How to solder an aluminum canister at home

There is a widespread belief that it is impossible to solder or tin aluminum (as well as alloys based on it) without special equipment for this.

Two factors are cited as an argument:

upon contact with air, a chemically resistant and refractory oxide film (AL2O3) is formed on the surface of the aluminum part, resulting in an obstacle to the tinning process;
The soldering process is significantly complicated by the fact that aluminum melts at a temperature of 660°C (for alloys this ranges from 500 to 640°C). In addition, the metal loses strength when, during the heating process, its temperature rises to 300°C (for alloys up to 250°C), which can cause a violation of the stability of aluminum structures.

Considering the above factors, it is truly impossible to solder aluminum using conventional means. The use of strong fluxes in combination with the use of special solders will help solve the problem. Let us consider these materials in detail.

How to solder aluminum at home with a soldering iron

Aluminum is highly durable and a good conductor of heat and electricity. It has a low specific gravity, is easy to process, and is environmentally friendly.

However, all these positive qualities create almost insurmountable obstacles when solving the problem of how to solder aluminum at home with a soldering iron.

This cannot be done using traditional methods, so you have to use special welding methods and optimally selected materials.

Technical difficulties in soldering aluminum products and parts

Soldering aluminum structures and other elements is always quite difficult, especially if it is done at home by novice craftsmen who have not fully studied the process.

Basically, such soldering is performed industrially using special equipment. However, it is quite possible to create the most suitable conditions for welding parts made of aluminum.

To achieve this goal, it is necessary to resolve several technical problems:

The biggest problem when soldering is caused by oxidation in the form of a film that appears on the surface as a result of contact between aluminum and air. Even if the metal is prepared, a coating forms on it almost immediately afterward. Such a film coating interferes with the joining process and adds many problems during the tinning and soldering process. In this situation, conventional types of solders and fluxes are completely unsuitable, since they do not guarantee a high-quality connection. The film is removed either by physical-mechanical means or with the help of strong chemicals.
One should also take into account the high temperatures at which aluminum begins to melt. It reaches a maximum of 600C. A temperature difference arises between the metal being soldered and its film, causing difficulties in the soldering process.
Due to the temperature regime, aluminum begins to noticeably lose its strength during the heating process. This moment occurs when the material being welded is heated to 250-300 degrees. Some aluminum alloys contain components whose melting point differs from the base metal.
Weak interaction of aluminum with traditional types of solders, consisting mainly of tin, cadmium and other elements. This leads to insufficient strength characteristics and reliability of the created seams. The problem of how to solder is solved using special solders containing zinc, which, in turn, has excellent contact with aluminum and penetrates into it. Adhesion occurs at the molecular level, providing the necessary strength of the connection.

Preparation for soldering aluminum parts

Great importance is attached to preparing aluminum for upcoming soldering.

There are several ways to do this to ensure connection reliability:

The connection area is pre-degreased and treated with rosin. After the substance is applied to the surface, sandpaper is placed here. Next, you need to turn on a powerful soldering iron and press the sandpaper firmly against the surface.
After this, the surface is rubbed and polished, and the joint itself is simultaneously tinning. An aluminum part is installed on the prepared surface, which can be soldered according to the usual scheme. If necessary, rosin can be replaced with oil used in sewing machines.
In the second option, metal shavings are added to the rosin, after which the resulting mixture is applied to the surface of the future joint. The soldering iron tip needs to be well heated and tinned, and then rub it over the entire working surface of the parts to be soldered until the chips melt. At the same time, solder is added here. In this case, the oxide is removed mechanically, and the solder immediately falls on the surface and protects it from the reappearance of the oxide film.
The third method is to pre-clean the surface. For this purpose, copper is used, through which the oxide film is removed. This method is one of the most difficult, since copper plating of the surface must be carried out in a special bath.

Selection of solder and flux for aluminum

Tin- and lead-based solders can be used to weld wires, elements and parts made of aluminum, provided they are thoroughly cleaned. Such soldering must be carried out using special flux solutions consisting of highly active substances.

However, such connections have insufficient strength due to the weak interaction of aluminum products with tin and lead, and the tendency to form corrosion. Therefore, special compounds are used in the form of anti-corrosion coating for surfaces made of this metal.

These compounds include solders containing copper, zinc, aluminum and silicon. They are produced both in our country and abroad.

Among domestic brands, the most widely used is TsOP-40, which contains 40% zinc and 60% tin, as well as compound 34A with aluminum (66%), copper (28%) and silicon (6%).

zinc affects not only the strength of aluminum contacts, but also their resistance to corrosion.

Electrical capacitance of a flat capacitor

Of all the known solders, the minimum temperature at which they begin to melt is those based on tin and lead.

