Soldering is one way to connect two parts, in which only the bonding material melts, and the surfaces of the elements themselves are completely preserved. You can use this method to combine different materials, rather small elements, fragile chips, connect or grow wires, fasten plates of hard alloys, to carry out anticorrosive processing.
Most often, rafting will be done on brass, which is an alloy of zinc and copper. Therefore before the beginning of works by the soldering iron it is necessary to study features of application of this material.
Brass soldering - some features
Most brass brazing is performed with a gas burner, and borax is used as solder, tin or other similar materials. At home, you can use a soldering iron or a special graphite electrode for this work.
In principle, brazing is reminiscent of cast iron, copper, steel. However, it has its subtleties and features, which must be taken into account.
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It is very important to choose a flux for brass soldering. An oxide film must be removed from the surface of the alloy to be processed during the bonding process. Ordinary rosin-alcohol flux is not able to do this, therefore it is necessary to use more active components, containing zinc chloride.
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Solder for brass soldering should be selected very carefully. For work with an alloy, which has a high copper content, copper-phosphorus and silver components are perfect. You can use the brass itself, but it must be taken into account, that its melting point as a solder should be lower, than the base alloy. Quite often brass is joined by means of a firm solder, example, L — CuP 6. Such connections are very strong.
The process of soldering brass
For the maximum efficiency of works it is necessary to prepare the following materials and tools:
- candle;
- copper;
- graphite crucible;
- silver;
- asbestos base;
- boric acid.
In some cases, bronze may be required.
solder preparation
First of all it is necessary to prepare tenol, which will include two parts silver and one part copper. To do this, using a gas burner, copper and silver will need to melt and weigh the required amount of material. Further, alloys are placed in a crucible and heated by the same gas burner.
Molten copper and silver are mixed by delay, and the crucible is placed in cold water. The hardened solder is flattened and cut. Then a large file is rubbed with shavings.
The dimensions of the graphite crucible should be approximately 20x20 millimeters. It can be made of graphite coal (contact trolleybus elements).
flux preparation
It is taken for this purpose 20 grams of borax powder and 20 grams of boric acid powder. The ingredients are thoroughly mixed and poured 250 milliliters of water. The resulting mixture is then boiled and cooled.
Ready-made compositions can also be used to connect brass parts. Fluxes have proved themselves well among domestic ones:
- PV-209H;
- PV-209;
- Storm.
Among the imported flux pastes from the German manufacturer Chemet.
Solder and flux are ready, you can now start soldering directly. To do this, the prepared parts must be carefully placed on a base of asbestos and begin the process of soldering.
- Surface details, the joints to be treated with flux and very carefully sprinkled with solder chips.
- Now the soldered elements need to be heated slowly. This should be done slowly and carefully, so that they do not overheat and deform.
- First you need to heat up a little, so that the solder melts a little and grabs the parts. Then about 700 degrees. The solder will flow into the cracks and firmly solder the elements. At this stage, special attention should be paid to the melting point. The difference between the melting of brass parts and solder is total 50 degrees, so you have to watch out for that, so as not to overheat the processed materials. Otherwise, you can get one big bar.
- The resulting seam should be the same color as the solder material. This is due to the diffusion of the parent metal into the solder.
- The last stage is cleaning of the received product from the remains of flux in the form of inflows and glassy drops.. To get rid of them, the product must be washed in three percent hot sulfuric acid. To do this, the elements should be immersed in it for a short time and then rinse thoroughly under running water. Sulfuric acid can be heated in a quartz glass test tube, placing it on a gas stove. In order not to interact with the acid, it is recommended to tie the processed parts to something before cleaning.
If you compare this method of soldering with the connection of elements with tin, then it is not simple. But time will not be wasted, as the connection will have increased reliability and strength.
Brass - soldering with a soldering iron
Brass and copper or brass and materials, containing copper, you can connect low-temperature soldering with a soldering iron with a power of c 100 W.
Tin-lead alloy PIC60 or higher must be used as solder. Orthophosphoric or soldering acid can serve as a flux.
Before working with brass, the oxide film should be removed and the surface degreased. Soldering should be carried out with good heating of the soldering iron.
exept this, before soldering it is necessary to pay careful attention to surface treatment by flux, which is carried out immediately before the rise of the heated soldering iron with solder.
You can use a soldering iron to connect brass using silver solders (PSr40 and above). However, the power of the soldering iron must be from 0,5 to 1 kw, and heating temperature - from 500C. It is recommended to use flux based on borax or you can use concentrated orthophosphoric acid.
In this way you can pour various formed in solid brass products (radiators) defects.
Brass soldering
Brass alloys as a solder are often used in construction when working with most metals. They can be used to connect copper parts, steel and even cast iron.
So, example, cast iron elements are quite difficult to weld, as this requires a special electrode, flux and serious warming up. At the same time, they can be easily connected with brass solder.
A very common method of soldering brass when connecting pipes butt, where it is very important, that their internal section remained constant. After applying this method, the external dimensions remain virtually unchanged, the inner section is preserved, and the joint is sealed.
With the help of brass solder, you can connect various parts of cooling systems in electronic devices, copper tubes of liquid cooling system in powerful servers.
However, it should be borne in mind, that brass seams are inferior to welds in strength, therefore, they should be treated with care.
In some cases, brassing or brazing of steel is used. It is used to apply anti-corrosion coating on steel surfaces. Ludit is most often suitable for processing small single products, on an industrial scale it is practically not used.
Hard soldering is sometimes used when joining low-alloy and carbon steel parts, where the brass solder must have a melting point higher 450 degrees.
In the process of soldering brass alloys should be borne in mind, zinc vapors that are toxic to humans may be released. Therefore indoors, where the work will be carried out, should be well ventilated.
With all the necessary materials and tools and strict adherence to the recommendations, the results of brass soldering will be the most positive. You can do all the work yourself, without the help of specialists, which is quite expensive.