home
Scud
What can be soldered with a soldering iron. Soldering with a soldering iron at home

What can be soldered with a soldering iron. Soldering with a soldering iron at home

Soldering skills modern life, saturated with electrical appliances and electronics, is as necessary as the ability to use a screwdriver and a plunger. There are many methods for soldering metals, but first of all you need to know how to solder with a soldering iron, although in living conditions feasible and other methods may also be needed. This article is intended to help those who want to master the technology of manual soldering work.

Note: We are not talking about soldering propylene and other plastics here. This, in fact, is not soldering - the technical process does not contain the necessary components of soldering work, solder and flux. Technologically, plastic soldering is closer to low-temperature resistance welding. The same applies to cold soldering - joining parts with conductive glue.

Soldering metals with solder is a rather complex physical and chemical process, but in operation it comes down to fairly simple techniques and operations. In order to solder correctly, without wandering into the wilds of theory, the rules for performing soldering work must be followed exactly . This is especially true for the choice of soldering method, solder and flux, depending on the type of parts to be connected and the requirements for the soldered joint. The main part of the presented material is devoted to the description of these and other details, without which a strong joint cannot be obtained.

Note: If you want to quickly solder something, you can watch a detailed video tutorial on the basics of soldering for beginners below. But keep in mind that it will not replace what follows in the text. In soldering work, the rule “do this, it will turn out this way” does not always apply. And in an established production, it happens that you have to rack your brains - what to do if it doesn’t work out right? Or, what needs to be done to make it work like this, if there is no way to do it this way.

Video: how to learn to solder - lesson for beginners

What is soldering?

Do-it-yourself soldering at home comes down to the following technological operations:

  • The soldered surfaces are cleaned of dirt, corrosion crusts, etc.
  • Clean until shiny, i.e. until there are no visible traces of oxides;
  • They are coated with flux - a substance that removes oxide residues and prevents oxidation of surfaces in the further process. For fluxing under tinning, it is preferable to use flux pastes rather than liquid or solid fluxes;
  • Then the surfaces are tinned - molten solder (an alloy specially designed for soldering) is applied to them, while it spreads into a thin film and chemically combines with the base metal;
  • The parts are pre-connected mechanically: by twisting, compression with tweezers, pliers, in a vice, clamp, etc.
  • Flux is also applied to prevent oxidation of the solder under heat;
  • While heating, more solder (perhaps a different one) is applied until a junction of the specified quality is obtained;
  • If soldering was carried out with a soldering iron with a tinned tip (see below), upon completion it is cleaned and coated with inactive flux. To ensure high-quality soldering, a regular soldering iron must be stored with a fluxed tip!

Necessary Retreat

Note: in the northern dialects of Russian there are also luds - underwater rock ridges - and even the whitefish fish that lives there. But in canonical Russian luds appear extremely rarely, so they can be ignored.

Stripping

Stripping after cleaning is the first tricky soldering operation. The use of abrasives for it is unacceptable! Their smallest particles, ingrained into the metal, cannot be completely removed. Subsequently, they become centers of processes that destroy the junction.

Clean the surfaces for soldering with a needle file, a file, or a scraper tool ( different types scrapers) or just a knife. But it is best, especially if current-carrying wires are being prepared for soldering, to immediately coat them with activated flux (see below), and after soldering, carefully remove its residues. It is convenient to do this with a toothbrush moistened with alcohol.

What and how to tin/solder?

For the following operations you will need a special electric heating tool: a soldering iron, a futor or a soldering torch. Soldering at home most often involves an electric soldering iron with a tinned copper tip. Its device is shown in pos. 1 pic. “For complete happiness” an amateur solderer needs 16-20 W rod soldering irons for microcircuits and printed circuit boards, pos. 2a, 40-50 W (item 2b), for electrical wires and wall-mounted radio electronics component, and 80-150 W (item 2c), for assembling small metal structures by soldering.

Design and types of electric soldering irons with tinned copper tip

If you are not going to work with microchips (phones, tablets, computers) and soldering steel with a thickness of more than 0.5-0.6 mm, you can get by with a set of soldering irons of 25 W (pos. 3a) and 60-65 W, pos. 3 b. Suddenly there will be a need to solder metal profiles with a wall thickness of up to 3-4 mm and/or a thick steel sheet, you will need a radiator “axe” soldering iron for 300-400 W, pos. 4.

The tips of low-power soldering irons (items 2a, 2b, 3a, 3b) are not initially forged and therefore oxidize (burn) quite quickly. To increase their durability, and at the same time to mold them in the desired way, the rod removed from the soldering iron is forged with a mechanic’s hammer on the anvil of a table vice. There is no need to “sharpen” it with a file after this, and it is not necessary, so as not to erase the outer compacted layer of copper. After forging, the tip is immediately coated with activated flux.

Now you will need hard rosin and soft, fairly refractory solder (see below): POS-10, POS-30 or POS-40. The soldering iron rod is inserted into place, fixed if there is a locking screw, and the soldering iron is connected to the network. As the flux boils away during heating, the tip is immersed in rosin so that it does not become exposed. When the rosin around the tip begins to bubble, rub it with a stick of solder until an even, dense layer is obtained over the entire surface of the tip. Filamentous solder on a coil is not very good in this case; it is for soldering small parts.

While we were preparing the soldering iron, the flux on the soldering surfaces did its job: under its layer they are clean, you can tin. The critical point here is the thickness of the parts:

  • Less than 1/8 of the diameter of the soldering iron rod - will heat through to the melting temperature of the solder in less than 7 seconds. The flux will not have time to boil away.
  • More than 1/6 of the same value - it will warm up in more than 10 s, the flux will boil away, the parts will become exposed and oxidize.
  • 1/8-1/6 of the diameter of the rod - it is necessary, most often based on your own experience, to tin with low-melting solder under a high-boiling flux. Or use a more powerful soldering iron.

In the first case, a drop of solder is taken onto the tip, transferred to the soldered surface, and if:

  • The wire is thin - easily, without pressure, move along the bare end with a tip from one side and then from the opposite side until the solder spreads. The wire is held with the tip down. A drop of excess solder that has flowed down there is removed with a soldering iron.
  • The wire is thick - the tip is moved in a spiral back and forth.
  • A flat thin long part - solder is applied to the end and the tip is moved along. When the untinned edges of the part appear behind the tip, apply more flux to the untinned area, take another drop of solder and continue tinning.
  • The long, wider part is the same as in the previous one. case, but the sting is led like a snake.
  • Wide part - the sting is moved in a spiral from the center to the edges.

To tinning thick parts, use filament solder with flux, the so-called. harpius: this is a thin flexible tube of solder foil, in the lumen of which there is powdered rosin. Tinning begins from the edge of long or from the middle of wide parts. The end of the harpius is applied to the place where tinning begins, and heated with a soldering iron until it melts. The sting movements are the same as before. cases. Solder is supplied under the sting as spent. Apply it to the sting - it will stick to it until a large drop forms, which flows where it is not needed.

Features of soldering wires

In the preliminary connection of soldered parts, the most problems arise with the wires: to do this, you have to touch them with your hands, which causes the metal surface to become dirty, and the wire solders have to withstand mechanical loads more often than other soldered joints.

