How to solder with solder paste with a soldering iron

Soldering with a soldering iron and flame

There are two methods of soldering - hard and soft solder. The choice of the desired method is determined by the nature of the load that the soldered parts will experience. If the connection will be subject to heavy loads, then hard solder is used.

When brazing is done correctly, the material at the joint bends under stress but does not break. The melting point of the solder used is in most cases lower than the melting point of the metals that make up the parts.

Jo is their connection - this is not the result of melting metals, as in welding: the connection occurs in the process of surface alloying of the contact areas with solder.

Soft soldering can be done with a soldering iron and a flame at temperatures from 180 to 400°C. Hard soldering requires significantly higher heat - over 450°C. This temperature can only be reached with a powerful burner.

Soldering refers to the permanent connection of metal parts using a binder - solder. Important importance is attached to the correct choice of solder and soldering temperature: without this, the connection will not work.

Fireproof Soldering Table

Tinning

To make tin solder stick better to parts, apply solder paste to both contact surfaces, which should be cleaned to a shine.

Dip the tip of a hot soldering iron into the solder paste. This will prevent tin solder and oxidized slag from sticking to the soldering iron and thereby reduce its heat.

Now heat the contact surface evenly with a soldering iron and press the solder so tightly that it spreads slightly. Avoid dripping.

Compound

It is better to first tack the parts with two spot solders. Apply solder to the preheated points on the top piece and place it on the bottom piece.

Keep the parts in position and heat the connection points. When a certain temperature is reached, the solder begins to spread - the parts are stuck.

After this, it is not difficult to finally form a continuous solder seam. Move the soldering iron along the joint of the parts at an angle to increase the heating area.

Soft soldered joints

Whenever possible, use overlapping solder joints - this increases the soldering area and strengthens the connection. Place the parts together so that the gap between them is 0.1-0.5 mm.

Brazed connections

Hard soldering leaves a thicker seam than soft soldering. You should apply a lot of brazing solder to make sure it goes everywhere. The soldered seam is then cleaned with a file.

Soldering pipes

Soldering sheet metal pipes is not easy: the twisted sheet warps when heated and tends to return to its original shape. Therefore, precise fixation and uniform heating are important here.

The auxiliary locking tool must provide strong clamping and at the same time be narrow.

A wide grip directly at the seam would disrupt the round shape of the pipe.

A high-power soldering iron evenly heats two edges of the sheet lying on top of each other. Use tin solder sparingly: it just needs to float!

Preparation for soldering also begins with tinning. Since the sheet is overlapped, one edge is tinned from the top side, the other from the bottom.

It is better to fix the position of a pipe twisted from a sheet with a clamp. You just need to apply a little solder on the outside, it will flow between the edges of the sheet and grab them.

Flame soldering

It is advisable to use soft soldering using a flame in cases where it is necessary to connect relatively thick or large parts. You can heat them with a flame faster and more evenly than with a soldering iron.

Almost all metals and their alloys are suitable for soft soldering. Do not solder light metals such as aluminum. There are solders designed for specific materials or for joining different metals. Before purchasing solder, ask the seller which one is best suited for the material and connection method you have chosen.

The main condition for a reliable solder connection is the cleanliness of the contact surfaces. Anti-corrosion grease or foreign deposits remaining on the surfaces are burned off with a flame. However, due to the relatively low temperature when soldering with soft solder (180-400°C), this is not always achieved. Therefore, only decorative joints can be butt soldered, since they do not experience heavy loads. If there are mechanical loads, they should be overlapped.

Precautionary measures

When carrying out soldering work, ensure good ventilation of the room. The fact is that solder, which contains heavy metals, emits toxic fumes when heated and melted. They, like the fumes from heated flux, are harmful to health. Soldering should be done with safety glasses and at a safe distance from flammable materials.

It is better to pre-fix such a corner butt joint with wire clamps: this will make it easier to solder the continuous seam.

Heat

The metal parts, cleaned to a shine, are fitted to each other. Work gloves prevent greasy stains from getting onto the surface.

Heat the parts evenly. Hold the burner at a slight angle to the surface. For safety reasons, support the parts with a wooden block.

Flame treatment from the edge to the middle. By the change in color, especially noticeable in copper and brass sheets, you can see how the sheet gradually heats up.

Preparation

To ensure a perfect connection, sand the contact areas of the parts with sandpaper until shiny.

Before soldering, ordinary wire, which must be bent accordingly, will help secure the parts to be connected in the desired position.

To protect the contact areas of parts from new oxidation, before soldering, dip the heated tin solder into ammonia powder - this is an excellent material for flux.

Brazing using a flame

All metals are suitable for brazing, including bronze and cast iron. This method can also be used to connect such different materials as steel and brass.

The process of hard soldering is not much different from soft soldering, only in the first case the work is performed at higher heating temperatures. For small thin-walled parts, a gas blowtorch is suitable.

Only the position of the vertically standing part is fixed with wire. The wire is bent so that the soldering area remains free.

Apply heat by slowly moving from the edge of the lower part to the joint area: this way you can prevent the parts from shifting relative to each other.

Apply solder a little at a time to ensure a neat solder seam.

