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How to solder with a soldering iron with rosin and tin. Learn how to solder correctly with a soldering iron How to solder with a soldering iron with rosin

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

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

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

Power selection

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

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

Preparing for work

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

Sharpening the tip

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

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

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

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

Soldering iron tinning

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

The first method of tinning a soldering iron tip:

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

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

Soldering technology

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

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

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

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

Preparation for soldering

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

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

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

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

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

Fluxing or tinning

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

Tinning

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

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

Tinning wires is a mandatory step when soldering

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

Flux processing

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

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

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

Preheating and temperature selection

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

When using a soldering station, proceed from the following rules:

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

Soldering

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

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

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

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

Device for more convenient soldering - third hand

How to learn to solder with a soldering iron

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

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

Normal soldering means:

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

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

After soldering is completed

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

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

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

Preparing the soldering iron for use

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

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

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

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

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

Fluxing or tinning

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

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

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

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

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

Preheating and temperature selection

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

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

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

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

Working with solder

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

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

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

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

Almost every man, be it an ardent fan of delving into radio equipment and electrical appliances or a simple owner, faced with a situation in which the process of connecting metals and wires is required, sooner or later will be forced to use a soldering iron, in this case you can try it yourself cope with the task by learning to solder.

Devices and tools required for the soldering process

In everyday life, when it is necessary to repair something basic, special experience and expensive units and tools for soldering are not required. The main ones are the following devices and tools:

Soldering iron. The main criteria when choosing it are the size, which must correspond to what you are going to solder, otherwise there is a risk of damage to adjacent circuit elements or poor-quality soldering of wires and power (it is advisable to purchase a pair of soldering irons, one for 25 watts for soldering microcircuits, the second for 40-watts). 60 watts in order to solder wider parts of parts).
Soldering iron stand. When working with a soldering iron for a long time, you often have to unplug it to avoid overheating, then wait until it warms up again. Due to the fact that the soldering device heats up to 300 degrees, you simply cannot do without a stand for it.
Rosin and solder. Rosin is an amorphous substance obtained from the resin of coniferous trees, very fragile under mechanical shock. What is rosin used for? When soldering, it is used to degrease the surface and remove oxide films. Solder is an alloy of two metals - lead and tin for soldering.

Preparing tools and materials for soldering

Soldering is the process of joining parts by introducing molten metal of a lower temperature into the area of their contact. Before you start soldering, you must carefully prepare for work:

Recommendations for competent work with a soldering iron using rosin

Rosin easily dissolves in organic compounds such as alcohol, acetone and others. When heated to 150 degrees, it is capable of breaking down chemical elements such as tin, lead, and copper.

Rosin is used in radio and electrical repair work as an antioxidant component for soldering. Her proper application will significantly reduce the spreading and surface tension of the solder, destroy the oxide film and prevent the formation of a new one.

Before you start soldering the necessary elements, you need to clean and then tin the contacts. To do this, place a piece of solid rosin on the part of the surface that will be soldered and press it with a soldering iron heated to the required temperature.

If the task is to solder a microcircuit, then you need to dip the soldering iron tip in rosin and coat the twisted wires with it, which will ensure free flow of tin to the soldering site.

If the solder was not used in sufficient quantity and a part of the twist or wire is visible in some places, it is necessary to repeat the previous step.

Next, having placed the solder at the soldering site, it is recommended to run the soldering iron tip over it, as a result of which it will melt. If the material is processed poorly, then it is possible that the solder will not stick to the surface.

Of course, it is possible to solder without using rosin, but the quality of the soldering joint and the aesthetic appearance of the product will be lost. If rosin is not available in everyday use, soldering acid, electrolyte from an old battery, pine resin dissolved in acetic acid, or acetylsalicylic acid may be useful as a replacement. And yet, the best solution is not only to use rosin when soldering, but also to use it in excess for more reliable bonding. Until the composition hardens, do not move parts of the solder.

With effective tinning, soldering will occur almost instantly, you just have to wait for the solder to cool completely. On many Internet sites you can find videos with simple lessons on how to use a soldering iron and learn how to solder. If you follow the detailed instructions, then the process itself is not particularly difficult; to achieve a positive result, you just need to do everything clearly and sequentially .

When thinking about how to properly use a soldering iron using rosin, do not forget about the need to carefully prepare tools and parts for the soldering process. When creating a permanent connection, the solder layer must be protected with rosin. For each individual soldering case, a soldering iron of the appropriate size and power may be suitable. When parts are connected correctly, soldering becomes reliable and durable.