Twists of wires

Before soldering the wires, they must be twisted correctly. The main types of wire twists for soldering are shown in Fig. Each of them has its own purpose:

  • Bandage twists are used to connect rigid (thick single-core) current-carrying wires, i.e. through which electrical power is transmitted. Especially – external wires. The band connection ensures sufficient electrical contact even if the oxidized junction is not soldered or overheated.
  • Grooved twists are made on wires in fusible insulation ( plain PVC, polyethylene), when it is necessary to completely spread the solder with minimal heating. Grooved twists are heated only along the groove.
  • Simple twists can be used to connect both single-core and multi-core wires that have just been stripped of insulation (shiny).
  • Simple sequential twisting, so-called. straight British, or simply British, is applicable for connecting current-carrying wires of flexible cables with a cross-section of up to 1.4 square meters. mm, not subject to regular heavy mechanical loads, e.g. electrical extension cords or temporary sheds.

Electrical wires that experience regular and/or constant mechanical stress must be multi-core. They are twisted as shown in the figure below: the ends are marked, the “brooms” are pushed into each other and twisted in the British way. Soldered with high-strength low-melting solder, e.g. POSK-50 (see below) with activated flux that does not require removal of residues, also see below.

Parallel (dead-end) twists of wires with a cross-section of over 0.7 square meters. mm, it is advisable to solder by immersion in molten solder, see below. Otherwise, you will have to heat it either for a long time, or with a too powerful soldering iron, which will cause the insulation to creep and the flux to boil away prematurely.

Note: single-core tinned wires - leads of radio electronics parts - it is permissible to solder end-to-end or with a crochet hook, see fig. on right.

What is soldered, but not soldered

Flexible coaxial cables and cables for computer networks such as twisted pair (“vitukha”) are not intended for connection by soldering. An experienced cable technician who has a complete understanding of the electrodynamics of signal transmission lines can, in exceptional cases, make a coupling on them. But when performed by an amateur, even if he is otherwise a qualified electronics engineer and installer, the throughput and noise immunity of the line will fall below the permissible level, up to complete loss.

How to clean and preserve the sting

The soldering iron tip is cleaned of solder residues by rubbing it against a soft porous or fibrous pad. Foam rubber is most often used, but this is not the best option: it burns and sticks to the sting. Best material To clean it, use natural felt or basalt cardboard. But even better is 2-step cleaning, first with a sponge-tangle made of metal tape, and then with felt. After cleaning, turn off the soldering iron, insert an even hotter tip into the solid rosin and wait until it stops bubbling. Then the tip is removed and held with the end down so that the excess rosin drains off. Once it has cooled completely, the soldering iron can be stored.

Solders and fluxes

Now it’s time to accurately select the working solder and flux for it, because... soldering, unlike half-solder, must not only adhere tightly to the base metal, but also be strong itself. Summary of Solders and Fluxes wide application from the old reference book is given in Fig. In relation to the present time, there is not much left to add to it.

Characteristics of solders and fluxes for wide application

Solders from POS-90 to Avia-2 are soft for low-temperature soldering. Only electrical contact is guaranteed. POS-30 and POS-40 solder copper, brass, bronze with inactive fluxes, and the same with steel, and steel with steel with active ones. POSSr-15 can be soldered galvanized sheets with inactive fluxes; other solders corrode the zinc to steel and the soldering soon falls off.

34A, MF-1 and PSR-25 hard solders, for high-temperature soldering. Solder 34A can be used to solder aluminum in a flame (see below, about soldering aluminum) with special fluxes, see ibid. MF1 solder is used to solder copper to steel with activated flux. “Low strength requirements” in this case means that the strength of the joint is closer to the strength of copper than steel. When soldered with a dry soldering iron (see below), PSR-25 is suitable for soldering jewelry, Tiffany stained glass, etc.

Soldering fluxes are divided into neutral (inactive, acid-free), which do not react chemically with the base metal or interact to an insignificant extent, activated, which chemically act on the base metal when heated, and active (acidic), which act on it even when cold. In regard to fluxes, our century has brought the most innovations; mostly still good, but let's start with the unpleasant ones.

First, technically pure acetone for washing rations is no longer widely available due to the fact that it is used in the underground production of drugs and itself has a narcotic effect. Substitutes for technical acetone are solvents 646 and 647.

Secondly, zinc chloride in activated flux pastes is often replaced with sodium teraborate - borax. Hydrochloric acid is a highly toxic, chemically aggressive volatile substance; Zinc chloride is also toxic, and when heated it sublimates, i.e. evaporates without melting. Borax is safe, but when heated it releases a large number of water of crystallization, which slightly worsens the quality of soldering.

Note: borax itself is a soldering flux for soldering by immersion in molten solder, see below.

Good news - now on sale the widest range fluxes for all cases of soldering life. For ordinary soldering work, you will need (see figure) inexpensive SCF (alcohol rosin, former CE, second in the list of acid-free fluxes in Table I.10 in the figure above) and soldering (etched) acid, this is the first acid flux on the list. SKF is suitable for soldering copper and its alloys, and soldering acid is suitable for steel.

SKF rations must be washed: rosin contains succinic acid, which destroys metal upon prolonged contact. In addition, accidentally spilled SCF instantly spreads over a large area and turns into an extremely sticky muck that takes a very long time to dry, the stains from which cannot be removed from clothes, furniture, or the floor and walls. In general, SKF is a good flux for soldering, but not for slow-witted people.

A complete substitute for SCF, but not so nasty if handled carelessly, is TAGS flux. Steel parts are more massive than is permissible for soldering with soldering acid, and more durable, they are soldered with F38 flux. The universal flux can be used to solder almost any metal in any combination, incl. aluminum, but the strength of the joint with it is not standardized. We'll come back to soldering aluminum later.

Note: Radio amateurs, keep in mind - there are now fluxes on sale for soldering enameled wires without stripping!

Other types of soldering

Hobbyists also often solder with a dry soldering iron with a bronze untinned tip, the so-called. soldering pencil, pos. 1 in Fig. It is good where solder spreading outside the soldering zone is unacceptable: in jewelry, stained glass, soldered objects of applied art. Sometimes surface-mounted microchips are also dry-soldered with pin spacing of 1.25 or 0.625 mm, but this is a risky business even for experienced specialists: poor thermal contact requires excessive soldering iron power and prolonged heating, and it is impossible to ensure stable heating during manual soldering. For dry soldering, use harpius from POSK-40, 45 or 50 and flux pastes that do not require removal of residues.

Other types of soldering that can be done at home

Dead-end twists of thick wires (see above) are soldered by immersion in a futorka - a bath of molten solder. Once upon a time, a futor was heated with a blowtorch (pos. 2a), but now this is primitive savagery: an electrofutor, or soldering bath (pos. 2) is cheaper, safer and gives best quality rations. The twist into the futor is introduced through a layer of boiling flux, which is applied to the solder after it has melted and warmed up to operating temperature. The simplest flux in this case is rosin powder, but it soon boils away and burns even faster. It is better to flux the futor with brown, and if the soldering bath is used for galvanizing small parts, then this is the only possible variant. In this case, the maximum temperature of the futor should not be lower than 500 degrees Celsius, because zinc melts at 440.

Finally, solid copper in products, e.g. pipes are soldered using high-temperature flame soldering. It always contains unburned particles that greedily absorb oxygen, so the flame has, as chemists say, restorative properties: it removes residual oxide and prevents the formation of new ones. At pos. 3 you can see how the flame of a special soldering torch literally blows out everything unnecessary from the soldering area.

Manual high-temperature flame soldering

High-temperature soldering is carried out, see Fig. on the right, evenly rubbing the soldering area with pressure 1 with a stick of hard solder 2. The flame of the torch 3 should follow the solder so that the hot spot is not exposed to air. First, the soldering zone is heated until the colors become tarnished. You can solder something else to the surface tinned with hard solder using soft solder as usual. For more information on flame soldering, see later when it comes to pipes.

