How to solder

How to solder correctly. Equipment and tools. Soldering Tips

How to solder correctly - the method of forming a permanent connection by introducing molten solder into the contact area is called soldering. In this case, the melting temperature of the solder should be lower than that of the parts being connected. To learn how to solder correctly, it is necessary, in addition to theory, to master this technology practically.

Soldering irons

Electric soldering irons produce voltages up to 220 volts. It is difficult to make a high-voltage heating element with a weak soldering iron, because a lot of thin conductor is required. This will lead to an increase in the size of the soldering iron and will compromise electrical safety.

The power of the soldering iron is selected taking into account the size of the parts. The larger the parts being connected, the more powerful the soldering iron should be.

The required temperature of the soldering iron core can be maintained either automatically or manually. For such purposes, thyristor-based regulators are used.

To increase the service life of the soldering iron, the tip of the tip is forged. Then copper acquires properties in which it is less susceptible to dissolution in solder. The tip is sharpened with a file to give it a special shape: cut or angular. The end of the tip in the form of a knife is made for soldering several contacts of parts at once.


The workplace must be equipped with a tool before the parts can be soldered correctly.


A heated soldering iron is usually placed on a stand, which serves as a location for the flux, as well as a working platform for soldering. A clamp with a piece of foam rubber is attached to the stand to clean the soldering iron tip.


It consists of clamps that move in height and angle, as well as a soldering iron holder and rosin.

Handy tools

They are necessary to support parts, clean the surface, and give a certain shape to the wire. Such tools are usually pliers, tweezers, pliers, wire cutters, a knife, etc.

Soldering Tips

  • Application of materials. One of the materials used for soldering is tin. However, its melting point does not exceed 230 degrees. When installing radio components that are small in size, they fail due to overheating. Solder, composed of tin and lead, melts at a temperature of 180 degrees and is also cheaper. The quality of the connection is not inferior to tin soldering. In general, pure tin is rarely used. When installing radio components, POS-61 solder is used. The number is the percentage of tin content. To remove traces of oxides at the soldering site, fluxes are used. In tinsmithing, acids are used for such purposes. But they are not suitable for electrical connections. Here we need fluxes that are neutral to the contacts. Let's figure out how to properly solder using rosin to protect against oxidation.

Rosin-based flux is passive. It protects the liquid solder from air during soldering, preventing the formation of oxides. However, it does not remove them from the surface. It is convenient to solder with solder in the form of a tube, inside of which there is rosin.

In places with difficult accessibility, a solution of rosin in alcohol is used.

  • The core (tip) of the soldering iron must be cleaned and coated with solder in order to avoid the formation of oxide deposits, which interfere with operation.
  • Soldering surfaces must be cleaned and tinned for a good soldering connection.
  • The soldering areas are first heated with a soldering iron, then connected and soldered.

How to solder correctly with a soldering iron

  • The soldering surfaces are cleaned with sandpaper and degreased with gasoline or acetone.
  • The soldering iron tip is cleaned with a file, sandpaper and other tools to remove oxides and carbon deposits.
  • The soldering iron is heated, dipped in rosin, and tinned. To properly tin the tip, take a wooden block and rub the solder on the tip. The surface of the working area should turn silver.
  • Warming up the solder. A particle the size of a drop of solder is applied with a soldering iron to the surfaces to be joined and leveled. If necessary, more solder is added to completely cover the joint. The contact between the core and the wire is assumed to be maximum. Rosin must be present on the solder to avoid the formation of oxides. It is recommended to do soldering in one step, since after several touching times the solder oxidizes due to the evaporation of rosin. While the solder is cooling, the parts cannot be moved, as cracks will form, which will reduce the strength and quality of the connection.
  • The remaining rosin is removed with alcohol and a brush.

Soldering conductors

Now let's figure out how to solder the wires correctly. The ends of the wire for connection are stripped of insulation and heated. The size of the core must be selected according to the size of the parts. If the core is too large, then the parts nearby will overheat when soldering. If it is too small, the soldering will be poor quality.

It is better to remove the wire insulation with a knife or wire cutters. If the wires are multi-core, then the wires are twisted and then tinned. To do this, the stripped end of the wire is dipped into a container with rosin, a drop of solder is applied to the copper wires and passed several times. In this case, the wire is rotated to cover it with solder on all sides.

The wires are twisted to form a common axis. One conductor is twisted along the other. Rosin is applied to the joint to be joined, followed by solder. The connection is warmed up for 3 seconds.

If there is not enough solder, you need to add it. Sometimes it is not clear why a powerful soldering iron does not warm up the contact, and how to solder. Heat comes from bottom to top. The twist needs to be heated from below. When the heating is sufficient, the solder spreads evenly, and when there is little heat, the result is loose solder.

After soldering, heat shrink is placed on the contact to create insulation. You can heat the heat shrink with a lighter.

Copper and aluminum wires must not be twisted together. To connect them, an intermediate structure is used in the form of a terminal clamp, a bolted connection, or a layer of another metal. There is a solder for aluminum that is combined with copper wire and is used to solder them.

How to solder radio components correctly

Soldering of radio components is carried out by preliminary twisting, or overlapping, using a heat sink. Many parts of radio elements are afraid of strong heating above 70 degrees.

On the circuit board, the hole for attaching the part is covered with solder. Next, the rosin-coated and tinned end of the part is inserted into this hole, heated and moistened with solder. In this case, the tip should touch the board and the part simultaneously. Excess solder is removed with copper braiding. If all solder points look the same, then the soldering is done well.

A soldering iron without solder cannot be kept hot for a long time and cannot be overheated. Oxides are formed, and again it will be necessary to clean and tinning the tip. There should always be rosin on the heated core of the soldering iron. And if the breaks between soldering are long enough, then it is recommended to turn off the soldering iron. Oxidized unnecessary solder is removed from the core with a sponge.

Some elements and parts of circuits fail under the influence of static electricity. To prevent this from happening, the body of the soldering iron must be connected to ground.

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Learning to solder wires - consideration of all the nuances of soldering

Soldering wires with a soldering iron is not difficult, so even an inexperienced electrician can handle this method of connecting copper wires. Next, we will tell you how to properly solder wires in a distribution box - the place where electrical wiring is carried out in rooms.

The technology will be provided step by step, with pictures and video examples, so that you can more clearly understand how to solder two wires together. We immediately draw your attention to the fact that we will tell you how to solder copper wires. This is due to the fact that aluminum conductors are practically no longer used at home.

GOST standards recommend avoiding the connection of different non-ferrous metals (aluminum and copper conductors), so the only safe option for a private house and apartment is to solder the copper cable cores.

Step 1 – Prepare the tool

First, you need to prepare a soldering iron for soldering wires with your own hands. All that is required is to thoroughly clean the tip from solder residues or other possible contaminants.

For this you can use a regular file. In addition, you must prepare solder and flux, without which you will not be able to solder wires with a soldering iron. As for solder, in order to solder the wires, you can use either an alloy of tin and lead, or a special thread, as shown in the photo below.

