How to make a crucible for melting lead with your own hands? DIY crucible furnace DIY steel crucible

Date: 04/30/2018
Category: Magic tools, weapons, devices and armor - Mod Thaumcraft 3, 4, 5, 6
Views: 2455

How to create

To create this device we will need a regular boiler. Let's take it in our hands magic wand and press RMB pointing at the boiler. I would like to note that in Thaumcraft 3, when using a wand, 25 vis will be spent, and in Thaumcraft 4, in turn, any wand will do and no units of magic will be spent from it.
Now we will need to pick up a bucket and fill it with lava. Since fire and lava are sources of heat for the crucible. In version 4 of Thaumcraft, you can also use Nitor or flowing lava.
In Thaumcraft 4.1 you can improve the crucible using Thaumotory, now the tool does not require water. But note that it needs warmth.
All that remains is to dig a hole and pour lava into it. It will not be possible to place a cauldron directly on the lava; place any block nearby and place the cauldron. It all roughly looks like this:

Usage

First, pour water into it (take a bucket of water in your hands). The water in the crucible must boil after a certain time due to the heat source. Using the thaumonomicon, you now need to find out the necessary aspects for the item you need or to carry out transmutation, after which you will need to throw the items with aspects into boiling water. Further actions depend on the version of the mod.
In Thaumcraft 3, to get a crafted item you will need to use a magic wand with the required number of charges. If you throw more aspects into the crucible, an equal number of objects will be created or transmutations will be carried out.
In Thaumcraft 4, after you throw aspects into the cauldron, you need to throw in the main ingredient (catalyst) and if there are enough aspects in the crucible to complete the reaction, then you will receive the desired item. For example, to get nitor, you must add the following aspects to the cauldron: Lux, Potentia and Ignis (3 pieces each), and the main ingredient will be glow dust. As long as there are enough aspects in the cauldron, each glow dust thrown will allow you to get a new nitor. If at least one aspect is missing, then the decomposition of light dust will begin.

Important: Essences in Thaumcraft 4 tend to degrade quickly, so we do not recommend loading a huge amount of essences for mass crafting in order to avoid contamination, spoilage and pointless waste of essence. Degrading the essence will make the process of crafting the item impossible or difficult. For example, Lux can turn into Aer or Ignis. The time after which this process will begin is 5-10 seconds.

Improvement

You can “upgrade” the crucible's functions using auxiliary elements in the game. In Thaumcraft 3, you can add up to 4 stills to the crucible (by pressing RMB). They are needed to collect unnecessary aspects for operations.

In Thaumcraft 4, you can add mystical fur to the crucible to speed up the boiling process. In this version, distillation cubes are not added, but an alchemical furnace is used to separate the essences.

Features and facts

If the player somehow stands on the crucible, he will begin to receive damage in the form of half a heart, at which time the “Corpus” aspect will automatically be added to the crucible.
If you put on the "glasses of revelation", you will be able to see all the aspects that are in the crucible. They will appear above the crucible.
When you hold down the “Shift” key and RMB on the crucible with a magic stick, all aspects contained in it will turn into an aura, while at the same time turning into damage. If there are stills next to the crucible, then the aspects will go there. Well, if all the aspects do not fit into the cubes, then the remaining ones will turn into damage.

To melt metals, special heat-resistant bowls called crucibles are used. They are very popular in jewelry workshops, laboratories and the metallurgical industry. But for a full-fledged process, it is not enough to acquire a simple object with a heat-resistant surface, because different types of iron require their own product, which must comply chemical composition and fit a specific temperature regime. These facilities also produce a finished alloy, which remains to be given the correct shape.

Sometimes it happens that such devices may be needed in private business, but purchasing them is expensive pleasure. Therefore, it is more profitable to make a crucible with your own hands - you can save a significant share of the budget. Yes, the procedure will require certain skills and patience, but in the end you will get a vessel that is not inferior to factory analogues. It is also important to decide on the types of objects to be melted in order to make a suitable bowl. If you plan to work with different metals, it is recommended to create several products.

As an alternative, you can use an electric crucible, which you can do yourself without much difficulty. It has several uses, but the main one is gold refining.