It’s funny, but in some sources the soldering torch is called a soldering station. Well, a rewrite is a rewrite, whatever you get from it. In fact, a desktop soldering station (see next figure) is equipment for thin soldering work: with microchips, etc., where overheating, spreading of solder where it is not needed, and other flaws are unacceptable. The soldering station accurately maintains the set temperature in the soldering zone, and, if the station is gas, it controls the gas supply there. In this case, the torch is included in its kit, but the soldering torch itself, the soldering station, is nothing more than a quarry - St. Basil's Cathedral.

Desktop soldering stations

How to solder aluminum

Fluxes for aluminum soldering

Thanks to modern fluxes, soldering aluminum has become generally no more difficult than copper. F-61A flux is intended for low-temperature soldering, see fig. Solder – any analogue of Avia solders; There are different ones on sale. The only thing is that it is better to insert a tinned bronze rod into the soldering iron with notches on the tip approximately like a file. Under the layer of flux, it will easily scrape off the strong oxide film, which prevents aluminum from being soldered just like that.

F-34A flux is intended for high-temperature soldering of aluminum with 34A solder. However, you need to be very careful when heating the soldering zone with a flame: the melting point of aluminum itself is only 660 Celsius. Therefore, for high-temperature soldering of aluminum it is better to use flameless chamber soldering (furnace-heated soldering), but the equipment for it is expensive.

Copper plating of aluminum for soldering

There is also a “pioneer” method of soldering aluminum with preliminary copper plating. It is suitable when only electrical contact is required and mechanical stress in the soldering area is excluded, for example, if it is necessary to connect an aluminum casing to the common busbar of a printed circuit board. “In a pioneering way,” aluminum soldering is carried out on the installation shown in Fig. left. Powder copper sulfate pour in a heap into the soldering zone. A harder toothbrush, wrapped in bare copper wire, is dipped into distilled water and the vitriol is rubbed with pressure. When a copper spot appears on the aluminum, it is tinned and soldered as usual.

Fine soldering

Soldering printed circuit boards has its own peculiarities. How to solder parts onto printed circuit boards, in general, see the small master class in the drawings. Tinning of wires is no longer necessary, because the terminals of the radio components and chips are already tinned.

In amateur conditions, firstly, there is little point in tinning all current-carrying paths if the device operates at frequencies up to 40-50 MHz. In industrial production, boards are tinned using low-temperature methods, for example. spraying or galvanic. Heating the tracks along their entire length with a soldering iron will worsen their adhesion to the base and increase the likelihood of delamination. After installing the component, it is better to varnish the board. This will immediately darken the copper, but this will not affect the performance of the device in any way, unless we are talking about microwaves.

Soldering radio-electronic components onto a printed circuit board

Then, look at the ugly thing on the left of the trail. rice. For such a marriage, and in the bad memory of the Soviet MEP (Ministry of Electronic Industry), installers were demoted to loaders or helpers. It's not even about appearance or excessive consumption of expensive solder, and, firstly, the fact that during the cooling of these plaques both the mounting pads and the parts overheated. And large heavy influxes of solder are rather inert weights for already weakened tracks. Radio amateurs are well aware of the effect: if you accidentally push a “cuttlefish” board onto the floor, 1-2 or more tracks peel off. Without waiting for the first re-soldering.

Incorrectly and correctly soldered circuit boards

Solder beads on printed circuit boards must be round and smooth with a height of no more than 0.7 times the diameter of the mounting pad, see on the right in Fig. The tips of the leads should protrude slightly from the beads. By the way, the board is completely homemade. There is a way at home to make a printed edit as accurate and clear as a factory one, and even display the inscriptions you want. White spots are reflections from the varnish during photography.

Swellings that are concave and especially wrinkled are also a defect. Just a concave bead means that there is not enough solder, and a wrinkled bead means that air has penetrated into the solder. If the assembled device does not work and there is a suspicion of a faulty connection, look first in these places.

ICs and chips

In essence, an integrated circuit (IC) and a chip are the same thing, but for clarity, as is generally accepted in technology, we will leave the “microchip” microcircuits in DIP packages, up to and including large ones in terms of the degree of integration, with pins separated by 2.5 mm, installed in mounting holes or soldering pins if the board is multilayer. Let the chips be ultra-large “million-dollar” ICs, mounted on the surface, with pin pitches of 1.25 mm or less, and the microchips – miniature ICs in the same cases for phones, tablets, and laptops. We do not touch processors and other “stones” with rigid multi-row pins: they are not soldered, but installed in special sockets, which are sealed into the board once when it is assembled at the enterprise.

Soldering iron grounding

Modern CMOS (CMOS) ICs are the same in sensitivity to static electricity as TTL and TTLSh, holding a potential of 150 V for 100 ms without damage. The amplitude value of the effective network voltage is 220 V - 310 V (220x1.414). Hence the conclusion: you need a low-voltage soldering iron, for a voltage of 12-42V, connected through a step-down transformer on the hardware, not through a pulse generator or capacitive ballast! Then even a direct test on the tip will not ruin expensive chips.

There are still random, and even more dangerous, surges in mains voltage: welding was turned on nearby, there was a power surge, the wiring sparked, etc. Most reliable way to protect yourself from them - do not remove “stray” potentials from the soldering iron tip, and do not let them escape from there. For this purpose, even at special enterprises of the USSR, the circuit for switching on soldering irons was used, shown in the figure:

Grounding diagram for a low-voltage electric soldering iron

The connection point C1 C2 and the transformer core are connected directly to the circuit protective grounding, and to the middle point of the secondary winding - the screen winding (an open coil of copper foil) and the grounding conductors of the workplaces. This point is connected to the circuit with a separate wire. If the transformer has sufficient power, you can connect as many soldering irons as you like to it, without worrying about grounding each one individually. At home, points a and b are connected to a common ground terminal with separate wires.

Microcircuits, soldering

Microcircuits in DIP packages are soldered like other electronic components. Soldering iron – up to 25 W. Solder – POS-61; flux - TAGS or alcohol rosin. You need to wash off its remains with acetone or its substitutes: alcohol takes the rosin hard, and it is not possible to completely wash it off between the legs either with a brush or a rag.

As for chips, and especially microchips, soldering them manually is strongly not recommended for specialists of any level: this is a lottery with very problematic winnings and very likely losses. If it comes to such subtleties as repairing phones and tablets, you will have to fork out for a soldering station. Using it is not much more difficult than a hand soldering iron, see the video below, and the prices of quite decent soldering stations are now affordable.

Video: microcircuit soldering lessons

Microcircuits, desoldering

“Correctly”, ICs are not desoldered for testing during repairs. They are diagnosed on site using special testers and methods, and the unusable ones are removed once and for all. But amateurs cannot always afford it, so just in case, below we provide a video about methods for desoldering ICs in DIP packages. Craftsmen also manage to desolder chips with microchips, for example, by slipping a nichrome wire under a number of pins and heating them with dry soldering irons, but this is an even less winning lottery than manual installation of large and extra-large ICs.

Video: desoldering microcircuits - 3 ways

How to solder pipes

Copper pipes are soldered using a high-temperature method with any hard copper solder with activated flux paste, which does not require removal of residues. Next, there are 3 options:

  • In copper (brass, bronze) couplings - soldering fittings.
  • With full distribution.
  • With incomplete distribution and compression.

Soldering copper pipes into fittings is more reliable than others, but requires significant additional costs for couplings. The only case when it is irreplaceable is a drainage device; then a tee fitting is used. Both soldered surfaces are not tinned in advance, but are coated with flux. Then the pipe is inserted into the fitting, securely fixed and the joint is soldered. Soldering is considered complete when the solder stops going into the gap between the pipe and the coupling (0.5-1 mm is needed) and protrudes outward as a small bead. The fastener is removed no earlier than 3-5 minutes after the solder has hardened, when the joint can already be held by hand, otherwise the solder will not gain strength and the joint will eventually leak.

