Soldering brass and copper at home. Brass soldering technology. How to use brass solder

Brass parts, unlike steel, are easy to process, and this is precisely why useful quality alloy, it becomes possible to solder brass at home, without resorting to industrial methods. To create a wide variety of things, soldering is required - connecting wires and metal parts. To do it correctly, you need a gas burner, a graphite crucible, an asbestos base, as well as silver, copper and boric acid.

Soldering brass is much easier than soldering steel, which allows it to be done at home.

Preparation for soldering brass products

To clean the alloy, you can use oxalic acid. If you don’t have it at hand, you can look at various household products. They are applied to brass products, after which it will begin to darken quite quickly. Then you can get rid of the deposits by taking a thin brush and cleaning the parts in plain water. After this, you will need soda, which is poured into the brass product. After a few minutes, the soda is washed off. If oxalic acid is present, it is diluted in proportions of 20 grams per liter of hot or cold water. It is not recommended to breathe over the solution, and you should also protect your hands with gloves. The container must be plastic to avoid exposure to other metals. Once the brass part has been processed, it should be wiped down and dried.

Oxalic acid is used to clean the alloy.

To solder brass most effectively, you should not use regular tin soldering, as it leaves quite noticeable marks. Besides this, she can't boast great strength. In order to solder brass, it is recommended to use another method that provides increased reliability. Effective and reliable soldering of brass parts is ensured by the use of a gas torch. To make solder from brass, you should take copper and silver in proportions of 1:2, mix thoroughly and fuse together using a graphite crucible and a gas torch. The crucible is placed in a container with cold water, and only after this is it possible to remove the molten and solidified solder. It must be flattened and cut or ground into shavings, which can be done with a large file. After this you will need borax powder and boric acid, each ingredient should weigh 20 grams. Based on these substances, flux is produced. The resulting powder mixture is poured with a quarter liter of water.

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Solders for soldering brass parts

Soldering with a gas torch must be done extremely carefully, with maximum temperature at 700 degrees.

Brass parts that require soldering are placed on an asbestos base. The connected parts are sprinkled with solder, cut into small pieces and pre-sharpened. The joint is then gently heated using a gas torch. This work must be done as carefully as possible. When soldering parts, the temperature should gradually approach a certain level. The maximum permissible level is 700 degrees, but if you exceed it, you may encounter hopeless damage to all parts. When it is necessary to solder large and massive parts, their heating should be gradual to avoid negative consequences. When soldering small and thin parts, the heating process occurs in a very short terms, so it is important to treat it carefully.

Of course, conventional soldering with tin is much simpler than a similar method, but it is thanks to it that the reliability and strength of the soldering of brass parts will be much higher. It is important to remember some features of brass soldering, such as the evaporation of zinc when it is very hot. In addition, the surface of the alloy is covered with an oxide film. Brass, which contains less than 15% zinc, is oxidized and becomes coated with a film containing interlocking particles of copper oxide and zinc oxide. Copper alloys, in which zinc is contained in much large quantities, oxidizing, form a film consisting mainly of zinc oxide. The problem with such alloys is that copper oxide is removed more easily and quickly than zinc oxide.

The finished product is washed with hot 3% sulfuric acid.

If conventional low-temperature soldering is carried out using solder containing lead and tin or other tinols, the oxide film must be removed from metal surfaces. Here it is possible to use rosin-alcohol or more active fluxes. To process brass with a high zinc content, for example, L63, it is necessary to use a flux that contains zinc chloride. It is important to remember that brass has some of the worst melting properties with tin-lead solders. This feature leads to the fact that intermetallic layers slowly begin to grow during the soldering process. They have a positive effect on the weld, and an improvement in the mechanical properties of metals can be expected.

You should not hope that soldering, which uses tin-lead solders of L63 brass, will lead to high-quality connections. Their adhesive strength and quality will be inferior to copper if the conditions are the same. The tensile strength indicator for copper parts soldered with tin will reach 90 MPa, and for brass parts it will not reach 60 MPa. Soldering of brass parts containing a high copper content can be carried out with PSR 72, 45, 25 and 12 solders. Sometimes in such cases it is permissible to use copper-phosphorus brass or a brass alloy that melts at a low temperature. This is mainly applicable to gas soldering.

At high level zinc, it is possible to use PSR 40 solder. The use of phosphorous solders is completely unsuitable, because there is a high probability of a solder joint having low ductility. This is explained by the formation of zinc phosphides, which are distinguished by their fragility. Hard solder is also very common, used when joining large products, for example, for working with brass and copper pipes and heating systems in general. The advantage of hard solders is the high strength of the resulting joints.