General manufacturing steps

To begin with, the raw materials are prepared, and here everything depends on the model of the future tank. It is better to take components with a reserve, because the first thing is unlikely to work out. Also, for safety reasons, you should carry out production away from open fire, and choose a well-ventilated area.

It is safer to carry out work in a garage or special extension.
The second stage is mixing the materials and giving the casting the necessary parameters. For these purposes, plaster molds are used. Creating the outlines is not difficult, and such information is easy to find on the Internet. Then they paste it with a homogeneous material outer part layout, forming a future homemade refractory crucible. It is also important to give it the required depth and thickness.
And the last step is the drying process: the workpiece is placed in cardboard box and cover with a lid. This will allow the casting to dry and remove excess water from it. Sometimes heat treatment may be required, however, the important point is to control the annealing temperature and protect the skin of the hands and face. If the heat is too intense, the item will burst and there is a chance of severe burns. Detailed instructions How to make a crucible yourself and at home will be discussed in the following chapters.
Making a clay crucible
Here you can’t do without fireclay clay, which is sold in any building materials store. It tolerates extreme thermal effects very well, is cheap, and there are unlikely to be any problems finding it. As a last resort, you can make a crucible from crushed fireclay bricks. You will also have to buy liquid glass and mix all the ingredients for a homogeneous base. The proportions look something like this:
7 units of clay;
3 units of fireclay;
10 spoons of liquid glass.

All components are added in stages: clay and fireclay are mixed until smooth, and water is gradually added to them. The main goal is to create a mixture that will not stick to your hands. When the required consistency is obtained, glass is added and everything is thoroughly mixed. The main thing here is to bring the object to a state where the plane stops cracking. The mixture is ready, and for storage it is recommended to use thick cellophane, or wrap it in 7-10 layers of film.
Before sculpting, you will have to remove any remaining air by hitting the substance about 8-12 times on a hard surface.

The mixed material is applied inside the model, its depth and thickness are formed. It is better to create a semicircular bottom, which will give a greater effect during future melting of iron filings. Also, the substance must be pressed tightly against the model so that air does not form between the planes, and for greater convenience it is recommended to wet your hands with water.
Afterwards, the tank is sent for drying: it is placed in a container made of cardboard or plastic and placed in a dry place. A few hours will be enough to remove any remaining moisture. Also, the product will settle a little, and it will be easy to remove it from the mold. A refractory vessel made of fireclay bricks will last for a long time of use, however, the last point of creation should be the firing procedure in a furnace and at T = 800 °C. And the thing can be used for its intended purpose. For ease of operation, you will need a crucible furnace, which you can make yourself. For easy installation you can weld a structure of several pipes to form a cylinder. Usually it is fixed on two parallel posts so that it does not touch the ground. And here the thickness of the walls (minimum 5 mm) and the stability of the product are taken into account (it must easily withstand T = 1600 °C or more).
How to make a graphite crucible
low overall weight;
resistance to hot alloys;
good thermal conductivity;
strength increases with increasing temperature.

If you take the easy route, you can take a graphite rod, and the crucible is almost ready. All that remains is to attach the bottom.
If the required tube is not found, everything can be done using two molds of different sizes, which are inserted one into the other, and the free space will allow you to add required sizes. Initially, you need to pour the mortar into an empty container, and you should not spare it. The fact is that the powder will compact and settle. Next, add liquid glass (about 15 ml) and mix everything thoroughly. It is recommended to place the mixed mass in a large cylindrical container (you can use a plastic cup) and press a hole into a small one, leaving the bottom thick enough.
As a result, a vessel will come out, which is given time to dry. In this case, heat treatment will also be required to remove excess liquid. If all the steps were correct, then you will have a high-quality graphite crucible, made by yourself.
Assembling a cast iron crucible
This type is the worst, but sometimes he brings good benefit. All that is required is to place a cast iron glass of a smaller diameter in a metal bowl, and fill the free space with sand and clay.
Next, everything is heated in the oven until the mixture melts and takes on the same type of substance. Afterwards, the cup will harden, and iron can be melted in it. This is basic information on how to make a crucible at home and at minimal cost.