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Source: https://www.remontiruemlegko.ru/payka-payalynikom-i-plamenem.html

How to solder with solder paste

The issue of soldering polypropylene pipes today is acute for every owner of his apartment. After all, everyone, without exception, wants high-quality fastening of pipes, since this directly depends on:

service life of the plumbing or heating system,
the need for repair costs.

Therefore, many are interested in how to properly solder pipes in order to avoid troubles in the future. To solder polypropylene pipes, you need, of course, a special soldering iron. But what to do if there is no such tool in the house? The answer is simple: use available materials and tools. For example, a gas burner.

Undoubtedly, every home should have a gas burner. But if it is not there, when choosing this tool you should take into account its main parameters:

gas used;
cylinder connection.

This soldering method is suitable not only for small-diameter pipes, but also for soldering large-diameter pipes. Using a gas torch, you can independently repair or install a heating system in a short period of time.
Soldering requires:

accuracy,
attentiveness,
commitment to quality,
preparation for the main work.

Polypropylene pipe: soldering instructions

Let's consider step by step how to efficiently solder pipes: Step 1. Select pipes of a suitable diameter. Please note: newly purchased pipes must match the old ones in diameter. This will help avoid problems during connection. Step 2. Having measured, cut off the required section of pipe.

Do not forget to add an additional 25 millimeters, which will subsequently remain fused into the fitting. Step 3. Heat the pipe and fitting using a torch. This must be done at the same time. Step 4. After this, the parts need to be connected and held for a while, waiting for them to cool.

Please note: Before installing the pipes, it is necessary to draw up a detailed diagram according to which they will be connected. It is necessary to mark the installation locations of rotary angles, tees and taps.

Consider tips and recommendations that will help you get the job done efficiently:

It is recommended to purchase connecting parts and pipes from predominantly one manufacturer. This is an important point, since each manufacturer has its own technology for manufacturing these elements. This means that the melting temperature of the parts may vary, which is not suitable for a monolithic structure.
Before the main work, the parts must be cleaned and degreased, which will avoid compromising the quality of the connection.
Practice first on sections of pipe so that you know what effort is required to obtain the expected result. Please note: the pipe inserted into the fitting must not be rotated under any circumstances, this will compromise the strength of the connection, since the surfaces of the parts will gather in waves.
If you choose quality, don't skimp! Good products will last longer, which will save you money in the future.
If the room temperature is below +5°C, there is no need to take risks and start work, because its effectiveness is significantly reduced. The connections in this case will be fragile, and the connecting parts will require additional heating. And this is fraught with unnecessary melting and deformation of elements.

Soldering wires: how to solder if you don’t have a soldering iron?

Surely many have encountered the need to connect two wires, but do not have a soldering iron at hand.
All that remains is to rely on the ingenuity of contemporaries, who offer easy soldering methods that everyone can master. The following materials are offered on the modern market:

Solder paste;
Soldering tape.

Soldering without a soldering iron using paste

Solder paste is a mechanical mixture of flux, solder powder and lubricant, that is, a binder.

Manufacturers of solder pastes practice making them based on silver, which makes it possible to use this mixture for soldering different types of nickel, steel, and copper alloys.

Requirements for pastes

Solder paste should:

exfoliate very quickly, but do not oxidize;
be viscous (which is very important!) and maintain deformation;
have adhesive properties;
washable in ordinary solvents;
do not flow beyond the boundaries of the applied layer;
do not leave indelible residues after application;
do not affect the technical properties of the board.

Why do you need a soldering station?

Soldering steps

Step 1. The primary task is to prepare the wires. We clean the surface of the wire by using a utility knife or wire cutters. Step 2. Twist the wires. Step 3. Carefully coat the soldering area with soldering paste. You need to apply drops of paste evenly over the entire surface of the wire. Step 4. Warm up the application area.

You can use a regular lighter for this. After heating, the paste will form a strong solder. Step 5. We put a heat-shrinkable tube on the wire, which we also treat with a flame so that it is evenly distributed over the surface of the wire.

Please note: This soldering method is primarily suitable for fastening small-diameter wires, such as headphone wires.

Solder paste in water supply systems

Surprisingly, solder pastes are applicable in water supply. These substances have special requirements:

Silver or copper is added to the solder, and this increases the melting point. This makes the alloy mechanically strong and durable.
Flux or solder is not allowed to contain toxic substances, so it does not contain lead or any toxic metals.
The flux should be easily washed off with water and in no case cause corrosion.

Soldering using soldering tape

Soldering tape is a material used for installing electrical wiring, repairing or replacing it, in domestic and field conditions, as well as in the automotive industry.
Let's look at the soldering process using solder tape step by step: Step 1. You need to remove the insulation from the wire, that is, strip it with wire cutters. Step 2. Twist the wires, and then wrap the twist with solder tape.

After removing the protective film, apply the side with flux to the surface of the wire and crimp it. Step 3. Heat the winding area with a match or lighter until the solder completely spreads over the surface of the wire. Step 4. Wait until it cools, then remove excess flux.

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As you can see, you don’t have to rush out and buy a soldering iron to solder wires; you can use the methods described above.

This will save both time and money.

