The soldering process is the chemical joining of two metals using solder. Moreover, the crystal structure of the metal does not change. That is, the connected parts remain with their technical characteristics.

The connection itself is quite reliable, but much will depend on the type of solder and soldering technology. In addition, it should be noted that not all metals can be joined by this process. Basic metals, especially steel (iron), can be soldered together.

There are three technologies for soldering iron with tin:

1. soldering iron To do this, you will have to use soft solders with a high lead content;
2. blowtorch. This will require hard solders with a high tin content;
3. electrical soldering of iron.

The first method is used if the iron will not be subjected to heavy loads during operation. The second is tinning of iron with tin, when tin solder is applied to the surface of a metal product and rubbed over its entire plane in a thin layer.

This technology requires soldering flux. The third option is used on a production scale, for which special equipment is used.

Soldering sheet metal

Soldering tin (thin sheet iron) is a common process in the manufacture of metal containers. But often, even at home, it is necessary to fasten sheets of iron together, assembling sealed structures. Therefore, before soldering one sheet to another, you need to prepare everything you need.

For the process of soldering iron with tin, you will need solder with a small concentration of tin, for example, POS-40, flux, a soldering iron and an awl.

In the process of soldering iron, flux acts as a solvent and an oxidizing agent at the same time. That is, the metal is immediately wetted and protected from oxidative processes. Rosin and hydrochloric acid or zinc chloride and boric acid.

As for the soldering iron, for high-quality tin soldering it is better to choose an electric tool with a power of more than 40 W. The old soldering tool, which is heated by the flame of a fire, is practically not used today, even at home.

Sequencing

Here are the main stages of this process:

• cleaning of joined sheets;
• applying flux;
• heating up the soldering iron and tinning;
• soldering with tin;
• cleaning the joint with gasoline.

Cleaning is carried out mechanically with sandpaper. If the contamination is large, you will have to treat it with a solvent. If it is not possible to clean it using this method, then etching is carried out with sulfuric acid.

Two pieces of sheet iron are brought to each other at a distance of 0.3 mm. Their edges are treated with paste-like flux using a brush. The soldering iron tip is cleaned with sandpaper, and the tool itself is turned on electrical network through the socket. To check whether it has heated up well, you need to place its tip in the ammonia mixture, which should boil.

Now the stage of tinning the iron is carried out. That is, with the help of or its alloy, the edges of two sheets of tin are processed in order to cover them with a tin layer, which will perform protective functions against metal corrosion.

Everything is ready, all that remains is to solder the two ends of the sheets. The soldering iron tip is brought to the joint along with the tin solder, and they both move smoothly along the joint boundary.

In this case, the tip must be pressed not with a sharp end, but with a flat edge, due to which the parts being connected will warm up at the same time, which will affect the high quality of the iron soldering.

Features of working with galvanized products

Soldering galvanized tin cleanly technological process no different from the previous one. But the technology has its own subtle nuances that affect the quality of the final result.

You cannot solder galvanized steel with solders that contain large amounts of antimony. This substance, when in contact with zinc coating, creates a weak seam.

It is better to use boric acid and zinc chloride as flux. If the products themselves have already been tinned with tin during the production process, then rosin can be used as a flux.

When a connection is made between galvanized iron (sheet) and wire, the latter must be bent at a right angle to increase the contact area of ​​the two products.

The rest of the process is carried out exactly the same. By the way, it doesn’t matter whether the wire was made of galvanized or ordinary steel.

There are several more important points that must be taken into account in the process of soldering galvanized products. If solder rods based on tin and lead are used for soldering iron, then it is better to add flux based on zinc chloride and ammonium chloride. The ratio is 5:1 respectively.

Tin and cadmium based solder requires caustic soda as a flux additive.

If galvanized iron products, the protective layer of which contains more than 2% aluminum, are connected to each other, then solder based on tin and zinc is used. And hydrochloric acid and petroleum jelly (stearin) are used as flux.

Regardless of which parts or assemblies are connected by soldering, it is necessary, after the process is completed and the seam has cooled, to rinse the joint with water to remove any remaining flux.

Safety precautions

Soldering iron with tin is an unsafe process. Therefore, precautions must be strictly observed. Protective gloves are put on your hands, and a stand must be installed under the soldering iron so that the heated tip does not touch the table and available materials. And the procedure itself must be carried out carefully.

Despite the apparent simplicity of the soldering operation, it is actually a serious procedure. And you need to treat it with great attention. Something was missed, they were even applied incorrectly, and we can assume that the quality of the joint has dropped sharply. Therefore, it is important to approach each stage responsibly, especially when it comes to cleaning two joined iron products.

Any radio amateur or home DIYer who is interested in radio design, electrical appliance repair, and other activities related to electrical and electronic devices should be able to solder. You can read about how to solder with a soldering iron with rosin in many manuals. But it is very important to have not only theoretical knowledge, but also practical skills and work experience. Let's look at the basic requirements and stages of learning how to solder. What every radio amateur needs to know?

For a beginner radio amateur, it is very important to know the basics of working with a soldering iron.

Amateur radio soldering kit

Every fan of working with radio-electronic devices should have a minimum set of tools. This includes pliers, screwdrivers, files, wire cutters and much, much more. But the most important elements soldering kit are: the soldering iron itself (their variety is quite large, everyone should choose a convenient model to suit their preferences), solder (a metal alloy based on a different combination of lead and tin) and flux (the most common of them is rosin - a product of processing pine resin) . It is also worth adding tweezers here, which can greatly facilitate the soldering of small elements. Let's take a closer look at the parts of this set.