Today there are a huge number of different ovens. Some furnaces are used to heat your premises, others are used to prepare delicious food, and there are also furnaces in which they melt various metals, alloys, and also store already melted material. They are also called melting crucible furnaces. These furnaces are especially popular among large enterprises, factories, and laboratories. But you and I understand the size of melting they do there, and this does not mean that if you need to melt several kilograms of aluminum at home, you will be forced to buy expensive imported equipment. You can absolutely easily make a crucible furnace with your own hands. To do this you need three important things:

Types of crucibles

What are crucibles? Crucibles are containers made of fireproof material, in which metals are melted by heating to a certain temperature. The following materials are commonly used to make crucibles: cast iron, ceramics and graphite.

Ceramic crucibles are considered the best option for the production of various alloys, especially those based on palladium, since when using these materials no changes occur in the composition of the substance itself. Only in ceramic crucibles can you confidently melt various base metals and alloys based on cobalt, chromium and molybdenum.

Graphite crucibles, in turn, have higher oxidation resistance and a longer service life. This type of crucible is universal for melting any metals, but they are especially good for zinc alloys and brass, as well as directly for use in induction furnaces. Graphite crucibles flawlessly cope with the melting and thermal holding of aluminum in electric furnaces at temperatures up to 800°C.

Graphite crucibles are most often used for casting gold and other precious metals.

Cast iron crucibles are not used so often in production; they have a fairly narrow specialty and have a number of disadvantages: insufficiently high melting temperature, high reactivity, ability to oxidize and interact with other elements, short service life. But on the other hand, cast iron has one significant advantage: it is cheap and accessible. That is why when installing our homemade crucible furnace we will use this particular material.

Crucible furnace material

Now let's start searching for materials, yes, yes, just searching, since you can find everything you need at your dacha, in the garage or barn, what yesterday was garbage and littered your yard, or some other places, now will become elements of your future homemade crucible furnace.

In order to install a crucible furnace with your own hands, you will need the following materials:

a piece of cast iron pipe (you determine its dimensions yourself), the main thing is that the wall thickness is 4-5 mm,
small sheet of metal (for the spout),
piece of reinforcement
1 nut,
1 screw

If you found or bought everything necessary materials, we can start installing the crucible furnace with our own hands. Usually the crucible is made in the shape of a cone or cylinder.

Making a crucible furnace

The easiest and simplest way to make a crucible is to simply weld it from a piece of pipe suitable diameter. When choosing the trim itself, you need to consider several important factors.

First, the width of the walls should be at least half a centimeter. Second, your scrap must be made of a metal that melts at a higher temperature than the alloys you plan to melt. Cast iron is ideal for this. After this, the pipe must be cleaned, or all excess can be simply burned in the oven. Now your homemade crucible furnace is in no way inferior to any other.

To safely remove molten metal from the crucible, attach a small spout to it. To do this, grind the top a little with a grinder and go through it with a file. To make it, use a piece of metal cut at an angle.

You can also attach a handle to your homemade crucible furnace; use a nut and screw the handle into it, which will help you immerse and remove the crucible from the furnace more safely. All you need is a couple of turns of the handle, and your crucible will be held in a death grip, thus preventing accidental tipping or spilling of molten aluminum on yourself or people who may be nearby at that moment. All the safety measures mentioned above will come in very handy when melting non-ferrous metals at home. As you can now see, installing a crucible furnace with your own hands is a fairly simple task. I hope you will now never ask yourself again: how to make a crucible furnace?

Induction crucible furnace: advantages and disadvantages

A crucible induction furnace is a special installation for melting metals and alloys by high-frequency electromagnetic influence on them.

The most important working part of an induction-type crucible furnace is the inductor - in other words, a conductor wound without a core - inside which a melting crucible, usually shaped like a cylinder, is placed. As a rule, it is made of fire-resistant material.

