It is preferable to braze copper at home than cooking, since the process is easier and faster, moreover, there is no need to purchase or rent expensive equipment. Compounds made according to all the rules are durable and reliable, while maintaining their resistance to various kinds of loads, both thermal and mechanical.
Copper pipes have anti-corrosion properties that protect them from the damaging effects of rust.
In order to solder copper pipes with your own hands, you will need the following materials and tools:
- pipe cutter;
- pipe expander;
- steel brushes;
- steel brush;
- burner / hairdryer.
Pipe soldering process and technology
First you need to use a pipe cutter to cut the required piece of pipe. At the point of cutting it is necessary to pass with a brush in order to remove all roughness and burrs, with the same purpose the inner surface is processed with the help of a brush.
Tools for soldering copper pipes.
With the help of a pipe expander, another section of the pipe is expanded to the required diameter, since the pipeline components must have a small gap when entering each other. The edge of the expanded part of the pipe is also brushed to rid the copper before soldering from dirt and irregularities.
On that part of the pipe, which is smaller in diameter, a flux is uniformly applied with a thin layer. The parts are joined, the excess flux that has gone outside is removed with a soft, damp cloth. The connection must be uniformly heated using a burner or a hairdryer. The signal to the end of the soldering is the silver color, which acquires the flux with a sufficient degree of heating.
Additionally, according to the technology of copper soldering, the solder is brought to the pipe connection line. When it melts and fills the joint, it must be left to cool at room temperature. After the solder cools, the compound is again wiped with a damp cloth to remove residual chemicals of various kinds.Back to table of contents
Work with a soldering iron
When the soldering iron is plugged in for the first time after a long break, smoke may come from the burning particles of oil used to store the tool, or the remaining amount of rosin burns. Most often, this does not mean anything dangerous and it is enough to ventilate the room. Before you solder the copper, you need to check the tip of the soldering iron and prepare it to work properly. The tip can be given almost any shape according to the needs of the master, but commercially available stingers are diverse.
Soldering iron design.
If you plan to solder massive copper parts, then there should be a large area of contact between the soldering iron and the parts, as this provides the best thermal conductivity. For small parts such as copper wire, sharpening in the shape of a sharp cone is best. Preparing parts for soldering is no different from preparing for joining with a gas torch and consists of cleaning and degreasing joints.
The quality and appearance of soldering is largely dependent on the temperature of the soldering iron. In case of insufficient temperature, the solder will not spread over the surface and will fall into an ugly lump, which has insufficient adhesion strength with details. If the temperature does not reach the norm quite a bit, outwardly the soldering may look spread and high-quality, in this case it gives a matte color to the solder and some of its friability.
The temperature required for the parts to be joined must exceed by 20-40ºC the temperature at which the solder begins to flow and melt. This is important, since in contact with the parts to be joined, the soldering iron will inevitably lose some heat. At soldering stations, the required temperature can be achieved by simply setting the regulator to the desired position. If an ordinary soldering iron is used, where there is no temperature sensor, rosin can be used for an approximate determination of the desired degree. If at the touch of a soldering iron it boils and produces a lot of steam, but does not burn, but hangs on the sting, the temperature is suitable for soldering copper.
Harmful when working with parts and overheating of the soldering iron, as in this case, the flux burns and charred before they cover the surface of the soldered parts. Overheating in appearance can be determined by the appeared film of dark color oxides on the solder. Solder on the superheated tip of the soldering iron can not be kept and immediately drains from it.Back to table of contents
Ways to work with a soldering iron
Tools required for soldering.
There are two main technologies that can be used when joining parts with a soldering iron. When using the first technology, the solder from the tip of the soldering iron seems to blend into the parts that need to be joined. The second method involves soldering directly to the parts that need to be connected. Any of the methods implies that the soldering parts must be prepared and fastened in a comfortable position.
When feeding is performed from the tip of the soldering tip, a small amount of solder is melted directly on it. After that the sting joins the details demanding connection, solder spreads on them in the right places. Uniform distribution is provided by the movements of the red-hot tip along the seam. A sufficient amount of solder is considered if the sting has acquired a silver sheen. Excess solder changes the shape of the sting and forms an ugly seam. If the solder is fed to the alloy, the parts need to be preheated with a soldering iron. Feed solder will melt and fill the seams and joints.Back to table of contents
Low temperature brazing
The chemical composition of cast and deformed copper.
This kind of compound is used for the most part at home and helps to organize air conditioning, heating and water supply systems using propane burners. At that, the copper pipe heats up to 200-250ºC, and if soft solder is used, the torch flame must be constantly moved during the soldering process, monitoring the uniform heating of the joint.
If during the soldering process when the soldering iron is touched with a bar, the solder does not melt, it is necessary to continue heating, continuously and evenly moving the flame. As soon as the solder begins to flow and melts, the flame is removed and waited for the solder to completely spread, filling the gap between the products completely. At the same time, it is not recommended to add solder additionally in order to avoid the formation of surplus, which may leak into the pipes.
If you solder copper using standard solder rods, then its volume should be equal to the diameter of the pipes being joined. It is more convenient before beginning the process to bend the required size of the solder with the letter “G” in order not to be mistaken with the dimensions. The strength of copper at low-temperature brazing remains the same, but the mechanical characteristics fall in quality.Back to table of contents
High temperature brazing
If a copper product will be operated at high temperatures, which are considered to be temperatures above 110º, high-temperature brazing is used as a joining method. For safety net this method is used for heating systems. To make a connection of this kind, a temperature of at least 700ºC is required, therefore only the flame method is used.
If the solder in this case will be used copper-phosphorus, in the process you can do without the use of flux. The burner is placed on an average flame, the temperature of which should be in the range of 700-900ºC, the pipes are heated evenly, but their position in space can be any.
If the ends of the products heat up evenly and to the desired temperature, the solder fills the mounting gap qualitatively.
Readiness of the connection is checked with a whole solder rod, which melts upon completion of work. To the quality of the seam was higher, the bar is preheated.
This method of connection implies, if necessary, the use of a building dryer for heating pipes, instead of a burner. But this tool can only be used to connect small pipes. Manipulations with the hair dryer produce the same as with the burner. The advantages of this type of connection are high strength of the seam and its further durability when operating in high temperature mode. The disadvantages are the inevitable annealing of copper occurring at such temperatures. It should be noted that to perform this work requires sufficient qualifications and experience, since copper is easy to overheat and cause these metal breaks.