How to properly solder with rosin

Tin with rosin for soldering

In many situations, soldering requires great skill. Combining the functions of solders and flux mixtures in one product greatly simplifies the work.

There are several types of such products, each of which has its own characteristics - these are paste mixtures, ready-made solder with rosin, made in the form of wire, and tubular solder with flux. The choice is determined by the soldering mode, the nature of the part, and the requirements for the seam joint.

Wire with rosin

Combining two consumables in one product significantly simplifies the procedure and improves the efficiency and effectiveness of the work. If rosin as a flux is added separately, there is a high probability of adding an excess amount.

In the finished wire with flux, the ratio is fixed, stipulated by GOST.

Most often, products are supplied in a coil or coil. The version with wire packaging in coils is intended for continuous operation on an industrial scale. The assortment includes products of a wide variety of thicknesses.

Products in the form of coils are used for slightly smaller scales of use.

This option is suitable for both individual craftsmen and repair businesses. The thickness of the wire packaged in coils varies from 0.8 mm to the maximum possible 2 mm.

The solder component is an alloy of 2/5 parts lead and 3/5 parts tin. Each solder granule is surrounded by rosin, the total concentration of which varies from 0.8% to 1.2%.

The convenience of the wire is due to its flexibility . When soldering, such a mixture can be easily introduced into any gap, where it will melt and provide good envelopment of the parts and the formation of a strong seam.

The disadvantage is the low melting point of the mixture . Parts made from refractory alloys cannot be soldered with such consumables.

Working with solder wire containing rosin flux is similar to standard soldering. First, the parts need to be cleaned, then heated to the required temperature and consumables introduced into the work area.

Tube arrangement

The use of materials with dual functions in the form of tubes is economically and technologically beneficial. Consumption is reduced by almost 40%, and there is no need to remove the remaining flux after soldering.

Tubular solder contains 1, 3 or 5 internal channels into which flux is placed. There are several advantages of using this type of consumables:

• simultaneous supply of two trains to the working area;
• improvement of the final result;
• increase in work speed;
• simplification of soldering in hard-to-reach areas;
• reducing losses of funds;
• possibility of strict dosing;
• eliminating the possibility of dirt getting into the flux.

Tubes with one internal cavity can make soldering a little more difficult due to the rapid flow of flux into the work area. When working with multichannel solders containing flux, such troubles are unlikely.

In any case, you need to get used to using tubular products and learn how to properly regulate the solder supply speed. In general, the flow of flux through several channels minimizes the likelihood of disruption of the soldering technology.

Dry work will be completely eliminated. The flux enters the work area evenly through several channels, which leads to improved joint quality.

Solder material composition

The tubes contain both traditional and special solders.

As a solder mass for many metals and alloys, in particular for copper, a common alloy of tin and lead with eutectic properties is used.

The ratio of metals may vary to some extent. Recommendations for the use of such tubes correspond to the instructions for the use of homogeneous solders made of tin and lead.

For surface mounting work, it is better to choose products with a diameter from 0.46 to 1 mm. To solder miniature parts, flux solders containing silver additives are produced. The maximum melting point of the product is 188℃. The diameter of such tubes is 0.46 mm and 0.56 mm.

Solders with tin and copper have higher melting points, reaching 227℃. the tin content in them varies. Tubes are produced with fluxes in which the tin concentration is 95.5% and 99%. Some types of products contain silver additives.

For soldering elements of aluminum lamps, special solders with fluxes containing 80% lead, 18% tin and about 2% silver are supplied. Slight variation in the ratio of components allows you to expand the range of melting temperatures. The minimum is 178, the maximum is 270 ℃.

In most cases, the tubes contain purified rosin as fluxes. Strict dosing almost completely eliminates the possibility of residue formation. If any are discovered after finishing work, they do not need to be deleted.

When choosing consumables, you should pay attention to the manufacturer's information. The technology for producing solders with flux is quite simple, which increases the likelihood of counterfeits.

In low-quality products, the ratio of external and internal components may be disrupted. In professional production, the flux content usually varies from 1% to 4% of the total weight of the tube.

  Soldering an aluminum engine cooling radiator

Tips for use

To work with tubular consumables, you can take any soldering iron. It is important that its shape and dimensions provide the required contact with the parts.

If necessary, the tip should be cleaned by tinning using tubular solder with flux. If there is a lot of dirt on the sting, you should first treat it with a special sponge.