If we compare crucible induction furnaces with other types of similar equipment, they have the following advantages:

the effect on the processed material occurs directly, without any intermediate heating elements, which makes it possible to avoid unnecessary energy losses
the ability to create atmospheres of a given type in the crucible at the required value of the pressure itself
uniform heating of the entire volume of material, as well as high intensity of melt circulation
the possibility of completely draining the melt, which is necessary during periodic work, thus making it easy to switch from working with one alloy to another
ecological smelting process due to the absence of emissions of harmful combustion products into the atmosphere
the operating features of the installation lead to the possibility of complete automation of the entire smelting process;
ease of process management, simplicity and ease of maintenance;

The disadvantages of induction crucible furnaces include:

The slag in induction crucible furnaces is heated directly from the metal, which is why its temperature will always be lower.

Compared to others, the durability of the lining is low at very high melt temperatures, as well as the presence of sharp fluctuations in the temperature of the lining when the metal is completely drained.

But still, the advantages of induction crucible furnaces over other melting units are much higher, thanks to which they managed to find enough wide application in a wide variety of industries.

Classification of crucible furnaces

Depending on where the smelting process takes place, furnaces are distinguished:

open (work outdoors)
vacuum (work in vacuum)
compressor (operation under excess pressure).

On organizing the time process:

periodic action
half continuous
continuous action

Furnaces are also distinguished depending on the design of the melting crucible:

with ceramic crucible
with conductive metal crucible
with conductive graphite crucible
with a water-cooled metal crucible.

Who is a crucible furnace suitable for?

A crucible furnace is convenient in cases where it is necessary to melt small volumes of material, where it is not practical or economically profitable to buy a powerful melting installation with serious energy consumption, and which will ultimately take up a significant part of your work space. It is in this case that most enterprises begin to look for a more profitable alternative. And they find it in crucible furnaces, which are able to fully satisfy the needs of consumers in terms of heating temperature, low energy consumption, saving working space, and a modern convenient design and ease of use can provide the most optimal conditions labor.

Almost every item has several types and purposes, including stoves. There are stoves for heating rooms and for cooking food, and there are special devices for melting metals or storing them in molten form. Such devices are called crucible melting furnaces. They have a specific purpose and therefore the list of enterprises where they have found their application is quite small. These are mainly factories and laboratories. But what to do if you need to melt metal for some purpose at home? Buying such equipment is very expensive, but it is quite possible to make it yourself. This requires minimal knowledge in this area, desire and time.

Types of crucibles

A crucible furnace is a container made of refractory material in which metal is heated to a certain temperature. The main materials from which crucibles are made:

ceramics;
graphite;
cast iron.

Crucible furnaces are used as in factories where more hardware, and in small enterprises, for example, for the manufacture of jewelry.

Ceramic ovens- This best option. When metals are melted in a ceramic crucible, no changes occur in the substance itself. Therefore, in such crucibles there are no problems Even base metals or alloys can be melted from cobalt, chromium or palladium.

Graphite crucibles. Such furnaces are characterized by a long service life and high resistance to oxidation, which makes them universal for melting any metals and especially alloys based on zinc and brass. In addition, they are often used in induction furnaces. Graphite crucibles can withstand very high temperatures, such as eight hundred degrees to melt aluminum.

Cast iron crucibles are perhaps the worst of the three listed. They have high reactivity, rapid oxidation and interaction with other metals, and cast iron does not resist high temperatures well. For these reasons cast iron crucibles are very rare, but they are inexpensive and quite accessible.

This article will look at methods for making three types of homemade crucibles.

Crucible furnaces

Inductor assembly

The heating element of the crucible arm at home is usually an inductor. He has cylindrical shape with a cavity inside. A homemade crucible with metal shavings is placed in this cavity. Inductor made of fireproof material, inside it is a winding of wire, most often copper wire is used. Using a special generator, current is supplied to this winding, which creates an electromagnetic field. Which, in turn, creates an eddy current in the crucible and in the metal placed in it. They melt the chips. The inductor itself is assembled from 4 vacuum tubes with a parallel connection. Such an inductor can be connected to a regular outlet.

There is another option for assembling an inductor with your own hands from an electromagnetic core and two layers of winding. First layer – 10 turns copper wire with a thickness of 4 mm, and the second is one turn, the material for which is a metal plate with a cross-section of 15 * 5 millimeters. The electromagnetic core is U-shaped and consists of a set of steel plates. The first winding is made around the plates, which is placed in an insulated housing, the secondary winding connects the core and metal bars, between which there should be a distance equal to the dimensions of the crucible. This entire structure is placed in the furnace body.