How pipes with full distribution are soldered is shown on the left in Fig. The “distributed” soldering holds the same pressure as the fitting one, but requires additional pressure. special tools for unrolling the socket and increased solder consumption. Fixing the soldered pipe is not necessary; it can be pushed into the socket with a twist until it jams tightly, so soldering with full distribution is often done in places that are inconvenient for installing the clamp.

Soldering copper pipes

In home wiring made from thin-walled pipes of small diameter, where the pressure is already low and its losses are insignificant, soldering with incomplete expansion of one pipe and narrowing of the other may be advisable, pos. I on the right in Fig. To prepare the pipes, a round stick made of hard wood with a conical tip of 10-12 degrees on one side and a truncated-conical hole of 15-20 degrees on the other, pos. II, is sufficient. The ends of the pipes are processed until they fit into each other without jamming for approx. by 10-12 mm. The surfaces are tinned in advance, more flux is applied to the tinned ones and they are connected until they jam. Then they heat until the solder melts and prop up the narrowed pipe until it jams. Solder consumption is minimal.

The most important condition for the reliability of such a joint is that the narrowing must be oriented along the flow of water, pos. III. Bernoulli's school law is a generalization for an ideal fluid in a wide pipe, and for a real fluid in a narrow pipe, due to its (liquid) viscosity, the maximum pressure jump shifts opposite to the current, pos. IV. A component of pressure force arises, pressing the narrowed pipe against the distributor, and the soldering turns out to be very reliable.

Oh yes, soldering iron stands. The classic one, on the left in the figure, is suitable for any rod. Where the trays for solder and rosin should be placed on it is up to you; there are no regulations. For low-power soldering irons with an apron, simplified stands-brackets in the center are suitable.

Correct and incorrect stands for soldering irons

Soldering stations are equipped mainly with spring or tubular cradle-sockets for soldering irons. In them, the entire hot part of the tool is inaccessible to touch, but it is more likely to pass the soldering iron past them, concentrating on soldering small “scattered” parts. But what you definitely shouldn’t do, and what is directly prohibited by TB, is a stand made from scrap materials, in which the soldering iron lies on the trays for Supplies, on the right in Fig.

Soldering with a soldering iron is a physical and chemical technological operation for producing a permanent connection metal parts by introducing a metal with a lower melting point into the gap between them.

Soldering with a soldering iron is much easier than it seems at first glance. The technology of soldering with a soldering iron was successfully used by the Egyptians 5 thousand years ago and little has changed since then.

Requirements for the technological process of soldering and installation of radio elements are set out in OST 107.460092.024-93 “Soldering of electrical connections of radio-electronic equipment. General requirements for typical technological operations."

The soldering process with a soldering iron begins with preparing the surfaces of the parts to be soldered. To do this, it is necessary to remove traces of dirt, if any, and oxide film from the surfaces. Depending on the thickness of the film and the shape of the surface, it is cleaned with a file or sandpaper. Small areas and round wires can be trimmed with a knife blade. The result should be a shiny surface without oxide stains or shells. Grease stains are removed by wiping with a rag soaked in acetone or white alcohol solvent (refined gasoline).

After preparing the surfaces, they must be covered with a layer of solder and tinned. To do this, flux is applied to the surface and a soldering iron tip with solder is applied.

For better heat transfer from the soldering iron tip to the part, you need to apply the tip so that the contact area is maximum. The cut of the soldering iron tip with solder must be parallel to the surface of the part.

The most important thing when soldering with a soldering iron is to warm the soldered surfaces to the temperature of molten solder. If the soldering is not heated sufficiently, the solder will turn out dull and have low mechanical strength. If it overheats, the solder will not spread over the surface of the parts being soldered and soldering will not work at all.

After completing the preparation described above, the parts are applied to each other, and soldering is performed with an electric soldering iron. Soldering time, depending on the thickness and weight of the parts, ranges from 1 to 10 seconds. Many electronic components allow soldering time of no more than 2 seconds. As soon as the solder spreads evenly over the surfaces of the parts, the soldering iron is moved to the side. Displacement of parts relative to each other until the solder has completely solidified is not permissible, otherwise mechanical strength and the solder tightness will be low. If this happens by chance, you need to perform the soldering procedure again.

The solder on the tip of a hot soldering iron, while waiting for soldering, becomes covered with oxides and residues of burnt flux. The tip must be cleaned before soldering. For cleaning, it is convenient to use a moistened piece of foam rubber of any density. It is enough to quickly run the sting along the foam rubber and all the dirt will remain on it.

Before soldering, surfaces or wires that are connected by soldering must be tinned. This is a guarantee of the quality of the solder joint and the pleasure of working. If you do not have experience working with a soldering iron, then before performing important work on soldering with a soldering iron, you must first practice a little. It's easier to start with a single-core copper wire, like electrical wiring. The first step is to remove the insulation from the conductor.

How to tin copper wires

When the insulation is removed, you need to assess the condition of the conductor. As a rule, in new wires, the copper conductors are not covered with oxides and can be serviced without stripping. It is enough to take a little solder on the soldering iron tip, touch the rosin with it and move the tip along the surface of the conductor. If the surface of the conductor is clean, the solder will spread in a thin layer over it.

If there is not enough solder, then an additional portion is taken with a touch of rosin. And so on until the entire conductor is completely tinned. It is more convenient to tin the wires by placing them on a wooden platform, for which I use a stand for a soldering iron. Usually, in the place where I always puddle, rosin accumulates and the process goes faster, you can grab more solder without touching it, once again with a sting of rosin.

Sometimes, contrary to expectations, although the conductor seems to be free of oxides, it does not want to be tinned. Then I put it on an aspirin tablet and warm it up for a couple of seconds, and then puddle it on the site. It works right away without any problems. Even copper wire with obvious oxidation, without preliminary mechanical cleaning, with aspirin it is immediately torn with a thin layer of solder.

If you managed to tin the conductors with a soldering iron, as in the photo, then congratulations on your first successful work by soldering.

It is difficult to get good soldering with a soldering iron the first time. There may be several reasons for this. The soldering iron is too hot for this type of solder; this can be determined by the rapidly forming dark film of oxides on the solder, which is located on the tip of the soldering iron. When the soldering iron tip is heated excessively, the working blade of the tip becomes covered with black oxide, and the solder is not retained on the tip. The temperature of the soldering iron tip is not sufficient. In this case, the soldering becomes loose and looks matte.

Only using a temperature controller can help here. Insufficient heating of the wire during servicing occurs when there is a small amount of solder on the working part of the tip. The contact area is small, and heat is poorly transferred to the conductor. You need to practice until you can tin the wires as in the photo above.

After tinning a wire with a soldering iron, excess solder often remains on it in the form of beads. In order to get a thin and uniform layer, you need to place the wire vertically, end down, the soldering iron vertically with the tip up, and move the tip along the wire. The solder is heavy and all of it will transfer to the soldering iron tip. Just before this operation, you need to remove all the solder from the tip by hitting it lightly on the stand. In this way, you can remove excess from the soldering area and on printed circuit boards.

The next stage of the training is to tin a stranded copper wire with a soldering iron; the task is somewhat more difficult, especially if the wire is coated with oxide. Remove oxide film mechanically It’s difficult, you need to unravel the conductors and strip each one individually. When I removed the insulation from the wires using a thermal method, I discovered that the top conductor was all riddled with oxide, and the bottom one was unraveling. This is perhaps the most difficult case for tinning. But they tin with the same ease as single-core ones.