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Soldering iron features

For a beginner radio amateur, a soldering iron with a power of 40 W is suitable.

If you are a novice craftsman, then it is best to purchase a regular soldering iron for a 220 V network with a power of 40 W. This is the basis from which it is better not to deviate in order to avoid a lot of problems. In the future, as your skill grows, you can purchase a power regulator for your soldering iron, which will help you independently regulate the temperature of your soldering iron tip and, accordingly, carry out more delicate work. When soldering, the cleanliness of the tip surface is extremely important, since a film of oxides constantly forms on it, preventing good contact with the solder. To do this, you need to warm up the soldering iron and clean its tip with sandpaper. After this, dip the soldering iron in rosin so that a dark, damp film forms on the surface of the tip. Then you can dip the tip of the tip into the solder and rub it there so that the solder covers the work surface in an even layer. Later, when a new film of oxides is formed, the operation can be repeated.

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Solder is an alloy of tin and lead.

Using solder, metal structural elements are connected to each other.

Solder is a mandatory part of soldering in radio electronics. It is he who helps connect various metal structural elements together. From a chemical point of view, it is an alloy of lead and tin, the proportions can vary significantly depending on the manufacturer and the job being performed. Most often, solder is sold in the form of a silver-metallic wire, but there are options in the form of a hollow tube, the inside of which is pre-filled with rosin (flux) for ease of soldering. But still, experienced craftsmen prefer to choose wire solder, since flux will still be needed for each soldering, only its quantity differs. Each type of solder has its own alphanumeric marking, which indicates to buyers its performance characteristics and composition.

For example, there are varieties of solders such as POS 40 or POS 60. The abbreviation stands for tin-lead solder, and the number indicates the percentage of the main element of the alloy - tin. Many craftsmen prefer to work with pure tin or alloys with the highest possible content. The higher the lead level, the higher the melting point and the darker the color. The same POS 60 has a melting point of 190 degrees Celsius.

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Flux Features

The main task of fluxes is to clean metal oxides from the surface of the elements being joined. In addition, such compositions prevent the appearance of these oxides in the future. Flux also helps improve contact between parts by wetting and preparing the surface for contact with solder. You can see for yourself the effectiveness of the flux on specific example. Try soldering with a soldering iron with and without rosin. The fact is that the main metal of the tip is copper, which very quickly during the heating process becomes covered with a film of oxides that prevents contact with the solder; it will simply roll off the surface of the soldering iron in hot drops. But as soon as you dip the tip into the rosin, a wet-looking film of flux will form on the surface of the soldering iron, which will hold the solder on the soldering iron tip and allow you to carry out soldering work. When speaking of flux, most craftsmen mean pine rosin. It is she who most often plays this role, outwardly resembling frozen pieces of amber. The same rosin is used to treat the bows of musical instruments.

But pine resin is not the only flux option. In addition, to work with metal utensils, zinc dissolved in hydrochloric acid is used; this mixture is called soldering acid. But this composition is not applicable in radio engineering due to its causticity. One drop is enough to destroy an important connection or metal wire. Acids cannot be used in soldering radio components. best gumboil- this is rosin. But sometimes craftsmen use alcohol solutions of rosin when it is necessary to treat contacts in hard-to-reach places. To do this, ground rosin is dissolved in alcohol and then applied in a thin layer to the site of the future connection.

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A few secrets of soldering

In principle, there are no particular difficulties in soldering various metal elements together. You can solder, especially without going into any nuances of craftsmanship, but if you want to do the job efficiently, it’s worth considering a few small secrets.

If you have never dealt with a soldering iron before, we recommend that you practice a little. To do this, you can take several pieces copper wire in the shell. With it you can develop skills in proper tinning and soldering.

In addition to those nuances that are listed when describing the main components of soldering (soldering iron, flux and solder), you need to take into account others:

1. When soldering, the cleanliness of the surfaces being connected is extremely important. All contact points must be thoroughly cleaned and prepared for soldering. To do this, you must first clean the future soldering area with a knife or sandpaper. As you clean, you will see the metal become lighter and brighter. This involves removing the thin and unnoticeable film of copper oxides that covers the surface of your wire. After physically cleaning the contacts, you need to dip the tip of a heated soldering iron into rosin and transfer a little rosin onto the surface to be treated. Carefully and carefully disperse the molten flux over the workpiece. As a result, your working surface should be cleaned of oxides and covered with a film of rosin.
2. It is extremely important to correctly connect the conductors together, as well as warm up the place of future connection. To do this, you need to evenly and tightly press the ends of the soldered conductors, which were previously tinned, as described above, to each other, and then apply a soldering iron tip with a drop of molten solder on it to the junction. Hold for a while, let the conductors warm up enough so that the solder alloy spreads and fills the entire space between the elements being fused. The heating should be such that the solder spreads over the working surface and does not harden in one lump. Remove the soldering iron and let the solder cool. Do not move the conductors under any circumstances. It is better if they cool down for at least 10 seconds. Now the solder securely holds both conductors together.
3. If the surface to be soldered is large and there is not enough solder to fill it all, then simply wait until the first batch of solder has cooled and apply another one with a soldering iron. Achieve even distribution of the alloy over the surface being treated. Solder that has frozen in a lump is an indicator of poor quality work by a beginner. For a real master, solder covers the surface like a second skin, evenly and on all sides.

Soldering with a soldering iron is one of the most common and simple ways soldering, however it has two significant limitations. Firstly, a soldering iron can only be soldered with low-melting (soft) solders, and secondly, it is impossible (or, in any case, difficult) to solder massive parts with a large heat sink - due to the impossibility of heating them to the melting temperature of the solder. The last limitation is overcome by heating the part to be soldered with an external heat source - a gas burner, electric or gas stove, or some other method - but this complicates the soldering process.