Brass soldering is used when you need to connect small metal parts. For example, it is used in artistic forging when assembling a general composition or in a home workshop. In this case, ornamental steel with a flat or square section, where the contact area is larger than that of round rods. In addition to the fact that brass can be used as a solder to solder parts made from this material, there are also some tricks to get a high-quality seam.

How to use brass solder

Before soldering can begin, the product must be assembled. To do this, the individual parts are fastened together using metal wire(bindras). When the preparation is completed, everything is placed together in a gorg, where heating occurs until the metal is red-hot. Extreme care must be taken when laying. To clear space in the coals for the product, a poker is used, the fuel remains on the grate sufficiently large and even layer. When working with coal, it is important to ensure that it does not fall on the forge, even in the smallest pieces. The blowing of the forge should not be strong in order to obtain uniform calcination.

As a rule, borax acts as a flux. Before application, it is moistened with water over the entire surface, after which soldering begins. Leaving the flux in place, take a rod of brass and run it where the connections should be. At this moment, the flame in the forge changes its color to green. During the soldering process, the product blank should not move or move from its original location. This will help to avoid accidental displacement of parts relative to each other, so as not to spoil the seam, both from the point of view of visual appeal and the reliability of the seam.

If the composition contains many elements, then welding occurs differently. In those places where soldering will be done, from the very beginning the brass is laid out in pieces, in the expectation that when heated it will begin to spread, as a result of which the parts will be held together.

Brass can be used in individual pieces, shavings or sawdust, sprinkled in the welding areas. At the same time, they must meet the requirements of purity so that there are no impurities or foreign inclusions. Iron filings and other metal small details removed using a magnet.

To solder smaller parts, clay with salt added to it is used as a fastening material. But when assembling individual parts, the wire used for fastening is not iron, but brass. After this, the product is sprinkled with borax, coated with clay and carefully placed on a sheet of metal, which is sent to the forge. You also need to blow lightly; the clay should be heated evenly. After it dries, the air supply becomes more active. Clay that has begun to crack indicates that the parts are securely fastened together. Soldering of individual parts occurs using brass wire, which at this point melts and holds the parts together. At the end of the process, the forge is turned off, the finished forged product must cool down. The final stage is to remove clay and flux, and remove excess solder using a file.

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Soldering brass with a gas torch

Quite often craftsmen wonder how to solder brass. If it is necessary to fasten brass parts, a slightly different technology is used. Brass parts lend themselves well to processing, soldering, after which they are specially blackened. Many people use tin as solder in this case: it is available in almost every workshop and is easily melted with a regular soldering iron.

The method is quite simple, but has significant disadvantages:

• the finished seam stands out against the background of brass with a white color, while not everyone immediately comes out thin and neat;
• the seam turns out to be fragile and cannot withstand bending;
• During the blackening process, both metals behave differently, the tin weld is different from the brass part in color, they have different shades.

Soldering using special solder for brass and flux will help to avoid such problems. As a result, the seam is difficult to distinguish from the base metal of the product by color; it is characterized by high strength, and chemical composition much more similar to brass than tin.

Working with brass is more likely to be welding due to the high temperatures for which an ordinary soldering iron is not suitable, but it is commonly called soldering mainly due to the fact that solder is used.

First of all, the solder is prepared.

It consists of silver and copper in a ratio of 2:1, which must be alloyed together at gas burner. Copper is more refractory, so you can start with it and then pour in the molten silver and mix with a wire bent into a hook. The finished solder is cooled, rolled out in a roller or on an anvil, and then cut into pieces. There are more affordable way: Using a coarse file, go over the casting to create shavings.

Next, flux is prepared. Powdered borax is mixed with powdered boric acid in equal parts 20 g each, then pour a glass of water. In order for the ingredients to dissolve well, it all needs to be boiled. As one of the options for use, it can be recommended to evaporate the water, calcinate the solid ready-made flux and grind it into powder, which is subsequently mixed with solder.

In our practice we often have to deal with brass parts. They are well processed, soldered and then blackened. Most people solder brass with a soldering iron using regular tin solder. This method, along with its simplicity, has three serious drawbacks: the seam turns out white, noticeable, and few people manage to immediately make this seam thin; the seam turns out to be relatively weak; when bent, it can easily come apart; When blackened, tin may behave differently than brass and the weld will turn out to be a completely different color or shade. This article will tell you about the method of soldering brass using a gas torch with special solder and flux. The resulting weld is practically indistinguishable in color from the main parts, very durable and chemically much closer to brass than tin.