Source: https://respect-kovka.com/kak-payat-payalnoy-pastoy/

How to solder with solder paste - How to use solder paste: application methods, instructions

Today, soldering with solder paste is recognized as an effective method for connecting surface contacts of microcircuits and printed circuit boards. At the same time, there are certain difficulties of work, which can be described as the complexity of the technological process at home, and how to use flux for soldering will be suggested by the advice and recommendations of specialists. The main advantages of the technology can be expressed as follows:

Solder paste can be applied to printed circuit boards with very small parts and components.

Applying solder paste to the board

You do not need to use a soldering iron with a high operating temperature; you can use a soldering iron or soldering irons with medium load characteristics.
The paste is used in cases where there are no other options for ensuring a high-quality surface connection.

General classification of pastes for soldering microcircuits and circuit boards

According to generally accepted rules and regulations, the use of the following components is allowed in order to know how to use soldering flux for home and industrial purposes.

Solders with powder forms and crushing options.
Flux components.
Binding materials.
General additives and special activators.

Tin, silver, and traditional lead are used as components for solder. At the same time, the use of lead has recently faded into the background, and solder paste is applied through a stencil using lead-free components.

Next, you need to consider the following before soldering with solder paste; a special flux is used in each component, which plays a kind of role as a degreaser.

A significant role in this case is played by SMD components, which are used in most groups of printing pastes, and the shelf life of solder paste due to the presence of active chemical components is no more than 6 months.

But, during this shelf life, you need to remember that solder paste should be stored only in certain temperature conditions, namely from +2 C to +10 C.

Solder paste manufacturing options

In addition to the main components that make up the basis of the material, the technological instructions for using solder paste imply several types and categories:

No laundering.
Washing.
Soluble version, based on aqueous liquid.
Contains halogens.
Halogen-free.

It should be taken into account that the properties of solder paste and how to use it in certain conditions depend on the presence of main and auxiliary components, but in any case, in those pastes that do not have a water base, rosin is necessarily present. In this case, a weak solvent must be used for washing.

How to properly solder with solder paste?

In order to achieve the best effect of the soldering process, we recommend following some rules:

We carry out high-quality degreasing of the board surface using special preparations, then ensure drying of the microcircuit and board.
We fix the boards only in a horizontal position for technological soldering.
Apply the paste evenly at the joints.
We apply paste to the legs of the SMD parts, in addition to the main components of the working board of the microcircuit.

If we use bottom heating, we use a hairdryer, which carefully dries the entire plane of the printed circuit board being processed. By carefully directing the hot air stream of the hair dryer, we ensure that the flux spreads.
After the flux on the surface to be treated has evaporated, it is necessary to increase the temperature of the hair dryer for further high-quality connection.
We monitor the entire process visually.
At the end of the work, we carry out additional technological cleaning with a special preparation.

Some tricks for soldering work

If in a factory setting the entire soldering process is worked out automatically, then using solder paste yourself has some tricks. Be sure to degrease the printed circuit board, do not forget to wet all contacts where there are traces of oxides. If you have not used the board for a long time, and despite its good condition, we also degrease it.

Solder paste as the main processing material should have good substance, that is, the solder paste should not be too thin or too thick, that is, the substance should be somewhere in between. The best option would be the well-known “sour cream” substance. The wetting process must be followed throughout the soldering process.

Soldering substance

Only a thin layer of solder paste is applied over the entire plane of the board. A thicker layer of paste is used for contacts of SMD components. But, for very simple structural connections, this processing method is unacceptable.

"Note!

For a very large board, where it is not possible to use a soldering mechanism, it is allowed to use a soldering hair dryer, special heating devices and even an iron, but remember that the operating heating temperature should not exceed +150 C, and you also need to ensure that there is no the effect of warping the board during the heating process.”

During operation, sediment and sludge are formed, which must be removed very carefully. For these purposes, you can use a traditional soldering iron, which has a special tip known as a “microwave”.

Soldering tools

To carry out independent work using solder paste, you will need the following tools and materials:

Technological soldering iron (temperature no more than +300 C).
Side cutters, as well as technological tweezers for processing joints.
An awl or a special sharp needle.
Solder composition for processing.
Magnifying device (glass or magnifying glass).
Liquid flux with neutral, no-clean characteristics.
A syringe with which we will apply flux.
Soldering hair dryer.

Soldering tools

If there is no no-clean flux, in rare cases it is possible to use an alcohol solution with rosin, but remember, such a drug can be used, but you are unlikely to have a sufficient effect, so this option is considered as a backup.

It is also not recommended to use a 220 Volt soldering iron. An auxiliary method is a soldering iron with a voltage of 12 V-36 V, with a power rating of 20-30 Watts. A soldering hair dryer can only be used as a backup or main option, but do not forget that heating must be carried out evenly for the entire plane of the microcircuit, and at the same time, first to spread the flux, then increase the temperature to dry the microcircuit.

During the work process, we be sure to comply with safety requirements, ventilate the room, and take into account that you are working with electrically hazardous tools and harmful chemical substances used for soldering.