The first thing you need to do is place the conductor on an aspirin tablet and, while heating it with a soldering iron, move it so that all the conductors of the wire are moistened with the aspirin composition (aspirin melts when heated).

Next, tin on the pad with rosin, as described above, with the only difference that you need to press the wire with the tip of the soldering iron to the pad and during the tinning process, rotate the wire in one direction so that the conductors are intertwined into a single whole.

This is what copper wires look like after tinning.

From such an end of the tinned wire, you can use pliers to form a ring, for example, for threaded connection to the contacts of a socket, switch or chandelier socket, or solder to a brass contact or printed circuit board. Try to make such soldering with a soldering iron.

The main thing when connecting parts by soldering is not to move them relative to each other until the solder has hardened.

Soldering any parts with a soldering iron is not much different from soldering wires. If you managed to tin and solder a stranded wire with high quality, then you can perform any soldering.

How to tin a very thin enameled copper conductor

It is easy to tin a thin conductor with a diameter of less than 0.2 mm, insulated with enamel, with a soldering iron if you use vinyl chloride. Insulating tubes and the insulation of many wires are made from this plastic. You need to put the wire on the insulation and lightly press it with the tip of the soldering iron, then pull the wire through, turning it each time. The heating of vinyl chloride releases chlorine, which destroys the enamel and the wire is easily tinned.

This technology is irreplaceable when soldering wires of the licendrate type with a soldering iron, which is a lot of thin wires coated with enamel and twisted into one conductor.

Using an aspirin tablet, it is also easy to tin an enameled thin wire with a soldering iron; the wire is pulled between the aspirin tablet and the soldering iron tip in the same way. There should be a sufficient amount of solder and rosin on the tip.

Soldering radio components with a soldering iron

When repairing electrical appliances, it is often necessary to desolder radioelements from the printed circuit board and solder them back. Although this operation is not complicated, it still requires adherence to a certain soldering technology.

Soldering resistors, diodes, capacitors with a soldering iron

In order to remove a two-terminal radio element, such as a resistor or diode, from a printed circuit board, you need to heat the soldering area with a soldering iron until the solder melts and pull the radio element output out of the board. Usually they remove the resistor terminal from the printed circuit board by prying it by the terminal with tweezers, but the tweezers often slip off, especially if the radio element terminal on the solder side is bent.


For ease of operation, the tweezer jaws need to be ground down a little; the resulting grip will prevent the tweezer jaws from slipping.


When working on dismantling radio elements, one more hand is always missing; you need to work with a soldering iron, tweezers and also hold the printed circuit board.

My third hand is a desktop vise, with the help of which a part-free section of the printed circuit board can be clamped, and by placing the vise on any side face, the printed circuit board can be oriented in three dimensions. Soldering with a soldering iron will be convenient.

After desoldering the part from the board, the mounting holes are filled with solder. It is convenient to free the hole from solder with a toothpick, a sharpened match or a wooden stick.

The tip of the soldering iron melts the solder, the toothpick is inserted into the hole and rotates, the soldering iron is removed, after the solder has hardened, the toothpick is removed from the hole.

Before installing a new radio element for soldering, it is imperative to make sure that its terminals are solderable, especially if its release date is not known. It is best to simply tin the leads with a soldering iron and then solder the element. Then the soldering will be reliable and the work will be a pleasure, not a pain.

How to solder SMD LEDs and other leadless components with a soldering iron

Currently, leadless SMD components are widely used in the manufacture of electronic devices. SMD components do not have traditional copper lead wires. Such radioelements are connected to the tracks of the printed circuit board by soldering to them contact pads located directly on the component body. Soldering such a component is not difficult, since it is possible to solder each contact individually with a low-power soldering iron (10-12 W).

But during repairs, it becomes necessary to desolder SMD components to check or replace them, or desolder them from an unnecessary printed circuit board for use as spare parts. In this case, in order not to overheat and break the component, it is necessary to simultaneously warm up all its terminals.

If you often have to desolder SMD components, then it makes sense to make a set for a soldering iron special stings, branching at the end into two or three small ones. With such tips, it will be easy to desolder SMD components without damaging them, even if they are glued to the printed circuit board.


But there are situations when a low-power soldering iron is not at hand, but in the existing powerful soldering iron, the tip is stuck and it is impossible to remove it. There is also a simple way out of this situation. You can wind a copper wire with a diameter of one millimeter around the soldering iron tip, as in the photo. Make a kind of nozzle and use it to successfully desolder SMD components. The photo shows how I soldered SMD LEDs when repairing LED lamps. LED housings are very delicate and practically do not allow even small mechanical impacts.

If necessary, the nozzle can be easily removed and you can use the soldering iron for its intended purpose. The width between the ends of the nozzle can be easily changed, thereby adjusting for soldering SMD components of different sizes. The attachment can be used instead of a low-power soldering iron, soldering small parts and soldering thin conductors to LED strips.

How to solder LED strip with a soldering iron

The technology for soldering LED strips is not much different from soldering other parts. But due to the fact that the base of the printed circuit board is a thin and flexible tape, soldering time must be kept to a minimum to prevent the printed tracks from peeling off.


Repairing an iron car body by soldering

In ancient times, when I drove a Soviet car, the technology of soldering iron with a soldering iron helped in eliminating corrosion of the car body. If you simply clean the area covered with rust and apply paint, then after a while the rust will appear again. By covering the cleaned area with a soldering iron with a thin layer of solder, rust will never appear again.

I also had to solder through corrosion holes in the sills and the area of ​​the wheel arches of the car body with a soldering iron. To do this, you need to clean the surface around the hole with a one-centimeter strip and tin the solder with a soldering iron. Cut out a pattern for the future patch from thick paper. Next, using the pattern from brass 0.2-0.3 mm thick, cut out a patch and tin the area that will be soldered with a soldering iron with a thick layer of solder. If necessary, the patch is given the desired shape. You can simply tap the patch, placing it on thick, dense rubber. File the edges of the outer side of the patch to nothing. All that remains is to apply the patch to the hole in the body and heat it well with a 100-watt soldering iron along the seam. Putty, primer, paint, and the body will be like new, and the repaired area will never rust again.

The ability to solder in modern life, saturated with electrical appliances and electronics, is as necessary as the ability to use a screwdriver. There are many methods for soldering metals, but first of all you need to know how to solder correctly with a soldering iron. This seemingly simple action has a lot of subtleties and nuances - starting with the choice of tool and ending with safety measures when working with it.

General issues

Metals are used; they tend to spread over the surface if they are in molten form. This is facilitated by the forces of gravity and moderate tension. This property allows you to connect multiple parts. They are covered with a layer of solder, fixing the elements in a certain position.

It would seem that everything is elementary: he melted the metal and covered the place where the parts were attached. In practice, a more complex situation is observed, because it is important that the part is both durable and conductive electric shock. Ideally, the layer should be thin, but with maximum coverage.

To better spr When performing this operation, you need to consider the following points:

The ability to do this correctly is the key to success. Everything is not so complicated, because there are many universal options with which you can easily solve most current soldering problems. All the necessary information is contained on the labels, so before purchasing any brand, carefully read what is written there.

Typically, fluxes are needed for etching and removing the oxide film. In addition, their use is an excellent way to protect against corrosion. Without them, it is difficult to imagine complete preparation for soldering, because if the parts are not tinned, then high-quality joints will not be achieved. As a rule, these substances are mixtures of salts, alkalis and acids.

