Correct brass soldering. Brass soldering - a reliable connection at home Is it possible to solder brass

Brass is widespread in everyday life, and the question of how to solder brass is very important for some. The repair of many home appliances depends on how the metal is soldered. This process differs markedly from joining other metals. It has a number of specific features and causes certain difficulties. However, if certain conditions are met, then the soldering will be within the reach of any person.

Brass is widely used in everyday life, and in case of breakage of brass products, the question arises of how to solder it.

Features of brazing copper alloys

In everyday life, different parts are often used, in which brass and bronze are used. These copper alloys are very similar in appearance, but have a different composition and their own characteristics. Brass is a copper-zinc alloy with the addition of tin, aluminum and other metals. Bronze is an alloy of copper with tin, aluminum, lead and other substances. Brass, to which tin is added, approaches the composition of bronze, but still its basis is zinc.

Materials and tools for brass soldering.

Has its own characteristic difficulties. During thermal action, zinc actively evaporates from the alloy, forming a dense film of zinc oxide and copper. The zinc oxide film is destroyed with great difficulty, and its formation with a zinc content of more than 15% in brass occurs rather quickly. Rosin, even in combination with alcohol, cannot cope with such a film, which requires the use of special fluxes.

If tin-lead solder is used for brass brazing, the joint has low mechanical strength. So, the place of brass soldering with tin-lead solder has a strength 1.6 times less than copper soldering. This is due to the appearance of pores in the brazed joint due to the evaporation of zinc.

Brazing methods for bronze depend on its composition. Tin and nickel bronzes are easily soldered with tin-lead solders. When soldering aluminum and beryllium bronzes, hardly soluble films appear, which necessitates the use of special solders and fluxes.

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Soldering fluxes

For brass soldering you need a drill - a special flux.

Fluxes are designed to remove the film from the surface of the metals to be soldered and to protect against the formation of new films in the soldering zone. While rosin is quite enough to combine copper, another, much more aggressive flux is needed for brass. The composition of the flux for different brass needs a different one, which is caused by the introduction of some metals into the composition of the brass. For common brasses such as LS59 and L63, the use of zinc chloride with a small content of boric acid is sufficient. When brazing brass with additives of lead and silicon, for example, brass of the LKS80 type, a flux based on a compound of potassium with fluorine and boron or based on borax is recommended.

At home, you can make the following flux that will work with most brass. It is necessary to prepare 20 g of borax in powder and 20 g of boric acid in powder. Powders in dry form are well mixed and filled with 200 ml of water. Then the mixture is boiled and cooled.

Of the ready-made compositions, the following can be recommended as fluxes for brass: domestic - "Bura" flux; fluxes PV-209 and PV-209X. From imported fluxes of German production should be noted: Chemet FLISIL-NS-Pulver and Chemet FLISIL-NS-Paste flux-paste.

Brazing of bronzes can be carried out under flux from chloride salts (for example, zinc) with the addition of of hydrochloric acid... If soldering is done on high temperatures ah, it is better to use boric acid in combination with chlorates and fluorides. To combine aluminum and manganese bronzes, you will have to use active fluxes from phosphoric or hydrofluoric acid. Phosphoric acid is commonly used from the available funds.

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The solder for brass must be copper-phosphorous. solders

Solder is a metal that, in a molten state, penetrates into the metals to be brazed and, after cooling, joins them. Consequently, it should have a melting point well below the melting point of brass and still have good adhesion to it while in the form of a melt. Conventional alloys of tin with lead should be used in brasses only when connecting non-critical parts, where there are no requirements for mechanical strength and appearance.

The composition of the used solder depends on the type of brass. If the copper component predominates in brass, then you can use silver solders from PSr12 to PSr72, solders with a brass content from PMTs36 to PMTs54 and copper-phosphorous solders. In the case of a predominance of zinc content, silver solder should be used not lower than PSr40. The use of phosphorous compounds leads to a noticeable decrease in the mechanical strength of the joint due to the formation of fragile phosphorus zinc compounds. Cheaper brass-based solders of the PMTs type can only be used in parts that do not feel vibration and shock. When bonded with silver and phosphorous solders, brass dissolves quite strongly, which should be taken into account, and the time for soldering and heating metals should be reduced.