Source: https://ice-people.ru/payal-2/kak-payat-payalnoj-pastoj-kak-polzovatsya-payalnoj-pastoj-sposoby-naneseniya-instrukciya.html

Solder paste: making at home. Types of composition and rules of use

To fasten elements by soldering, it is necessary to use special materials that have a lower melting point. Many radio amateurs use the old approach - solder. It is necessary to use flux or acid along with it.

Modern compounds called pastes help speed up the soldering process. They initially include all the necessary components and do not require any additives.

We’ll try to figure out what the features of this material are and how to apply solder paste correctly.

Solder paste and its properties

Initially, these compositions were used in SMT-type technologies. Currently, their scope of distribution has expanded significantly. The paste includes the following main components:

Solder is in powder form with varying degrees of crushing. As a rule, alloys selected include tin, lead, and silver. Lead-free pastes have become especially widespread.
Flux for degreasing.
Necessary additives for binding. They simplify the installation and fastening of SMD components on boards. Larger board sizes require a more viscous paste.
Activators and additional components.

High-quality soldering is ensured if the storage period and conditions are met. Most components have a shelf life of no more than six months. For storage and transportation, it is necessary to ensure a regime from +2 to +10°C.

In the photo of solder paste you can see their typical modifications.

However, when choosing, you need to pay attention to the material’s compliance with the following requirements:

high level of soldering work with the strength of the resulting connections, preventing spattering and the formation of balls;
necessary adhesive parameters, thanks to which the elements are held until soldering;
resistance to spreading during initial heating;
absence or minimal amount of easily removable flux remaining after work;
applicability of dispensing or screen printing technology;
permissible for long-term storage.

Varieties

The market widely offers products from the best solder paste manufacturers under the brands Qualitek, UNIVERSAL, Felder, HERAEUS, ALPHA, etc. The entire product line can be divided into groups by type:

According to the chemical composition of the flux - halogen-containing and halogen-free.
According to the need for laundering - those requiring processing and those not requiring. Pastes of the first type can be washed with water (water-soluble) or special liquids.
Depending on the solder - lead-containing and lead-free.
By temperature – low, medium and high temperature.

If the paste is not washed off with water, then it contains rosin. In this case, the parts must be washed with solvents.

It is important to take into account this feature - an increase in the degree of solderability of elements and SMD components is accompanied by a decrease in the reliability of fastening. And, for example, halogen-containing compounds improve manufacturability, but are characterized by somewhat low reliability.

Important Specifications

If you are interested in the question of which solder paste to choose, then you need to pay attention to the physicochemical properties of the mixture. They depend on the presence of binding components that affect the consistency, adhesive parameters, and level of adhesion.

These properties include:

composition of elements - presence or absence of lead, presence of alloying additives;
size of solder particles according to IliS;
the shape of the particles, which affects the dosage possibilities;
viscosity, affecting application technology - the need for a dispenser or stencil;
level of solderability, determined by the oxidation and contamination of solder particles.

If no-clean pastes do not cause corrosion, then water-washable pastes can cause such processes at the soldering site, since they include some organic components.

Paste technology

If you have not used this composition yet, then our instructions for working with solder paste will help you:

First you need to clean the board, degrease and dry thoroughly;
install the board horizontally and fix it in this position;
the paste is applied evenly at the specified connecting points without gaps;
small and smd elements are placed on the board;
in some cases, for greater reliability, it is necessary to treat the chip legs with paste;
in the case of lower heating of the board, it is necessary to run a hair dryer and warm up the upper area with the fastening element with a warm stream;
after the flux has evaporated, the temperature should be increased to the solder melting level;
soldering must be constantly controlled;
let cool and wash the board.

To manipulate microcircuits, you need to use a soldering iron at +250 - +300 Co. It is allowed to use models 20-30 W and 12-36 V.

Soldering irons with conical tips should not be used. Increased efficiency of manipulation is ensured by the use of a very thin wire to contact the tip with the paste.

You can solder SMD components like this:

place them on the contact pad;
apply the paste to the legs;
under the influence of a soldering iron at a given temperature, the paste spreads over the contact area;
leave the elements to cool.

To solder wires, solder paste is applied to the wires in the connection area. Then a soldering iron is applied to the paste.

Making at home

Often ready-made soldering material is not at hand, so it is advisable to know how to make solder paste with your own hands. To do this, you need to prepare a rod of tin-lead solder and fat for soldering. If you don’t have the second component, then regular Vaseline plus LTI-120 flux can replace it.

The solder must be thoroughly crushed using a file, a needle file and a mechanical attachment with a drill. The crumb should be fine. It is collected in a container and Vaseline is added in a 1:1 ratio, as well as a little flux.

The ingredients are mixed. For quality mixing, the mixture should be heated in a water bath. You can store it in a large medical syringe. Using it, the paste will then be applied to the required areas.

Solder paste photo

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Source: http://sdelatlegko.ru/payalnaya-pasta/

Solder paste for soldering without a soldering iron - Metalworker's Handbook

Soldering is a simple matter, so many can do it without even holding a soldering iron in their hands. But there are times when this device is not nearby, but you need to solder something. This is where the dilemma arises, how to solder without a soldering iron, and whether it is even possible to carry out such a procedure without having the necessary tool or the ability to use it.