Flux is necessary so that during soldering the solder evenly covers the materials being soldered. In addition, flux removes the oxide film from copper conductors, which significantly impairs the reliability of the connection. As a flux, you can use either rosin or special soldering acid. Both options are popular among craftsmen.

Another important stage of preparation is creating a suitable workplace. You should have an outlet and a stand for a soldering iron nearby so that the technology of soldering wires with your own hands is safe.

By the way, you can make a soldering iron with your own hands, which will not take much time and effort. A homemade device will serve you for quite a long time, as you can see for yourself!

Step 2 – Tinning

So, if you need to solder two power wires together, then first of all you must remove the polyethylene insulation and tin the exposed wires, especially if they are very thin.

Before soldering, the stranded conductor is first twisted and then treated with flux, on top of which a thin layer of heated solder is applied.

Before soldering, be sure to prepare the tip of the soldering iron - dip it in flux (in the same rosin as shown in the photo), and then in tin so that the tip is covered with a small layer of solder.

Tinning wires for soldering is quite simple - first you must place the bare wire on the rosin, then heat this place with a soldering iron so that the wires are immersed in the flux. After this, you need to take it out and treat it evenly on all sides with solder.

To properly apply the heated tin-lead alloy to the surface, twist the wire in your hands while tinning. If you need to connect the wires in a junction box, for convenience, you can use acid instead of rosin.

It is enough to simply apply it with a brush to the surface that you need to solder.

If the conductors have a large cross-section (thick), tinning is performed in a similar way. The only difference is that you do not need to pre-twist the cores, like a stranded conductor.

After you have completed the tinning, you can move on to the soldering process. We immediately draw your attention to the fact that it is necessary to carry out work only when the electricity is turned off. Soldering live wires is strictly prohibited!

Step 3 – Solder the wires

Well, the last thing left is to solder the two prepared wires in the junction box. All you need to do is twist or overlap the wires and heat the joint with a soldering iron. The solder will melt and after it hardens, it will reliably connect the electrical conductors. We discussed tips for connecting wires by soldering in a junction box separately.

An important point - do not move the wires during soldering, otherwise the connection will not be reliable enough.

It should also be noted that preliminary tinning does not need to be done, but simply twist the wires together in a junction box, treat them with flux and solder them properly. However, we do not recommend you soldering this way, because in this case the connection will be much worse.


How to solder correctly with a soldering iron and rosin

Knowledge of how to solder correctly is needed not only by radio amateurs and electrical installation specialists. Every home handyman has to deal with the need for soldering when repairing electrical appliances.

Preparing the soldering iron for use

Before soldering with a soldering iron, you should properly prepare it for work. In everyday life, an electric soldering iron with a copper tip is most often used, which, during storage and use, gradually becomes covered with a layer of oxide and is subject to mechanical damage. To obtain a solder joint of good quality, the soldering iron is prepared for use in the following sequence:

  1. Using a finely cut file, clean the working part of the tip to a length of 1 cm from the edge. After cleaning, the tool should acquire a reddish color, characteristic of copper, and a metallic luster. During stripping, the tip is given a wedge-shaped, beveled, cone-shaped shape in order to solder what the master needs.
  2. Plug in the soldering iron and heat it to operating temperature.
  3. The tip must be tinned and covered with a thin layer of tin - the same solder used to solder the connected conductors. To do this, the tip of the tool is immersed in rosin, and then a piece of solder is passed along it. You should not use a solder rod with rosin inside for tinning a soldering iron. To distribute the solder evenly, rub the working edges against a metal surface.

During operation, the half-plate will burn and wear off, so the soldering iron will have to be cleaned and tinned several times during the soldering process. You can clean the tip with a piece of sandpaper.

If the master uses a tool with a nickel-plated, non-burnable rod, it will have to be cleaned with a special sponge or damp cloth. They tin such a sting in molten rosin, running a piece of solder over it.

Soldering can only be learned on the job, but before that it is advisable to become familiar with the basic operations.

Fluxing or tinning

The traditional and most affordable flux is rosin. If desired, you can solder with a solid substance or its alcohol solution (SKF, Rosin-gel, etc.), as well as TAGS flux.

The legs of radio components or chips are covered with half-milk at the factory. But to get rid of oxides, you can tin them again before installation, lubricating them with liquid flux and covering them with an even layer of molten solder.

Before processing with flux or tinning, copper wire is cleaned with fine emery cloth. This removes the oxide layer or enamel insulation. Liquid flux is applied with a brush, and then the soldering area is heated with a soldering iron and covered with a thin layer of tin. Tinning in solid rosin is done as follows:

  • melt a piece of the substance on a stand and heat the conductor in it;
  • feed the solder rod and distribute the molten metal evenly over the wire.

Correctly soldering massive copper, bronze or steel parts should be done using active fluxes that contain acids (F-34A, Glycerin-hydrazine, etc.). They will help create an even layer of poluda and firmly connect parts of large objects. Tin is applied to large surfaces with a soldering iron, spreading solder evenly over them. After working with active flux, acid residues should be neutralized with an alkaline solution (for example, soda).

Preheating and temperature selection

It is difficult for beginners to determine at what temperature the tool can start working. The degree of heating should be selected depending on the type of material:

  • soldering microcircuits requires heating no higher than +250°C, otherwise the parts may be damaged;
  • large individual radio components can withstand heating up to +300°C;
  • Tinning and joining of copper wire can occur at +400°C or slightly lower;
  • massive parts can be heated at the maximum power of the soldering iron (about +400°C).

Many models of instruments have a thermostat, and it is easy to determine the degree of heating. But in the absence of a sensor, it is worth keeping in mind that a household soldering iron can be heated to a maximum of +350 +400°C. You can start working with the tool if the rosin and solder melt within 1-2 seconds. Most POS grade solders have a melting point of about +250°C.

Even an experienced craftsman will not be able to solder correctly with a soldering iron that is not heated enough. With low heat, the solder structure becomes spongy or granular after solidification. Soldering does not have sufficient strength and does not ensure good contact between the parts, and such work is considered a defect.

Working with solder

When heated sufficiently, the molten solder should become flowable. For small jobs, you can take a drop of alloy on the tip of the tool and transfer it to the parts to be joined. But it is more convenient to use thin wire (rod) of different sections. Often inside the wire there is a layer of rosin, which helps to solder correctly with a soldering iron without distraction from the process.

With this method, a hot tool heats the surface of the connected conductors or parts. The end of the solder rod is brought to the tip and pushed a little (1-3 mm) under it. The metal instantly melts, after which the remainder of the rod is removed, and the solder is heated with a soldering iron until it acquires a bright shine.

When working with radio components, you need to take into account that heating is dangerous for them. All operations are performed within 1-2 seconds.

When soldering connections of single-core wires of large cross-section, you can use a thick rod. When the tool is heated sufficiently, it also melts quickly, but you can distribute it over the surfaces to be soldered more slowly, trying to fill all the grooves of the twist.