The highest melting point belongs to compounds with an aluminum-silicon structure, as well as with aluminum, copper and silicon. In the first case, similar types of solders melt when the temperature reaches 590-600 degrees, and in the second - at 530-550 degrees.

They are selected for each specific case, when parts with large dimensions, with good heat dissipation or refractory aluminum connections are connected.

Technological processes are inextricably linked with special types of fluxes used for better interaction of all welding components.

Selecting the most suitable material is considered a rather difficult undertaking. This is especially important when the process uses tin-lead solder.

The structure of such fluxes includes elements that form its increased activity when interacting with aluminum.

Among them are triethanolamine, ammonium fluoroborate, zinc fluoroborate and other similar components.

One of the most popular flux substances produced in Russia is the F64 substance, which is characterized by high activity. The quality of this connection allows you to solder metal parts made of aluminum without removing the refractory oxide coating located on the surface.

Soldering aluminum components

The procedure and technical process for welding aluminum are exactly the same as for other types of non-ferrous metals.

Among home craftsmen, the following two options are most often used:

High-temperature soldering used for welding large-sized elements. This category includes aluminum structures with thick walls and increased mass, which require a temperature of 550-650C to heat up.
Soldering at low temperatures of 250-300C, which is quite enough for installing wires of electronic equipment and welding small items used in everyday life. Aluminum wires are connected in the same mode in any electrical network.

Connections at high temperatures occur using special heating elements. One of them is a burner, which requires gas in the form of propane or butane to operate. If such a burner is not available, home craftsmen use various types of blowtorches.

Welding at high temperatures requires constant control over the degree of heating of the surfaces of the parts being joined. To do this, take one of the refractory solders in a small amount, and after it begins to melt, we can talk about reaching the desired temperature.

In this case, the heating of the part stops, otherwise it will simply melt and collapse.

Soldering at low temperatures is carried out with a 100-200 W electric soldering iron. The power of a soldering iron depends on the size of the components being connected: the larger the part, the more powerful a soldering iron will be required to heat it up. The conductors are easily connected with a 50 W soldering iron.

Regardless of the temperature conditions, connections are made in the same way, and all actions are performed in the following order:

The place of future connection of parts or cables is processed mechanically. For this purpose, any cleaning agents are used that weaken oxidative deposits, providing more complete interaction with the flux substance.
The joint must be degreased with acetone, gasoline, alcohol and other organic solvents.
Before soldering aluminum with a soldering iron or torch at home, the parts are firmly fixed in the most convenient position.
Flux is applied to the prepared surface. If the substance is used in liquid form, it is applied with a brush.
The connection point is heated using an electric soldering iron of sufficient power or a gas burner. Next, molten solder is applied here and distributed in an even layer.
Metal surfaces are connected and fixed in the desired position.
After the solder has cooled and the parts have set, the joint is washed with running water. Flux residues are washed away and do not cause corrosion in the future.

Rivet

If you don’t have glue on hand, but you have a lot of metal working tools in your house, you can make a rivet. You need:

a good hammer (it should fit tightly on the handle);
hacksaw;
chisel;
pliers;
vice;
wire cutters;
anvil;
metal plate;
thick wire - copper or aluminum.

The procedure for repairing a pan:

Cut a piece of wire 10-12 cm.
Clamp it in a vice.
Using light blows of a hammer, flatten one end to form a cap - it should be larger than the hole.
Insert the free end of the wire into the hole so that the cap covers it.
Trim the free end.
Flatten it so that the other side also has a cap covering the hole.

How to solder an aluminum canister at home - Metalworker's Guide

There is a widespread belief that it is impossible to solder or tin aluminum (as well as alloys based on it) without special equipment for this.

Two factors are cited as an argument:

upon contact with air, a chemically resistant and refractory oxide film (AL2O3) is formed on the surface of the aluminum part, resulting in an obstacle to the tinning process;
The soldering process is significantly complicated by the fact that aluminum melts at a temperature of 660°C (for alloys this ranges from 500 to 640°C). In addition, the metal loses strength when, during the heating process, its temperature rises to 300°C (for alloys up to 250°C), which can cause a violation of the stability of aluminum structures.

Solder

Commonly used low-melting solder bases are tin (Sn), lead (Pb), cadmium (Cd), bismuth (Bi) and zinc (Zn). The problem is that aluminum is practically insoluble in these metals (with the exception of zinc), which makes the connection unreliable.

By using a flux with high activity and properly treating the joints, you can use tin-lead solder, but it is better to avoid such a solution. Moreover, a solder joint based on the Sn-Pb system has low corrosion resistance. Applying a paint coating to the soldering area allows you to get rid of this drawback.

