Rules for working with a soldering iron. How to solder correctly with a soldering iron, consider typical mistakes. What do you need to solder?

Soldering with a soldering iron is one of the most common and simplest soldering methods, but 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, the required power of the soldering iron is also affected by 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, and the advantages include better soldering quality than that of 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 electricity well 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 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 (electric or gas soldering iron, gas torch, 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 on the outside, there can always be foreign substances on its surface - preservative grease, various contaminants. 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 overlay soldering of sheet metal. 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.

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My relationship with radio and microelectronics can be described with a wonderful anecdote about Leo Tolstoy, who loved to play the balalaika, but did not know how. Sometimes he writes the next chapter of War and Peace, and he himself thinks “trendy-brandy trendy-brandy...”. After courses in electrical engineering and microelectronics at my beloved Moscow Aviation Institute, plus endless explanations from my brother, which I forget almost immediately, in principle, I manage to assemble simple circuits and even come up with my own, fortunately now, if I don’t want to tinker with analog signals, amplifications, interference, etc. you can find a ready-made micro-assembly and stay in the more or less understandable world of digital microelectronics.

To the point. Today we will talk about soldering. I know that this scares off many beginners who want to play with microcontrollers. But firstly, you can use
So, we are almost there. I’m writing everything in such detail because, honestly, it was a breakthrough for me. As I accidentally discovered, all you need to solder simple components is a soldering iron, the most common one with an awl-shaped tip:

And solder with flux inside:

It's all about the process. You need to do this:

The part is inserted into the board and must be secured (you won't have a second hand to hold).
Take a soldering iron in one hand, and a wire of solder in the other (it’s convenient if it’s in a special dispenser, like in the picture).
Take solder to the soldering iron NO NEED.
Touch the tip of the soldering iron to the soldering area and heat it. Usually it's 3-4 seconds.
Then, without removing the soldering iron, with your other hand, touch the tip of the solder wire with flux to the soldering area. In reality, at this point all three parts come into contact at once: the soldering element and its hole on the board, the soldering iron and the solder. After a second, “pshhhhhh” happens, the tip of the solder wire melts (and a little flux flows out of it) and the required amount of it goes to the soldering site. After a second, you can remove the soldering iron with solder and blow.

The key point here, as you already understood, is the supply of solder and flux directly to the soldering site. And the flux “built-in” into the solder provides the required minimum amount of it, reducing clogging of the board to a minimum.

It is clear that the waiting time in each phase requires at least minimal practice, but nothing more. I am sure that any beginner can solder Maximite in an hour using this method.

Let me remind you of the main signs of good soldering:

A lot of solder does not mean high-quality contact. A drop of solder at the contact site should cover it on all sides, without any potholes, but not be an excessively large bulb.
The color of the solder should be closer to shiny, not matte.
If the board is double-sided and the holes are not metallized, you need to solder it using the specified technology on both sides.

It is worth noting that all of the above applies to soldering elements that are inserted into holes on the board. For soldering planar parts, the process is a little more complicated, but doable. Planar elements take up less space, but require a more precise location of the “spots” for them.

Planar elements (of course, not the smallest ones) are even easier for soldering in some ways, although for homemade devices you will already have to etch the board, since using planar elements will not be particularly convenient on a breadboard.

So, a small, almost theoretical bonus about soldering planar elements. These can be microcircuits, transistors, resistors, capacitors, etc. I repeat, at home there are objective restrictions on the size of elements that can be soldered with a regular soldering iron. Below I will give a list of what I personally soldered with a regular 220V soldering iron.

To solder a planar element, it will no longer be possible to use solder on the go, since too much of it can “come off”, “flooding” several legs at once. Therefore, it is necessary to first, in some way, tin the spots where the component is planned to be placed. Here, alas, you can’t do without liquid flux (at least I didn’t succeed).

Drop a little liquid flux onto the patch (or patches), take just a little solder on the soldering iron (you can do it without flux). For planar elements, very little solder is generally needed. Then lightly touch each patch with the tip of the soldering iron. A little solder should come off on it. Every penny “will not take” more than necessary.