For the repair and connection of permanently fixed parts (for example, radiators or pipes), special hard solders with a complex composition are often used. Nice results shows a solder of the L-CuP6 type having a melting point of the order of 730 ° C.

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DIY solder preparation

Silver solders are also suitable for brass packs.

In order to solve the problem of brass soldering, you should prepare the required solder with your own hands. Most suitable for all brasses is silver solder; it should be cooked. Melting of metals must be carried out in a crucible that can withstand significant thermal effects. Most simply, such a crucible is made of contact carbon elements for trolley buses. Burnt-out elements are readily available and can be useful for the crucible. In such a graphite element, a recess of about 2x2 cm is made, and a groove about 5 mm wide is machined into the recess (to facilitate removal of the solder).

The solder requires a 2: 1 ratio of silver and copper. The required amount of metals is measured and lowered into the crucible. Using a gas burner, the metals are melted in the crucible. To simplify the melting process, the metals should first be crumbled as much as possible. The melt is mixed with a steel or ceramic (porcelain) rod. After cooling, this alloy can be used as a solder.

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Soldering with a soldering iron

A soldering iron for brass soldering must be at least 100 watts.

A sufficiently high quality of the connection by the method of low-temperature brazing is achieved when brass and copper are brazed or when brass is brazed with a predominance of copper content in them. In this case, a 100 W soldering iron is sufficient. Soldering or phosphoric acid can be used as a flux. Before brazing, the brass surface must be thoroughly treated to remove the oxide film and degrease the surface. Tin-lead solder not lower than POS60 is used as a solder. Soldering is carried out when the metal soldering zone is well heated with a soldering iron.

The soldering iron can be used to solder brass and silver solders at least PSr40. To do this, you will have to arm yourself with a powerful soldering iron (0.5-1 kW). The flux must be concentrated phosphoric acid or borax-based flux. The heating temperature of the soldering zone must be at least 500 ° C. Before brazing, special attention should be paid to the thoroughness of the surface treatment with flux. Processing should be carried out immediately before bringing a heated soldering iron with solder. In this way, defects can be melted in massive brass products (for example, radiators).

In the previous materials, we examined electric soldering irons and gas torches used in soldering, as well as familiarized ourselves with solders and fluxes.

Important!!! Use ONLY LEAD-FREE solder for all food handling equipment.

Do not forget that when soldering, hot objects, aggressive liquids, voltage of 220 V are used. Be extremely vigilant, be careful.

In this article, let's move on to practice and solder the copper. Along the way, we will consider the features of its soldering.

Soldering copper and brass is not very different from each other. The main difference is thermal conductivity, which is several times higher for copper. Therefore, brass is even easier to solder.

Copper and brass are soldered with tin solder; rosin, phosphoric acid and soldering acid are used as flux. You can also solder with aspirin, but this is a last resort.

I prefer to solder copper with phosphoric acid, but it does not have to be cleaned mechanically.

Let's look at the example of soldering two copper pipes together.

First, you need to expand one of the ends. I used pliers for this purpose.

On the contrary, we sharpen the second end a little so that it goes into the extended part.

Before soldering, the contacting parts of the tubes must be tinned, that is, covered with a layer of tin. Yes, not just cover, but cover with high quality so that the metals do not peel off from each other. For this, the surface to be tinned must be heated not below the melting point of the solder. And since copper has a very high thermal conductivity, it will be very difficult to warm up even a not very thick tube with one soldering iron.

For preheating, I use a gas torch, and then I quickly apply flux and use a soldering iron tip to apply and spread the solder.

At the same time, overheating the part is as bad as not heating it up. I am guided by the color of copper, as soon as it starts to darken a little - that means enough.

A well-tinned surface has a uniform shine, and does not lag behind the tube even when severely scratched.

When repairing them, the owners have to resort to soldering technology. Since this method of joining metals has specific features, beginners may encounter difficulties in the course of work. Therefore, they are interested in how to solder brass. If you know the technology and follow the recommendations of specialists, everyone can cope with this procedure. You will find information on how to solder brass at home in this article.

About alloy composition

In everyday life, there are many different parts containing brass and bronze. Despite the external similarity of these copper alloys, they have different compositions. Brass is in which tin, aluminum and other metals are added during production. Bronze is a combination of tin, aluminum, lead and other substances with copper. The composition of brass with the addition of tin is close to bronze, but zinc predominates in the metal base.