For soldering aluminum parts, it is advisable to use solder based on silicon, copper, aluminum, silver or zinc. For example 34A, which consists of aluminum (66%), copper (28%) and silicon (6%), or the more common TsOP-40 (Sn - 60%, Zn - 40%).

Domestic solder – TsOP-40

Note that the higher the percentage of zinc in the solder, the stronger the connection and the higher its resistance to corrosion.

High-temperature solder is considered to be solder consisting of metals such as copper, silicon and aluminum.

For example, like the above-mentioned domestic solder 34A, or its foreign analogue “Aluminium-13”, which contains 87% aluminum and 13% silicon, which allows soldering at temperatures from 590 to 600°C.

"Aluminum-13" produced by Chemet

Flux

When choosing a flux, it is necessary to take into account that not all of them can be active towards aluminum. We can recommend using products from a domestic manufacturer for such purposes - F-59A, F-61A, F-64, they consist of ammonium fluoroborates with the addition of triethanolamine. As a rule, the bottle is marked “for aluminum” or “for aluminum soldering.”

Domestic flux

For high-temperature soldering, you should purchase flux produced under the brand 34A. It consists of potassium chloride (50%), lithium chloride (32%), sodium fluoride (10%) and zinc chloride (8%). This composition is most optimal if high-temperature soldering is performed.

Recommended flux for packing at high temperatures

Surface preparation

Before you begin tinning, you must complete the following steps:

degrease the surface using acetone, gasoline or any other solvent;
remove the oxide film from the place where soldering will be performed. For cleaning, use sandpaper, an abrasive wheel or a brush with steel wire bristles. As an alternative, etching can be used, but this procedure is not so common due to its specificity.

It should be taken into account that it will not be possible to completely remove the oxide film, since a new formation will immediately appear in the cleaned area. Therefore, stripping is carried out not with the goal of completely removing the film, but to reduce its thickness in order to simplify the task of the flux.

Heating the soldering area

To solder small parts, you can use a soldering iron with a power of at least 100W. Massive items will require a more powerful heating tool.

Soldering iron 300 Watt

The best option for heating is to use a gas burner or blowtorch.

Simple gas burner

When using a burner as a heating tool, the following nuances should be taken into account:

Do not overheat the base metal, as it may melt. Therefore, it is necessary to regularly monitor the temperature during the process. This can be done by touching the solder to the heated element. Melting the solder will let you know that the required temperature has been reached;
Oxygen should not be used to enrich the gas mixture, since it promotes strong oxidation of the metal surface.

Soldering instructions

The process of soldering aluminum parts does not have its own distinctive features; it is carried out in the same way as with steel or copper.

The algorithm of actions is as follows:

the soldering area is degreased and cleaned;
the parts are fixed in the desired position;
the connection area heats up;
touch the solder rod (containing active flux) to the joint. If flux-free solder is used, then flux is applied to destroy the oxide film, after which a solid piece of solder is rubbed over the soldering area.

A brush with steel wire bristles is also used to break down the aluminum oxide film. This simple tool is used to rub molten solder over an aluminum surface.

Soldering aluminum - complete video instructions https://www..com/watch?v=ESFInizLE9U

What to do if you don’t have the necessary materials?

When it is not possible to prepare all the materials necessary for soldering, you can use an alternative method that uses tin or tin-lead solder. As for the flux, it is replaced by rosin. To prevent the formation of a new aluminum oxide film in place of the old one, stripping is carried out under a layer of molten rosin.

The soldering iron, in addition to its direct purpose, will be used as a tool that destroys the oxide film. To do this, a special scraper is put on its sting. You can increase the effectiveness of the process by adding metal filings to the rosin.

The process is carried out as follows:

use a heated tinned soldering iron to melt the rosin at the soldering site;
When the rosin completely covers the surface, they begin to rub it with a soldering iron tip. As a result, metal filings and stings destroy the aluminum oxide film. Since the layer of molten rosin does not allow air to penetrate to the aluminum surface, an oxide film does not form on it. As the film is destroyed, tinning of the part will occur;
When the tinning process is completed, the parts are joined and heated until the melting temperature of the solder is reached.

It must be warned that the process of soldering aluminum without special materials is a rather troublesome process with no guarantee of successful completion. Therefore, it is better not to waste your time and energy on such work, especially since the quality and reliability of such a connection will be questionable.

It is much easier to buy active flux and high-temperature solder, with which soldering aluminum even at home will not cause difficulties.

Soldering aluminum at home: techniques and principles, fluxes and solders

Aluminum is a material with good strength and high thermal and electrical conductivity.

These positive qualities contribute to the widespread use of metal in industry and everyday life.

Quite often there is a need to connect aluminum parts or seal a hole in an aluminum container. But not everyone knows how to solder aluminum at home.