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Many people have had moments in their lives when the wire in the charger, headphones, laptop power supply, or somewhere else broke or broke. What can be done in this case? How can I help myself fix the problem, at least temporarily, until I can solve the problem in a more rational and reliable way?

As it turns out, nothing is impossible. You can solder without a soldering iron. In the most unpredictable situations, it is always possible to solve the problem using improvised methods.

Necessary equipment

Of course, soldering without a soldering iron implies the presence of the most primitive tool and solder. It’s good if you also have rosin or acid, although in extreme cases just an aspirin tablet will do. Among the tools we can highlight:

pliers;
knife;
foil;
textile;
solder paste;
file or coarse sandpaper;
source of fire.

It is not necessary to have all this together. Some tools can easily be replaced with what you have on hand. Instead of a file, you can take a knife , and sticks of the desired shape can successfully replace pliers. The main thing here is to turn on your imagination.

Tinning of parts

Whatever surface is offered for soldering, it is necessary to prepare it, that is, tin it. This will allow you to more reliably connect the parts together, and will also greatly simplify the process itself. To work you will need rosin (or soldering acid) and tin.

To carry out the tinning process, you will need a container where the solder and rosin will be melted. You can use a lid from iron cans, a small metal box, or something similar to a trough. Tin shavings are rubbed here using a file or sandpaper. It’s good if you have tin-lead solder - it’s more convenient to work with. If it is not there, then you will have to use rosin or acid.

Everything is clear with acid, just immerse the stripped edge of the wire in it, and then continue soldering. You will have to do the same with rosin as with tin, but it is not at all necessary to grind it off with a file. Its pieces can be large, since the melting point of rosin is much lower than that of tin, so even large pieces will have time to melt before the metal melts.

The container must be held over a fire source until the tin is completely melted. Next, the bare or stripped ends of the wire are placed first in rosin, and then in molten tin. When the result is satisfactory, that is, the exposed wire is well covered with a layer of metal, the container can be set aside.

If it is necessary to tin a flat-shaped part, then the algorithm of actions will be slightly different. Here, fine tin shavings and rosin are poured directly onto the surface of the part. Next, this part is heated , as a result of which the molten tin will evenly cover it. Remove excess with a rag or sandpaper.

Do not forget that when working with fire, iron parts will heat up, so you need to handle them with pliers or a rag to avoid getting burned. No one has canceled basic safety precautions.

Soldering wires

To solder small-section copper wires without a soldering iron, no complicated steps are required.

It is enough to simply twist the already tinned ends of the wire together, then use a match, lighter or other directed flame to warm them up well.

The solder left on the hairs during tinning is quite enough for them to be firmly connected to each other. After this, it is important not to forget to insulate the exposed areas with electrical tape, hot glue or another available method.

Wires of larger cross-section (up to 2 mm) can be soldered in a similar way. If there is not enough solder from tinning, then tin shavings are carefully placed on the twist, after which the soldered area is also heated. When the tin melts and fills all the voids between the wire hairs, soldering can be stopped. But don’t forget to insulate the exposed area.

If you need to solder a wire to a flat part or connect two parts of a flat shape to each other, then you need to pour crushed solder onto the tinned place, then attach the wire and heat the parts until the tin is completely melted. In the case of two flat parts, the tinned surface is also covered with pieces of tin, another flat part is placed, they are compressed and heated.

Connection with groove

You can solder without a soldering iron in another interesting way. To implement this, you need a small piece of thick foil. This method allows you to solder fairly thick wires with a cross-section of up to 3 millimeters. This method is also interesting because it does not require pre-tinning.

First, you need to strip the ends of the wires by about 30 mm, and securely twist the exposed parts together. Now a small rectangle is cut out of the foil of such a size that the prepared ends can be completely covered with it. Foil is wound onto the wires in the form of a funnel, into which small pieces of rosin and tin shavings are poured. The ends of the groove are twisted to prevent the contents from spilling out.

Now the resulting structure must be heated until the tin and rosin melt. After this, all that remains is to wait for the soldered parts to cool down. The remaining foil is removed and, if necessary, the weld area is treated with a file, needle file or emery cloth. This method is perfect when you need to quickly and without tools solder wires in the field.

Cooking pasta

You can solder without a soldering iron using solder paste. Having prepared such a solution, you can connect not only wires and flat elements, but also some radio components, and also solder the wire to the board without a soldering iron.

To make solder paste, you will need to mix 32 ml of hydrochloric acid with 12 ml of water. 8.1 g of zinc is added to the resulting solution, and after dissolving it, another 7.8 g of tin. All this is done in glass or enamel containers. When the reaction is complete, all that remains is to evaporate the water to form a paste-like mixture.

Now another 7.4 g of lead, 14.8 g of tin, 10 ml of glycerin, 7.5 g of dry ammonia, 29.6 g of powdered zinc and 9.4 g of rosin should be added to the paste. All components must first be heated and brought to a dusty state.

When the composition is ready, it can always be used for its intended purpose. It is preferable to store the paste in a tightly closed glass container. Soldering with this composition is extremely simple:

The areas of parts to be soldered are cleaned.
Using a brush, apply a thin layer of paste to the joints.
The area where the parts are to be welded or soldered is heated with a candle, lighter or other method. It is highly preferable to use a turbo lighter or a gas torch with a directed flame. However, in their absence, any source of open fire will do.