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What and how to solder microcircuits

Modern radio-electronic devices cannot be imagined without microcircuits - complex parts into which, in fact, dozens, or even hundreds of simple, elementary components are integrated.

Microchips make devices light and compact. You have to pay for this with the convenience and ease of installation and the rather high price of the parts. The price of a microcircuit does not play an important role in determining the overall price of the product in which it is used.

If such a part is damaged during installation, when replacing it with a new one, the cost may increase significantly. It is not difficult to solder a thick wire, a large resistor or a capacitor, all you need is basic soldering skills.

The microcircuit must be soldered in a completely different way.

To avoid annoying misunderstandings, when soldering microcircuits it is necessary to use certain tools and follow certain rules based on extensive experience and knowledge.

Soldering equipment

To solder microcircuits, you can use various soldering equipment, ranging from the simplest soldering iron to complex devices and soldering stations using infrared radiation.

A soldering iron for soldering microcircuits should be low-power, preferably designed for a supply voltage of 12 V. The tip of such a soldering iron should be sharply sharpened to a cone and well tinned.

To desolder microcircuits, a vacuum desoldering pump can be used - a tool that allows you to remove solder from the legs on the board one by one. This tool is similar to a syringe in which the piston is spring-loaded upward. Before starting work, it is pressed into the body and fixed, and when necessary, it is released by pressing a button and rises under the action of a spring, collecting solder from the contact.

A hot-air station is considered a more advanced equipment, which allows both dismantling of microcircuits and soldering with hot air. This station has in its arsenal a hairdryer with adjustable air flow temperature.

A piece of equipment such as a heat table is very popular when soldering microcircuits. It heats the board from below, while installation or dismantling is carried out from above. Optionally, the heating table can be equipped with top heating.

On an industrial scale, soldering of microcircuits is carried out by special machines using infrared radiation. In this case, the circuit is preheated, soldered directly, and the contacts of the legs are cooled step by step.

At home

Soldering microcircuits at home may be required to repair complex household appliances and computer motherboards.

As a rule, to solder the legs of the microcircuit, use a soldering iron or soldering gun.

Working with a soldering iron is carried out using regular solder or solder paste.

Recently, lead-free solder with a higher melting point has become increasingly used for soldering. This is necessary to reduce the harmful effects of lead on the body.

What equipment will be required?

To solder microcircuits, in addition to the soldering equipment itself, you will need some other equipment.

If the microcircuit is new and made in a BGA package, then the solder is already applied to the legs in the form of small balls. Hence the name - Ball Grid Array, which means an array of balls. These enclosures are designed for surface mounting. This means that the part is installed on the board, and each leg is soldered to the contact pads with a quick, precise action.

If the microcircuit has already been used in another device and is used as used spare parts, it is necessary to perform a reballing. Reballing is the process of restoring the solder balls on the legs. Sometimes it is also used in the case of a blade - loss of contact of the legs with the contact patches.

To carry out reballing, you will need a stencil - a plate of refractory material with holes located in accordance with the location of the microcircuit pins. There are ready-made universal stencils for several of the most common types of microcircuits.

Solder paste and flux

For proper soldering of microcircuits, certain conditions must be met. If the work is carried out with a soldering iron, then its tip should be well tinned.

For this, flux is used - a substance that dissolves the oxide film and protects the tip from oxidation before being coated with solder during soldering of the microcircuit.

The most common flux is pine rosin in a solid, crystalline form. But to solder a microcircuit, such a flux is not suitable. Its legs and contact spots are treated with liquid flux. You can make it yourself by dissolving rosin in alcohol or acid, or you can buy it ready-made.

In this case, it is more convenient to use solder in the form of filler wire. Sometimes it may contain powdered rosin flux inside. You can purchase a ready-made soldering kit for soldering microcircuits, which includes rosin, liquid flux with a brush, and several types of solder.

When reballing, solder paste is used, which is a base of viscous material that contains tiny balls of solder and flux. This paste is applied in a thin layer to the legs of the microcircuit from the back of the stencil. After this, the paste is heated with a hairdryer or infrared soldering iron until the solder and rosin melt. After hardening, they form balls on the legs of the microcircuit.

Work order

Before starting work, it is necessary to prepare all tools, materials and devices so that they are at hand.

When installing or dismantling, the board can be placed on a thermal table. If a soldering gun is used for dismantling, then to prevent its impact on other components, you need to isolate them. This can be done by installing plates made of refractory material, for example, strips cut from old circuit boards that have become unusable.

When using a desoldering pump for dismantling, the process is more accurate, but takes longer. The desoldering pump “charges” as it cleans each leg. As it fills with pieces of solidified solder, it needs to be cleaned.

There are several soldering rules that must be followed:

  • Soldering the microcircuits on the board must be done quickly so as not to overheat the sensitive part;
  • You can hold each leg with tweezers during soldering to provide additional heat removal from the body;
  • When installing using a hair dryer or infrared soldering iron, you must monitor the temperature of the part so that it does not rise above 240-280 °C.

Electronic parts are very sensitive to static electricity. Therefore, when assembling, it is better to use an antistatic mat that is placed under the board.

Why dry chips?

Chips are microcircuits housed in BGA packages. The name, apparently, came from an abbreviation that meant “Numerical Integrated Processor”.

Based on experience, professionals have a strong opinion that during storage, transportation, and shipment, chips absorb moisture and during soldering, it increases in volume and destroys the part.

The effect of moisture on the chip can be seen if the latter is heated. Blisters and bubbles will form on its surface long before the temperature rises to a value sufficient to melt the solder. One can only imagine what is happening inside the part.

To avoid the undesirable consequences of moisture in the chip body, when installing boards, the chips are dried before soldering. This procedure helps remove moisture from the case.

Drying rules

Drying of chips must be carried out observing temperature conditions and duration. New chips that were purchased in a store, from a warehouse, or sent by mail are recommended to be dried for at least 24 hours at a temperature of 125 °C. For this you can use special drying ovens. You can dry the chip by placing it on a hot plate.

The drying temperature must be controlled to prevent overheating and failure of the part.

If the chips were dried and stored under normal room conditions before installation, it is enough to dry them for 8-10 hours.

Considering the cost of the parts, it is obviously better to dry them in order to proceed with installation with confidence, than to try to solder an undried chip. Troubles can result not only in wasted money, but also in lost time.


Types and technologies of soldering

Soldering is a permanent connection of materials, used in some cases as the main method after welding. Types and features of soldering, step-by-step instructions for carrying out the basic methods of soldering and tinning - this is the necessary information when doing the work yourself.

There are a lot of methods for soldering materials (welding, soldering, joining in a gas chamber and in a special oven, soldering pipes), but all this is just soldering of materials, not welding.

Types and features of this method

The process is divided into the following categories:

– a method of heating and filling the molten solder of the seam at the joint;

– characteristics of hardening and crystal lattice of a seam or surface coating during tinning;

– method of removing oxide film from the surface;

– a method with improved time characteristics for heating the joint;

– type of loads on the parts being connected.