What are the features of using copper alloys

Many beginners ask the question of how to solder bronze and brass. The interest is due to the fact that soldering is fraught with some difficulties. In the course of thermal action, active evaporation of the zinc alloy occurs, as a result of which a dense film of zinc and copper oxides is formed. It is rather difficult to destroy it. According to experts, rosin will not cope with this task either.

The master will have to use special fluxes. If tin-lead solder is used, there is a risk that the joint will have low mechanical strength. Unlike copper soldering, in this case, the strength indicator will be one and a half times lower. The reason for this is volatile zinc. The choice of brazing method for bronze parts will depend on its composition. Bronze with a high tin and nickel content should be brazed using tin-lead solders. Bronze containing aluminum and beryllium is best connected with special solders and fluxes.

About fluxes

Their task is to remove the formed film from the surface of the metals to be joined and prevent its further appearance. According to experts, rosin is suitable for soldering copper products. The situation is different with brass. How to solder this alloy correctly? Which flux to choose? Such questions are very often asked by beginners. Experienced craftsmen advise using a more "aggressive" flux than rosin. Since metals are used as additives in the production of brass, fluxes with different compositions should be taken for brazing. To work with the most common brands of brass L63 and LS59, a flux containing zinc chloride and boric acid is intended. For LKS80 with lead and silicon, a borax-based flux containing boron, potassium and fluorine will be the best option. On the shelves specialized stores there are already ready-made compositions. Experts recommend paying attention to the PV-209, PV-209X and Bura fluxes. Those who want to save money can prepare a flux at home.

About handicraft flux

According to numerous consumer reviews, this composition can be used with different brands of brass. Preparing a flux is not very difficult. You need to take 20 g of borax powder and mix with boric acid, which also requires no more than 20 g. The composition in dry form is thoroughly mixed. Then the mixture must be poured with water (200 ml). Before use, the mixture should be boiled and cooled.

About solder

This molten metal is used for soldering. IN liquid state it penetrates into the metals being brazed, and then cools down, as a result of which the connection occurs. The melting temperature of the solder must necessarily be lower than the melting temperature of the metals themselves. For those who are wondering if brass can be soldered with tin, experienced craftsmen it is recommended to use a solder with good adhesion. Conventional alloys containing tin and lead are best used where high mechanical strength is not required. Also solder is suitable when it is not important appearance junction points.

About the compositions of solders

The choice of solder depends on the brass grade. PSr12-PSr72, brass PMTs36-PMTs54 and copper-phosphorus are recommended for brass with a predominance of copper in its composition. If there is more zinc in the metal, then you need to work with silver solders from PSr40 at least. With phosphorous compounds, fragile phosphorus zinc compounds are formed, which reduces the mechanical strength of the adhesion. For parts that are not exposed to shock and vibration during their operation, MPTs brass solders are suitable. Note that brass can easily dissolve, so craftsmen using silver and phosphorous solders should reduce the heating and soldering time.

To work with permanently fixed parts (radiators and pipes), experienced craftsmen recommend using special hard solders with complex compositions. According to numerous consumer reviews, L-CuP6, which melts at a temperature of 730 degrees, is very popular. You can also prepare solder at home.

How to do it

For brass soldering, it is best to use silver solder. It is desirable that the melting point was a special crucible adapted for significant thermal effects. As a material for crucibles, contact carbon elements for a trolleybus can be used. In a heated state, they are of no value, and a craftsman can adapt them for making solder. Make a 20 x 20 mm notch in this product. Next, a groove should be made to it. It will be easier to remove the solder if its width is 0.5 cm.

Solder is made from silver and copper (2: 1). After taking the required amount of metals, they should be placed in the crucible. Their heat treatment is carried out gas burner... Some masters pre-crumble consumables. In this case, the melting procedure is much easier. Next, a steel or ceramic (porcelain) rod is added to the composition. Brass can be soldered when the handicraft solder is completely solidified.

