How and with what to solder aluminum wires

Methods for soldering aluminum wires

Despite the fact that in modern construction, during electrical work, aluminum cables are increasingly being replaced by copper cables, aluminum remains an indispensable material in the manufacture of large-section wires and cables.

The reasons for this lie on the surface - the electrical resistivity of aluminum is approximately one and a half times greater than that of copper, and the volumetric weight is three times less.

With a large conductor cross-section, when weight is more important than strength, the choice in favor of aluminum is obvious. The cross-sectional area of ​​an aluminum conductor will be one and a half times greater than that of a copper conductor, and at the same time, aluminum will still be two times lighter than copper. Soldering, among other methods, is used to connect wires.

Soldering methods

The problem with using aluminum conductors is their rapid oxidation. The oxide film significantly impedes the passage of electric current during connections. To do this, twisted aluminum wires are soldered.

You can solder aluminum wires in a junction box using a soldering iron or a gas torch. It is more difficult to use a soldering iron due to the inability to accurately heat to the required temperature. And for aluminum, overheating is just as unacceptable as underheating.

Metal has high thermal conductivity, and the insulation over a large area from the soldering point can simply melt.

It is easier to regulate the heating temperature with a gas burner, but it takes a long time to prepare the surface. However, it is the torch that will need to be used if it is necessary to solder any massive parts to each other. In any case, when soldering aluminum wires, they need to be prepared.

Preliminary processing

The difficulty with soldering is that aluminum itself is a very low-melting material (660 ℃) and if heated carelessly it can melt.

Another factor that makes soldering aluminum wires difficult is rapid oxidation in air.

The oxide film on the surface of the material reliably protects aluminum from the effects of all kinds of external factors, but it also prevents the adhesion of solder to the material and must be removed.

It is almost impossible to mechanically remove the oxide film under normal conditions. The material is instantly oxidized and covered with a new film. You can mechanically remove the oxide film under the oil layer.

But before this, the oil must be heated to 200 ℃ in order to remove any active oxygen that may be present there. This method is very inconvenient at home and labor-intensive.

Therefore, the ends of aluminum conductors must be tinned before soldering. Using rosin or most other fluxes will not work due to the high chemical resistance of the oxide film. It does not dissolve even with organic acids.

To tin the wires, you must use both a special flux and a mechanical method.

Of course, this must be done before the wires are twisted, otherwise it will not be possible to mechanically clean the entire surface of the wire. Only the tinned ends can be twisted together and soldered.

Working with a soldering iron

In order to solder aluminum with a soldering iron, there are several methods, the essence of which is to clean immediately under the flux layer in direct contact with the molten solder.

The first method is that aluminum conductors, before soldering, are cleaned with a hot tinned soldering iron using a mixture of rosin and steel filings.

Sawdust has an abrasive effect, rosin removes all impurities and immediately the cleaned areas are covered with solder, which should be on the soldering iron tip.

The second method involves stripping the aluminum wire on medium-grit sandpaper directly under the influence of a hot soldering iron with solder and flux.

Gas burner

Processing with a gas burner is carried out when the parts are in the position relative to each other in which they will be used. The processing smoothly transitions into the soldering process itself.

This happens as follows:

• the burner heats the surfaces of aluminum parts;
• upon reaching the temperature at which the metal is reduced from the oxide, the film is mechanically peeled off;
• under the influence of a flame, the parts are coated with flux, and solder is introduced into the soldering area.

If the parts are thick, then their edges must be cut at an angle of 45°. Typically, heating occurs to the melting point of tin, when the solder spreads and fills the twist groove.

Differences in technology when using flux

Thanks to the achievements of modern science and technology, flux compositions for aluminum have been obtained that actively dissolve the oxide film and protect the material from further oxidation.

Examples of such drugs are formulations labeled F-59A and F-61A. The letter A means that these compounds are intended for soldering aluminum.

When using these fluxes, soldering aluminum wires is greatly facilitated. It is enough to simply treat the finished twist with flux, without even heating it, and then, after heating it with a soldering iron or torch, apply solder.

It will spread over the entire surface of the wires and adhere well, providing a strong and electrically conductive solder joint.

Features of soldering stranded wires

Stranded wires must be soldered only using a special flux, since their mechanical processing is almost impossible. Soldering technology differs in that each wire must first be well treated with flux.

To do this, the bundle will have to be untwisted and fluffed. After processing, each thin wire conductor is covered with solder and the bundle is twisted. After this, twist the two ends and solder it.

Can it be connected to copper?

Situations often arise when it is necessary to connect an aluminum wire to a copper wire. This is perhaps the only case where soldering cannot be used.

It's all about the aluminum itself. It cannot be soldered to other metals at all due to its physical and chemical properties. When connecting directly to copper, galvanic corrosion will occur between the two active metals and will quickly destroy the connection.

