heating appliances such as an iron, oven or gas stove, it is unlikely to achieve such a temperature. Therefore, smelting aluminum at home becomes possible with the appropriate equipment and, of course, the raw material for smelting - aluminum.
For melting aluminum, a crucible is usually used. DIY muffle furnace . The peculiarity of this furnace is the top loading into the working chamber of the so-called crucible - a special ladle for melting aluminum, into which the raw materials are placed. The compact dimensions of the muffle furnace with vertical loading make it easy to store and use it at home on the balcony, in the garage or in the country house.
Now let's talk directly about the process of melting aluminum at home.
As already mentioned, to melt aluminum in a muffle furnace you need a crucible. It is usually made of a fire-resistant material or a metal with a much higher melting point than aluminum.
Corundum, graphite, porcelain, quartz, cast iron or steel are used to make crucibles. I managed to make a crucible from steel myself. You can buy a crucible from other materials ready-made, but making a homemade crucible from steel turned out to be much easier and more practical, especially if you have welding machine and basic skills in welding and operating an angle grinder.
The crucible size should be selected based on the amount of aluminum you want to melt. Heat must be transferred evenly from the hot crucible to the raw material. In turn, the crucible should also be heated evenly. For a muffle furnace of my design, I plan to make several crucibles of different volumes to work with one or two heating elements at the same time.
The aluminum is packed into the crucible as tightly as possible. To do this, it is advisable to grind the raw materials and slightly compress them. I used regular aluminum wire for melting, so I just cut it with wire cutters and pressed it tightly with pliers.
When melted, aluminum decreases significantly in volume compared to source material(after all, in principle, we then melt it), therefore, in the process of melting aluminum at home, we will need to periodically add raw materials to the crucible.
It should be noted that this can be extremely dangerous! The whole point is that moisture can linger somewhere in the raw materials we add, and when water gets into the molten aluminum, a sharp splash occurs, and the metal can splash out of the muffle furnace, damaging you with serious burns. And there will be absolutely disastrous consequences if molten metal gets into your eyes. Therefore, always monitor your safety - work exclusively in protective glasses or a mask, and even better - in a special fire-resistant metallurgist suit.
During the process of melting aluminum at home, an oxide film will form on the surface of the molten metal and any slag will float to the surface. The amount of slag depends on the quality of the raw materials used to melt aluminum. Somewhere it was tinted, somewhere it was stained - all this will leave the metal in the form of slag. Immediately before casting molten aluminum into molds, it is recommended to remove the slag using a special device.
Also after aluminum melted and formed a homogeneous shiny drop, as the liquid terminator did in the film “Terminator 2″, it is recommended to keep the crucible in the oven a little longer to give the molten aluminum greater fluidity. This will greatly simplify further casting.