To be completely sure that the working part of the soldering iron is clean, you can use special paste-like products.

Do not allow the work area to overheat. To do this, it is important to monitor both the heating temperature of the soldering iron and the duration of soldering.

Soldering printed circuit boards requires special attention. The work area must first be thoroughly cleaned. You can buy specially designed solvents for this.

Each procedure for soldering parts on the board should last no more than 2 s. During this time, one connection must be made. If more time is spent, the wetting capabilities of the fluxes may not be enough. As a result, the strength of the connection between the electronic components and the board will deteriorate.

Handling tubing containing solder and flux takes some getting used to. The end result and convenience in subsequent work justify minor difficulties at the beginning.

Source: https://rem-serv.com/olovo-s-kanifolyu-dlya-payki/

How to replace rosin

When soldering at home, rosin can be replaced with:

How can you replace rosin when soldering?	Description of the analogue
Aspirin	It is the most affordable and easy-to-use replacement option. Acetylsalicylic acid is probably in every first aid kit. This is an acid that is not aggressive. An aqueous or alcoholic solution of aspirin effectively copes with oxidation. Soldering with such a solution is accompanied by the release of a strong unpleasant odor, so the room should be well ventilated.
Fat	An option that melts well, spreads, and protects the surface from oxidation. An important advantage is low cost. However, when heated, it provokes a specific odor. In addition, this is not the most convenient material for soldering, since it has a peculiar consistency.
Resin	Resin from trees is suitable. The resin melts well, spreads, and is an ideal option for tinning. Since it does not have any aggressive properties, it can be used for any type of soldering. However, this material is not as highly active as regular rosin.
Amber	Probably the best option for replacing rosin when soldering, since it has the most similar characteristics to it. However, amber will not always be appropriate, since it has a fairly high cost, so it is better to consider other options for replacement.
Rosin for musical instruments	This option may be relevant because it is a very good alternative to classic rosin for soldering. However, you need to take into account that, unlike ordinary rosin, it costs much more.

When soldering various materials, rosin is used because it can improve the quality of work and also prevents the development of negative phenomena such as oxidative processes. Rosin is the most affordable and easy-to-use material.

However, there are times when this material is not at hand. In such cases, the question arises of what can replace rosin at home.

How can you replace rosin when soldering?

This question is faced by people who have an urgent need to find an analogue from improvised means that have characteristics similar to rosin. There are many replacement options that experts recommend.

It can be used as tree resin, which is the best analogue of rosin, or even aspirin. It is recommended that the concentration of the medication be as high as possible - this is the only way to get the desired result when soldering. It can be dissolved in water and alcohol.

It is also possible to use rosin, which is used to lubricate musical instruments. We must not forget about animal fats, which help fight oxidative processes. This is probably the most affordable option at home.

Amber will also be an excellent analogue, since it has the most similar characteristics to ordinary rosin. However, its use is not always appropriate, since it is much more expensive than traditional material.

Non-standard replacement options

If you need to replace rosin, you can use the electrolyte from an old salt battery, but not an alkaline battery. Also, if there is very little rosin left, it can be diluted in alcohol and the resulting solution can be used for soldering.

You can use acids with stearin (paraffin). They qualitatively protect the surface from oxidation.

What you need to know when using alternative methods

There are no significant differences when using analogues. They, just like rosin, are applied to the work surface or the soldering iron tip is dipped in them.

The only difference can be in preparation. The fat should be transferred to a small container and slightly warmed. You need to make a solution from aspirin. Amber and resins can be used without any preparation.

Instead of rosin, you can use not only acids, but also other available means. They will act as a good flux that protects the surface from oxidation.

All of the above analogues are suitable for soldering, since they have characteristics similar to traditional rosin. However, before use, it is important to study the features of each material.

Source: https://Chem-zamenit.ru/texnika-i-avto/kanifol.html

What is flux solder and how to use it?

Reading time: 6 minutes

Solder and flux for soldering are indispensable tools for many home and professional craftsmen. With their help you can achieve high-quality, even seams. Manufacturers offer many types of fluxes and solders. There is even solder on the market that has flux inside! And all this variety is difficult to understand if you have never used solders and fluxes.

We decided to make your task easier and tell you about the types of solders and fluxes and their applications. You will learn how low-melting solders differ from high-melting solders, what active and passive fluxes are, and how to use these materials in your work.