Take the element with tweezers. Firstly, it’s more convenient, and secondly, the tweezers will remove heat, which is very important for planar elements. Attach the element to the soldering site, holding it with tweezers. If this is a microcircuit, then you need to hold it by the leg that you are soldering. For microcircuits, heat dissipation is especially important, so you can use two tweezers. You hold the part with one, and attach the second to the soldered leg (there are tweezers with a clamp that you don’t need to hold with your hands). With your second hand, you again apply a drop of liquid flux to the soldering area (perhaps a little will get on the microcircuit), with the same hand you take the soldering iron and touch the soldering area for a second. Since solder and flux are already there, the soldered leg will “immerse” in the solder applied at the tinning stage. The procedure is then repeated for all legs. If necessary, you can add liquid flux.

When you buy liquid flux, also buy board cleaning fluid. Alas, with liquid flux, it is better to wash the board after soldering.

I’ll say right away that I’m by no means a professional, or even an advanced amateur in soldering. I did all this with a regular soldering iron. Pros have their own methods and equipment.

Of course, soldering a planar element requires much more skill. But it’s still quite possible at home. And if you don’t solder microcircuits, but only the simplest elements, then everything is still simplified. Microcircuits can be purchased already soldered into blocks or in the form of ready-made assemblies.

Here are pictures of what I personally successfully soldered after a little practice.

This is the simplest type of case. These can be installed in pads, which are the same in terms of soldering complexity. These are simply soldered according to the first instructions.

The next two are more difficult. Here you already need to solder according to the second instructions with a neat heat sink and liquid flux.

Elementary planar components, such as the resistors below, are very easy to solder:

But there is, of course, a limit. This goodness is already beyond my abilities.

Finally, a couple of cheap but very useful things that are worth buying in addition to a soldering iron, solder, tweezers and wire cutters:

Good luck with your soldering! The smell of rosin is cool!

Whatever innovations the modern market of tools for radio repair offers, soldering iron remains one of the most reliable and safe devices.

The process of soldering wires and microcircuits is considered effective because it allows you to achieve the strongest possible connection between wires and small parts.

This result can be achieved by adding a special material to the contact area - solder, which has a lower melting point than that of the parts being connected.

Thus, soldering with a soldering iron is the effect of a certain temperature on different metal surfaces for their durable and high-quality connection. However, before you start working with a soldering iron, you should first understand the rules of soldering and other intricacies of this process.

What you need for soldering with a soldering iron

To solder something, you first need to prepare all the tools necessary for this process.

With all the necessary tools at hand, you can start working with a soldering iron.

How to solder correctly with a soldering iron and rosin

Rosin has such unique qualities, such as ease of dissolution in various organic compounds, for example, acetone or alcohol. When heated, this substance can break down complex chemical compounds such as copper, tin or lead. Therefore, proper use of rosin helps reduce the likelihood of spreading of the substance, destruction of the oxide coating, as well as high-quality tinning of soldered elements.

You also need to take into account that the thinner the tip of the soldering iron, the easier it will be to work with it, especially when it comes to soldering very thin wires and parts. Therefore, if it has not yet been sharpened, this should be done before starting work.

Process description

There should not be any particular difficulties when working with the tool. For everything to go smoothly, it is best to first practice working with rosin on parts that you won’t mind throwing away later. After all, experience always comes with practice.

Soldering wires

In order to correctly solder copper wires using rosin, you must follow a certain sequence of actions.

As you can see, there are no particular difficulties with soldering wires using rosin. The main thing is not to forget to tin the wire and check the quality of the soldering. If necessary, tinning should be repeated several times until the wires are firmly connected with solder.

Having figured out how to use a soldering iron, you should consider several recommendations for working with this tool.

If you take note of these little tricks, then the process of soldering the parts will go quickly, and most importantly, efficiently.

Summing up

A soldering iron is a universal tool, with which you can quickly connect broken wires or contacts, as well as quickly repair a microcircuit or connect light metal surfaces.

The ease of operation of the device allows any man to learn how to use it in the shortest possible time.

And what is important: working with a soldering iron does not require any professional skills.

Soldering with a soldering iron is a physical and chemical technological operation for obtaining a permanent connection of metal parts by introducing 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 before the solder has completely solidified is not permissible, otherwise the mechanical strength and tightness of the soldering 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 a copper wire with obvious oxidation, without preliminary mechanical stripping, with aspirin is immediately torn by 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 soldering job.