Before you solder with a soldering iron, you need to get everything you need. The main tools and materials without which soldering is impossible include the soldering iron itself, solder and flux.

Soldering irons

Depending on the heating method, soldering irons can be “conventional” - electric (with a spiral or ceramic heater), gas (with a gas burner), hot-air (heat is transferred by air flow), and induction. Massive hammer soldering irons can be heated not only with electricity, but also in the old fashioned way - with an open flame.

You can learn how to use such a soldering iron from the descriptions of the technology of tin work, which is where they were used most often. Nowadays, electric soldering irons are usually used due to their availability and ease of use. But the first soldering irons were heated over an open flame.

The main parameter by which a soldering iron is selected is its power, which determines the amount of heat flow transferred to the parts being soldered. Devices with a power of up to 40 W are used for soldering electronic components. Thin-walled parts (with a wall thickness of up to 1 mm) require a power of 80-100 W.

For parts with a wall thickness of 2 mm or more, soldering irons with a power above 100 W will be needed. These are, in particular, electric hammer soldering irons that consume up to 250 W and higher. The most energy-intensive soldering irons include, for example, the Ersa Hammer 550 hammer soldering iron with a power of 550 W. It is capable of heating up to a temperature of 600°C and is designed for soldering particularly massive parts - radiators, machine parts. But it has an inadequate price.

In addition to the massiveness of the part, on required power soldering iron also affects the thermal conductivity of the metal being soldered. As it increases, the power of the device and its heating temperature must be increased. When soldering parts made of copper with a soldering iron, it must be heated more than when soldering a part of the same mass, but made of steel. By the way, when working with copper products, a situation may arise when, due to the high thermal conductivity of the metal, during soldering, desoldering of previously completed areas will occur.

Solders

When soldering with electric soldering irons, low-temperature tin-lead (POS-30, POS-40, POS-61), tin-silver (PSr-2, PSr-2.5) or other solders and pure tin are used. The disadvantages of solders containing lead include the harmfulness of the latter, the advantages - best quality soldering than lead-free solders. Pure tin is used for soldering food utensils.

Fluxes

It is generally accepted that tin, silver, gold, copper, brass, bronze, lead, and nickel silver can be soldered well. Satisfactory - carbon and low-alloy steels, nickel, zinc. Poor - aluminum, high-alloy and stainless steels, aluminum bronze, cast iron, chrome, titanium, magnesium. However, without disputing these data, we can say that there is no poorly soldered metal, there is poor preparation of the part, incorrectly selected flux and incorrect temperature conditions.

Selecting the right flux for soldering means solving the main problem of soldering. It is the quality of the flux that primarily determines the solderability of a particular metal, the ease or difficulty of the soldering process itself, and the strength of the connection. The flux must correspond to the material of the products being soldered - in its ability to destroy its oxide film.

Acidic (active) fluxes, such as "Soldering Acid" based on zinc chloride, cannot be used when soldering electronic components, as they conduct well electricity and cause corrosion, however, due to their aggressiveness, they prepare the surface very well and are therefore indispensable when soldering metal structures, and the more chemically resistant the metal, the more active the flux should be. Residues of active fluxes must be carefully removed after soldering is completed.

Effective fluxes for soldering steel are an aqueous solution of zinc chloride, soldering acids based on it, and LTI-120 flux. You can also use other, stronger fluxes, of which there are plenty on the market.

The main difference between soldering stainless steels with a soldering iron and soldering carbon and low-alloy steels is the need to use more active fluxes, which are required to destroy the chemically resistant oxides with which stainless steels are coated. As for cast iron, it needs to be soldered with high-temperature soldering, and, therefore, an electric soldering iron is not suitable for this purpose.

For stainless steel, phosphoric acid is used. Specialized fluxes, such as F-38, also cope well with chemically resistant oxide films.

For galvanized iron, you can use a composition containing rosin, ethyl alcohol, zinc chloride and ammonium chloride (LK-2 flux).

Auxiliary materials and devices

You can do without some devices and materials used for soldering, but their presence makes the work much more convenient and comfortable.

Soldering iron stand serves to ensure that the heated soldering iron does not touch the table or other objects. If it does not come with a soldering iron, you can purchase it separately or make it yourself. The simplest stand can be made from a thin sheet of tin, cutting grooves in it for storing tools.

Wet viscose or foam rubber sponge, placed in a socket to prevent falling out, it is much more convenient to clean the tip of the soldering iron than with a regular cloth. Brass shavings can also serve for the same purposes.

You can remove excess solder from the surface of parts using special suction or braids. The first one, in appearance and design, resembles a syringe equipped with a spring. Before use, it must be cocked by recessing the rod head. By bringing the nose to the molten solder, the spring is released by pressing the release button. As a result, excess solder is drawn into the removal head.

It is a braid of fluxed thin copper wires. By placing its end on the solder and pressing it on top with a soldering iron, thanks to capillary forces you can collect all the excess solder in it like a blotter. The tip of the braid, saturated with solder, is simply cut off.

A very useful device is called third hand(Third-Hand Tool). When working with a soldering iron, sometimes there are catastrophically “not enough hands” - one is occupied with the soldering iron itself, the other with the solder, but you still need to hold the soldered parts in a certain position. The “third hand” is convenient because its clamps can be easily installed in any position relative to each other.

Soldering holder "Third hand"

The parts being soldered are heated to high temperatures; touching them can cause you to get burned. Therefore, it is desirable to have various clamping devices that allow the manipulation of heated parts - pliers, tweezers, clamps.