The main importance when choosing a welding method is the melting temperature characteristics of different types of solders. Solder melts at temperatures up to 4600 - the process is called low-temperature. Above this heating value – high temperature.

The simplest is low-temperature using flux. Its energy consumption is low, the ability to connect thin parts made of steel and alloys, an increased level of thermal conductivity and soldering of metals of different compositions are the main advantages of this type.

High-temperature soldering has some advantages:

  • Under flux, the connection is sealed, with a dense base of the seam.
  • For work at home, small gas burners are used.
  • The connection is obtained only on materials with a melting point above 460 degrees.

Another type is the compositional method.

Used when installing metal structures with large bending angles. By using composite solder with fillers made from low-melting additives, a strong and reliable connection of structural components is achieved. At the same time, the edges of the workpieces only heat up, and the molten solder fills all the voids and connects the parts.

They are divided according to the methods of solder production. Here it is generally accepted that solder can be ready-made (tin) and obtained through a chemical reaction when heating the soldering materials. The most commonly used is ready-made solder. It is heated to a liquid state, it fills the joints of the parts and, when cooled, makes the connection permanent and reliable. It is held on the surface of the parts by capillarity, which guarantees a sufficient level of strength at the joint.

When a chemical reaction is used, solder and flux are released from the soldering materials. In this case, solder liquid is formed. It fills the seam between the parts, cools down and does its job.

To obtain good joining quality, the heat source used to melt the solder and carry out the soldering reaction is of great importance. The most famous and accessible to everyone is a soldering iron. The use of gas burners and industrial hair dryers is often required.

For the low-temperature method, various soldering irons are most often used. With this method, by heating the surface of the soldering area, remove part of the solder with the tip of the tool and fill the hole or edges of the surfaces to be joined in the molten state. To obtain a more reliable, hermetically sealed connection, be sure to heat the soldering areas.

For the high-temperature method, you can use high-power electric soldering irons. But it is better to use gas and other types of burners for this type. A blowtorch using gasoline, kerosene, as well as burners using methane or propane-butane - these tools will allow you to perform high-quality soldering even in the field.

After a short lesson in theory, we move on to the practical lesson. Soldering microcircuits and making circuit boards for radio equipment will always allow you to have a well-paid job, and the ability to solder will also come in handy for the household. Therefore, we will consider this type of soldering in more detail.

Step-by-step instructions for soldering with an electric soldering iron

Carrying out this work involves performing several operations:

Before you start working with different materials and thicknesses, you should select the right soldering iron based on power, tip size and shape.

The choice of this tool is quite large. From large copper soldering irons, heated by a torch or in a forge, to miniature soldering irons for soldering microcircuits and other parts. But the best choice for our business is a small, lightweight and reliable acoustic soldering iron.

The power should not exceed 35 W, but should not be less than 20 W. This choice will allow you to make a connection of guaranteed quality. A device with grounding will comply with TB requirements.

To carry out soldering of sheet metal and copper pipes, it is better to use industrial powerful types of tools.

  • The next job will be to prepare a set of tools.

The work may require:

– soldering iron;

– pliers and side cutters;

– knife for cutting wires;

– round and flat needle files;

– sandpaper for cleaning the soldering area;

– rosin and other types of fluxes;

– various types of solders.

  • We are making final preparations. To do this, we perform the following work:
  1. We prepare the tip of the sting. To do this, we clean its surface using a flat needle file or a velvet file. Before doing this, you can use pliers to remove large deposits of solder.

If the tip of the tip is damaged, it should be ground off, keeping the angle of the edges at 450. After this, it needs to be tinned, for which we first dip the heated soldering iron into rosin, then pick up a little solder, distributing it evenly over the entire plane of the tip edges.

  1. We prepare a stand for the equipment; for better fixation, you can prepare clamps to secure the parts. We cover the work table with a sheet of textolite or other heat-insulating material.
  2. Cleaning and degreasing of surfaces for pre-tinning and soldering. To do this, first remove the oxidized areas with sandpaper, then wipe these areas with solvent or soldering acid. We wipe the surface with a clean rag and the preparatory work is completed.
  • Performing work on soldering and tinning of wires and radio parts. This procedure is carried out in several stages:
  1. We install the soldering iron on the safety stand. Then we plug it into the outlet.
  2. After a short period of time, dip the tip of the soldering iron into rosin to check the level of heating of the tip. In the case of boiling and melting of rosin, heating can be considered sufficient.
  3. We tin the surfaces to be joined. To do this, first dip the tip in rosin or treat it with soldering acid, then take a little solder on the tip and apply it to the surface of the part.
  4. It should be noted that the quality and correct choice of solder is of great importance in the work. The most used brand is POS. - 60 or 40. This is an alloy of lead and tin. Manufactured in the form of rods up to 3 mm in diameter.

To work with aluminum, use solder made from this material. For each type of solder, protective respirators and goggles should be used. Lead vapors have a detrimental effect on human health. The premises must have good ventilation.

  1. We press the joints that have not yet cooled down to each other to obtain the boundaries of applying the tin layer. Then we apply tin several times along the printed joints of the parts. After applying a sufficient layer, we connect the parts according to the marks, fasten them until the solder has completely hardened and cooled.

Soldering wires

To connect the wires, the same algorithm for carrying out the work is used. But with minor differences. First we tin the stripped ends, then we connect and twist them together. Then we solder the connection point. To do this, we bring solder to the wire with our left hand, and with a soldering iron with our right hand, remove it and apply a little solder to the heated wires.

To connect one wire to the middle of another, you need to remove the insulation at the junction and tin it. We strip the end of 2 wires of insulation and process it. Then we wind it and compress it on the prepared area. After that we solder this place. By performing this operation, you can be able to solder copper pipes and car radiators, connect different pieces of wires for equipment and electrical appliances.

Soldering radio components onto boards

Before working in critical areas, it is better to practice on used boards and soldering non-working parts. But such training should be carried out in several main stages:

  • We are carrying out preparatory work. We clean it with fine sandpaper and wipe the board with solvent. To protect the bridges on the board, it is better to wipe it with a soapy solution.
  • We arrange the parts according to the diagram. First, resistors and varistors should be mounted and secured. Then capacitors, transformers, and wire taps for measuring instruments are soldered.
  • First, we heat the fastening site, insert the antennae of the parts or wires into the holes and bring tin from the back side and drip it onto the soldering site. It turns out to be a drop of metal on the board, holding the part and ensuring good contact.
  • Use side cutters to remove excess solder metal and remnants of wiring. This operation is best carried out on cooled drops.

Having understood the principle of soldering wires and radio components, you can perform more complex types of this permanent connection. Using your skills, you can master the installation of heating and water supply systems for apartments and houses. The difference between this method is the absence of solder. Otherwise there are no differences.

Only the soldering iron itself and some accessories differ. Guides for the outer part of the pipe and the inner part of the fitting are installed at the fastening points. The heated sections are inserted into each other; when they cool down, they form an excellent hermetic connection. To better master this type of soldering, it is better to watch a video tutorial from a professional by following the link.