How to solder with a gas torch

How to solder brass? The procedure is as follows:

• Before starting the process, you need to warm up the metals. This work is carried out on heat-resistant materials. Experts advise using an asbestos plate.
• The parts to be soldered must be aligned with each other.
• Carefully wipe the surfaces at the place of soldering with flux.
• Cut the silver solder. Ultimately, it should be a shavings that should be poured into the place where the metals are joined.
• Adjust the flame in the gas burner. To set the solder to metal surfaces, the joint is first heated with a weak fire.
• Set the gas burner to 750 degrees for main heat. A red tint should appear on the brass surface. All gaps are filled with solder, then it spreads over the entire junction.
• Switch off the burner and allow the product to cool down. The procedure is considered to be performed correctly if a seam is obtained that does not differ much from metal.
• Flush the junction to remove flux residues.

How to solder brass with a soldering iron

This method is the most common because it is the easiest to complete. For those who do not know how to solder brass with a soldering iron at home, experts recommend adhering to the following algorithm of actions:

• At the very beginning, you need to clean the parts to be connected. Metal surfaces should be free from various foreign layers and dirt.
• Place the parts on a special fireproof stand. You can make it at home from improvised means.
• To remove all defects in the brass surface, treat the joint with flux.
• Sprinkle with crumb solder on top.
• Warm up with a soldering iron.

Very often, beginners ask the question of how to braze copper to brass. Experts advise using low-temperature brazing, which is able to provide a high-quality connection. For this purpose, you will need a soldering iron, the power of which is not more than 100 W, and phosphoric acid. Before work, the surface of the product is thoroughly degreased, the oxide film is removed from it. It is better to connect metals using POS60 tin-lead solder. To start soldering brass, the tool must be well warmed up.

To work with silver solders, you need a soldering iron, the power of which varies from 0.5 to 1 kW. Degreasing is carried out with a flux - concentrated phosphoric acid. Borax-based flux is also considered quite effective. In the soldering zone, a temperature of at least 500 degrees is formed.

Work with stainless steel

According to numerous reviews, home craftsmen often have to solder stainless steel with brass. Since the presence of nickel and chromium in the compositions of steel alloys does not exceed 25%, work with such materials is less laborious. In addition, this composition provides a reliable connection of stainless steel parts with other metals.

The exceptions are magnesium and aluminum. If a stainless steel with a significant nickel content, then as a result of its heating to 700 degrees, the formation of carbide compounds occurs. The longer the heating, the more intensively they form. For this reason, soldering should be done as quickly as possible. The risk of these compounds forming is minimal if titanium is added to the alloy during brazing. According to experienced craftsmen, you should be especially careful with riveted stainless steel. This is due to the fact that cracks may appear on the metal surface. To prevent their formation, soldering is performed after preliminary annealing of the parts.

Progress

Soldering stainless steel is performed as follows:

• First, the surface is thoroughly cleaned with sandpaper or a file.
• Further, the seam is treated with flux, namely soldering acid.
• Then the surfaces need to be tinned - apply a thin layer of solder containing tin and lead on them. It happens that it is not possible to apply the solder the first time. In this case, you will have to use a brush containing metal strands. They will be much more convenient to remove the oxide film that prevents tinning.
• Using a soldering iron and solder, the parts are soldered.

Finally

The soldering process may seem complicated only at first glance. There will be no problems if you master the technology and work with correctly selected consumables.

Brass brazing is used when small metal parts are to be joined. For example, it is used in artistic forging when assembling a general composition or in a home workshop. In this case, semi-finished steel with a flat or square section is most suitable, 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 from this material, there are also some tricks to get a quality seam.

How to use brass solder

Before you start soldering, the product must be assembled. For this, individual parts are fastened together by means of a metal wire (bindra). When the preparation is over, everything is put together in a gorg, where it heats up until the metal is red hot. Great care should be taken when laying down. A poker is used to clear the space in the coals for the product; a sufficiently large and even layer of fuel remains on the grate. When working with coal, it is important to ensure that it does not fall into the forging, even in the smallest pieces. The blowing of the forge should not be strong in order to obtain a uniform calcination.

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

If the composition contains many elements, then welding takes place in a different way. In those places where soldering will be carried out, 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 fastened.

Brass can be used in separate pieces, shavings or sawdust, poured into the welding places. Moreover, they must meet the purity requirements so that there are no impurities and impurities. Iron shavings and other small metal parts are removed by means of a magnet.