And if they are soldered using solder that is neutral to both materials, then the different coefficients of thermal expansion of the metals will quickly destroy the soldered contact. After all, when current passes through a conductor, it will certainly heat up, and after switching off, it will cool down.

Safety precautions

Safety precautions when soldering aluminum wires boil down to observing general precautions when working with electric heating devices, open flames and aggressive liquids, such as fluxes.

It is unacceptable to use faulty soldering irons with damaged insulation and with more power than necessary.

Do not use burners near flammable objects. When working indoors, forced ventilation must be properly organized.

Difficulties in soldering aluminum wires

The main difficulty when soldering aluminum wires, as indicated above, is the presence of an oxide film on the surface of the metal. Fighting it greatly slows down the soldering process.

And if you consider that aluminum wires are now used mainly for laying external power wiring, it becomes obvious that a regular soldering iron and sandpaper will not be enough in this case. Welding is increasingly being used to connect such wires.

Source: https://svaring.com/soldering/praktika/pajka-aljuminievyh-provodov

Soldering aluminum wires: technique, necessary materials and equipment

Every person at least once in his life has encountered a similar problem as a broken wire. Not many people want to make such a trivial request to a workshop, so they prefer to independently master the soldering technique and carry out repairs at home. It is quite possible to carry out this operation. But you need to know some nuances. We will tell you about all the intricacies of the work in our article today.

Sequence of work

Soldering aluminum wires together must be carried out in strict sequence:

• first of all, the surface of the conductors is thoroughly cleaned, since any foreign deposits can make the connection unreliable;
• then all stripped ends are coated with flux, which prevents oxidation of the wires during operation;
• When using a soldering iron, solder is melted, which is subsequently applied in an even, thin layer to the ends of the conductors.
• the wires must be carefully connected using tweezers or temporary twisting;
• to prevent the appearance of rust under the solder, you will additionally need to apply flux to the joint;
• after that, use a soldering iron to melt the solder and distribute it evenly around the joined ends;
• The final step is to thoroughly clean the soldering iron; special attention should be paid to the tip, which is best subsequently treated with inactive flux.

Welding connection

Soldering of copper and aluminum wires is often done using welding. This type of connection ensures reliable and monolithic contact. The work is performed on the ends of the conductors, which must first be stripped and twisted. Recently, inverter welding machines have been used to connect wires in this way.

All connections obtained through welding have excellent mechanical strength, and are also characterized by durability and excellent contact conductivity.

Flux

Soldering of aluminum wires is carried out using flux. This is a kind of mixture that is specially created to improve the quality of conductor connections. Melting of the flux begins before the soldering process, as it directly prepares the surface for joining.

Flux for soldering aluminum wires can be passive or active. The latter is distinguished by the fact that it contains acids and harmful volatile substances, which, immediately before soldering, etch the metal and also remove fat and oxides from it. Passive does not contain acids and acts on contaminants as a solvent. The most popular flux is rosin, which is made from wood resin.

Thanks to fluxes, it became possible to solder metals that would be almost impossible to join without them.

Additional accessories

To ensure that soldering aluminum wires does not lead to property damage, you need to ensure that you have additional devices. The soldering iron must have a stand. It will help protect surrounding objects from high temperatures. For soldering, you will also need to purchase a special pad that will be resistant to the effects of molten flux or solder.

To ensure your convenience while working, it is better to fix all items. To do this, you can use pliers that can be used to press the wire to the soldering site. It is recommended to use a clamp to secure the desoldering.

Process Features

To ensure that soldering aluminum wires with your own hands is done perfectly, experts recommend adhering to certain recommendations. Before you start connecting wires, be sure to check the soldering iron. It should be clean, there should be no shells or irregularities, as well as black deposits. If there are any deviations, then it needs to be cleaned.

To do this, you can use a file. During the operation, you should also pay attention to the condition of the soldering iron. Try to always keep it clean. It is best to start soldering on the side farthest from the insulation. Upon completion of the work, all connections must be insulated. To do this, it is recommended to use polyvinyl chloride or cotton insulation.

Temperature selection

You need to know how to use a soldering iron correctly. First of all, you need to learn how to determine whether the soldering area is hot enough. If you use a regular soldering iron for work, then you need to navigate by the behavior of the flux or rosin. If these components boil and release steam, this indicates a sufficient heating level.

Once the soldering area is properly heated, solder can be added, which can be applied in either liquid or solid form. In order for the connection to be of high quality, it is necessary to closely maintain the temperature and perform all actions carefully. It is not recommended to overheat or use large amounts of solder.

The final stage

To ensure a reliable connection of wires, the entire process must be performed competently and carefully. If the wires were treated with acid fluxes, then after they have cooled, it is necessary to wash off the remaining solder. This can be done using a damp cloth or sponge, which is pre-moistened in a soap solution and then dried a little.

The ability to solder independently in modern life is simply a necessary experience. Now there are many methods for joining different metals. But first of all, you need to have skills in working with a soldering iron. Only in this case can a reliable connection of the wires be ensured.