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In conclusion, it is worth recalling measures to ensure the safety of the respiratory tract and eyes when soldering. Using lead solders, you can get sick if you do not use respirators, gloves and glasses.

This method allows you to achieve excellent results when carrying out apartment heating using a heated floor system, soldering car radiators and plastic car components.

Any man who has at least a little understanding and knowledge of how to carry out work and use the acquired knowledge in practice can learn soldering.


How to learn to solder: step-by-step instructions, features and recommendations from professionals

A soldering iron is considered one of the most common tools that can be found in any owner’s home. It is not necessary to be a specialist and do soldering professionally. But every representative of the stronger sex must have general fundamental knowledge. Breaks in wires in electrical appliances, contacts in sockets, headphones, repairing circuit boards are frequent phenomena, when faced with which a person wants to learn how to learn to solder.

What is a soldering iron?

This is a special heat-emitting device with a power of 15 to 40 W, sufficient for soldering wires, circuit boards and microcircuits. There are soldering irons with higher power.

They are intended for small soldering - for resoldering poorly connected thick-diameter wires or for unsoldering XLR connectors.

The function of the heating element in soldering irons is performed by a nichrome wire, which is wound around a tube containing a “tip” - the working surface of the device. The tip is a copper rod that is heated by a nichrome wire.

The soldering iron uses copper because this metal has high thermal conductivity. Heat is supplied to the wire by electric current. The soldering iron device contains an insulator, which is mica. For safety reasons, it prevents the wires from contacting the metal tube and soldering iron casing.

Learning to solder correctly is easy, but only if you choose the right tool. Among the wide variety of these devices, an amateur craftsman who decides to start repairing office equipment should choose an acoustic soldering iron, which is small in size and has good performance. It has a low heat capacity, which is desirable for fine soldering work when assembling microcircuits.

It is better for a novice master to opt for a device whose power does not exceed 40 W. It is important that the soldering iron is also not weaker than 15 W, since the power in such a product will not be enough even to connect simple wires of office equipment. It is preferable to buy a tool with a three-way grounding plug.

Its presence will prevent possible voltage dissipation during the movement of electric current to the metal tube.

An industrial soldering iron is suitable for connecting calibration wires, chassis and stained glass work.

Which sting is better?

The working parts of soldering irons, depending on the size, are of two types:

  • ordinary, the diameter of which is 0.5 cm;
  • miniature with a diameter of 0.2 cm, used for soldering very thin wires and copper parts.

The working parts of soldering irons can have the shape of a needle, cone and blade. The last form is the most common, as it makes it possible to scoop out the required amount of solder. In addition, for ease of soldering, the tip can be straight or curved.

The soldering procedure involves joining two metal elements using a third one (solder). In this case, the melting temperature of the connected parts must be higher than that of the third element, which, in the molten state, penetrates into the spaces of the connected parts, as well as into their structure, providing a mechanical connection. At the same time, an electrical contact appears between the parts being connected.

What do you need for work?

The soldering procedure is not complicated. The question of how to learn to solder from scratch is easily resolved. To do this, just acquire the necessary material and, following the instructions, start training.

Where can I learn to solder?

You can train at home by soldering ordinary electrical wires. The main thing is to follow the safety instructions.

The work may require:

  • soldering iron (according to professionals, to work with small wires in electronics and radio engineering, a tool with a power of 20-40 W will be sufficient);
  • pliers;
  • knife;
  • scissors;
  • set of files;
  • sandpaper;
  • insulating tape;
  • rosin;
  • solder.

The question “how to learn to solder” will be resolved after several training sessions. The beginner will gain confidence and experience. Step-by-step soldering instructions can help him with this.

Where to begin?

  • Preparing the sting. To do this, using pliers and needle files, you need to clean the working part of the soldering iron. The tip should have an angle of 30-45 degrees. If the tip is damaged, it must be sharpened again to the required shape. After this, the tip is tinning - the heated soldering iron should be dipped first in rosin, and then in solder.
  • For safety reasons, it is necessary to prepare a pad for the soldering iron. This is due to the fact that the device heats up to a temperature of more than 300 degrees and operates under high electrical voltage. It is important to optimize your workplace when using a soldering iron. It is advisable that a piece of textolite or plywood be used as a lining. Special trays for solder and rosin are also required.
  • Cleaning the surfaces of metals to be joined under solder. To do this you will need sandpaper, solvent or soldering acid. It is important that there are no remaining oils, greases or other contaminants on the surfaces on which solder will be applied.

Sequence of work

How to learn to solder correctly will become clear if you follow the step-by-step instructions. Necessary:

  • Place the soldering iron on the stand and plug it into the mains.
  • Dip in rosin. This is done 5-7 minutes after connecting to the outlet. The purpose of this procedure is to check the heating temperature of the tip and get rid of scale. The soldering iron is considered ready for use if the rosin boils and melts. If it only softens, then the sting is not warmed up enough. When the soldering iron overheats, the rosin hisses and spatters. In this case, the device needs to cool down a little.
  • Treat surfaces with tinning. The joints of metal products are covered with molten solder.
  • Press the tinned surfaces together. Apply a new portion of solder in the places where they are combined with a soldering iron. The joined parts must be pressed until the solder cools and hardens.

Solder Use

Successful soldering is possible with skillful selection of the necessary solder - an alloy of tin and lead. The most common types of solder are POS-40 and POS-60. They are characterized by a low melting point (183 degrees) and are used in most soldering jobs to connect steel elements. This standard solder is in the form of a wire with a diameter of 2.5 mm, which is very convenient for working with microcircuits.

To solder aluminum parts, it is advisable to purchase special aluminum solder. During operation, it is important to remember that, when heated, tin-lead compounds emit gases that are very harmful to humans. Therefore, it is recommended to work with them in a well-ventilated area using special respirators, gloves and safety glasses.

How to learn to solder wires?

So how do you connect the wires? The operating sequence is standard for all types of soldering. The connected ends of the wires are tinned. But for reliable fastening, it is recommended to twist them tightly together. During the procedure, the soldering iron tip is directed to the joints with one hand, and solder wire is brought to this place with the other.

In some cases, twisting the wires is not possible. Then the ends of the wires to be connected must be laid parallel to each other and compressed with pliers. The work is performed with one hand, the second one directs the soldering iron tip with solder to the joint. Holding the ends of the wire should be done after removing the soldering iron tip from the soldering area.

Sometimes there is a need to connect the end of one wire to the middle of another. Twisting in this case is done by twisting the end of the wire around another to which it is attached.

It must be remembered that butt soldering of wires is not possible, since its reliability depends on the strength of the mechanical connection.

The question of how to learn to solder wires is one of the most pressing among Internet users. Having mastered the technique of splicing and soldering, craftsmen have the opportunity to independently, without the help of specialists, perform a number of the following tasks:

  • seamless heating equipment;
  • electric guitar cord extension;
  • connecting a USB cable to an antenna, etc.