Preparing the soldering iron for use

When you turn on the soldering iron for the first time, it may start to smoke. There is nothing wrong with this, the oils used to preserve the soldering iron simply burn out. You just need to ventilate the room.

Before using a soldering iron, you need to prepare its tip. Preparation depends on its original form. If the tip is made of bare copper, the tip can be forged into a screwdriver shape, this will seal the copper and make it more resistant to wear. You can simply sharpen it with sandpaper or a file, giving it the required shape - in the form of a sharp or truncated cone with a different angle, a tetrahedral pyramid, an angular bevel on one side. Nickel metal coatings are used to protect copper from oxidation. If the soldering iron has such a coating, then it cannot be forged or sharpened to avoid damaging the coating layer.

There is a standardized range of tip shapes, but you can, of course, use any shape suitable for the particular job.

When soldering massive parts, the contact area between the soldering iron and the part should be maximum to ensure better heat transfer. In this case, angular sharpening of a round rod (2 in the photo above) is considered the best. If you plan to solder small parts, then a sharp cone (4), knife or other shapes with small angles are suitable.

Instructions for working with a soldering iron that has an uncoated copper tip contain one mandatory requirement - tinning the “tip” of the new soldering iron in order to protect it from oxidation and wear. Moreover, this should be done during the first heating, without delay. Otherwise, the “tip” will be covered with a thin layer of scale, and the solder will not want to stick to it. This can be done in different ways. Warm up the soldering iron to operating temperature, touch the “tip” to the rosin, melt the solder on it and rub the solder on a piece of wood. Or wipe the heated tip with a rag moistened with a solution of zinc chloride, melt solder on it and rub it over the tip with a piece of ammonia or rock table salt. The main thing is that as a result of these operations, the working part of the tip is completely covered with a thin layer of solder.

The need to tin the tip is caused by the fact that the flux gradually corrodes, and the solder dissolves the tip. Due to loss of shape, the tip has to be sharpened regularly, and the more active the flux, the more often, sometimes several times a day. For nickel-plated tips, nickel blocks access to copper, protecting it, but such tips require careful handling, they are afraid of overheating, and it is not a fact that the manufacturer has made a sufficiently high-quality coating, for which they require an overpayment.

Preparing parts for soldering

Preparing parts for soldering involves performing the same operations regardless of what type of soldering (low-temperature or high-temperature) is performed, and what heating source (electrical or gas soldering iron, gas-burner, inductor or something else) is used.

First of all, this is cleaning the part from dirt and degreasing. There are no special subtleties here - you need to use solvents (gasoline, acetone or others) to clean the part from oils, fats, and dirt. If there is rust, it must be removed by any suitable mechanical method - using an emery wheel, wire brush or sandpaper. In the case of high-alloy and stainless steels, it is advisable to treat the edges being joined with an abrasive tool, since the oxide film of these metals is particularly strong.

Soldering temperature

The heating temperature of the soldering iron is the most important parameter; the quality of soldering depends on the temperature. Insufficient temperature manifests itself in the fact that the solder does not spread over the surface of the product, but forms a lump, despite the preparation of the surface with flux. But even if the soldering was successful in appearance (the solder melted and spread over the joint), the soldered joint turns out to be loose, matte in color, and has low mechanical strength.

The soldering temperature (temperature of the parts being soldered) should be 40-80°C higher than the melting temperature of the solder, and the heating temperature of the tip should be 20-40°C higher than the soldering temperature. The last requirement is due to the fact that when it comes into contact with the parts being soldered, the temperature of the soldering iron will decrease due to heat dissipation. Thus, the heating temperature of the tip should exceed the melting temperature of the solder by 60-120°C. If a soldering station is used, the required temperature is simply set by the regulator. When using a soldering iron without temperature control, its actual value, when using rosin as a flux, can be assessed by the behavior of the rosin when touched by the soldering iron. It should boil and release abundant steam, but not burn instantly, but remain on the tip in the form of boiling drops.

Overheating the soldering iron is also harmful; it causes combustion and charring of the flux until it activates the junction surface. Overheating is indicated by a dark film of oxides appearing on the solder located at the tip of the soldering iron, as well as by the fact that it does not stay on the “tip” and flows off it.

Soldering technique with a soldering iron

There are two main methods of soldering with a soldering iron:

• Supply (drain) of solder onto the parts to be soldered from the tip of the soldering iron.
• Supplying solder directly to the parts to be soldered (to the pad).

With any method, you must first prepare the parts for soldering, install and secure them in their original position, heat the soldering iron and moisten the joint with flux. Further steps differ depending on which method is used.

When feeding solder from a soldering iron, a certain amount of solder is melted on it (to keep it on the tip) and the “tip” is pressed against the parts being soldered. In this case, the flux will begin to boil and evaporate, and the molten solder will move from the soldering iron to the soldering joint. The movement of the tip along the future seam ensures the distribution of solder along the joint.

Solder on the jelly may be sufficient if the tip has simply acquired a metallic sheen. If the shape of the tip has noticeably changed, there is too much solder.

When applying solder directly to a junction, use a soldering iron to first heat the parts to soldering temperature, and then apply solder to the part or to the joint between the soldering iron and the part. As the solder melts, it will fill the joint between the parts being soldered. You should choose exactly how to solder with a soldering iron - the first or second method - depending on the nature of the work being performed. The first method is better for small parts, the second for large parts.

The basic requirements for high-quality soldering include:

• good heating of the soldering iron and parts being soldered;
• sufficient amount of flux;
• entering the required amount of solder - exactly as much as required, but no more.