During the soldering process, all recommendations must be strictly followed, since this process is considered quite complex and does not tolerate errors. This is especially true when choosing a connection method, flux and solder.

Soldering wires with your own hands at home will help you out more than once and help you in repairing any equipment.

Source: https://FB.ru/article/458258/payka-alyuminievyih-provodov-tehnika-vyipolneniya-neobhodimyie-materialyi-i-priboryi

How to solder aluminum: rules and methods for do-it-yourself aluminum soldering

A reliable way to connect wires when laying electrical communications is soldering. Unlike aluminum, copper conductors are easy to tinning. This imposes restrictions on the applicability of materials for electrical installations. But sometimes working with aluminum cannot be avoided. Soldering wires must follow certain rules. But after learning simple tinning methods, you can make the connection yourself.

Soldering aluminum wires

During electrical installation, the metal cores of the cables are connected by soldering. This guarantees reliable contact at the commutation point. However, while it is easy to apply solder to copper wire, coating aluminum conductor is a little more difficult. In addition, it is impossible to directly connect two metals - they form a galvanic couple. When an electric current passes through the twist, it will heat up.

For your information!

When cleaning the core, it is important not to damage the base metal. Notched aluminum can break easily.

The difficulty of soldering lies in the fact that there is an oxide film on the surface of the metal that is difficult to remove. It is formed instantly when aluminum comes into contact with oxygen in the air. This is due to the high chemical activity of the metal. Without the protective film, it would completely react with oxygen. To ensure that the solder evenly covers the wire and holds tightly to it, its surface is cleaned by etching with fluxes or without access to air.

Required materials and tools

For tinning, first of all you will need a soldering iron. For work, take a device with a power of about 60 W. Soldering is carried out in a well-ventilated area: when the flux is heated, toxic fumes are formed. It is advisable to equip the workplace with a hood. In addition, you should prepare the following:

1. Flux, soldering acid or rosin. The latter is diluted with alcohol in a ratio of 3:2.
2. Sharp knife.
3. Pliers, side cutters.
4. Fine grit sandpaper.
5. Electrical tape or heat shrink tubing.

Submerged Soldering

To remove the oxide film from the surface of aluminum, various fluxes are used (F-59A, FTBF-A, F-61A). The use of a certain composition depends on the characteristics of the metal and its further purpose. Soldering sequence:

1. Clean the core from insulation at a distance of 5 cm from the edge. In this case, the knife is held at an angle so as not to damage the core.
2. The metal surface is cleaned with fine sandpaper.
3. Cover the core with flux using a brush.
4. Clean the metal again with a knife.
5. The wire is tinned with a heated soldering iron.

Important!

Solder is applied from the end of the wire to avoid damage to the insulation.

During tinning, the soldering iron is moved back and forth along the wire, clearing the film from the aluminum surface. It will not be possible to coat the core evenly with solder the first time. The procedure is repeated for open areas. After obtaining the desired result, the end of the wire is washed with an aqueous solution of soda (5 tablespoons per 200 ml of liquid) to neutralize active acids. Flux residue under the insulation or solder will corrode the aluminum over time. As a result, the joint will heat up and char.

Tin and rosin

According to the operating rules for electrical installations, soldering of aluminum wires with acids is prohibited. This is due to the fact that the active substances cannot be completely removed. They react with the metal, destroying it. A seemingly reliable connection may break during operation.

Note!

To avoid possible breakage, aluminum is tinned using rosin dissolved in alcohol. However, this method cannot be used in hard-to-reach places.

The liquid mixture is prepared in a shallow metal bath. The viscosity should provide good coverage of the conductor. The depth of the container depends on the diameter of the core.

Tinning sequence:

1. The wire, stripped of insulation, is placed at the bottom of the bath. Pour in liquid rosin. The latter should exceed the metal by 5-8 mm.
2. Using a sharp knife directly in the liquid, scrape off the protective film from all sides of the core. Without air access in the rosin solution, the metal does not oxidize.
3. With a heated soldering iron they begin to tin the wire. The point of contact of the tip with the metal should be in the liquid at a distance of 2-3 mm from its surface. The core is covered around the circumference with gradual pulling out of the wire. When in contact with liquid, the tip will cool greatly. It is necessary to make stops to warm up the soldering iron.

Important!

Tinning in a solution of rosin with alcohol is associated with a lot of smoke - the procedure is performed outdoors or in a well-ventilated area.

When installing electrical wiring, soldering aluminum conductors will not cause any difficulties. To ensure reliable contact, it is enough to tin the metal surface using various fluxes or rosin.

Source: https://VGrafike.ru/pajka-aljuminievyh-provodov-slozhnosti-i-hitrosti/

How to solder aluminum to aluminum

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:

1. 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;
2. 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.

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

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

Source: https://moy-instrument.ru/masteru/kak-spayat-alyuminij-s-alyuminiem.html