Types of solders

Solder is a metal rod used to fill joints between two parts. It melts and mixes with the base metal or acts as a base metal altogether. May have different diameters. Made from tin, but with the addition of other metals. For example, lead zinc or copper. Can be low-melting or refractory.

Low-melting

Low melting point solders are most often used for small jobs. For example, when soldering radio equipment. Also, such solder is indispensable if soldering of radio-electronic elements is necessary. In the composition you can most often find a combination of tin with cadmium, bismuth, lead or zinc.

Based on the name, it is not difficult to guess that such solders melt easily. One small soldering iron is enough to melt them. If you need solder for working with radio electronics, then choose rods with a melting point of up to 140 degrees.

There are also special solders for tinning circuit boards. Their melting point does not exceed 100 degrees. Due to these properties, tinning is easier and faster. Solders have their own brands, but we will not focus on this. This is a topic for a separate article.

Let's just say that when soldering modern equipment, it is recommended to use lead-free solder and with a melting point of about 200 degrees. This is due to the peculiarities of foreign technology. It is manufactured in accordance with strict environmental regulations, according to which lead emits harmful fumes when soldering.

Refractory

Refractory solders are the antithesis of low-melting solders. Their melting point starts at 400 degrees. Such solders are used in professional industrial welding, where large parts need to be welded. Refractory solders contain a lot of copper, silver, nickel or magnesium. They are very strong and thick, so they are not used in home soldering. Such solders reveal their potential when welding refractory metals. For example, cast iron or brass.

Solder with flux

There is a separate category of solders - this is solder with flux inside. It's tubular solder. It is a hollow rod, the core of which contains flux. The rod melts during soldering, allowing flux to be released and perform a protective function. A striking example is Castolin 192 K flux solder and Brazetec Comet 3476U solder.

Such solders are very convenient to use because they perform two functions at once: practical and protective. There is no need to waste time applying flux and choosing it. But you must understand that such solders do not provide sufficient protection for the soldering area. They only slightly improve the quality of the seams. If you need a perfect result, it is better to use solder and flux separately from each other. Like two different materials.

But what flux is and why it is needed, you will find out further.

Types of fluxes

Flux is a substance applied to the soldering or welding site that protects the metal from oxidation and improves the quality of the seam. Flux can radically change the quality, including the evenness of the seam and its aesthetic characteristics. Therefore, you need to approach the choice of flux wisely.

There is a clear connection here with solder. The easier the solder melts, the better the properties of the flux are revealed. The flux should have a melting point slightly lower than the solder. Then you will achieve high-quality results.

Manufacturers offer two types of soldering fluxes: active and passive.

Chemically active

Chemically active fluxes contain acid-containing substances. They, in turn, are ways to destroy any plaque or signs of corrosion. Well-known hydrochloric acid, zinc chloride, etc. can be used as an acid-containing agent. If the soldering area is not cleaned of flux residues, the metal may deteriorate and new corrosion will appear.

The chemical activity of such fluxes is both an advantage and a disadvantage at the same time. If used improperly, such fluxes corrode metal and textolite if used in radio electronics. Do not forget that such fluxes can leave burns on the skin, so it is important to follow safety precautions. But when used correctly, active fluxes remove any plaque and corrosion, allowing you to improve the quality of work.

We do not recommend using chemically active fluxes in everyday soldering. They require attention and experience. And when soldering radio components, it is better not to use this type of flux at all. Because with a high probability it will corrode the textolite, and you will not be able to fix anything.

Chemically passive

Chemically passive fluxes are used very often. They do not have such pronounced oxidizing properties as chemically active ones, so they are easier to work with. Chemically passive fluxes remove grease and light stains, but not corrosion. These fluxes contain organic components, so they can be used when soldering radioelements.

Chemically passive fluxes protect the welding zone from oxidation and improve the quality of work. However, like chemically active ones.

Source: https://svarkaed.ru/rashodnye-materialy/flyus-i-svarochnaya-provoloka/chto-takoe-pripoj-s-flyusom-i-kak-ego-ispolzovat.html

What you need for soldering work

If in Soviet times there was a game for schoolchildren, the essence of which was to solder a radio-electronic microcircuit on their own, which they successfully did, but now the question of how to properly use a soldering iron puts many in a difficult position. Although learning how to solder with a soldering iron is not so difficult, and having mastered the basics for “dummies”, you will be able to carry out simple work on your own without turning to specialists.