Here are some tips on how to solder correctly with a soldering iron.

If the solder does not flow, but is smeared, it means that the temperature of the parts has not reached the required values, you need to increase the heating temperature of the soldering iron or use a more powerful device.

There is no need to add too much solder. High-quality soldering requires the presence of a minimum sufficient amount of material in the joint, at which the seam turns out to be slightly concave. If there is too much solder, there is no need to try to attach it somewhere at the joint; it is better to remove it with suction or braiding.

The quality of the junction is indicated by its color. High quality - the solder has a bright shine. Insufficient temperature makes the structure of the junction grainy and spongy - this is a definite defect. Burnt solder looks dull and has reduced strength, which in some cases may be quite acceptable.

When using active (acidic) fluxes, be sure to wash off their residues after soldering - with some detergent or ordinary alkaline soap. Otherwise, there is no guarantee that after some time the connection will not be destroyed by corrosion from remaining acids.

Tinning

Tinning - coating the metal surface with a thin layer of solder - can be either an independent, final operation, or an intermediate, preparatory stage of soldering. When this is the preparatory stage, successful tinning of the part in most cases means that the most difficult part of the soldering job (joining the solder to the metal) is done; soldering the tinned parts to each other is usually no longer difficult.

Wire tinning. Tinning the ends of electrical wires is one of the most common operations. It is carried out before soldering the wires to the contacts, soldering them together, or to ensure better contact with the terminals when connecting with bolts. It is convenient to make a ring from a tinned stranded wire, which ensures ease of attachment to the terminal and good contact.

Wires can be single-core or stranded, copper or aluminum, varnished or not, clean new or acidified old. Depending on these features, their servicing differs.

The easiest way to tin is single-core copper wire. If it is new, then it is not covered with oxides and tins even without stripping, you just need to apply flux to the surface of the wire, apply solder to the heated soldering iron and move the soldering iron along the wire, slightly turning the wire. As a rule, tinning proceeds without problems.

If the conductor does not want to tinker - due to the presence of varnish (enamel) - regular aspirin helps. Knowing how to solder with a soldering iron using an aspirin tablet (acetylsalicylic acid) can be very useful in some cases. You need to put it on a board, press the conductor to it and heat it for a few seconds with a soldering iron. At the same time, the tablet begins to melt, and the resulting acid destroys the varnish. After this, the wire usually tins easily.

If there is no aspirin, vinyl chloride insulation from electrical wires, which when heated, releases substances that destroy the varnish coating, also helps to remove the varnish that interferes with tinning from the surface of the conductor. You need to press the wires to a piece of insulation with a soldering iron and drag it several times between the insulation and the soldering iron. Then tin the wire as usual. When removing varnish using sandpaper or a knife, cuts and breaks of thin wire strands are common. When stripped by firing, the wire may lose strength and break easily.

It should be taken into account that melted polyvinyl chloride and aspirin release substances harmful to health into the air.

Also, for varnished (enamel) wires, you can purchase a special flux that removes the varnish.

New stranded copper wire can be tinned just as easily as solid copper wire. The only peculiarity is to rotate it in the direction in which the wires will twist and not unwind.

Old wires may be coated with oxides that prevent tinning. The same aspirin tablet will help to cope with them. You need to untwist the conductor, put it on aspirin and heat it for a few seconds with a soldering iron, moving the conductor back and forth - and the tinning problem will disappear.

To tinning an aluminum wire, you will need a special flux - for example, the one called “Flux for soldering aluminum”. This flux is universal and is also suitable for soldering metals with a chemically resistant oxide film - stainless steel, in particular. When using it, you just need to remember to clean the connection from flux residues afterwards to avoid corrosion.

If, when tinning the wires, excess surf has formed on them, you can remove it by placing the wire vertically, end down, and pressing a heated soldering iron to its end. Excess solder will flow from the wire onto the soldering iron.

Tinning a large metal surface

Tinning the surface of the metal may be necessary to protect it from corrosion or for subsequent soldering of another part to it. Even if a completely new sheet is tinned, which looks clean in appearance, there can always be foreign substances on its surface - preservative grease, various pollution. If a sheet covered with rust is tinned, then it needs cleaning all the more. Therefore, tinning always begins with thorough cleaning of the surface. Rust is cleaned off with emery cloth or a wire brush, fats and oils are removed with gasoline, acetone or another solvent.

Then, using a brush or other tool that matches the flux, flux is applied to the surface of the sheet (this may not be a paste-like flux as in the photo below, but, for example, a solution of zinc chloride or another active flux).

A soldering iron with a relatively large flat tip surface is heated to the required temperature and solder is applied to the surface of the part. It is advisable that the soldering iron power be about 100 W or higher.

Then apply the soldering iron to the solder on the part with the largest plane and keep it in this position. The heating time of the part depends on its size, the power of the soldering iron and the contact area. The achievement of the required temperature is indicated by boiling of the flux, melting of the solder and its spreading over the surface. The solder is gradually distributed over the surface.

After tinning, the metal surface is cleaned of flux residues with alcohol, acetone, gasoline, and soapy water (depending on the chemical composition of the flux).

If the solder does not spread over the metal surface, this may be due to poor cleaning of the surface before tinning, poor heating of the metal (due to insufficient soldering iron power, small contact area, insufficient time to warm up the metal of the part), or a dirty soldering iron tip. Another reason may be the wrong choice of flux or solder.

Tinning can be carried out by applying (draining) solder from a soldering iron and distributing it with a “tip” over the surface, or by supplying solder directly to the pad - the solder melts upon touching the heated metal of the part.