So, we get a furnace in which the inductor is located. Wires go from the inductor to the socket. A crucible is placed in this furnace in such a way as to enclose the bars. If it is placed correctly, a buzzing sound will be heard, indicating that tension has appeared and melting has begun. If there is no sound, then use the handle to move the crucible until the circuit is completely closed.

Assembling a cast iron crucible

A metal casing is taken and a glass made of cast iron is placed in it. A mixture of sand and clay is poured between them. A handle is attached to the side. After one or two heatings, the mixture will melt and harden. The crucible is ready. Chips are poured into it and placed in the inductor.

Making a crucible from clay

You can make a crucible from fireclay clay. This is an inexpensive option and also highly resistant to high temperatures. like this clay is used for laying stoves and it can be bought at any hardware store. Fireclay clay can withstand temperatures up to 1600 degrees Celsius.

So, you will need fireclay clay (sold in bags in hardware stores), liquid glass (sold there) and ground fireclay. It can be bought or made from fireclay bricks.

In order to make a mixture from which a crucible will be fashioned in the future, take 7 parts of clay, 3 parts of fireclay and 10 tablespoons of liquid glass per liter of dry mixture. Fireclay and clay are mixed until smooth. After this, water is slowly added. To avoid spoiling the workpiece You can add some of the mixture, and in the case large quantity water - add dry powder. You need to knead until the clay stops sticking to your hands.

Only after the clay of the desired consistency has been mixed can glass be added. When adding glass you need to mix everything thoroughly until the clay stops cracking. It is best to add glass to a lump of clay and roll it into a roll, then fold it several times and repeat the procedure until it stops cracking. The material for the crucible is ready. Until the moment when it is used, it must be stored in several layers of cellophane.

There is clay, now to make a crucible you need to take a mold, the easiest way is to use a plaster mold. How to make such a form can be found on any website on plaster modeling. So, directly making the crucible.

Before you start sculpting, you need to knock all the air out of the clay; to do this, you can lay a newspaper on the floor and forcefully throw a lump on it several times, ten times will be enough. Now take a lump of clay and carefully press it into the bottom of the mold, after which the walls of the product are formed in small lumps. Their thickness can be controlled along the edge of the mold. Very it is important to carefully press the clay into the mold so that no air cushions form there. After the crucible is sculpted, you need to make the inner surface smooth. To do this, just moisten the clay with water.

After this comes the moment of drying. The mold with clay is placed in a cardboard box and covered with a lid. After seven hours, all the water from the clay will evaporate and the shape of the future crucible will “shrink” a little, so getting it out of the mold is not particularly difficult. After this, the crucible continues to dry in the same box; as it dries, all defects will be eliminated by themselves and the pot will acquire a gray color. Sometimes small cracks may appear. They can be covered with wet clay. Next, the pots are fired at a temperature of 800 degrees in a muffle furnace. After firing, the crucible is ready for use.

Graphite crucible

Graphite is a material that has many unique properties. Positive qualities of graphite:

resistance to molten metals;
increase in strength with increasing temperature;
high heat resistance and thermal conductivity;
small specific gravity.

To make a crucible from this material you will need:

graphite powder;
solid graphite;
felt;
graphite tube;
fireclay mortar;
magnesite.

Some of these materials can be used as independent units. For example, a graphite tube is essentially already a crucible; you just need to make a bottom in it.

The principle of manufacturing from all materials is the same. Let's look at the example of mortar. Two forms are made. You can roll it out of thick paper to make it easier to remove later. External the shape has the configuration of a hollow cylinder, and the inner one is just a cylinder. The small cylinder is inserted into the wider one. The mixture will be poured between them. The mold is placed in a plastic cup and mortar powder is poured into it. You need to fall asleep with a slide, as it will sit down when you need to compact it. 15 cubes of liquid glass are poured into this powder using a syringe. Everything is mixed and the consistency is obtained shortcrust pastry. Stuff into the mold in small portions.