Soldering with a soldering iron

In order to start soldering, you need to prepare a workplace and the necessary tools. Regardless of the type of proposed work, the following requirements are imposed on the workplace:

• The presence of good lighting will allow you not only to work comfortably, but also to notice small flaws in the soldered parts, which is difficult if there is a lack of light;
• No flammable items;
• Free working space on which you can easily place the part to be soldered;
• The presence of ventilation will make work not only more comfortable, but also safer; inhaling molten rosin has a negative effect on the respiratory system;
• A magnifying glass makes it possible to work even with small parts and thin wires;
• A simple stand solves the problem of placing a heated soldering iron.

The next stage of preparation will be the choice of tool, and a beginner is always faced with the question of what is needed for soldering with a soldering iron.

Soldering iron selection

The basis of high-quality soldering is heating metal parts to the soldering temperature; accordingly, for each type of work it is recommended to use soldering irons of different capacities:

• For soldering radio components and microcircuits, it is best to use a soldering iron with a power of no more than 60 Watts, otherwise you can overheat the part or simply melt it;
• Parts up to 1 mm thick will warm up better when using a tool with a power of 80-100 Watts;
• Parts with a wall thickness of up to 2 mm require greater power and some experience in operation, so soldering of such parts will not be considered in this article.

After choosing the power of the soldering iron, you should prepare it for work, or rather, prepare the tip . There are soldering irons with replaceable tips that are suitable for different types of work.

Models with a copper tip are also available, which can be sharpened or given any desired shape using a hammer. A serious disadvantage of such tips is the need to constantly tin them so that an oxide film does not appear on the surface, which prevents the solder from sticking.

Manufacturers also produce a more expensive version with a nickel-plated coating, but it is afraid of overheating and requires careful handling.

What else do you need for soldering?

In addition to the soldering iron itself, you need the following for soldering:

• solder;
• rosin;
• soldering acids or fluxes.

Solder is the connecting material between the parts being soldered, and without it there is no way to work. Now stores sell specially prepared solders in the form of wires of various diameters twisted into a spiral, from which it is convenient to “pinch off” the required piece with a heated tip, but you can also use a piece of tin , but the work will not be so convenient.

Rosin is used to prepare the surface for the application of solder. Solder with rosin is distributed evenly, in the absence of the latter it rolls into drops, and does not stick to some surfaces at all.

Soldering acid, or flux, is necessary to prepare contacts for soldering. A beginner should know that the flux for each material being soldered is different, and you cannot use acid to solder aluminum on a copper wire, otherwise the solder simply won’t stick.

Soldering technology

The basis of any soldering is high-quality heating of the parts being soldered and then securing them with solder. two types of soldering can be distinguished : using flux or using rosin.

Soldering with rosin

Learning to solder with a soldering iron with rosin is more difficult, but once you master this skill, it will be possible to complete 90 percent of the work.

Let's look at the example of soldering wires to a board. First you need to warm up the wire; to do this, apply the tip of a heated soldering iron flat (it’s better if it’s a tip in the shape of a screwdriver), pressing as much as possible.

After a few seconds, the wire with the tip pressed to it is lowered into rosin, which, when boiling, is evenly distributed over all the wire cores. This way the wire is prepared for applying solder. Using a soldering iron tip, take a small part of the solder and apply a thin layer of it to the wire.

In this case, you should not get any drops or unaffected areas; ideally, you get the same wire, but in tin.

We clean the soldering iron tip with a metal sponge or cloth and, touching the rosin with the tip, run the tip over the board, leaving a thin layer of rosin on the surface. The surfaces are prepared. Ensuring maximum contact between the wire and the board, we press the tip with a thin layer of solder onto the wire and “stroke” the soldering area several times with a soldering iron for better heating. After this, let it cool and check the contact for strength.

If soldering is carried out correctly, the surface is shiny and the connection has maximum strength. If the surface looks dull and loose, it means that the rules for soldering with a soldering iron were violated and the connection is not so strong. But in some cases, this result is satisfactory.

Soldering with flux

To solder with flux, you just need to take the flux, dip a brush into it and apply it to the surface to be soldered. After this, you can apply solder or solder directly. Despite its apparent simplicity, working with acid has many nuances :

1. Each material has its own flux and they are not interchangeable, and in some cases even give the opposite effect;
2. You cannot use fluxes that are too active on microcircuits, as they can burn through the metal of the track;
3. If you do not remove the flux from the surface after work or do it with the wrong reagent, it will continue to destroy the metal;
4. The copper tip of a soldering iron, especially if it is sharpened, is destroyed by acid, and you have to constantly sharpen it.