What is heat shrink?

When splicing wires, professionals recommend using special heat-shrinkable tubes. Their diameter must be twice that of the wire. The tube is placed on one end of the wire. After mechanically interlocking with another wire and soldering, the heat shrink is dragged to the place where they are connected.

It should be positioned so that 1 cm remains at each end of the seam. After this, soldering is performed again. The heat shrink should evenly cover and heat the wire connection.

As a result of exposure of the tube to high temperatures, it is sealed, providing reliable insulation in the connection area, as well as strong mechanical adhesion.

How to learn to solder boards?

Before starting complex soldering, for example, working with diode strips, experts recommend that novice craftsmen acquire inexpensive budget boards. After practicing on them and mastering standard soldering techniques, after some time the beginner will learn how to solder microcircuits.

This type of soldering consists of successive steps:

  • Preparatory. Before starting work, you need to ensure a strong connection and reduce resistance. For this purpose, the surface must be thoroughly cleaned of grease and dust. For degreasing, you can use napkins and soap solution. Acetone is used when you need to clean the surface of a circuit to a shine. Methyl hydrate is recommended as a safer solvent. It is as effective as acetone, but has a less pungent odor.
  • Placement of board parts to be soldered. Before you learn how to solder circuits, you need to know the locations of all its elements. Flat parts must be soldered first. These are a resistor and a varistor. Then they move on to the capacitor, transistor, transformer, microphone and potentiometer. This sequence guarantees the safety of temperature-sensitive board elements.
  • Heating the joint to improve the thermal conductivity of the metal. The soldering iron tip must be pressed against the circuit components for a few seconds. It is important to prevent it from overheating. This will be indicated by bubbles appearing on the surface. In this case, the soldering iron must be removed from the soldering area.
  • Solder application. This is carried out until a slight elevation appears on the diagram.
  • Removal of surplus. Performed after the solder has hardened and cooled. It is recommended not to rush, but to give the circuit some time to cool down. This is important because the connections made may be damaged and the work will have to be done again.

Every man should learn how to solder circuits. This will make it possible to repair plugs, modems, etc. yourself.

Soldering as a process is not limited to working with copper wires and microcircuits. Having mastered the ability to use a soldering iron on wires, you can move on to subsequent, more complex operations using various solders and various metals.


How to learn how to solder correctly with an electric soldering iron: operating rules

The soldering procedure is a very simple operation if you follow the technological process and the availability of skills. This article will tell you how to solder correctly at home and explain the basics of soldering work.

Starting from the simplest soldering of wire strands and gradually mastering more complex actions, the skill and quality of connecting parts will increase. How to properly solder with a soldering iron with rosin and acid is described in the technological process of soldering work, which is radically different from welding.

In addition to conventional electric soldering irons, experienced craftsmen have professional soldering stations for repairing printed circuit boards of complex devices.

Soldering technology

There are four types of devices used for soldering: electric, induction, gas, hot air. Electric soldering irons have a spiral or ceramic type heater, gas soldering irons use a torch, and hot air soldering irons use an air flow. The most commonly used are electric soldering irons, which are very easy to use and affordable. They are divided according to power, which determines the release of heat flow to the contacting parts.

Soldering of electronic elements is carried out with electric soldering irons with a power of up to 40 W, and for thin-walled parts, devices of about 80-100 watts are used. More massive devices are used to work with metal with a wall thickness of 2 mm or more. These tools include hammer-type soldering irons with a power of over 250 W. The choice of an electric soldering iron is also influenced by the thermal conductivity of the workpiece.

The soldering process takes advantage of the ability of molten metal to flow well. This joining method makes the parts one-piece, united by a layer of solder after the hot mass has solidified. The amount of electrical conductivity depends on the quality of the soldering of the contacts. To learn how to work with a soldering iron, it is recommended to watch the corresponding video, as well as study the instructions for working with this electrical appliance.

Connecting parts by soldering is possible if two conditions are met:

  • cleanliness of the adhesion site;
  • compliance with temperature conditions.

Cleanliness of the soldering area

The presence of an oxide film on the legs of radio components prevents attachment to the solder surface. This process occurs at the atomic level, so the presence of contaminants will not ensure that it adheres reliably to the elements. Fluxes are used to prevent the formation of an oxide film. In order to understand how to properly solder with rosin or acid, familiarize yourself with the technology of their use.

Compliance with temperature conditions

Before you start soldering, you need to decide on the choice of alloy for the elements used. The temperature at which the solder goes into a molten state must be below the permissible temperature for the parts being soldered. This is especially true for aluminum compounds, as well as elements with large shrinkage during solidification, which interferes with the normal crystalline formation of the solder mass.

Basic mistakes when working with a soldering iron

The soldering process seems to be a very simple matter only to the uninitiated. However, it requires some knowledge and certain skills, depending on experience. Learning how to solder correctly with rosin, solder and acid is not difficult at all.

To do this, you need to familiarize yourself with the technology, the basic principles of performing work, and try to avoid the main mistakes. Before you learn how to solder with a soldering iron, you should carefully study the basic operating techniques, as well as some nuances. Dexterity comes gradually, as does the quality of the connections performed.

Typical mistakes made by beginners when using a soldering iron include:

  • don't drink;
  • overheat;
  • solder rolling;
  • chemical destruction.

Don't get lost

Poor soldering threatens the failure of electrical parts and occurs for several reasons. This occurs due to a poorly heated soldering iron tip, the use of a refractory alloy, the movement of contacts during the solidification of the mass, as well as an excessively cold soldering surface.


This process occurs when an electric soldering iron is used with more power than necessary, as well as a high temperature of its tip for a certain type of soldering work. In addition, overheating occurs when a heated soldering iron is exposed to the work area for a long time, or when refractory solder is used to connect elements with low temperature resistance. This leads to thermal destruction of connecting wires and parts, and a change in their characteristics.

Solder rolling

The rolling process occurs due to poor cleaning of the elements being connected. The oxidizing layer on them does not allow the alloy to spread well and get into small crevices. In addition, this occurs when the joints are poorly treated with flux, as well as the brand of flux does not match the metal being soldered. Rolling leads to poor contact and possible mechanical damage at the slightest external influence.

Chemical destruction

Chemical destruction occurs when the wrong flux is chosen, which does not match the type of elements being connected by electrical soldering. In addition, it can occur if the joints are not washed at the end of the work process. This threatens corrosion and destruction of the metal conductor.

This information will help you understand how to learn how to properly solder electrical connections to ensure reliable contact.

Preparatory process

At this stage, the electric soldering iron and the products to be connected are prepared. To determine what is needed to solder parts with a soldering iron, you need to have a minimum set of components at home. It consists of an electric soldering iron, fluxes for various materials, solder, and auxiliary tools. A new electric soldering iron may smoke when initially plugged into the mains. This is quite normal - this is how preservative oils burn out on its sting.