Soldering aluminum

One of the most well-known methods of joining metals, especially in electrical work, is soldering.

It provides lower resistance of connections, and, as a result, less heating under the influence of electric current.

Since aluminum, along with copper , is the main conductive material in electrical networks and devices, the need for soldering arises quite often.

The difficulty is that the “winged metal” in air is instantly covered with a film of oxide, to which the molten solder does not stick. It is necessary to remove the oxide layer using mechanical cleaning, but it forms again almost instantly.

In order to avoid the re-formation of the oxide film, many techniques have been developed. Among them:

Cleaning small parts under a layer of liquid flux.
The use of fluxes in conjunction with abrasive materials.
Using copper sulfate to create a copper film on an aluminum product.
Application of special fluxes and solders.

Cleaning under the flux layer

Small aluminum parts, such as conductors, can be cleaned by dipping part of the part into a liquid flux, which can be a regular rosin solution or soldering acid. Liquid flux will protect the area being cleaned from contact with oxygen and the formation of a film. Regular transformer oil has the same protective effect.

Abrasive materials

Iron filings are often added to the flux (the same rosin). During the soldering process, it is necessary to rub the heated area with the tip of the soldering iron. Under the influence of friction, the sawdust peels off the oxide layer, and the rosin blocks the access of oxygen to the liberated metal. Instead of sawdust, any crumbling abrasive can be used: sandpaper or even brick.

Using copper sulfate

An interesting method using galvanostegy. Two aluminum electrodes are dipped into a solution of copper sulfate and connected to the poles of an electric battery. The electrode connected to the positive is stripped.

As a result of electrolysis, copper begins to deposit on the cleaned surface. When the aluminum is completely covered with a copper film, the part is dried.

After this, soldering is much easier, because copper is an excellent material for this type of connection.

Special solders

The highest quality connection at home can be obtained using low-melting solders based on tin and copper and special fluxes.

The most popular domestic flux is F64, which allows you to solder aluminum parts without mechanical stripping.

So, for example, soldering aluminum to copper can be done without problems, or an aluminum tube can be sealed from the inside, which cannot be cleaned by any other means.

other methods

In some cases, it is better not to solder metal surfaces, but to glue them together. True, you won’t be able to cook food in sealed pans; this will only work as a bucket. But just in case, you need to know these methods. Adhesives suitable for you:

BF-2;
BF-4;
epoxy.

BF-2 and BF-4

These adhesives are made from phenol-formaldehyde resin, so cookware repaired with their help is not suitable for cooking. The method of application is simple:

Clean surfaces thoroughly to ensure no grease, rust or dirt remains.
Treat the gluing area and patch with acetone or gasoline.
Apply a thin layer of glue - it is more convenient to do this with a brush.
Allow the item to dry for about an hour.
Apply a second layer of glue.
Let it dry a little.
Place the surfaces against each other (for example, a metal plate to a hole), press.
Place the product in the oven and heat for an hour.

Epoxy adhesive

This solution consists of several components. He has:

epoxy resin;
dibutyl phthalate (plasticizer);
aluminum oxide or quartz flour;
hardener

After the patch is glued, the product must be placed in the oven, preheated to 200°C and heated for about three hours. This is the best variant. If you don’t have an oven, you can preheat it to 120°, and then leave the pan alone for a day, after which it will be ready for use. You can store food in it, but you shouldn’t cook it.

How to solder an aluminum canister at home - Metals, equipment, instructions

The procedure for soldering aluminum elements at home is a very problematic process, which is facilitated by the use of special materials.

The work is complicated by the immediate appearance of a thin oxide film at the stripping site, which interferes with soldering. An additional difficulty is created by the material itself, which has a low melting point (+660 °C).

Using solder for soldering aluminum, special strong fluxes and following technology, you can independently solder almost any aluminum object.

Features and principles of soldering

The low temperature value of metal melting complicates the technological process of soldering, as well as repairing products with your own hands.

Parts very quickly lose strength when heated, and structures reduce stability when the temperature reaches 300 degrees.

Low-melting solders consisting of bismuth, cadmium, indium, and tin come into difficult contact with aluminum and do not provide sufficient strength. Excellent solubility is observed in the metal in combination with zinc, which makes the soldered areas highly reliable.

Before soldering begins, aluminum elements are well cleaned of oxides and dirt. To do this, you can use mechanical force with brushes or use special fluxes made from a potent composition. Before the procedure itself, be sure to tin the areas to be treated.

The tin coating will protect the part from the formation of oxides. In order to reliably solder aluminum products, it is necessary to choose the right heating tool, taking into account the volume of metal being processed.

In addition, the reliability of the connection depends on the alloy chosen, as well as the flux for soldering aluminum.