For soldering you need:
- gas burner;
- asbestos base;
- graphite crucible (bath);
- silver;
- copper;
- borax;
- boric acid.

First you need to make solder. It will consist of 2 parts silver and 1 part copper. You need to fuse silver and copper (where can you get silver? - Do you know silver spoons? They are ideal). This can be done using the same gas burner. We weigh out the amount of silver and copper we need, place them in a graphite crucible and heat it with a burner. The crucible can be made from trolleybus contacts; there are a lot of them lying around at the final stops. The crucible size is approximately 20x50mm. A 5x40mm semicircular groove is selected to make it easier to remove the resulting bead of solder; to do this, lower the still hot crucible into water. When both metals melt, mix them with a steel wire - a hook. In principle, you can first melt copper (as a more refractory metal), and then add silver to the melt. Or vice versa - whoever likes it more.

The arrow shows the graphite bath. It is located in a brick "furnace".

That's it, the solder is ready. Let it cool, roll it out in a roller or flatten it on an anvil, then cut it into small pieces. You can simply grind the casting into shavings with a coarse file.

Now the flux. Take about 20 grams of borax (powder), the same amount of boric acid (powder), mix and pour a glass of water. Boil (to better dissolve the ingredients). That's it, the flux is ready. This amount of flux will last for the rest of your life. There is no need to worry about it being chemically hazardous. Boric acid is quite passive and does not harm your fingers or tools. In principle, you can evaporate the water, calcinate the already solid flux, crush it into powder and mix it with solder. The result is a dry mixture of solder and flux. But this is not for everyone.

Soldering process. You need to solder on something heat-resistant. Plates from the Buran's skin are best suited for this. But if Buran doesn’t fly over you, then you can get by with an asbestos plate. We place our parts to be soldered on it, moisten it with flux, sprinkle it with solder shavings (you only need a little bit of it) and begin to slowly heat it up. First, a little bit, so that the solder grabs the parts being soldered a little, then until red (approximately 700 degrees for this type of solder). Solder easily flows into the cracks between the parts and solders them tightly. At this stage, there are the following dangers: since the difference in the melting temperature of solder and brass parts is only about 50 degrees, you must be careful not to overheat them. Otherwise you will just get one big ingot. We must remember that small parts (for example, brass wire) heat up much faster than massive ones. Therefore, be careful. In this case, it is necessary to heat the entire structure slowly so that the large part has time to warm up.

The parts became red hot.

The resulting seam has almost the same color as the parts being soldered. This is due to the diffusion of the base metal into the solder as a result of soldering. Therefore, the same solder can be used when soldering silver - the seam will be white.

The last stage is washing the product from flux residues, which remains on the product in the form of glassy drops and sagging. To get rid of them you need finished product rinse in hot 3% sulfuric acid (or 15% when soldering gold). You can do this on gas stove, placing a quartz glass test tube with dilute acid on it. The product is simply lowered into it for a short time (it must first be tied to something that does not interact with acid) and then washed with running water.

I foresee the question: “Why can’t I use a soldering iron?” The answer is very simple: the melting temperature of solder is about 700 degrees, and a soldering iron can only give 200-250 degrees.
Those who have not used a gas burner before may ask, how long does a gas cylinder last? For normal use, consumption can be calculated at 1 liter per year.

Soldering is one of the methods of joining two parts, in which only the connecting material is melted, and the surfaces of the elements themselves are completely preserved. Using this method, you can connect dissimilar materials, rather small elements, fragile microcircuits, connect or grow wires, attach hard alloy plates, and carry out anti-corrosion treatment.

Most often, alloying is done using brass, which is an alloy of zinc and copper. Therefore, before starting work with a soldering iron, you should study the features of using this material.

Soldering brass - some features

Most often, brass soldering is performed with a gas torch, and borax, tin or other similar materials are used as solder. At home, you can use a soldering iron or a special graphite electrode for this work.

In principle, soldering brass is similar to processing cast iron, copper, and steel. However, it has its own subtleties and features that must be taken into account.

Brass soldering process

For maximum efficiency work needs to be prepared following materials and tools:

In some cases bronze may be needed.