Tips can have different shapes, suitable for various types of soldering. The new tip is tin-plated to protect against wear and oxidation. To do this, the heated tip is immersed in rosin, the metal is melted on it, and then rubbed on a wooden block. As a result of this procedure, the tip should be completely covered with alloy. During the soldering process, the flux gradually corrodes the copper tip, which requires periodic sharpening and repetition of the tinning procedure.

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Before soldering with rosin and tin with a soldering iron, the area is prepared. Parts used for electrical soldering are cleaned of contaminants and degreased. For this, various solvents based on acetone, gasoline and other liquids are used, and rust is removed mechanically. This is necessary to quickly remove the oxidizing film from the surfaces being joined.

Tinning or fluxing

Tinning involves covering the surface of the products to be joined with a thin layer of solder. This procedure is used in the preparatory process, as well as the intermediate and final ones. Using the preparatory procedure greatly facilitates the final connection of the elements, since already tinned parts are easily soldered.

Tinning the ends of wires of various diameters is one of the most common soldering operations. Flux is applied to the core that has been cleared of insulation, after which a tip with solder is passed along its surface. The molten metal easily transfers to the core and the tinning procedure is completed. To improve the procedure, it is recommended to mechanically strip the surface of wires and cables. Radio components do not require this preliminary procedure and can be easily soldered on boards.

Different fluxes are used for different metals being joined. They are designed specifically to work with certain materials. Fluxes for electric soldering of aluminum are also suitable for stainless steel products. In this case, it is necessary to clean the surface of the products from their residues after soldering is completed in order to avoid corrosion.

Soldering technique

The work is performed using a soldering iron by draining the solder from the tip onto the part and directly feeding it to the pad of the element being soldered. Regardless of the soldering method, the part is prepared, installed and secured in its working position. After this, the treatment area is wetted with flux and the electric soldering iron is heated. A video with a detailed demonstration of the process will show you how to solder with a soldering iron with rosin.

When the solder is drained from the tip, it is pressed against the soldered element. The flux boils and gradually evaporates, allowing the molten metal to flow smoothly from the tip to the joint. By carrying out translational movements with the sting along the area to be joined, the metal is distributed over the joint area and the area being treated is straightened.

Supplying the alloy to the soldering site involves preheating the elements to the desired joint temperature. After this, the soldering iron feeds the molten metal end-to-end between the tip and the part. This working method is more suitable for large parts.

After using various acid fluxes, they must be washed off to ensure the connection is protected from corrosion.

Solder Types

For soldering with electric soldering irons, low-temperature solders of the POS brand are used. These tin-lead materials are in the form of metal rods. According to GOST, these hard alloys have different tin contents in their composition. Depending on this, they are marked (POS-61, POS-40, POS-30). In addition to them, lead-free and other non-toxic soldering compounds are produced. They have a higher melting point and provide high joint hardness.

Some alloys have a low spreading temperature and are used for radioelements and microcircuits of numerous boards that are especially sensitive to overheating. The actively used ones include tin-silver compositions of the PSR type, as well as tin in its pure form. For numerous soldered parts, there are tables with the components used to connect them.

Soldering temperature

The heating temperature of the tip of an electric soldering iron directly determines the quality of the elements being soldered. Insufficient heating will not allow the metal to spread over the surface even when using flux. Such a connection will have a loose structure and low strength.

The tip temperature should be 40 °C higher than the soldering temperature value, and for soldered parts this indicator must be in the range of 40-80 °C. In this case, the soldering tip heats up 60-120 °C above the melting point of the solder. At soldering stations, the required temperature is set by a special regulator.

To visually determine the required heating, rosin is used as an indicator. It should release steam and boil, remaining on the tip in the form of small boiling drops.

Security measures

During the electrical soldering process, caustic gases are released that are hazardous to health, so work should be carried out in a well-ventilated area. In addition, the technological process is accompanied by periodic splashes of molten metal and flux. Use special glasses to protect your eyes.

Please note that corded electric soldering irons require special precautions because they have exposed metal parts. Pay special attention to the condition of the insulation of the power supply wire.

Make sure that it does not come into contact with the hot parts of the electric soldering iron, which can lead to an electrical short and a fire.


How to solder steel parts

Often there is a need to fasten steel parts without drilling and without welding. Soldering steel will help. But how to do it correctly, because there are special nuances here. A few recommendations from experts.

What kind of steel solders well?

Some grades of steel lend themselves well to soldering, while others are soldered with great difficulty and do not want to be combined with any solder or with any flux. As a rule, soft steels "for nails" are easy to solder. At the everyday level, this can also be explained by the fact that the material is dotted with microscopic craters and irregularities. But there are also electrical grades that are especially hard and elastic, and are used for shafts and precision mechanics. It's your luck here

The question is that it is impossible for a home craftsman to determine the brand by eye. You can only find out how well a given part made of steel, or an alloy close to it, is soldered by experimentation.

How to make a tin connection - procedure

It all depends on how successfully the part can be tinned and how strong the contact of the tin solder with the steel is. In order for the contact to be satisfactory, if possible at all, the following must be done:

  • steel stripping, chemical stripping under solder;
  • heating the part to the melting temperature of the solder, keeping the solder on the part under flux for some time in a fluid state.

Cleaning the steel is first done mechanically, using sandpaper, to remove layers of rust and dirt. Then a composition that reacts well with iron oxides is used as a flux.

The most harmless to use, but effective in this case, is orthophosphoric acid, which can be easily purchased at a car store as a “rust cleaner.”

The required power of heating devices depends entirely on the mass of the parts.

The process of soldering two steel parts

If you need to solder two large nails, then the power of one soldering iron 100 W will not be enough. To heat up a large nail or a similar weight steel part clamped in a vice, you need to use a hair dryer. Or a gas burner.

You will also need cotton wool on a stick to supply flux to the heating zone, and a soldering iron of 50 W or more.

  • The sanded steel is heated with a burner.
  • Phosphoric acid is applied to the hot part and molten tin solder is immediately applied with a soldering iron.

As a rule, steel parts that can be soldered develop a very strong bond with tin, i.e. When the metal is coated, it is tinned.

The same is repeated with another detail. Then the two parts located together are heated, and additional solder is applied to the contact area with a soldering iron.

How strong is the soldering of steel, can it be made stronger?

The strength of such a connection will be determined by many factors:

  • strength of bond between solder and metal,
  • connection area,
  • direction of the load in relation to the welded planes.

But in any case, the strength of tin soldering cannot be compared with what is commonly understood as the strength characteristic of steel or “metal welding”.

You can strengthen it by using another solder - special strong and more refractory compounds containing silver, zinc, copper, etc.

Another direction for increasing strength is to cover with solder not only the plane, but also the sidewalls of the part - covering the part with solder. Then the pull-off resistance under multidirectional loads will be greater.

Extra strong soldering, special solders

To use compounds that provide a strong connection with steel, with its own melting point of about 800 - 900 degrees, you need to use a graphite crucible.