There are two types of fluxes:

The choice is made based on the specific goals to be achieved. It is better to have both varieties in your arsenal.

Fixation is carried out using solders. As a rule, lead-tin grades (PLS) are used. After the marking there must be a number indicating the concentration of tin. The more impressive this indicator, the higher the resistance to mechanical stress and electrical conductivity. The melting point is lower. The lead in the compound is needed for hardening. Without it, tin will not be able to maintain its uniformity.

There are special types of solders on sale that do not contain lead (BP). It is replaced by indium or zinc. The big advantage of such compounds is the lack of toxicity. The melting point is higher, but the strength is much greater.

You can find low-melting grades. These are Wood and Rose solders. They spread at a temperature of 90−110 degrees. Such connections are used when creating and repairing equipment.

The variety of types of work and the conditions in which they are performed has given rise to several types soldering equipment.

Selecting a soldering iron tip

This part of the structure varies in shape and material from which it is made. The most primitive option is the awl-shaped sting. There are many variations: blade, cone, bevel, etc. When choosing a shape, you need to have an idea of ​​the work that will be performed by this tip. It is important to purchase something that will provide the maximum area of ​​contact with the surface.

Typically the material used is copper, to which various impurities are added (for example, chromium or nickel). This allows you to improve operational properties. In particular, durability is significantly increased.

A tip without a coating quickly becomes unusable. It has to be cleaned periodically and tinker. To level out this flaw, it is recommended to forge this element and grind it to give it one shape or another.

In various situations, this tool can be used with a number of features that are worth paying attention to. Not only the final quality, but also the degree of feasibility of the operation as a whole depends on this.

Soldering wiring

The ends are dipped in flux and then passed over them with a tip moistened with the same solution. It is important to shake off excess wires. Don't neglect this if you want to achieve a quality connection and flawless functioning.

When the preliminary stage is completed, we twist the wires and warm them up with a small amount of solder. All free space must be filled with the molten mixture.

If multi-wire conductors are involved, you can do without tinning. The ends are simply wetted and fixed without pre-treatment with a sting. Inside distribution boards This operation is not performed because the risk of corrosion is high. In addition, such structures do not belong to the detachable category.

Electronics repair

Correct approach can only be achieved experimentally. If you have never done such work, use the help of a specialist who will tell you how to how to use a soldering iron in this case, it is important that someone controls and deposits on time edits into the process. But if we are talking about standard printed microcircuit, even those who picked up the instrument for the first time can handle it.

Easiest to solder small output elements. We first fix them with some viscous substance in the holes. Press the tip tightly with reverse side for warming up. Then we introduce solder into the soldering area (there should not be too much of it).

If the output element is loose, first moisten it with flux. With this technique, a small drop of tin is transferred from the soldering iron to the leg. The substance flows down, filling the hole.

Large parts

Cable sleeves, tanks and dishes have a high heat capacity, so the process service and the connections look a little different.

First, we achieve complete immobility. This is done using clamps or plasticine (wax). Then spot welding is performed.

Next stage - tinning. It is performed in places of fixation. It is important to approach this process with the utmost care.

Then the free space is filled with solder. Special compounds are used that are characterized by their refractoriness and the ability to maintain tightness over a long period of time.

If you have to make a large seam, the role of a soldering iron can be played by a copper hatchet heated over a fire. This is all, what is needed for soldering in such cases.

Important points

Working with a soldering iron is not as simple as it might seem. The development of this skill will significantly expand the range of operations and technician, which you can use.

The art of soldering must be learned gradually. Starting from soldering wires and moving on to printed circuit boards, each method has its own subtleties both in the selection of consumables for soldering and in technology. Today we will share with readers the basics of soldering and basic work skills.

What is the essence of soldering

Soldering uses the ability of some metals in a molten state to effectively flow over the surface of others under the influence of gravity and moderate surface tension. The connection by soldering is permanent: the two parts being connected are, as it were, enveloped in a layer of solder and remain motionless after it hardens.

Since we will consider soldering specifically in the context of metal soldering, the most important parameters there will be mechanical strength and conductivity electrical connection. In most cases, these are directly proportional values ​​and if two parts are tightly grasped, then the conductivity between them will also be high. However, solder has a resistivity higher than even that of aluminum, so its layer should be as thin as possible and its hiding power as high as possible.

In order for soldering to be possible in principle, there are two conditions. The first and most important thing is the cleanliness of the parts at the soldering site. Solder attaches to the metal surface at the atomic level and the presence of even the slightest oxide film or contaminants will make reliable adhesion impossible.

The second condition is that the melting temperature of the solder must be significantly lower than the temperature of the parts being soldered. This seems obvious, but there are solders with a melting point higher than aluminum, for example. In addition, if the actual difference in melting temperatures is not high enough, when the solder solidifies, thermal shrinkage of the parts may prevent the normal formation of the solder crystal lattice.

Fluxes and solders - how to choose the right ones

For the reasons described above right choice flux and solder are almost half the success in the soldering business. Fortunately, there are quite universal brands suitable for most tasks. The area of ​​application of almost all fluxes and solders is clearly indicated on the labels, but some aspects of their use still need to be known.

Let's start with fluxes. They are used for etching parts, removing and dissolving the oxide film with further protection of the metal from corrosion. As long as the surface is covered with flux, you can be sure of its cleanliness, as well as that the molten tin will wet it well and spread.

Fluxes are distinguished by the type of metals and alloys of the parts being joined. Basically, these are mixtures of metal salts, acids and alkalis that actively react when heated with a soldering iron. Well, since there are quite a lot of oxide forms and contaminants, the cocktail must be specially selected for a specific type of metals and alloys.

Conventionally, soldering fluxes are divided into two types. Active fluxes are created on the basis of inorganic acids, mainly chloric and hydrochloric. Their disadvantage is that they need to be washed off immediately after soldering is completed, otherwise acid residues cause quite severe corrosion of the connection and themselves have a fairly high conductivity that can cause a short circuit. But you can solder almost anything with active fluxes.

The second type of flux is created primarily on the basis of rosin, which can also be used in its pure form. Liquid flux is much more convenient to apply; it also contains alcohol and/or glycerin, which completely evaporate when heated. Rosin fluxes are the least effective when soldering steel, but for non-ferrous metals and alloys they are mainly used or other compounds of organic chemistry. Rosin also requires rinsing because in the long term it promotes corrosion and can become conductive by picking up moisture from the air.

Liquid and solid rosin

With solders everything is somewhat simpler. Lead-tin solders of the POS brand are mainly used for soldering. The number after the marking indicates the tin content in the solder. The more it is, the higher the mechanical strength and electrical conductivity of the connection and the lower the melting temperature of the solder. Lead is used to normalize the solidification process; without it, the tin may crack or become covered with needles.

There are special types of solders, primarily lead-free (BP) and other non-toxic ones, in which lead is replaced by indium or zinc. The melting point of BP is higher than that of conventional ones, but the connection is stronger and more resistant to corrosion. There are also low-melting solders that spread already at 90-110 ºС. These include Wood and Rose alloys; they are used for soldering components that are sensitive to overheating. Special solders are mainly used in soldering radio equipment.

Power and types of soldering irons

The main difference between a soldering tool is the type of its power source. For ordinary people, the most familiar are network soldering irons powered by 220 V. They are used mainly for soldering wires and more massive parts, because it is almost impossible to overheat a copper wire, with the possible exception of melting the insulation.

The advantage of networked soldering irons is their high power. Due to it, high-quality and deep heating of the part is ensured, plus it does not require a bulky power supply for operation. Among the disadvantages, we can highlight the low ease of use: the soldering iron is quite heavy, the tip is located far from the handle and such a tool is not suitable for fine work.