The result is something like a glass turned upside down. To prevent the form from sticking to the table, it is best to do the entire procedure on cellophane. Then the mold is turned upside down and the inner cylinder is removed. It is also best to initially glue it with cellophane or tape. Then, when removing, the shape of the crucible will not be damaged.

After the crucible has dried, it must be placed in the inductor and heated. This is necessary do at low temperatures, since all the water should evaporate, despite the fact that outwardly it seems as if it is not there at all. If the crucible is not preheated and you immediately start melting in it, it will most likely burst. After warming up, when you tap the crucible, it will emit ringing sound. This indicates that the crucible is well made.

By following the instructions presented, you can quite easily acquire a homemade melting furnace that will last no less than a purchased one. The main thing is to take your time, be careful in your work and not violate manufacturing technologies.

Almost every item has several types and purposes. This truth also applies to ovens.

There are stoves for heating rooms and for cooking food, and there are special devices for melting metals or storing them in molten form.

Such devices are called crucible melting furnaces. They have a specific purpose and therefore the list of enterprises where they have found their application is quite small. These are mainly factories and laboratories. But what to do if you need to melt metal for some purpose at home? Buying such equipment is very expensive, but it is quite possible to make it yourself. This requires minimal knowledge in this area, desire and time.
A crucible furnace is a container made of refractory material in which metal is heated to a certain temperature. The main materials from which crucibles are made:
- ceramics;
- graphite;
- cast iron.
Crucible furnaces are used both in factories where metal products are manufactured, and in small enterprises, for example, for the manufacture of jewelry.
Ceramic stoves are the best option. When metals are melted in a ceramic crucible, no changes occur in the substance itself. Therefore, even base metals or alloys of cobalt, chromium or palladium can be melted in such crucibles without any problems.
Graphite crucibles. Such furnaces are characterized by a long service life and high resistance to oxidation, which makes them universal for melting any metals and especially alloys based on zinc and brass. In addition, they are often used in induction furnaces. Graphite crucibles can withstand very high temperatures, such as eight hundred degrees to melt aluminum.
Cast iron crucibles are perhaps the worst of the three listed. They have high reactivity, rapid oxidation and interaction with other metals, and cast iron does not resist high temperatures well. For these reasons, cast iron crucibles are very rare, but they are inexpensive and quite accessible.
This article will look at methods for making three types of homemade crucibles.

Crucible furnaces. Inductor assembly
The heating element of the crucible arm at home is usually an inductor. It has a cylindrical shape with a cavity inside. A homemade crucible with metal shavings is placed in this cavity. The inductor is made of fire-resistant material, inside it there is a wire winding, most often copper wire is used. Using a special generator, current is supplied to this winding, which creates an electromagnetic field. Which, in turn, creates an eddy current in the crucible and in the metal placed in it. They melt the chips. The inductor itself is assembled from 4 vacuum tubes with a parallel connection. Such an inductor can be connected to a regular outlet.
There is another option for assembling an inductor with your own hands from an electromagnetic core and two layers of winding. The first layer is 10 turns of copper wire with a thickness of 4 mm, and the second is one turn, the material for which is a metal plate with a cross-section of 15 * 5 millimeters. The electromagnetic core is U-shaped and consists of a set of steel plates. The first winding is made around the plates, which is placed in an insulated housing; the secondary winding connects the core and metal bars, between which there should be a distance equal to the dimensions of the crucible. This entire structure is placed in the furnace body.
So, we get a furnace in which the inductor is located. Wires go from the inductor to the socket. A crucible is placed in this furnace in such a way as to enclose the bars. If it is placed correctly, a buzzing sound will be heard, indicating that tension has appeared and melting has begun. If there is no sound, then use the handle to move the crucible until the circuit is completely closed.

Assembling a cast iron crucible
A metal casing is taken and a glass made of cast iron is placed in it. A mixture of sand and clay is poured between them. A handle is attached to the side. After one or two heatings, the mixture will melt and harden. The crucible is ready. Chips are poured into it and placed in the inductor.