In this way, it is quite possible to solder almost any parts and wires at home without a soldering iron, but the process of making the solder paste itself can be intimidating. But there is a much more attractive alternative - solder paste can be bought ready-made.

For soldering very small parts and thin wires, it is preferable to make solder paste with a slightly different composition . It will contain the following ingredients:

7.4 g lead powder;
7.3 g of zinc in dust form;
14 g glycerin;
4 g rosin;
14.8 g of powdered tin;
10 ml diethyl ether.

All components are mixed to a paste. Instead of diethyl ether, you can use 10 ml of rosin dissolved in glycerin. Using this tool, it becomes possible to solder a wire or part onto the board.

Homemade soldering jig

You can make a soldering iron from a candle or lighter. True, it is better to take the latter from good heat-resistant plastic, since a disposable Chinese device will not work for even a minute, and the metal device can get very hot. You will also need a piece of thick copper wire with a diameter of 3 to 5 millimeters and some thin wire for winding to the lighter.

How to choose a gas torch for soldering

The thick wire must be completely stripped of insulation, and then bent so that one part can be wound to a lighter or candle, and the opposite end is above the flame for constant heating. Such an improvised tip is capable of soldering even small parts (down to the tiniest resistors). True, you can’t do without tin and rosin. To make work more convenient, it is preferable to sharpen the working area of the tip.

Alternative Repair Methods

If a wire is broken and you urgently need to restore it, at least for a short time, then there are faster alternatives. True, without soldering, but quite capable of helping in emergency situations.

So, a broken wire can simply be cut at the break point and simply twisted together. It is important here not to confuse the polarity, since chargers have a constant voltage. It wouldn't hurt to insulate the twists either.

You can temporarily attach a wire with a flat surface. To do this, just tightly attach one part to the other and fill it with molten plastic. Such restoration will be sufficient if you use the resulting connection carefully and briefly.

No matter what happens, you can always find a way out of the current situation if you turn on your fantasy and imagination. Sometimes this will not help to repair the device, but it will allow you to urgently restore its functionality for a short time.

Source: https://ssk2121.com/payalnaya-pasta-dlya-payki-bez-payalnika/

Notes from a programmer

The J-antenna, also known as the J-pole, is a popular antenna among radio amateurs, typically used on VHF. I recently decided to make a J-antenna for 2 meters, simply because I've never made one before. At the same time, it was decided to try a new material for me, copper pipes.

Theory

The shape of the J-antenna really does not resemble the Latin letter J:

In fact, a J-antenna is a vertical dipole fed from below. The upper part is an antenna sheet with a length of λ/2, that is, a dipole. The lower part of the antenna is the matching section. It is a two-wire line with a length of λ/4.

The coaxial cable is connected to the antenna at some point in this section, as shown in the picture.

This ensures matching of a coaxial cable, which has a characteristic impedance of 50 Ohms, and a dipole, which, when powered from the edge, has a high resistance of several thousand Ohms.

Why does such a scheme agree on anything at all? To answer this question, consider two edge cases. Let's say we decide to feed the J-antenna at the very bottom of the matching section.

The question is, what is the input impedance of the antenna at this point? It is not difficult to guess that here we have a short circuit, that is, a resistance of 0 Ohm. Okay, now let's move up λ/4 and try to power the antenna here.

What input resistance will we see? It turns out that it is infinitely large, since the λ/4 section is nothing more than a quarter-wave transformer with 0 ohms at the end.

Intuition suggests that somewhere between these two extremes you can find any active resistance, at least 50 Ohms, at least 75 Ohms, at least any other. And indeed, in practice this is exactly what happens.

Practice

It was decided to make the antenna from copper pipes with a diameter of 10 mm. I've never soldered copper pipes before. As it turns out, it's not that difficult:

You will need the following tools: a vice, a gas cylinder, a gas torch, soldering paste for copper pipes, gardening gloves, a round file. Optionally - lead-free solder, pipe cutter. Pipes are easy to cut, so if you don't have a pipe cutter, a hacksaw, Dremel, or something like that will do. Plumbers only use lead-free solder because lead is toxic. But we are not going to pump water through pipes, so the good old POS-61 will do.

The following materials were used in the antenna: SO-239 connector, some thick copper wire, a copper pipe with a diameter of 10 mm (at least 2 meters, better with a margin), two 90° angles and two couplings for it, as well as some epoxy glue.

Soldering is carried out as follows. Solder paste is applied to the soldering site, and the corresponding fitting is put on - an angle or a coupling. Heat with a gas burner until the paste becomes a characteristic silver color.

This means that the optimal temperature has been reached. We move the burner to the side and poke a little solder into the soldering area. It should melt right away. Turn off the burner and wait for the copper to cool.

THIS IS INTERESTING: What should the soldering iron temperature be?

In words it is most likely not very clear, but you will find a lot of videos about how this is done.

Important! Be extremely careful with the gas burner. The gas combustion temperature in it is about 1000°C.