Overlapping sheet metal soldering

When repairing car bodies, all kinds of tin work, there is a need for soldering sheet metal onlay. There are two ways to solder sheet parts overlapping each other - by pre-tinning them, or by using soldering paste containing solder and flux.

In the first case, the overlapping areas of parts after mechanical cleaning and degreasing are pre-tinned. Then the parts of the connection are applied to each other with tinned surfaces, fixed with clamping devices and heated with a soldering iron from different sides to the melting temperature of the solder. Evidence of successful soldering is the flow of molten solder from the gap.

In the second method, after preparing the parts, the contact area of ​​one of the parts is covered with solder paste. Then the parts are fixed in the desired position, tightened with clamps and, as in the first case, the seam is heated with a soldering iron on both sides.

When purchasing solder paste, you need to pay attention to its purpose, because... Many solder pastes are designed for soldering electronics and do not contain active fluxes that allow you to solder steel.

When using the content of this site, you need to put active links to this site, visible to users and search robots.

LVital 21-07-2005 14:35

The question is this: there is a great desire to convert the Sheridan 397 to a Walter barrel (4.5mm, choke, 605mm length, Ф12). To do this, you will have to mill a ditch along the barrel and solder the barrel to the compressor. As far as I remember from owner reviews, the Sheridan barrel is brass and soldered. Will I be able to solder a steel barrel and what needs to be done for this? What flux, what solder, what soldering iron power is required for this?

Kiryan 21-07-2005 15:12

To solder steel, they use more refractory solders (most often containing copper and silver), and since the soldering temperature is high and the length of the barrel is not short, there is every reason to believe that the barrel will “lead away”.
As an option, solder the barrel in several places, or another option - put the barrel on (in) “eights” and solder only the eights to the pump (you can also put a strip on them for the optics.)

Youri 21-07-2005 15:57

You can solder with ordinary solder, having previously tinned the steel with phosphoric acid or, better yet, with a special flux
Subsequent rinsing with water is mandatory.
It is better to warm it up with a small gas burner and then with a soldering iron.

LVital 21-07-2005 16:12

What kind of special flux? Hydrochloric acid, or is an alcohol solution of rosin sufficient?

wellad 21-07-2005 16:30

The most affordable option, in my opinion, is a rust converter. Made on the basis of zinc chloride or phosphoric acid. Sold in auto parts stores. Part of the barrel is tinned for soldering, with obligatory washing with soapy water. Then you heat the barrel and the box with a burner and insert it at the same time. Molten solder should appear at the joint. You can’t heat it too much, otherwise the solder will burn. Rosin can help during warming up. Good luck.

Skunk 21-07-2005 16:42

Can be soldered with regular zinc chloride. Sold by men at the "hardware" market.

guron 21-07-2005 16:58

The active flux is called (less aggressive than orthophosphoric, I sometimes don’t rinse after it when I have time, I can’t say based on the composition) IMHO orthophosphoric is more effective. I’m tormented by another question - why are you planning to solder it? I just imagined how you would heat a 12 mm “crowbar” to 200-300 degrees, I was already feeling sick, wouldn’t it be better to clamp it down? Although I don’t know how it works there on the benzhiks, maybe it’s on it (the barrel holds everything together). By the way, they advised you to use solders with silver - screw them - you’ll get tired of heating them, it’s better to use low-temperature solders (Rose alloy, for example, or Wood - both less than 100 degrees) to tin the “crowbar” - heat glycerin on an electric stove (up to 100 degrees) and melt the “rose” in it - so it will not come into contact with oxygen, smear the “crowbar” with orthophosphoric acid and into this container. Tin the Bendzhik too, then combine it all and solder it with a hairdryer and soldering iron.
Everything that I wrote on Benjik was not checked, I only saw it in pictures, I’m just sharing my experience of soldering one large piece of iron to another, without using high powers.

Youri 21-07-2005 17:41

What kind of special flux? Hydrochloric acid, or is an alcohol solution of rosin sufficient?

We sell fluxes in radio stores on Mitino
different fluxes
- orthophosphoric and hydrochloric acids require thorough water rinsing
There are fluxes that do not require rinsing
I have several types
-for aluminum
-nichrome and stainless steel
- for steel without washing
- for bronze alloys
they cost pennies
find a way to send it and I will send it to you

guron 21-07-2005 19:10

By the way, they have specifications, maybe there are similar ones in Ukraine. They really cost pennies. I exchanged 5 liters of LTI-120 + half a liter of orthophosphoric, oxalate, and a liter of active flux for half a liter of alcohol. And I generally carried bulk reagents home for free

guron 21-07-2005 19:23

I also remembered that here on the floor below they solder stainless steel to aluminum with a special paste, albeit at a high temperature

Alter 21-07-2005 20:35

A guy taught me how to solder. He did this on other products.
I cleaned the part to a roughness of approximately 6.3 and degreased it. Same thing with the other part. Then I warmed up the wallpaper at home gas stove, but not to the point of red heat)). About 200-250 degrees. And in your case you need to hold it longer - the thickness is large. I took soldering acid (necessarily with zinc) and *while it was hot* dripped it onto the surface. You need a soldering iron with a power of more than 100W, but you can use this one. I tinned both parts until they sparkled. But the temperature must be maintained! I let it cool a little, then heated it on gas again so that the tin flowed slightly and quickly connected, then heated it a little again - then you’ll pull it off. But be warned. If you shoot in winter, troubles (tin plague) are possible. In general, soldering the barrel is not good. You need to coat the sliding fit and place it tightly on two crackers. If something happens you can *replay*))

SlepoySn 21-07-2005 20:52

Solder with brass.

KVK 21-07-2005 22:17

Won't he lead?