To solder smaller parts, clay with salt added to it is used as a fastening material. But when assembling individual parts for fastening, a wire is used not from iron, but from brass. After that, the product is sprinkled with brown, coated with clay and carefully placed on a sheet of metal, which is sent to the forge. You also need to blow weakly, the clay should be heated evenly. After it dries up, the air supply is more active. Clay, which has begun to crack, indicates that the fastening of the parts is reliable. Soldering of individual parts takes place by means of brass wire, which by this time melts and holds the parts together. At the end of the process, the furnace turns off, the finished forged product must cool down. The final stage is the removal of clay and flux, the excess solder is cleaned out with a file.

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Brass brazing with a gas torch

Quite often, craftsmen ask themselves 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 a solder in this case: it is found in almost every workshop and can be easily melted with an ordinary soldering iron.

The method is quite simple, but has significant drawbacks:

• the finished seam stands out against the background of brass in white, while not all of them immediately come out thin and neat;
• the seam turns out to be fragile, does not withstand bends;
• in the process of blackening, both metals behave differently, the tin seam differs from the brass part in color, they have different shades.

Soldering using a 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 highly durable, and chemical composition much more similar to brass than tin.

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

First of all, the solder is prepared.

It contains silver and copper in a ratio of 2: 1, which must be fused together on a gas burner. Copper is more refractory, so you can start with it and then pour in molten silver and stir with a wire bent in the form of a hook. The finished solder is cooled, rolled in rollers or on an anvil, and then cut in parts. There is a more affordable way: use a coarse file to walk over the casting so that chips are formed.

Next, the flux is procured. Borax in powder is mixed with powdered boric acid in equal parts of 20 g, after which it is poured into a glass of water. In order for the ingredients to dissolve well, all this needs to be boiled. As one of the options for use, it is possible to advise to evaporate the water, calcine the solid ready-made flux and grind it into powder, which is subsequently mixed with the solder.

Brass brazing has its own characteristics due to the evaporation of hot zinc, as well as the formation of an oxide film on the metal surface. Brasses containing up to 15% zinc are oxidized by a film that consists of cohesive particles of CuO and ZnO. In copper alloys containing sufficient a large number of zinc, the oxide film consists mainly of ZnO, which are much more problematic to remove than in the case of a copper oxide film.

The following tools and materials are useful for soldering:

• Asbestos base;
• Gas-burner;
• Graphite crucible;
• Copper, silver, borax, boric acid.

Cooking the solder

First, you need to make tinol at home, which will consist of both silver and copper in a 2: 1 ratio, respectively. To do this, you need to fuse silver and copper using a gas burner. Next, you need to weigh the required amount of silver and copper, after which they must be placed in a crucible and heated with a gas burner.

A graphite crucible can be made from graphite coals (contact trolleybus elements), which are easy to find at the terminal stops of electric transport. Regarding the size of the crucible, it should be approximately 20x20 millimeters.

Then we select a 5x40 mm semicircular groove in order to make it easier to remove the solder bead (the hot crucible is lowered into the water). Once the copper and silver are melted, you can begin stirring the tinol components with a wire.

Cooking flux

Thus, the solder is ready for use, but it still needs to be cooled, rolled out, and cut into small pieces. Now you need to start preparing the flux. To do this, take 20 grams of borax (powder), as well as in equal proportions of boric acid (powder), then thoroughly mix the ingredients and pour a glass of water. Next, boil and cool the finished flux.

We work as follows:

1. You need to solder on some heat-resistant material. If you are soldering radiators, do the work fully. To this end, we stocked up with an asbestos plate. Thus, we place on non-soldered parts, then moisten with flux, sprinkle with solder. Next, we begin to warm up a little.
2. First, we heat a little so that the solder adheres to the details, after which we bring the procedure to the appearance of a red tint.
3. The solder simply flows into the gap between the parts, soldering them together very tightly. It is worth paying attention to the fact that the difference between the melting point of brass and solder is about 50 grams. C, and therefore you should not overheat the material.
4. The resulting seam has one pronounced color with the part to be soldered.
5. This is followed by rinsing the product from the flux: we rinse the product in hot sulfuric acid (3%).

So, we get excellent adhesion of brass products that will last for many years.