Solder preparation

First of all, it is necessary to prepare tenol, which will contain two parts of silver and one part of copper. For this using a gas torch copper and silver it will be necessary to melt and weigh out the required amount of material. Next, the alloys are placed in a crucible and heated with the same gas burner.

The molten copper and silver are mixed using a wire, and the crucible is placed in cold water. The solidified solder is flattened and cut. Then shavings are rubbed from it with a large file.

The dimensions of the graphite crucible should be approximately 20x20 millimeters. It can be made from graphite coals (contact trolleybus elements).

Flux preparation

To do this, take 20 grams of borax powder and 20 grams of boric acid powder. The ingredients are thoroughly mixed and filled with 250 milliliters of water. The resulting mixture is then boiled and cooled.

To connect brass parts, you can use ready-made compositions. Among the domestic ones, the following fluxes have proven themselves well:

• PV-209X;
• PV-209;
• Borax.

Among the imported ones, we can note flux pastes German manufacturer Chemet.

The solder and flux are ready, now you can proceed directly to soldering. To do this, the prepared parts must be carefully placed on an asbestos base and begin the soldering process.

If we compare this soldering method with connecting elements using tin, then it is no different in simplicity. But the time will not be wasted, since the connection will have increased reliability and strength.

Brass - soldering with a soldering iron

Brass and copper, or brass and materials containing copper, can be joined by low temperature soldering using a 100-watt soldering iron.

The solder should be used tin-lead alloy POS60 or higher. Phosphoric or soldering acid can serve as a flux.

Before working with brass, remove the oxide film and degrease the surface. Soldering should be done with the soldering iron well heated.

In addition, before soldering, it is necessary to pay careful attention to surface treatment with flux, which is carried out immediately before bringing a heated soldering iron with solder.

Using a soldering iron you can join brass using silver solders (PSr40 and higher). However, the power of the soldering iron should be from 0.5 to 1 kW, and the heating temperature should be from 500C. It is recommended to use borax-based flux, or you can use concentrated phosphoric acid.

In this way, you can fill in various defects formed in solid brass products (radiators).

Brass soldering

Brass alloys as solder are often used in construction when working with most metals. With their help, you can connect parts made of copper, steel and even cast iron.

For example, cast iron elements are quite difficult to weld, since for this requires a special electrode, flux and serious heating. At the same time, they can be joined quite easily using brass solder.

A very common method is brass soldering when connecting pipes end-to-end, where it is very important that their internal cross-section remains constant. After using this method, the external dimensions remain practically unchanged, the internal cross-section is preserved, and the joint is reliably sealed.

Using brass solder, you can connect various parts of cooling systems in electronic devices, copper tubes of a liquid cooling system in powerful servers.

However, it should be borne in mind that brass seams are inferior in strength to welded joints, so they should be treated with care.

In some cases, tinning or brazing steel is used. It is used to apply anti-corrosion coating on the surface of steel parts. Tinning is most often suitable for processing small individual products, in industrial scale it is practically not used.

When connecting parts made of low-alloy and carbon steels, it is sometimes used hard soldering, where the brass solder must have a melting point above 450 degrees.

When soldering brass alloys, it should be borne in mind that zinc fumes, which are toxic to humans, may be released. Therefore, there must be good ventilation in the room where work will be carried out.

If everyone is present necessary materials and tools and strict adherence to recommendations, the results of brass soldering will be the most positive. You can do all the work yourself, without resorting to the help of specialists, which is very expensive.

Soldering brass with a gas torch, tin, tin-lead and other similar solders is very common, although many do not dare to pick up the appropriate tool. Below we will discuss all the intricacies of this process, areas of application, as well as ways to carry it out yourself at home.

1

Soldering is one of the ways to obtain a permanent connection. It is carried out by introducing molten solder between two elements. This means that the melting temperature of the latter should be slightly lower than that of the materials of the main parts. Using this process, dissimilar metals can be joined together, and in some situations this is the only way possible way fastenings

Many people equate this combination of metals with welding, but what they have in common is only the end result. The essence is completely different. Their most important difference is that when welding work melting of the base material occurs. In soldering, only the metal bond melts, so that the integrity of the processed parts is completely preserved. Thanks to this, it becomes possible to work with fairly small elements without worrying that they are deformed, and the structure and properties of the materials being soldered will remain the same.

However, it is worth considering that compared to the same welding, the connection will be less strong. This is due to the softness of the solder, but if we are talking about brass products, then this material when exposed to high temperatures, it releases zinc, and the seam becomes more porous, which also negatively affects the adhesion strength. Moreover, the location of the elements plays a role, so butt soldering is quite unreliable, it is better to do it with an overlap.