Soldering methods

Soldering of aluminum products is carried out with an electric soldering iron, a blowtorch or a gas torch. There are three ways to solder various aluminum objects:

with rosin;
using solders;
electrochemical method.

With rosin

This option for soldering aluminum objects, wires, cables is used for small parts.

To do this, the cleaned section of the electrical wire is covered with rosin and placed on a piece of sandpaper with a medium grain size. The wire is pressed from above with the tinned tip of a heated soldering iron.

This action is carried out several times, after which the procedure of soldering the electrical wires itself is performed. You can use a rosin solution in diethyl ether.

In this case, the end of the soldering iron is not removed from the end being tinned, but rosin is added on top. An electric soldering iron with a power of about 50 W is suitable for twisting thin aluminum wires. With an aluminum thickness of about 1 mm, a 100 W soldering iron is required, and parts larger than 2 mm require preheating of the joint.

Using solders

This method is the most common and is used in electrical engineering, in the repair of automobile parts, as well as other products. Before soldering aluminum, the area to be soldered is pre-coated with an alloy and the tin-plated elements are subsequently connected. Pre-tinned parts are connected to each other, as well as to other alloys and metals.

Soldering of elements can be carried out using light alloy solders containing tin, zinc, and cadmium. In addition, refractory materials based on aluminum are actively used.

Why are light alloy compounds used? Because they allow you to solder an aluminum product at temperatures up to 400 degrees. This does not produce qualitative changes in the properties of the metal and maintains its strength.

Compositions with cadmium and tin do not create sufficient contact reliability and are susceptible to corrosive effects. Refractory materials containing zinc, copper, and aluminum-based silicon do not have these disadvantages.

Electrochemical method

This procedure requires a plating facility. With its help, copper plating is carried out on the surface of a product or wire. In its absence, independent processing of the part is used.

To do this, apply a few drops of a saturated solution of copper sulfate to the area cleaned with sandpaper.

After this, the negative pole of an independent power supply is connected to the workpiece.

They can be a battery, an accumulator, or any electrical rectifier.

A cleaned copper wire with a diameter of about 1 mm, located in an insulated stand, is connected to the positive terminal.

During the electrolysis process, copper will gradually deposit on the part, after which the area is tinning and dried using an electric soldering iron. After this, you can easily solder the tinned area.

Solders, materials, fluxes

Soldering of aluminum with tin is carried out subject to the use of highly active fluxes, as well as good cleaning of parts of the parts. Such tin compounds require additional coating with special compounds, since they have low strength and poor protection against corrosion processes.

How to solder aluminum elements? High-quality solder joints are obtained by using solders with silicon, aluminum, zinc, and copper. These materials are produced by both domestic and many foreign manufacturers.

Domestic brands of rods are represented by the most used solders TsOP40, which according to GOST contain 60% tin and 40% zinc, as well as 34A (aluminum - 66%, silicon - 6%, copper - 28%). The zinc used gives high strength to the contact area and provides good corrosion resistance.

These alloys are used to work with large-sized parts (radiators, pipes) with high heat dissipation using a heating pad or objects made of aluminum alloys that have a fairly high melting temperature. Novice repairmen can familiarize themselves with the soldering process by watching an instructional video. This will help to avoid many unpleasant nuances during the work process.

In addition to solders, aluminum soldering requires the use of special fluxes containing ammonium fluoroborate, zinc fluoroborate, as well as triethanolamine and other elements.

The most popular is the domestic F64, which has increased chemical activity. It can be used even without first removing the oxide film from products.

In addition to it, 34A is used, containing lithium, potassium and zinc chlorides, as well as sodium fluoride.

Preparation of products

Reliability, as well as excellent quality of connections, is ensured not only by using the right technology, but also by preparatory work. These include the treatment of sealed surfaces. It is necessary to remove contaminants and thin oxide films.

Mechanical processing is carried out using sandpaper, a metal brush, stainless steel wire mesh or a grinding machine. In addition, various acid solutions are used for cleaning.

Surface degreasing is carried out using solvents, as well as gasoline or acetone. On the cleaned aluminum area, an oxide film appears almost immediately, but its thickness is significantly lower than the original one, which facilitates the soldering process.

Heating tools

How to solder aluminum at home? Electric soldering irons are used to solder small-sized aluminum products at home. They are a universal tool, quite convenient for soldering wires, repairing small tubes and other elements.

They require a minimum of working space, as well as the presence of an electrical network. Repair of large-sized products and welding are performed with a gas torch that uses argon, butane, and propane.

To solder aluminum objects at home, you can use a standard blowtorch.