Soldering stations use thermal control to maintain a stable temperature level. Such soldering irons do not have significant power, usually 40 W is already the ceiling. However, for heat-sensitive electronics and soldering small parts, this tool is best suited.

Choosing a tip and caring for it

Soldering iron tips are distinguished by shape and material. The shape is simple: the most primitive and at the same time universal is the awl-shaped sting. Variations are possible in the shape of a spatula, a cone with a blunt end, with a bevel, and others. The main task when choosing a shape is to achieve the maximum area of ​​contact with a specific type of parts to be soldered, so that the heating is powerful and at the same time short-lived.

In terms of material, almost all tips are copper, but they come with or without coating. Copper tips are coated with chromium and nickel to increase heat resistance and eliminate oxidation of the copper surface. Coated tips are very durable, but are slightly less wet with solder and require careful handling. To clean them, brass shavings and viscose sponges are used.

Uncoated tips can rightfully be classified as consumables for soldering. During operation, such a tip periodically becomes covered with a layer of oxides and the solder stops sticking to it. The working edge needs to be re-cleaned and tinned, so with intensive use the tip wears off quite quickly. To slow down the burning of the tip, it is recommended to first forge it and then sharpen it to give the desired shape.

Soldering wires

Soldering wires is the easiest. We dip the ends of the cores into the flux solution and run a soldering iron along them, the tip of which is generously moistened with flux. During the tinning process, it is advisable to shake off excess molten solder. After application, the half wires are formed into a twist, and then thoroughly heated with a small amount of solder, filling the free space between the wires.

Another method is also possible, when before twisting the wires are simply thoroughly moistened with flux and soldered without prior tinning. This method is especially popular when soldering stranded conductors and small-diameter wiring. If the flux is of high quality, and the soldering iron provides sufficiently strong heating, even a twist of 3-4 “fluffy” wires of 1.5 mm 2 each will be well saturated with tin and will be reliably soldered.

Please note that in electrical installations, that is, inside distribution boxes, it is not customary to solder wiring. Primarily due to the inseparability of the connection, plus the solder has a significant contact resistance and there is always a high risk of corrosion. Wires are soldered exclusively for connections inside electrical appliances or for tinning the ends of stranded wires before tightening them with screw terminals.

Working with electronic components

Soldering electronics is the most extensive and complex topic that requires experience, skills and special equipment. However, even an amateur can replace a faulty element on a printed circuit board even with only a network soldering iron.

Lead-out elements (those with legs) are the easiest to solder. They are preliminarily fixed (plasticine, wax) with pins in the holes of the board. Then, on the reverse side, the soldering iron is pressed tightly against the tail to warm it up, after which a solder wire containing flux is inserted into the soldering site. You don’t need too much tin, just enough so that it flows into the hole from all sides and forms a kind of elongated cap.

If the lead element dangles and needs to be held by hand, then the soldering area is first moistened with flux. A very small amount is needed; here it is optimal to use bottles of nail polish, pre-washed with acetone. With this soldering technique, tin is collected on the soldering iron in a small amount and a drop of it is carefully brought to the terminal of the element 1-2 mm from the surface of the board. The solder flows down the leg, uniformly filling the hole, after which the soldering iron can be removed.

It is very important that the parts to be joined remain motionless until the solder has completely cooled. Even the slightest violation of the shape of tin during crystallization leads to the so-called cold soldering - crushing the entire mass of solder into many small crystals. A characteristic sign of this phenomenon is a sharp clouding of the solder. It needs to be reheated and wait until it cools evenly, completely still.

Poor quality, cold soldering

To maintain tin in liquid state, it is enough for the soldering iron to contact the tinned surface of the tip with any point of the moistened area. If the soldering iron literally sticks to the parts being soldered, this indicates a lack of heating power. For soldering heat-sensitive semiconductor elements and microcircuits, regular solder can be mixed with fusible solder.

Soldering of massive parts

Finally, we'll briefly talk about soldering parts with high heat capacity, such as cable joints, tanks or cookware. The requirement for the immobility of the joint is most important here; large parts are pre-connected with clamps, small parts with lumps of plasticine; before soldering the joint, it is grabbed pointwise in several places and the clamps are removed.

Massive parts are soldered as usual - first, solder at the joint, then fill the seam with liquid solder. However, special solder is used for these purposes, usually refractory and capable of maintaining high tightness, as well as withstanding partial heating well.

When soldering like this, it is extremely important to keep the parts well heated. For these purposes, the soldering seam immediately before the soldering site is heated with a gas burner, and instead of a conventional electric soldering iron, a massive copper hatchet is used. It is also constantly heated in the flame of a burner, simultaneously wetting it with solder, and then the joint is filled, partially melting the previous seam by a few millimeters.

A similar heated soldering technique can also be used when working with a regular soldering iron, for example, when soldering thick cable cores. The sting in this case acts only as an operational tool for carefully distributing the tin, and the main source of heating is a gas burner.

One of the most reliable methods of connecting wires and parts is soldering. How to solder correctly with a soldering iron, how to prepare a soldering iron for work, how to get reliable connection- more on all this later.

In everyday life, “ordinary” electric soldering irons are used. There are those that operate from 220 V, there are from 380 V, there are from 12 V. The latter are characterized by low power. They are used mainly in enterprises in areas with increased danger. They can also be used for domestic purposes, but they heat up slowly, and the power is not enough...

You need to choose the one that fits comfortably in your hand

Power selection

The power of the soldering iron is selected depending on the nature of the work:


IN household It is enough to have two soldering irons - one low-power - 40-60 W, and one “medium” - about 100 W. With their help, it will be possible to cover about 85-95% of needs. But it is still better to entrust the soldering of thick-walled parts to a professional - this requires specific experience.

Preparing for work

When the soldering iron is plugged in for the first time, it often starts to smoke. This burns out the lubricants that were used in the production process. When the smoke stops coming out, turn off the soldering iron and wait until it cools down. Next you need to sharpen the tip.

Sharpening the tip

Next, you need to prepare the tip for work. It is a cylindrical rod made of copper alloy. It is fixed using a clamping screw, which is located at the very end of the heat chamber. In more expensive models, the tip may be slightly sharpened, but basically there is no sharpening.

We will change the very tip of the sting. You can use a hammer (flatten the copper as you need), a file or emery (just grind off the unnecessary). The shape of the tip is chosen depending on the intended type of work. It can be:

  • Flatten it into a spatula (like a screwdriver) or make it flat on one side (angled sharpening). This type of sharpening is needed if massive parts will be soldered. This sharpening increases the contact surface and improves heat transfer.
  • You can grind the edge of the tip into a sharp cone (pyramid) if you plan to work with small parts (thin wires, electrical parts). This makes it easier to control the degree of heating.
  • The same cone, but not so sharp, is suitable for working with conductors of larger diameter.

Sharpening with a “spatula” is considered more universal. If it is formed with a hammer, the copper will be compacted and the tip will need to be adjusted less often. The width of the “shovel” can be made larger or smaller by trimming it on the sides with a file or emery. With this type of sharpening you can work with thin and medium-sized parts to be soldered (rotate the tip to the desired position).

Soldering iron tinning

If the soldering iron tip does not have a protective coating, it must be tinned - covered with a thin layer of tin. This will protect it from corrosion and rapid wear. This is done the first time you turn on the instrument, when the smoke has ceased to be emitted.

The first method of tinning a soldering iron tip:

  • bring to operating temperature;
  • touch the rosin;
  • melt the solder and rub it along the entire tip (you can use a wooden sliver).