In addition to knowledge, working with a soldering iron requires accuracy and precision, and having learned how to solder simple parts, it will not be difficult to move on to soldering thinner circuit boards, or, conversely, thick wires, various elements, rhinestones, and subsequently even solder plates together.

One of the most reliable methods of connecting wires is soldering. This is a process in which the space between two conductors is filled with molten solder. In this case, the melting temperature of the solder must be lower than the melting temperature of the metals being joined. At home, soldering is most often used with a soldering iron - a small device powered by electricity. For normal operation, the power of the soldering iron must be at least 80-100 W.

What you need for soldering with a soldering iron

In addition to the soldering iron itself, you will need solders, rosin or fluxes; it is advisable to have a stand. While working, you may need a small file and small pliers.

Source: https://crast.ru/instrumenty/chto-nuzhno-dlja-pajalnyh-rabot

Which solder is better to use with or without rosin?

Various types of solders have appeared on the market. Radio amateurs are interested in which consumables are best used for soldering - with or without rosin inside. It must be taken into account that such an operation as connecting elements with thermal effects cannot occur without the use of auxiliary components .

Solder with rosin

When assembling or repairing electronic boards and various electrical devices, radio components are fixed by soldering. Workers attach them to the required areas with a soldering iron, where solder serves as consumables.

At the same time, the processed parts remain solid and are not subject to melting. An alloy is melted, which wets and attaches electronic components. For good adhesion, surfaces must be cleaned with fluxes .

To simplify the work process and improve the quality of connections, universal rosin solders were created.

The developers saved the craftsmen from collecting additional substances and performing unnecessary operations by including the optimal amount of resin in the product.

They are produced in the form of hollow wires, the space of which is filled with components:

• Rosin.
• Synthetic.
• Water-washable.

Soldering with tubular material does not require additional fluxing, which increases productivity. During production, solders differ:

• m rosin.
• Wire thickness

Finished products go on sale with different configurations in the form of:

1. Coils - where a wire up to 2mm thick is wound around a rod. Surfacing material is convenient to use in home and industrial workshops; you just need to select the parameters.
2. Tubes - formed for work at home due to the small number in one set.
3. Bays - which are more suitable for industrial enterprises. Wire of different sizes is packaged here; the buyer chooses the thickness and length according to his needs.

When choosing, the consumer relies on the convenience and quality of the work performed. For standard procedures with known execution modes, any brand from the POS category is suitable - 61 , 60 , 90 . The main component in these solders will be an alloy of silver or tin. Reduced joint strength increases the softness and wettability of the workpieces.

To join refractory metals, surfacing without internal fluxes is used.

Types and features of solders without rosin

Electronic elements are not connected by welding; soldering is used during repairs. This process requires good solder and an auxiliary component - rosin or flux of any type. The metal alloy used to fix the parts wets the areas being joined, and the rosin cleans them. The solder must be thermally and electrically stable.

Consumables are:

1. Solid with a melting point above 450 degrees.
2. Soft.

Consumables produced:

• Granules.
• With rods.
• Wire.
• Powder.
• Foil.
• Plates.

When choosing the right solder, consider:

• Properties of the metal being joined.
• Mechanical strength of the adhesive.
• Corrosion resistance with conductivity.

For fastening boards in radio equipment, the POS-61 due to its acceptable melting point (up to 190 degrees). If you are working with a device sensitive to overheating, choose POSK 50-18. For processing objects with hard properties, the PMC marking, which contains copper and zinc, is suitable. “PSR” indicates an alloy of silver with additives in different percentages:

• Tin.
• Lead.
• Copper.
• Zinc.

There are also samples where phosphorus is added in addition to the metal component.

General properties of solders

According to their intended purpose, consumables with or without rosin perform one task, soldering electronic elements. You can emphasize the same:

1. Form, if the production produces solders in the form of wire.
2. High degree of wetting of joined surfaces.
3. Using one tool for work - a soldering iron.
4. The process involves heating and melting the solder.
5. Composition of alloys for low melting temperatures.
6. Easy soldering.

There are many different types of solders on sale, which does not create difficulties in choosing them.

What are the differences between consumables?