When using gas burners, it is necessary to constantly monitor their flame, which characterizes a balanced supply of oxygen and gases. With the correct gas mixture, the fiery tongue has a bright blue color. A dim hue, as well as a small flame, indicate an excess of oxygen.

Technological process

The technology for soldering aluminum objects is similar to the process of joining parts of other metal materials. The first step is to clean and degrease the areas of future adhesion. Then the connected elements are installed in working position for ease of processing.

Flux is applied to the prepared area, and the initially cold product begins to heat up using an electric soldering iron or a torch. As the temperature rises, the solder bar begins to melt, which must constantly touch the surface of the elements, controlling the heating process.

Soldering aluminum elements at home with an electric soldering iron is done in a well-ventilated room, as hazardous compounds are released during operation.

Using flux-free solder requires compliance with some nuances. To prevent the oxide film from interfering with the alloy getting onto the parts, the end of the rod makes scratching movements along the area where the elements are soldered. This breaks the oxide integrity and the solder comes into contact with the metal being processed.

Destruction of the oxide layer during soldering can be done using another method. To do this, the area to be treated is scratched with a metal brush or a stainless steel rod.

To ensure maximum strength of aluminum parts in the soldered area, the treated areas are pre-tinned. Compliance with the technology of soldering aluminum elements guarantees excellent quality of the connection, as well as its protection against corrosion.

How and with what to solder aluminum at home?

Until recently, aluminum was perhaps the most common “electrical” material. Significantly cheaper than copper, it has good electrical properties. That’s why all the wires of high-voltage lines are made from it: light, good conductor, ductile, low-oxidation.

You can solder aluminum. Although wires made of this metal can be easier to connect in other ways: through screw terminal blocks, by welding. Often in junction boxes the aluminum wires were simply twisted tightly. This method was used when apartments usually did not have particularly high energy consumption.

But now, with the saturation of the market with powerful and varied household appliances, it is necessary to bring the entire household power supply network to a quality that would be oriented towards serious energy consumption, approaching industrial consumption. And in this case, it is better to solder aluminum at home than to twist it.

Properties of aluminum as a metal and conductor

Aluminum stands in the periodic table immediately behind sodium and magnesium - active metals, even flammable in air. Therefore, it is a light and very active metal. Its thermal and electrical conductivity is lower than that of copper.

But since aluminum is lighter than copper, products made from it, where precisely these properties are important, with the same mass turn out to be geometrically large in size. And due to convection, heat removal from aluminum parts can be greater than from copper parts.

Aluminum's activity works against soldering, a standard electrical and mechanical joining operation for many metals. Because the activity is such that it immediately oxidizes in air.

Install the bolt

This method has a significant drawback - the enamel cannot be restored in this way. Just the opposite - it will gradually peel off. So this option can be regarded as temporary. If you urgently need to repair a small hole in the bottom and absolutely don’t care what happens to the pan later, you can’t think of a better way. The enamel can then be restored.

How to repair an enamel pan? Very simple. You need:

bolt of suitable size;
drill;
metal drill.

The hole is rarely exactly the right shape. Therefore, first of all, it needs to be brought into relative order:

Take a 3 mm drill (if you have a 2 mm bolt, then you need the same drill).
Drill the hole, giving it the most correct shape possible.
Insert the bolt.
Tighten the nut firmly from the inside.

Important! It’s hardly worth cooking in such a pan, but you can boil water for a long time - as well as use it for other purposes (for example, if it is steel or enameled, you can use it in it, etc.).

Soldering aluminum at home: instructions

There is a widespread belief that it is impossible to solder or tin aluminum (as well as alloys based on it) without special equipment for this.

Two factors are cited as an argument:

upon contact with air, a chemically resistant and refractory oxide film (AL2O3) is formed on the surface of the aluminum part, resulting in an obstacle to the tinning process;
The soldering process is significantly complicated by the fact that aluminum melts at a temperature of 660°C (for alloys this ranges from 500 to 640°C). In addition, the metal loses strength when, during the heating process, its temperature rises to 300°C (for alloys up to 250°C), which can cause a violation of the stability of aluminum structures.

Advantages and disadvantages of metal utensils

At the moment, the selection of dishes on store shelves is surprising, both in color and shape, and in the materials used for production. Of course, many people prefer dishes made of ceramics or glass, but metal is a classic option that is invariably in demand. There is a justification for this, because this material has a number of advantages, namely:

Easy to care for.
Low cost.
Resistant to high temperatures and temperature changes.
Heats up and cools down quickly.

However, metal, like any material, has disadvantages, for example, not in all cases the dishes can be repaired. The following types of metal are used to produce kitchen utensils:

Aluminum.
Stainless steel.
Enameled steel.

Important! Cast iron cookware is also in demand, as it has a number of advantages, however, there is no point in talking about it, since cast iron cookware cannot be repaired.