Second way. Moisten a rag with a solution of zinc chloride and rub the heated tip on the rag. Melt the solder and rub it with a piece of table rock salt over the entire surface of the tip. In any case, the copper should be covered with a thin layer of tin.

Soldering technology

Almost everyone now uses electric soldering irons. Those whose work involves soldering prefer to have a soldering station, “hobbyists” prefer to make do with ordinary soldering irons without regulators. Having several soldering irons of different power is enough for different types of work.

To figure out how to solder correctly with a soldering iron, you need to have a good understanding of the process in general, then delve into the nuances. So let's start with brief description sequences of actions.

Soldering involves a sequence of repeated actions. We will talk about soldering wires or radio parts. These are the ones you encounter more often on the farm. The actions are:


This completes the soldering. It is necessary to cool the solder and check the quality of the connection. If everything is done correctly, the soldering area will have a bright shine. If the solder appears dull and porous, this is a sign of insufficient temperature during soldering. The soldering itself is called “cold” and does not provide the required electrical contact. It is easily destroyed - just pull the wires in different directions or even pick it up with something. The soldering area may also be charred - this is a sign of a reverse error - too high temperature. In the case of wires, this is often accompanied by melting of the insulation. However, electrical parameters are normal. But, if the conductors are soldered when installing the wiring, it is better to redo it.

Preparation for soldering

First, let's talk about how to properly solder wires with a soldering iron. First you need to remove the insulation. The length of the exposed area can be different - if you are going to solder wiring - power wires, expose 10-15 cm. If you need to solder low-current conductors (the same headphones, for example), the length of the exposed area is small - 7-10 mm.

After removing the insulation, the wires must be inspected. If there is varnish or oxide film on them, it must be removed. Freshly stripped wires usually do not have an oxide film, and sometimes varnish is present (copper is not red in color, but brownish). Oxide film and varnish can be removed in several ways:

  • Mechanically. Use fine grit sandpaper. It is used to process the exposed part of the wire. This can be done with single-core wires of fairly large diameter. Sanding thin wires is inconvenient. Stranded ones can generally be cut off.
  • Chemical method. Oxides are highly soluble in alcohol and solvents. The varnish protective coating is removed using acetylsalicylic acid (regular pharmacy aspirin). The wire is placed on the tablet and heated with a soldering iron. Acid will corrode the varnish.

In the case of varnished (enameled) wires, you can do without stripping - you need to use a special flux, which is called “Flux for soldering enamel wires”. It itself destroys the protective coating during soldering. Just so that it does not subsequently begin to destroy the conductors, it must be removed after soldering is completed (with a damp cloth or sponge).

If you need to solder a wire to some metal surface (for example, a ground wire to a circuit), the preparation process does not change much. The area to which the wire will be soldered must be cleaned to bare metal. First, all contaminants (including paint, rust, etc.) are mechanically removed, after which the surface is degreased using alcohol or a solvent. Next you can solder.

Fluxing or tinning

When soldering, the main thing is to ensure good contact between the parts being soldered. To do this, before starting soldering, the parts to be joined must be tinned or treated with flux. These two processes are interchangeable. Their main purpose is to improve the quality of the connection and facilitate the process itself.

Tinning

To process the wires you will need a well-heated soldering iron, a piece of rosin, and a small amount of solder.

We take the stripped wire, lay it on rosin, and heat it with a soldering iron. While warming up, we turn the conductor. When the wire is completely covered in molten rosin, put a little solder on the soldering iron tip (just touch it with the tip). Then we remove the wire from the rosin and run the tip of the tip along the exposed conductor.

Tinning wires is a mandatory step when soldering

In this case, the solder covers the metal with a thin film. If it is copper, it turns from yellow to silver. The wire also needs to be turned a little, and the tip must be moved up/down. If the conductor is well prepared, it becomes completely silver, without gaps or yellow paths.

Flux treatment

Here everything is both simpler and more complicated. Easier in the sense that you only need the composition and a brush. Dip the brush into the flux and apply a thin layer of the compound to the soldering area. All. This is simplicity.

Difficulty in choosing flux. There are many varieties of this composition and you need to select your own for each type of work. Since we are now talking about how to properly solder wires or electronic components (boards) with a soldering iron, we will give several examples of good fluxes for this type of work:


For soldering electronic components (printed circuit boards), do not use active (acid) fluxes. Better - water or alcohol based. Acidic ones have good electrical conductivity, which can disrupt the operation of the device. They are also very chemically active and can cause destruction of insulation and corrosion of metals. Due to their activity, they prepare metals very well for soldering, so they are used if it is necessary to solder a wire to metal (the pad itself is processed). The most common representative is “Soldering Acid”.

Preheating and temperature selection

If you want to know how to solder correctly with a soldering iron, you need to learn how to determine whether the soldering area is hot enough. If you use a regular soldering iron, you can navigate by the behavior of rosin or flux. At a sufficient level of heating, they actively boil, release steam, but do not burn. If you lift the tip, drops of boiling rosin remain on the tip of the tip.

Using soldering station based on the following rules:


That is, at the station we set it 60-120°C higher than the melting temperature of the solder. As you can see, the temperature gap is large. How to choose? Depends on the thermal conductivity of the metals being soldered. The better it removes heat, the higher the temperature should be.

Soldering

When the soldering area is hot enough, you can add solder. It is introduced in two ways - molten, in the form of a drop on the soldering iron tip, or in solid form (solder wire) directly into the soldering zone. The first method is used if the soldering area is small, the second - for large areas.

If you need to add a small amount of solder, touch it with the soldering iron tip. There is enough solder if the tip turns white and not yellow. If a drop hangs, this is too much, it must be removed. You can tap the edge of the stand a couple of times. Then they immediately return to the soldering zone, running the tip along the soldering area.

In the second case, we insert the solder wire directly into the soldering zone. When heated, it begins to melt, spreading and filling the voids between the wires, taking the place of evaporating flux or rosin. In this case, you need to remove the solder in time - its excess also does not have a very good effect on the quality of soldering. In the case of soldering wires, this is not so critical, but when soldering electronic elements on boards it is very important.

In order for the soldering to be of high quality, everything must be done carefully: strip the wires, warm up the soldering area. But overheating is also undesirable, as is too much solder. This is where you need measure and experience, and you can gain it by repeating all the steps a certain number of times.

Device for more convenient soldering - third hand

How to learn to solder with a soldering iron

To begin, take several pieces of single-core wire of small diameter (you can use installation wires, those used in communications, etc.) - they are easier to work with. Cut them into small pieces and practice on them. Try to solder the two wires together first. By the way, after tinning or fluxing, it is better to twist them together. This will increase the contact area and make it easier to hold the wires in place.

When soldering is reliable several times, you can increase the number of wires. They will also need to be twisted, but you will have to use pliers (two wires can be twisted by hand).

Normal soldering means:


After you have mastered soldering several wires (three...five), you can try stranded wires. The difficulty lies in stripping and tinning. You can only strip it using a chemical method, and tin it by first twisting the wires. Then you can try to twist the tinned conductors, but this is quite difficult. You will have to hold them with tweezers.

When this is mastered, you can train on wires of a larger cross-section - 1.5 mm or 2.5 mm. These are the wires that are used when laying wiring in an apartment or house. Here you can train on them. Everyone too, but working with them is more difficult.

After soldering is completed

If the wires were treated with acid fluxes, after the solder has cooled, its remains must be washed off. To do this, use a damp cloth or sponge. They are soaked in the solution detergent or soap, then remove moisture and dry.

You know how to solder correctly with a soldering iron, now you need to acquire practical skills.

Sections