SLAYER 22-07-2005 12:47

How he will behave.

Only solder with soft solder. Tin with phosphoric or hydrochloric acid, even without zinc, twist with wire and heat to the melting temperature of the solder, coat with flux. The solder will spread neatly over the tinned areas and solder everything beautifully.

I can also give you solder with a melting point of 90C, if I don’t have the usual POSP. And I will give acid, phosphoric and hydrochloric, and flux. Solder to your health.

Kaynin 22-07-2005 01:06

With such a question you need to go to the smoothbore.

and they will tell you that it takes years to learn to solder barrels by hand.

Maybe, really, how to fix it mechanically?

Or is the question about maintaining external similarity?

wellad 22-07-2005 01:08

When soldering, brass must be heated until red hot. With such a volume of metal, you will have to take a blowtorch or an acetylene torch. Of course you can solder it, but where will the cold barrel look? Alloy Rose rules.

SHURUP 22-07-2005 01:15

LVital. It is impossible to provide acceptable mechanical strength with soft solders (tin-lead, Wood, Rose), they can only be sealed.
On a hot summer day in the sun, splashes of Rose or Wood alloy will also splash into your eyes. There are millions of recipes for hard solders and just as many fluxes. And if you have never held a gas burner in your hands, have pity on the fan. Find a specialist, not someone who cuts scrap metal, but someone who has an idea about PSR.
Reading the advice on the forum and soldering it is very dangerous for the device.

SLAYER 22-07-2005 01:50

Vital, is that moderator that I soldered to the barrel of the Sheridan pistol with an alloy with 90C melting still holding on? I didn't have anything else then.
And here’s how Errrero solders the barrels with POS-40 tin-lead solder, which is approximately 230C, 40% tin.

blacksmith 22-07-2005 03:46

Steel is perfectly soldered with aspirin (acetylsalicylic acid), or any damn solder.
IMHO

IV 22-07-2005 08:00

It seems to me that if you solder, then use low-temperature solder, otherwise it might lead to problems. But. Why doesn't anyone remember glues? With modern adhesives you can glue it so hard that you can’t pull it off. There was a topic here somewhere, they glued the cocking hook onto a gas spring, and you yourself know the force there. It makes sense to look in this direction. No heating. You just can’t buy good glue on the market, you need to look for specialized companies and consult there. Requirements: strength and no shrinkage.

alhimik 22-07-2005 10:09

solder with brass solder.
Or zinc - they are stronger although they melt at higher temperatures.
Flux: zinc chloride, hydrochloric acid.

guron 22-07-2005 10:39

quote: Originally posted by SHURUP:

On a hot summer day in the sun, splashes of Rose or Wood alloy will also splash into your eyes

Well, this is not necessary. There is a decent size heat sink here, and even with a soldering iron you won’t be able to immediately heat up this soldering.

Kiryan 22-07-2005 12:47

I wonder how you will heat 600 mm. trunk at home??
There is a very high probability that he will be taken away. You definitely won’t heat it up on a gas burner - I’ve tried it myself (not a bastard, but no less a piece of iron)
IMHO the most steering option is three eights, one full 8 and two trimmed ones. Since there are 8 at the end of the pump cylinder, you will also strengthen the attachment point for the pump handle, and two at 1/3 and 2/3 of the barrel and you will also put a bar under the OP on them. Spot heating in area 8 will not lead to anything or anywhere.

LVital 22-07-2005 13:27

Thanks everyone for a bunch of ideas. Sit and choose for your health

2 SHURUP: I have never soldered large parts, especially steel. Wires, transistors, microcircuits - that was the case.
2 SLAYER: holding on, thanks for the offer. Heating the barrel with a heating element is a thought.
2 Kiryan: thank you, it’s bad that the view will change.
2 blacksmith: I will definitely practice with aspirin.
2 alhimik: soldering steel to brass with brass is already welding, and I think for me it’s simply unrealistic.

2 IV: this seems to be IT. It won't lead anyone anywhere, and there's no need to warm it up.

LaMuD 22-07-2005 13:35

Soldered with Rose alloy and phosphoric acid on an electric stove. It holds up well, but soldering the horseradish will work out beautifully. There is no need to spoil a beautiful rifle, but it is better if your hands really itch unbearably, then either glue or mold a couple of clamps from quick steel or epoxy with a plasticizer (epoxy with toner for a laser is a very durable and not fragile material). You can even make collapsible ones because you can lay the film and then drill holes and cut threads.

Why is Ben such a bad gun?

beginner 22-07-2005 13:43

quote: Originally posted by LaMuD:
Why is Ben such a bad gun?

I join the question

LVital 22-07-2005 15:34

Not that bad at all.
- it’s brass, and my brush is brass, but I hate cleaning with a fishing line and rags
- I don’t like the rifling on the output. Somewhat rough. If I succeed, I'll post a photo.
- rather than being bullied with a moderator on your own trunk, it’s better to be bullied with a new trunk IMHO, fuss the same way.
- I have a 605mm LW barrel with a diameter of 12mm. If it weren't for him, there would be no questions

SwD 22-07-2005 15:46

Change the brush to a nylon brush
- polish the trunk

How about a brass tube/rings/half rings for the new barrel?
Solder brass, insert iron...

beginner 22-07-2005 15:51

By the way, Demyan seemed to be putting a strangler on Bendzhik.

and just helping with advice to a person who is planning to mill a Walter barrel is... I don’t even know what to compare it with. Well, what kind of bad operation should be performed on a child...
Maybe I have this attitude towards the trunk because I’m in MSC, with our ZOO troubles? Don't know...

beginner 22-07-2005 18:42

quote: Originally posted by LVital:

What could happen to him? Or should the phrase “Walter barrel” be pronounced aspirated?

yeah.
Maybe it’s worth trying to build something “more different” with this trunk? PSP there with a paintball tank?