Why do soldering problems occur?

This metal has many advantages, in particular, lightness and flexibility. In addition, thanks to the oxide film formed on its surface, the metal is practically neutral and does not react with aggressive environments or food products.

However, it is precisely this property of the metal that poses a problem in cases where it is necessary to connect several aluminum parts using soldering.

Aluminum radiator

Most often, aluminum is used as a material for the manufacture of various radiators: heating systems, cooling electronic components, automotive fluids, etc. This use is due to the low heat capacity and high thermal conductivity of the metal.

Despite the fairly low chemical activity, time and temperature take their toll and cracks appear in the housings of aluminum radiators, which are quite problematic to repair.

Microcracks that appear in radiators may not even be visible to the human eye, but they can leak quite a large amount of liquid, which will have to be regularly added to the cooling system.

Repairing the cooling system is quite an expensive undertaking. Often, service centers or auto repair shops, without particularly straining, simply change the entire radiator instead of fixing it by soldering the hole.

Soldering of several elements

You can fix the hole yourself in two ways: by soldering or using cold welding. However, in both cases you will have to face one serious problem.

Aluminum immediately oxidizes in air

When aluminum interacts with air, it immediately oxidizes, and its surface is covered with a thin film of oxide.

The oxide has insulating properties and traditional materials used as solder are not able to not only connect two aluminum surfaces, but even simply “stick” well to the surface that the oxide covers.

This is why soldering aluminum is very, very difficult.

Soldering with a regular soldering iron does not give the desired results. You can even say that it does not give any results, since even when using special fluxes for soldering, instead of an even soldered seam, you regularly end up with an uneven pile of solder, which clearly does not have good contact with any of the soldered surfaces.

Heating the damaged area

If you need to solder a small product, then it is enough to choose a soldering iron with a power of 100 W. If you need to repair larger products, then the heating element should be more powerful - about 300 W. The best option in this case is a gas burner or a blowtorch. If you decide to use a burner, then you should remember some nuances:

do not overheat the part, because it can simply melt - always control the temperature;
Never use oxygen, as it will cause oxidation of the metal.

Special solders

The highest quality connection at home can be obtained using low-melting solders based on tin and copper and special fluxes. The most popular domestic flux is F64, which allows you to solder aluminum parts without mechanical stripping. So, for example, soldering aluminum to copper can be done without problems, or an aluminum tube can be sealed from the inside, which cannot be cleaned by any other means.

In this case, conventional low-melting tin-lead solders with a melting point of 200−350 degrees are used. The soldering iron should be quite powerful - from 100 W and above. The reason is the high thermal conductivity of aluminum. An insufficiently powerful soldering iron simply will not be able to heat the soldering area to the melting temperature of the solder. Only very small parts (mainly in radio electronics) can be connected with a 60 W soldering iron.

A soldering iron is not suitable for soldering large aluminum parts. Here it is better to use any gas burner that provides heating up to 500-600 degrees, and one of the specialized solders. One of the most popular is HTS-2000 - a flux-free solder for soldering aluminum, copper, zinc and even titanium.

Read also: How to desolder an LED from an LED light bulb

It has several advantages:

Low melting point (390 degrees Celsius).
Can be used without flux.
Reliability of the connection (in many cases it can replace argon welding).

True, HTS-2000 does not exclude the stripping process. Moreover, during the soldering process it is necessary to remove the oxide film with a solder rod or a wire brush to ensure a reliable connection. However, this method allows you to perform such work as sealing leaky aluminum containers, for example, cans, or even car aluminum radiators.

In addition, HTS-2000 is practically the only (with the exception of argon) way of joining two “winged” metals: aluminum and titanium.

There are other high temperature solders designed specifically for aluminum soldering. For example, 34A, which contains two-thirds aluminum, as well as copper and silicon. But the melting point of such solders is 500-600 degrees Celsius, which is close to the melting point of aluminum itself.

Therefore, using high-temperature solders at home is dangerous - an aluminum part can be irreparably damaged when heated to such high temperatures.

Soldering aluminum at home is a real way to repair household utensils, household and automobile aluminum radiators, pipes, plumbing fixtures and much more. In industrial conditions, soldering and welding of parts made of this material is carried out using automated equipment. At home, soldering and welding aluminum is also possible.

To do this, use an ordinary soldering iron, ordinary POS-50 and POS-61 solders containing tin. In addition, it is possible to use a magnesium welding stick or use a gas torch.

Once you have chosen your solder, you need to select a soldering flux. The biggest secret when soldering aluminum is to work quickly , connecting the parts to be soldered immediately after they have been cleaned of oxide.