The antenna dimensions are not very critical. In our case, the wavelength λ is equal to:

>>> 300_000_000/145_000_000
2.0689655172413794

I took exactly 2 meters. The distance between the conductors in the matching section is about 1-3% of λ. I used a piece of pipe 4 cm long at the bottom of the antenna. After soldering the corners, the total distance was 6 cm:

The couplings are soldered to the SO-239 connector as in the photo and put on the pipes. In order for the couplings to slide along the pipes, they need to be slightly processed from the inside with a file. We carry the antenna to a future location for permanent installation. Personally, I placed it on the balcony, attaching it with nylon ties to a PVC pipe. Then we match the antenna by moving the couplings along the matching section.

In my case, the EU1KY analyzer showed perfect agreement:

We go to the local repeater and make sure that the correspondents receive us well. All that remains is to solder the couplings in this position, seal the remaining holes in the pipes with epoxy, add a shut-off choke, and the antenna is ready!

Conclusion

Some radio amateurs report that the J-pole also works in the 70 cm range, at the third harmonic. I was able to adjust the above antenna normally only in the range of 2 meters, at 70 cm everything is very bad. Even if you manage to tune the antenna to two bands simultaneously, at 70 cm its radiation pattern will leave much to be desired. It’s also not very clear what to do with the cut-off throttle. In other words, you should not expect multi-band performance from a J antenna.

Have you ever made a J-antenna or perhaps related ones (Slim Jim, Super-J), and if so, what materials did you use?

Source: https://eax.me/j-pole-antenna/

Soldering with solder paste

Soldering of parts to the surface of a printed circuit board is carried out mainly using solder paste. The composition of pastes can vary greatly, but basically the main components are solder, flux and binder. Any soldering paste looks like a thick and viscous mixture of chemicals.

Special qualities of materials for soldering

It is known that connecting elements by soldering is possible when using a material with a lower melting point. For simple amateur circuits, solder is still used together with flux or acid. The paste, which contains both components, as well as various additives, significantly speeds up the process of soldering complex printed circuit boards with SMD elements. Widely used in electronics production.

Let's look at the main components of soldering paste:

powdered solder of different crushing qualities;
flux;
binding components;
various additives and activators.

Various alloys with tin, lead and silver are chosen as solder materials. Recently, lead-free solder pastes have become the most popular.

Each solder paste contains flux, which acts as a degreaser. In addition, an adhesive binder is required, which facilitates the installation and fixation of SMD components on printed circuit boards. The larger the board size and the higher the elemental density, the more important it is to use more viscous solder pastes.

The shelf life of the paste has a big impact on the quality of soldering of SMD components. Since the composition usually contains active chemical components, its use and storage period is very short, no more than 6 months. During storage and transportation, it is necessary to maintain the temperature from +2 to +10. Only if all conditions are met, high-quality soldering is possible.

Variety of solder pastes

Depending on the use of various components, there are several types of solder pastes:

washing;
without washing;
water soluble;
halogen-containing;
halogen-free.

The properties vary depending on the use of the flux included in its composition. Any paste that is not washed off with water contains rosin. To wash products from such a paste, you must use a solvent.

The general rule for contained elements and SMD components is that the better the solderability, the lower the reliability. Maintaining a compromise between these important properties is the key to effective functioning. The use of halogen-containing pastes significantly increases manufacturability, but somewhat reduces reliability.

Methods of using soldering pastes

In order to obtain a high-quality and reliable connection of SMD elements on a printed circuit board, you must perform certain actions:

high-quality cleaning and degreasing of the printed circuit board followed by drying;
fixing the board in a horizontal position;
uniform and thorough application of solder paste to joints;
installation of small and SMD elements on the surface of the board; for more reliable soldering, it is recommended to additionally apply paste to the legs of the microcircuits;
when the board is heated from the bottom, the hair dryer is turned on and the upper part with the installed elements is heated with a gentle flow of warm air;
after the flux has evaporated, the temperature of the hair dryer increases to the melting temperature of the solder;
the soldering process is visually controlled;
After cooling, the final washing of the printed circuit board is performed.

Basic tricks of high-quality soldering

In order to efficiently connect elements using soldering paste, you should take care of some points. First of all, it is important to clean and degrease the board, especially if oxides are noticeable, or the board has been lying unused for a long time. In this case, it is advisable to tin all the contact pads with low-melting solder.

Solder paste should have a convenient consistency. That is, it should not be too liquid or too thick. A “sour cream” structure is most suitable, as it will wet the surface well. Wettability plays a huge role in the reliability and quality of the solder joint.

When soldering SMD elements, it is important to apply a thin layer of paste. A thick layer can short-circuit the pins of the microcircuits. Soldering simple elements does not imply such subtlety.

If the printed circuit board is of significant size, it is advisable to use bottom heating with a hairdryer, iron or special means at a temperature of 150 degrees Celsius. If this is not provided for, the board may warp.

Excess and remnants of solder can be easily removed with a soldering iron with a variety of attachments. For example, to remove residues of substances used for soldering between the legs of microcircuits, it is convenient to use a “wave” tip.

Source: https://rem-serv.com/payka-s-pomoschyu-payalnoy-pasty/

Types and methods of applying solder pastes

The quality of electronic equipment largely depends on the strength of the connection between circuit components and printed circuit boards. Good soldering is ensured by solder paste. This mixture serves several functions.