Making a crucible from clay
You can make a crucible from fireclay clay. This is an inexpensive option and also highly resistant to high temperatures. This clay is used for laying stoves and can be purchased at any hardware store. Fireclay clay can withstand temperatures up to 1600 degrees Celsius.
So, you will need fireclay clay (sold in bags in hardware stores), liquid glass (sold there) and ground fireclay. It can be bought or made from fireclay bricks.
In order to make a mixture from which a crucible will be fashioned in the future, take 7 parts of clay, 3 parts of fireclay and 10 tablespoons of liquid glass per liter of dry mixture. Fireclay and clay are mixed until smooth. After this, water is slowly added. In order not to spoil the workpiece, you can pour out part of the mixture, and in case of a large amount of water, add dry powder. You need to knead until the clay stops sticking to your hands.
Only after the clay of the desired consistency has been mixed can glass be added. When adding glass, you need to thoroughly knead everything until the clay stops cracking. It is best to add glass to a lump of clay and roll it into a roll, then fold it several times and repeat the procedure until it stops cracking. The material for the crucible is ready. Until the moment when it is used, it must be stored in several layers of cellophane.
There is clay, now to make a crucible you need to take a mold, the easiest way is to use a plaster mold. How to make such a form can be found on any website on plaster modeling. So, directly making the crucible. Before you start sculpting, you need to knock all the air out of the clay; to do this, you can lay a newspaper on the floor and forcefully throw a lump on it several times, ten times will be enough. Now take a lump of clay and carefully press it into the bottom of the mold, after which the walls of the product are formed in small lumps. Their thickness can be controlled along the edge of the mold. It is very important to carefully press the clay into the mold so that no air cushions form there. After the crucible is sculpted, you need to make the inner surface smooth. To do this, just moisten the clay with water.
After this comes the moment of drying. The mold with clay is placed in a cardboard box and covered with a lid. After seven hours, all the water from the clay will evaporate and the shape of the future crucible will “shrink” a little, so getting it out of the mold is not particularly difficult. After this, the crucible continues to dry in the same box; as it dries, all defects will be eliminated by themselves and the pot will acquire a gray color. Sometimes small cracks may appear. They can be covered with wet clay. Next, the pots are fired at a temperature of 800 degrees in a muffle furnace. After firing, the crucible is ready for use.

Graphite crucible
Graphite is a material that has many unique properties. Positive qualities of graphite:
- resistance to exposure to molten metals;
- increase in strength with increasing temperature;
- high heat resistance and thermal conductivity;
- low specific gravity.
To make a crucible from this material you will need:
- graphite powder;
- solid graphite;
- felt;
- graphite tube;
- fireclay mortar;
- magnesite.
Some of these materials can be used as independent units. For example, a graphite tube is essentially already a crucible; you just need to make a bottom in it.
The principle of manufacturing from all materials is the same. Let's look at the example of mortar. Two forms are made. You can roll it out of thick paper to make it easier to remove later. The outer shape is a hollow cylinder configuration, while the inner one is just a cylinder. The small cylinder is inserted into the wider one. The mixture will be poured between them. The mold is placed in a plastic cup and mortar powder is poured into it. You need to fall asleep with a slide, as it will sit down when you need to compact it. 15 cubes of liquid glass are poured into this powder using a syringe. Everything is mixed and the consistency of shortcrust pastry is obtained. Stuff into the mold in small portions.
The result is something like a glass turned upside down. To prevent the form from sticking to the table, it is best to do the entire procedure on cellophane. Then the mold is turned upside down and the inner cylinder is removed. It is also best to initially glue it with cellophane or tape. Then, when removing, the shape of the crucible will not be damaged.
After the crucible has dried, it must be placed in the inductor and heated. This must be done at low temperatures, since all the water should evaporate, despite the fact that outwardly it seems as if it is not there at all. If the crucible is not preheated and you immediately start melting in it, it will most likely burst. After warming up, when you tap the crucible, it will make a ringing sound. This indicates that the crucible is well made.
By following the instructions presented, you can quite easily acquire a homemade melting furnace that will last no less than a purchased one. The main thing is to take your time, be careful in your work and not violate manufacturing technologies.