One and the same characteristic creates both similarity of products with each other and difference. This is their production in the form of wires. But in samples without rosin:

• There is no hollow space, they are made whole.
• For soldering, you need to use flux separately.
• In addition to wire types, they produce various configurations and forms - sheets, powders.

All items with internal filling:

• They have a tubular appearance.
• The hollow space is filled with rosin.
• Soldering operations are performed without fluxing.
• Not used for refractory metals.

The master chooses the composition with which it will be convenient for him to work in each specific case.

Who should use each solder and when?

A radio engineer uses a tubular element, the cavity of which is filled with rosin, when it is necessary to carry out soldering:

• In the device, repair the electronic device.
• For small areas, using tubes or reel kits.
• At an industrial enterprise, if there is a coil, ensuring compliance with all technological processes and properties of the metal being soldered.
• With low melting points.

Soldering without internal fillers allows you to perform actions with different:

• Refractory metals.
• Temperature conditions of melting depending on the composition of the alloy.
• Overheating-sensitive elements - fuses, transistors.
• Radio technical products – wires, technical boards.
• Tin and connect copper and bronze parts to obtain a sealed seam.

The master determines the area of ​​work and selects the substance that is suitable for specific work. It is good to attach radio components using wire with rosin. To connect elements made of bismuth or cadmium, it is better to select separately solder and flux that meet the requirements of the alloys.

Source: https://vchemraznica.ru/kakoj-pripoj-luchshe-ispolzovat-s-kanifolyu-ili-bez/

What is better to solder: rosin or flux?

The soldering iron can be used not only in the home workshop, but also in any workshop. It can be used to repair broken cables and restore broken electrical tools or equipment. To use a soldering iron effectively, you need to choose the right materials for the job: rosin or flux.

Pros and cons of rosin

This material is considered an excellent dielectric. When using it, finished solder joints do not lose their properties, and the soldering properties remain high . Rosin has a high level of resistance to moisture.

Rosin is especially often used by home craftsmen. This became possible thanks to the positive properties of the material. For example:

• ease and accessibility of use;
• low cost;
• low melting temperature. Thanks to this, it can be used at low soldering temperatures;
• moisture resistance;
• long shelf life;
• has the ability to destroy oxide films that form on the melting surface;
• harmlessness.

When working with rosin, you must also take into account the disadvantages inherent in the material. Among them are the following:

• low level of activity, which requires its use during soldering more than 1 time;
• hygroscopicity (it is possible that moisture can be absorbed from the vapor after soldering, contributing to the development of the corrosion process);
• used for soldering connections of low complexity;
• its fragility complicates its storage and transportation.

There are several types of rosin, each of which is intended for soldering certain materials: gum, extraction, tallow.

Flux has the ability to protect metal joints from oxidation, improving the quality of soldering and promoting uniform distribution of solder. Among the advantages of the material, you can pay attention to the following:

• low melting point;
• low specific gravity;
• spreads well and quickly, wetting the surface of the work surface;
• resistance to fading and evaporation;
• ease of removal with solvent;
• does not contribute to the development of corrosion;
• compatibility with soluble fats and oxide films.

It is impossible not to mention some of the disadvantages of soldering flux. For example:

• during work, interaction products that are harmful to health are released;
• hygroscopicity.

Due to exposure to high temperatures, the structure of the material changes and its reuse becomes impossible.

What's better

Rosin is applied to the working surface from the soldering iron tip, and flux is specially applied to it. By preliminary preparing the surface (removing film), it is possible to improve the quality of soldering. Thanks to this, soldering using flux is more technologically advanced and of higher quality than rosin.

At the same time, soldering with rosin is several times easier than with flux. Experts do not recommend using acids when soldering: they do not evaporate completely, which eventually leads to destruction of the surface.

What is better to choose for soldering, rosin or flux? It is difficult to give a definite answer to the question: it all depends on the type and size of the working surface. For soldering small parts or circuit boards, it is better to use liquid flux.

Rosin in the form of a stone is ideal when it is necessary to tinning large parts (areas): car radiator . In other cases, it is recommended to use dissolved rosin.

When preparing it yourself, you can choose the required thickness of rosin.

When choosing between rosin and flux, you need to take into account a number of criteria: size, material, purpose of the area for soldering.

Source: https://TehnoPanorama.ru/giroskuter/chem-luchshe-payat-kanifolyu-ili-flyusom.html