Characteristics

The paste-like mass contains solder, fixing agents and flux. To create consistency, solvents, stabilizers, substances to maintain stable viscosity, and activators are added to the paste.

The solder component can be represented by eutectic alloys of lead and tin, the content of which is 62-63%, with or without the addition of silver. Sometimes solder is represented by lead-free alloys of tin (95.5-96.5%) and silver with or without copper additives.

The size of the particles of the viscous mass is of great importance, depending on which a stencil or solder paste dispenser should be used for application. Both methods can be implemented without a soldering iron.

If the particles are round in shape, you can use both a stencil and a dispenser. Spherical grains are usually obtained due to the atomization of the solder component during the production of solder paste.

The size and shape of the particles cause possible difficulties in application.

Solder paste with very small particles due to the large surface area in contact with air can oxidize quickly. Small grains can form solder balls. Very large round particles and grains of irregular shape tend to clog the stencil.

According to the size and shape of the particles, solder pastes are divided into 6 types. The choice must be made taking into account the output step and the size of the stencil windows.

Flux as a component of solder

Flux components are also subject to classification. There are 3 types of fluxes in solder pastes:

rosin;
water-washable;
no-wash.

The rosin group of fluxes is represented by activated, moderately activated and completely non-activated compositions. Soldering fluxes that have not been activated show the least activity.

The most widely used fluxes are those with medium activity. They clean the surface well, spread over it, and wet the parts to be joined. However, they can cause corrosion. Therefore, after soldering, the working area must be washed with special solvents or hot aqueous solutions.

Soldering fluxes that have undergone significant activation are used for heavily oxidized parts. After soldering, the workplace is washed with organic mixtures with alcohol.

Water-washable flux compositions are based on organic acids. They are highly active and contribute to the formation of a good seam, but require mandatory washing with purified hot water.

No laundering is required when working with fluxes made from synthetic or natural resins. Even if there are residues on the surface after soldering, this will not harm the product.

The residue does not conduct current and is resistant to oxidation. It does not need to be washed. If desired, washing can be done with special solvents or hot aqueous solutions.

Rheological features

Important characteristics of surface mount solder pastes are viscosity, adhesiveness, durability, and the ability to create a three-dimensional connection on the board.

Knowledge of quantitative indicators of rheological properties allows you to choose the right printer for applying solder paste, which can rationally dispense portions.

The paste is applied taking into account the tendency to increase the viscosity of the paste mass. A decrease in viscosity occurs with increasing temperature. To successfully solder with solder paste, you need to periodically add new portions to the mass and monitor the temperature readings in the working area. This can be easily done using screen printing machines equipped with thermal sensors.

Many packages of imported pastes indicate “lifetime”. The value determines the time interval from the moment the can is unsealed until the end of soldering, during which the rheological properties will remain unchanged.

If the indicator is low, you will have to work quickly to obtain a high-quality connection. Now there are mixtures on sale with a “lifetime” of 72 hours. You can work slowly with such tools.

An important characteristic is the stickiness of the solder paste, which reflects the ability of the part to stay on the board before starting work.

Some pastes can fix electronic components for more than a day, which is convenient when installing large boards. Compositions with low adhesiveness are capable of holding the element for 4 hours.

There is a wide range of solder pastes on sale, some of which are sold in a syringe for manual or automatic dispensing, others in cans or cartridges.

Products in cans are intended for screen printing machines. They are made of metal sheets with great scrupulousness, which makes it possible to cut out cells on the board for applying solder paste with an accuracy of 0.1 mm.

Special types of stencils can regulate the thickness of the paste-like mass. The machines can operate in both manual and automatic modes. Expensive models are additionally equipped with a stencil cleaning system, which significantly increases work productivity.

Storage conditions

Multi-component solder mixtures are influenced by external factors. The conditions required for proper storage are indicated on the packaging. They should be read and strictly followed.

Be sure to indicate not only the temperature suitable for storage, but also the range of its possible deviations.

Usually, when the storage temperature exceeds 30℃, the mixture will deteriorate irreversibly. Very cold environments may impair the performance of activators contained in solder or thermal paste.

The time it takes for the paste to reach room temperature is of great importance. It is important to know:

how long it needs to be stirred;
what temperature and air humidity should be maintained when using the paste;
how long it can be stored under the specified conditions.

When the air is humid, solder balls may appear in the solder mass due to water absorption. The shelf life and storage conditions of solder pastes differ and depend on the composition. If you follow the manufacturers' instructions, the quality of soldering will meet your expectations.

For plumbing systems

A completely separate group consists of paste-like compositions intended for installation of fittings made of copper and its alloys in water supply systems with a soldering iron. These compositions are subject to special requirements, which are strictly regulated by GOST.

None of the paste components can be toxic. The flux must completely prevent oxidation of the seam and the penetration of corrosion products into the water.

Water supply pastes are completely unsuitable for working with electronic circuits for many reasons, in particular because copper or silver is often added to them to increase the strength of the connection. Such compositions are not used in electronics.

Source: https://svaring.com/soldering/pripoj/pajalnye-pasty