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. It is difficult to remove the oxide film mechanically; you need to unravel the conductors and clean 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 for the soldering iron to make a set of special tips that branch 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 avoid peeling of the printed tracks.

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.

Many people can solder wires and radio components, but not everyone can solder metal. In this article I will outline the principle of metal soldering as briefly as possible and with examples.

Introduction

Let's start with a general understanding of soldering. Soldering is a physical and chemical process of obtaining a connection as a result of the interaction of solder and the metal being soldered. It is similar to fusion welding, but there are still differences between them. When welding at the seam, the parts being welded melt, but when soldering, the material being soldered does not melt. Also, unlike welding, soldering is carried out at temperatures below the melting point of the metal being soldered. The formation of a seam during soldering occurs by filling the gap between the parts being connected with solder, i.e. the process occurs due to wetting and capillary effect.

The question arises, why use soldering if welding holds parts together better. This has its advantages:

Soldering is more accessible than welding.
When soldering, the connections become detachable.
Small parts cannot be welded.

Soldering is a fairly strong connection if you follow the technology.

Equipment

To solder metal, the following basic equipment is required:

♦ Soldering iron . The power depends on the size of the parts being soldered. For soldering small parts (tin, wire, bolts), a 60-watt soldering iron will do; for larger ones, 100 watts or more. I use 2 soldering irons - 65 and 100 W, which is quite enough for home use.

I will not dwell in detail on how to tin a soldering iron; there are separate articles about this on the Internet. I'll just say the main thing:

- When you turn on the soldering iron for the first time, you need to let it burn - put it on the street and wait until it stops stinking and smoking.

— The tin should evenly cover the tip. When heated, the tip will burn out, it will need to be sharpened and re-tinned.

♦ Soldering acid and solder . A wooden stick is used to apply the acid.

♦ Accessories . These include a file and emery, which are necessary for cleaning the soldering iron and parts.

The soldering iron also needs a stand. The simplest thing that can be used as a stand is any metal object from which the soldering iron will not roll off.

Various tools, such as vices and pliers, are used to hold the parts to be soldered. The parts can also be secured with nails on the board.

Soldering Basics

Let's now figure out which metals are easy to solder:

Silver
Brass
Nickel
Iron
Stainless steel

The remaining metals are soldered using special fluxes and other technology. This topic will not be addressed in this article.

We've sorted out the metals, now let's start studying the soldering process:

We clean the place where the seam will be located. For this I use .
We degrease the joint using acetone, gasoline, etc.
Apply soldering acid to the seam with a wooden stick. We do this as smoothly as possible, because... In the future, solder will spread exactly over this area.
Remove oxides (if any) from a pre-tinned soldering iron and touch the solder stick with it. The solder should lie on the tip in an even drop. If this does not happen, then the soldering iron is poorly tinned.
We touch the place of adhesion with the sting. You cannot expect that soldering will occur at the first touch of the soldering iron. To do this, it is necessary to heat the surfaces to be soldered to the melting temperature of the solder. The heat from the soldering iron is not immediately transferred to the place to be soldered. Tin, wires and other thin parts warm up quite quickly, but not instantly. It takes a relatively long time to heat up thick materials.
To solder thin parts, you need to move the soldering iron quite slowly, moving it further when the solder spreads and floods the seam. When soldering thick objects, you have to hold the soldering iron in one place for a relatively long time and wait until the surfaces to be soldered warm up and the solder spreads along the seam.
After holding the soldering iron for a certain distance, move it a little back, then forward again and back again, until the solder flows out in an even and clean path. As the solder is used up, it is collected from the stick. You should not collect a lot of solder, especially if the surfaces to be soldered are evenly and tightly connected; Excess solder will cause sagging.
After soldering is completed, it is necessary to wash off the remaining acid with water. If the acid is difficult to wash off, use soap. Unwashed acid will lead to oxidation of the metal.

It is best to learn soldering on tinplate. It does not need to be cleaned, but it must be degreased. In the presence of fat, the acid does not wet the surface of the tin. Below are examples of soldering wires and sheet metal. You can repeat all this for training.

Soldering tin/sheet metal