The work should only be carried out by specialists in metal smelting. It is necessary to know the basics of metal melting, the procedure for handling melts and safety precautions. In general, soldering of steel with heavy-duty solders is performed at specialized enterprises.

Possible solder composition:

  • 55% zinc, 45% copper, some silicon to increase fluidity.

The composition is melted under a layer of coal in a graphite crucible. Steel parts to be soldered are heated with a gas burner. Phosphoric acid is used as a flux. The melt is fed to the parts. As a rule, tinning and soldering are carried out during one heating of both the parts and the solder.

But such soldering of steel is more complex than simple welding.


How to learn to solder with a soldering iron from scratch


Any novice radio amateur, one way or another connected with electronics, has to solve the problem of how to learn how to solder with a soldering iron from scratch. At first glance, there is nothing complicated about this, but this is a common misconception of all novice electronics engineers, since without practical skills it is impossible to ensure a reliable and high-quality soldering connection.

What is soldering and what is the essence of the process

The end result of soldering is the joining of two metal elements. The soldering process itself is provided by an independent metal with a much lower melting point. It is this metal that performs the function of solder.

Each soldering method is based on the principle of heating metal elements at the connection point. The heating temperature must exceed the temperature at which the metal used for solder melts. In this mode, the solder metal, being molten, freely flows into the spaces and crevices between the parts, partially penetrating even into the metal structure itself. After solidification, a mechanical bond and electrical contact are formed in this place.

There are two main conditions, without which it will simply be impossible to solve the problem of how to solder correctly:

  • At the point of soldering, the elements must be as clean as possible. The connection to the surface is carried out at the molecular level, and even a small dirt or oxide film will significantly reduce the reliability of the contact. It is quite possible that the parts will not connect at all.
  • Compliance with the temperature regime mentioned earlier. If the temperature difference is insufficient, the solder crystal lattice will not be able to form normally due to thermal shrinkage during solidification.

Copper and its alloys are well joined with traditional solders. They are suitable for steel, aluminum and other metals. The only serious limitation is the soldering of large metal parts due to the impossibility of heating them to the required temperatures.

Most often, solder consists of a tin-lead alloy, which may contain varying amounts of tin. The percentage of content is displayed in the marking, for example, POS-40 or POS-60.

The melting temperature also depends on this indicator; for the first solder it is 235 degrees, and for the second it is 183 degrees. The melting point of POSV-33 solder, consisting of tin, lead and bismuth, is even lower.

Joining aluminum parts requires special solders with a high melting point.

Another important component is fluxes, with the help of which metal surfaces are cleaned of oxides in the form of films. The most widespread is rosin, which protects heated metal from contact with air.

Selection of fluxes and solders

Since the quality of soldering joints largely depends on the correct choice of fluxes and solders, these materials should be considered in more detail. Currently, there are a large number of these components suitable for almost all types of soldering.

The main function of fluxes is to pickle metal parts, remove the oxide film and subsequently protect the surface from corrosion. Flux coating ensures its cleanliness, good wetting and spreading of tin.

Fluxes are selected in accordance with the metals and alloys that need to be joined. The composition of any flux includes metal salts, alkalis and acids that actively react to increased temperature. In this regard, there is a conditional division of these materials into two types.

The first of them is active; it is based on hydrochloric, perchloric and other inorganic acids. Their aggressive effect on metal requires quick rinsing after finishing work. This is the only drawback of such fluxes, but with their help you can join almost any metals. They are available in liquid form and are considered more convenient for application. They add alcohol or glycerin, which completely evaporate when heated.

The second type of flux consists of rosin and is used for joining non-ferrous metals. For steel parts they are considered less effective. At the end of the work, the rosin must be washed off, since over time it causes corrosion and becomes an electrical conductor when left in a humid environment for a long time.

Solder for work is easier to select. Lead and tin compounds marked PIC are mainly used. The percentage of tin content is indicated by numbers following the letters. A higher tin content in solder provides higher mechanical strength and electrical conductivity of connections. At the same time, the melting temperature of solder with a high proportion of tin also decreases. The addition of lead normalizes solidification and prevents the tin from spreading.

Some modern solders are produced without lead (BP), instead of which zinc or indium is added. They have a higher melting point, but the joints are more durable and resistant to corrosion. And, on the contrary, there are solders made of light alloys that can spread from 90-110 degrees. They are used to connect components that are highly sensitive to overheating.

Soldering iron selection

There are several types of soldering irons used at home. They are designed for different voltages and can operate from 12, 220 and 380 volts.

The power of a particular soldering iron is selected based on the work performed:

  • Soldering of electronic parts and components – 40-60 W.
  • Parts up to 1 mm thick – 80-100 W.
  • Elements 2 mm thick require a power of 100 W or more.

As a rule, home craftsmen have two soldering irons - low and medium power, capable of solving almost all problems. Training can be completed at any of them. It is recommended to solder thick-walled parts using professional equipment.

Preparation for soldering

The very first time you connect the soldering iron to the network, it will definitely smoke. At this moment, the factory lubricant burns out. After the emission of smoke stops, the soldering iron must be turned off and allowed to cool. Then, before soldering, you need to sharpen the tip.

The soldering iron tip is made in the form of a cylindrical rod. The material is copper alloy. Fixation is carried out with a clamping screw. In most cases, the tip comes without sharpening, and therefore it should be prepared. You can change the shape using a hammer, file or sandpaper.

Each type of work requires its own tip configuration:

  • The shape is flat or blade-shaped by flattening. Flat corner sharpening may be required to join massive parts.
  • Sharpening in the shape of a sharp cone or pyramid is required in order to solder small parts.
  • A less sharp cone is needed for soldering thick conductors and large parts.

In the absence of a protective coating, the tip of the tool must be tinning. A thin layer of tin is applied to the surface of the working part. This procedure is performed during the first start-up, when there is no longer any smoke emission. After the tool is ready, we learn to solder.

Methods for soldering parts and components

Soldering wires is considered the easiest procedure. The ends of each wire are dipped into the dissolved flux, after which it is necessary to go over them with a soldering iron, the tip of which is also well moistened with flux.

During tinning itself, it is recommended to shake off all excess solder. During the joining process, a twist is gradually formed. It warms up, and all free space is filled with tin.

In another case, the ends are soaked in flux, and soldering is done immediately, without tinning. This method is often used in connections of thin conductors or many wire strands. With a good flux and a powerful soldering iron, a high-quality and reliable connection is ensured.

Working with electronics is much more difficult. This already requires certain knowledge and practical skills. However, even a novice master can perform simple steps to repair the circuit:

  • Before soldering, the terminal elements with legs must be fixed in their holes with wax or plasticine. On the other side of the board, the soldering iron must be pressed tightly to the terminal to warm it up. Next, thin solder in the form of a wire with flux is inserted into this place. Very little tin is required, the main thing is that it flows evenly into the hole from all sides.
  • If the hole is too large and the legs are dangling in it, this area should be moistened with a small amount of flux. Next, the tin is brought to the leg and flows down it, after which the hole is evenly filled.


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