PS. everything is imho.

OVM 22-07-2005 19:55

Hmm... Excuse me, gentlemen, but a man wants to solder a barrel in Bendzhik, that’s a problem!
The original one was soldered, did it lead? FIG! Steel can be easily soldered, it is enough to first separately tin the barrel (after cleaning and degreasing) with zinc chloride, and a soldering iron for the barrel needs 100 watts, a small gas burner is better, by the way they sell these for a regular lighter cylinder, in Moscow a cylinder costs ~ 80 rubles, a burner 800 rub. Next - strength, yes! Ordinary tin-lead solder - for the eyes! There's no point in soldering with brass - nafig, nafig.
The barrel won't move!!! Guys, the barrel diameter is 12 mm! It will be connected to the pump pipe, temperature ~ 260C, what kind of leash?! Why doesn’t the original barrel lead when soldering? Would you say the same materials? But the cross-section is different...and the expansion of steel and brass is not very different.

Solder it! Regular low-melting solder will be fine!

In general, for one normal piece of advice (not mine!) there are 10 pieces, like “I hear a ringing, but I don’t know where it is...” (I didn’t want to offend anyone)

Sincerely,
Oleg

LVital 22-07-2005 20:00

Sorry, I deleted my message myself for lack of political correctness, but you managed to see and respond

I don’t see a problem using a round cutter 2mm deep for a barrel that has a diameter of 12mm. In the sense that I don’t think that anything will deteriorate on the barrel from this procedure. Surely you will need to order from a competent milling machine so that he can make the mandrel and all that. Besides, I don't see where this thin trunk, in fact, the liner can be adapted. You can’t hang it out to its full length - it will sow. There is one beautiful idea like a bullpup, but the technical knowledge is not enough to draw up competent drawings, so that project is still on the back burner.

LVital 01-08-2005 12:19

Because the answer is a brass pipe with a diameter of about 25mm and a wall thickness of about 1mm.

Ivanovich 01-08-2005 22:27

Then it is better to drill 2 holes in the prism along the barrel and pipe and cut it into several parts so that the alignment does not go wrong, and then solder it.

LVital 02-08-2005 12:00

Wait, what holes and who to cut?! The pipe is a pump and cannot be cut.

Ivanovich 02-08-2005 18:46

Take a piece of metal 120-150mm long, 30-32mm thick, drill 2 parallel holes in it, one for the pipe, the other for the barrel, i.e. 25mm and 16mm will make a receiver. If you don’t need it, you can cut it into pieces to make brackets.
They will have a clear alignment. The 16mm barrel is easy to hang and produces a great bunch. Why solder it I don’t understand

2dogs 10-08-2005 11:37

I haven’t really checked it myself, but I point it out.

6. Cold adhesion.

Some items, as you know, cannot be soldered at high temperatures without being damaged. For such items, the following composition is recommended. Copper precipitated in powder form is mixed in a porcelain mortar with concentrated sulfuric acid until
a loose dough-like mass, to the total weight of which is added gradually, with constant stirring, 70 parts of mercury. When a homogeneous amalgam is obtained in this way, it is washed well in hot water to remove the acid and then allow it to cool. After 10-12 hours, the amalgam becomes so hard that it cuts tin. In this form, the composition is already quite
ready for use, for which it is heated to the consistency of softened wax and objects are soldered; Once cooled, this amalgam holds the soldered parts very tightly.

The ability to solder in modern life, saturated with electrical appliances and electronics, is just 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.

Fluxes

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 amount of water of crystallization, which slightly impairs the quality of soldering.

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

The good news is that there is now a wide range of fluxes on sale for all soldering occasions. 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 the metal with 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 for soldering good gumboil, but not for slow-witted people with weaklings.

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.

Dead-end twists of thick wires (see above) are soldered by immersion in a futorka - a bath of molten solder. Once upon a time, the futorka was heated with a blowtorch (pos. 2a), but now this is primitive savagery: an electrofutorka, or soldering bath (pos. 2) is cheaper, safer and gives better soldering quality. The twist is introduced into the futor 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.

High-temperature soldering is carried out, see Fig. on the right, evenly rubbing the soldering area with pressure 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. To tinned brazing You can solder something else onto the surface with 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 fine 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.

How to solder aluminum

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, it is better to use flameless chamber soldering (furnace-heated soldering) for high-temperature aluminum soldering, but the equipment for it is expensive.

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. Copper sulfate powder is poured in a heap into the soldering zone. A stiffer toothbrush wrapped naked copper wire, dip in distilled water and rub the vitriol 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.

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.

Solder sagging on printed circuit boards must be round, smooth, and no more than 0.7 times the diameter of the installation site, 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.

Concave and even more so wrinkled sagging is 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 assembled device does not work and there is a suspicion of a problem, look first of all at such 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, emissions mains voltage: welding was turned on nearby, the network was thrown, the wiring sparked, etc. The most reliable way to protect yourself from them is not to remove “stray” potentials from the soldering iron tip, but not to 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:

The connection point C1-C2 and the transformer core are connected directly to the protective grounding loop, and the screen winding (an open turn of copper foil) and the grounding conductors of the workplaces are connected to the middle point of the secondary winding. 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. It’s not much more difficult to use than a hand soldering iron, see the video below, and the prices are quite decent soldering stations are now available.

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. There are then 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 unfolding 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.

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 point 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.

What else?

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.