Knowing how to solder with a soldering iron is very useful in everyday life. There are a number of techniques on how to do this, but it is best to master the theoretical part before starting the work process.

Peculiarities

There are many ways to learn how to solder with a soldering iron from scratch. To do this, you will need a soldering iron - a device designed to heat parts or flux during tinning and soldering. The tool is brought to the area where the parts are soldered, touching them with the so-called tip. The tip is the working part of the tool, which is heated using a blowtorch or electricity. Rosin is most often used for soldering, but to work with this material you need to know how to properly solder with a soldering iron with rosin.

Before soldering, you need to perform a number of actions:

If you're working with a metal like aluminum, it's worth knowing its characteristics. The melting point of aluminum is 660.1 degrees. A small amount is applied to the joint area and then leveled. The contact point must be covered.

The working process

A kind of connector between two components is called soldering. Its main role is to create a sufficiently strong connection.

Solder is a metal alloy that can be divided into two large groups. Soft solders have a melting point of up to 300 degrees; this type is used in electronics.

The next type of solder is the hard group, in which the melting point exceeds 300 degrees. This type is actively used for reliable joining of metals.

The soldering sequence is as follows:

the surface is first cleaned of corrosion or any other type of contamination;
the next step is complete cleansing until it acquires its characteristic shine. Traces of oxides should not be visible;
For coating, flux is used, which removes oxide residues and minimizes the appearance of surface oxidation. The best choice in this case is flux paste. Liquid or solid fluxes are not suitable;
the master carries out tinning. Solder is applied to a certain area of the surface in molten form, after which it spreads evenly;
using twisting and compression with tweezers or a clamp, the main parts are connected;
The flux application procedure is repeated. This is necessary to minimize the risk of solder oxidation under high temperature;
Solder is applied along with heating;
It is also important to note that when using a tool with a tinned tip, it must be cleaned using inactive flux. The soldering iron must be stored with a fluxed tip. This affects the quality of further work.

Cleaning

The procedure for cleaning the soldering iron tip is carried out by rubbing it against a soft porous or fibrous lining. The best option would be to choose natural felt. An alternative would be to use basalt cardboard. Two-stage cleaning is considered high-quality.
The first step concerns the use of a sponge-tangle made of metal tape.
The second stage of cleaning involves the use of felt.

At the end the instrument is turned off. The stage when the master inserts a hot sting into solid rosin is considered important. You need to wait until it stops blowing bubbles. After this, the master removes the sting, holding it with the end down. This way, the excess rosin will drain off. Once the instrument has cooled completely, it can be stored.

Pipe soldering

Based on the technological features of this procedure, the masters use the following stages of action:

You can perform the procedure yourself. If you are unable to complete the procedure, then it is best to use the services of a specialist. It is best to solder the first element first. It is necessary to cool and cut the part in order to check the quality of workmanship. If there are errors, this will be noticeable. During installation work or during pipeline repairs, this skill will come in handy.

Soldering wires

The most common question concerns how to solder correctly with a soldering iron. First, you need to free the ends of the wires from the insulation using a knife or wire cutters. The parameters of the cores must correspond to the dimensions of the parts. not too large, then neighboring areas will not be damaged in the process. A small soldering iron, by comparison, achieves unreliable, low-quality results. It is quite difficult to warm up parts with it.

If you are soldering stranded wire, then you need to twist it, then tin it. The procedure is as follows. The wire is dipped into a bath of rosin. The craftsman runs a drop of solder across the surface of the copper wires. The coating should be even, covering all sides. Excess rosin is removed.

Solder is classified as a weak alloy. It is characterized by low reliability, because it is damaged under the influence of small loads. In the process, rosin is applied to the wires, followed by solder. The heating time for the twist is 2–3 seconds.

If we are talking about single-core wires, then they are first cleaned until they acquire a shine, then dipped in rosin. The connection takes approximately 3–5 seconds. Then a large-diameter heat-shrinkable tube is placed over the exposed wire. Following this procedure will ensure a high level of insulation.

Soldering

When asking a question about how to properly solder microchips with a soldering iron, it is better to entrust such work to a specialist. After all, the work itself is quite scrupulous and requires experience and a certain skill.

For proper soldering, it is necessary to take time to prepare the parts needed in the tooling process. Familiarize yourself with the theoretical aspect, and then consolidate your knowledge in practice.

It is necessary to remember to protect the layer of molten solder with flux. The operation you perform also matters. Based on this, you need to select a device of appropriate power and with a suitable tip shape.

By following the basic rules for using the device and the recommendations of specialists, you will be able to connect the parts in the correct way, thanks to which the soldering will last a really long time.