Today, it is soldering that occupies one of the leading positions in the creation of permanent connections, second only to . Thus, it is very difficult for electronics engineers who are forced to work with rather fragile microcircuits to imagine their profession without the participation of this process. In addition, solder joints are also very relevant in electrical applications, if you need to extend or simply connect wires.

This method is also used to make connections in refrigerators, heat exchangers and other installations. Very often it is used for fastening plates made of hard alloys to cutting tool. You can also attach thin-walled parts to a thick sheet. In addition, sometimes anti-corrosion treatment is carried out using tinning. In general, the scope of application is quite wide.

Soldering can be high or low temperature. In the first case, the connection is more reliable, plus it has increased thermal stability (this is due to the fact that solders for this type of processing have a higher melting point). Thus, after such exposure, parts can operate at much higher temperatures. high temperatures compared to parts connected in the second way. However, this type also has its drawbacks, since we are talking about excessively high temperatures, it will not be possible to carry out this process with a simple soldering iron. It is necessary for him special equipment, which greatly complicates the work.

2

Most often, you have to work with a soldering iron on an alloy of copper and zinc called brass. This material is predominantly found in industry and household, so radiators, pipes and many other products are made from this material. Therefore, let's look at the features of working with it. Firstly, it is very important to choose the right flux for soldering brass. After all, ordinary rosin-alcohol is unable to remove the oxide film from its surface well, so it is necessary to use more active components, the basis of which can be zinc chloride.

For soldering elements in salt baths, fluxes containing borax or potassium fluoroborate have been used. Typically their content in the solution is about five percent. They promote better flow of the binder component into the gaps.

Secondly, with special attention Solder for brass soldering should also be selected. Silver and copper-phosphorus components are ideal for gas environments. They are also applicable for working with brass, where there is a high copper content. In the latter case, even brass can be used as solder, but its melting point must be significantly lower than that of the main alloy from which the parts are made. Brass brazing is very common. So, for example, to connect radiators, copper pipes and other elements heating systems L-CuP6 is used. At all, brazing alloys benefit compared to soft ones, since the strength of the connection will be greater.

It is also important to consider the situation when the material of the parts being connected is different, for example, how copper is soldered to brass. At home, this process is quite feasible, the main thing is to know some of its features and what kind of solder should be used. When heated, an oxide film forms on the surface of brass, and excessive heat also contributes to the evaporation of zinc from this alloy, which enters the liquid metal binder. In this regard, the seams become more porous, which contributes to the deterioration of adhesion strength.

Moreover, due to of this property High-temperature soldering is very rarely used in special furnaces. What about soldering in gas environments, it is better to do this using flux, but if this is not possible, then a layer of nickel or copper should be applied to the surface of brass parts. Such a solution will avoid the release of zinc and, accordingly, the connections will be more reliable. Some solders contain substances that also act as flux, which makes the job easier because you don’t have to juggle a lot of components while working.. An example is copper-phosphorus solder.

3

Having studied all the features of the process and become familiar with all possible components, you should pay attention directly to the question of how to solder brass. After all, it occurs very often in our everyday lives, and the budget does not always allow for hiring specialists, so we have to cope on our own. Moreover, all we need is:

• gas burner (sometimes you can get by with a simple soldering iron),
• solder,
• flux,
• borax.

Without the last two elements, the seam, of course, will work, but it will be quite weak, white, and the folds, if any, can come apart very quickly.

So, let's start collecting everything you need. This list includes: gas torch, asbestos base, graphite crucible, borax, solder and boric acid. Solder is prepared as follows: take one part copper and two silver, then put them in a crucible and melt them, heating them on a gas burner, not forgetting to stir. Once the mixture is homogeneous, place the container in cold water to allow the contents to cool. Then it can either be cut or used in the form of shavings.

To make flux, you will need a drill for brass soldering and boric acid, which are taken in a 1:1 ratio and filled with water. So, taking 20 grams of each component, you will need 250 ml of liquid. Now let's proceed directly to the process. We take the parts, treat their surface with flux and sprinkle with solder shavings. Then we bring it to a gas burner and heat it up to about 700 °C. Beware of overheating, because thin brass parts heat up very quickly and can become deformed. Massive elements must be heated gradually. Soldering can be considered complete. Of course, with a soldering iron this procedure It’s much easier to do, but it’s more reliable with a torch.