Process Features

The surface of aluminum parts is covered with an oxide film, which has high chemical resistance, as well as a melting point 2 times higher than pure metal. In the range from +250° C to +300° C, aluminum becomes unstable and melts. The minimum melting temperature of the oxide film is +500° C.

When soldering, the parts being connected under the outer layer begin to melt. Therefore, the shareholder needs to eliminate the negative impact of the oxide layer. The principle of all methods is based on film removal, as well as increasing adhesive properties.

Methods for removing the oxide layer:

mechanical - the use of abrasive tools for stripping;
chemical - the use of fluxes with special compositions;
electrochemical - based on electrolysis processes.

Both methods are carried out only in an environment without oxygen.

Welding an aluminum flask

Aluminum and aluminum alloys are widely used in the manufacture of various types of products, in this case, soldiers’ or officers’ flasks and others for milk, for example. Flasks were popular during World War II among soldiers of the Soviet army and the Wehrmacht.

The main advantages of using aluminum is that it is resistant to corrosion, which makes it possible to use it to create durable and high-quality soldier canteens.

often see various food utensils made from aluminum because they have a long service life. In terms of the ratio of strength and fluidity to density, aluminum is significantly superior to cast iron, low-alloy and low-carbon steels. To some extent, their properties are inferior to high-alloy steels of increased strength, as well as titanium alloys, which have greater strength than steel products.

To weld soldiers' and officers' flasks, welding in an inert argon gas environment is used. The work is carried out using a non-consumable electrode, mainly tungsten. During long-term operation, oxide build-ups accumulate on the working surface of the tungsten electrode, which significantly reduce the properties of the electrode and affect the quality of welding.

How to remove oxide film

The film is removed from the metal surface in several ways, the most effective being chemical and mechanical. Both methods require an airless environment in which there is no oxygen to work.

The chemical method is based on the deposition of zinc or copper on the surface of the workpiece by electrolysis. Copper sulfate in the form of a concentrated solution is applied to the area prepared for soldering. The negative terminal of a battery or other power source is attached to a clean area of metal. One end of the copper wire is connected to the positive terminal, the other is dipped into a solution on the surface of the aluminum. As a result of electrolysis, copper or zinc is deposited in a thin layer on the aluminum and adheres tightly to it. Now you can solder aluminum with tin.

An oil film is used to remove the oxide. For this method, it is better to use synthetic or transformer oil with a low water content. Other types of oils need to be kept at a temperature of +150...+200°C, the water will evaporate. At higher temperatures, the contents will begin to splatter. Dehydrated oil is applied to the surface of the aluminum part. Use sandpaper to rub the aluminum under the applied layer to remove the oxide.

The emery cloth is replaced with a scalpel, a serrated soldering iron tip, or iron filings obtained from a nail rubbed with a file. The shavings are poured onto the oil and the soldering iron tip is rubbed over the surface, removing the oxide layer. It is advisable to heat a massive part with a hot air stream. The solder is dipped into the oil droplet with a soldering iron and rubbed over the soldering area. To improve the soldering process, rosin or other flux is added.

For soldering aluminum wires, fluxes based on acetylsalicylic or orthophosphoric acid, boric or sodium salts have been created. Rosin is rarely used; it is ineffective in the case of aluminum. Fluxes are used when soldering wires, pots and other things.

Preparation of products

Mechanical processing is carried out using sandpaper, a metal brush, stainless steel wire mesh or a grinding machine. In addition, various acid solutions are used for cleaning.

Materials used

To complete the work you will need to prepare the following materials:

flux;
solder.

To obtain high-quality seams, you need to use a flux for soldering aluminum based on zinc, silicon, and copper. The joints are strong, durable, resistant to corrosion, static and dynamic loads.

Solders with the following markings are suitable for soldering aluminum:

TsOP-40 - refractory tin-zinc composition;
POS - light alloy solder;
34A - alloy based on copper and silicon;
“Aluminium-13” is a foreign analogue of 34A.

The use of flux improves the adhesion of metal to solder, resulting in a strong connection. The durability of the seam, the strength characteristics of the product, and the resistance of the material to the negative influences of the external environment depend on its choice. Fluxes contain active elements: zinc or ammonium fluoroborate, triethanolamine.

Solder fat comes in the following types:

neutral based on rosin and stearin - it is thick, capable of removing small contaminants, and adheres well to the surface of the metals being welded;
active with a complex chemical composition - effectively removes oxides and traces of corrosion, increases soldering properties.

The fat contains zinc and ammonium chloride, paraffin, and auxiliary substances.

Solder fat has the following advantages:

easy tinning due to spreading in a thin layer;
availability;
dosage accuracy;
no traces after use.

It is recommended to use the following brands of fluxes: F-64, F-61A, F-59A, 34A, F-5, F-124.