What is this soldering?

One of the most useful skills for anyone professionally involved in the maintenance and repair of various equipment is the ability to solder. This is a way of joining metals together using another, more fusible metal. Soldering is a process used to form an unbreakable bond between metal parts made of different materials by introducing a molten material (solder) with a lower melting point between the parts. The process involves the penetration of one substance (metal) into another at a high temperature, which provides mechanical strength and high electrical conductivity to the joint once it has hardened. The result is the creation of durable joints in products made of steel, cast iron, glass, graphite, ceramics, synthetic materials and others. According to modern concepts, the formation of solder compounds takes place in two stages: the formation and development of a physical contact and the formation of a chemical bond between the atoms of the contacting surfaces as a result of the quantum-mechanical interaction of their electron shells. In this process, one of the metals is the conductor to be welded and the other is the solder. We can separate the two most common methods: soft soldering, which is carried out at temperatures below 450 degrees Celsius, and brazing, which is carried out when the temperature exceeds 450 degrees Celsius. The differences between the two methods are, of course, the temperature at which the work is carried out and the course of the entire soldering process.

Soft soldering

Soft soldering is the most commonly used soldering method. It is used by do-it-yourselfers and professionals alike. The process itself is very simple, so anyone can manage it. All you need is a basic model of soldering iron. Speaking of the composition of soft solder, it is mainly tin, but also bismuth, cadmium or antimony. The melting point varies from 183 to 280 degrees Celsius. Soft solder can come in various forms such as wire, stick, powder or plate. It is ideal for joining steel, zinc, brass and copper components. It is also used to join metal alloys. Soldering with soft solders is done with soldering irons, gas torches or dipping in baths of molten solder. It can be used to join electronic circuits, electrical wires, repair pipes or seal roofs and gutters.

Brazing

This type of soldering requires professional tools. It is also worth having experience, as working at quite high temperatures can be dangerous. The standard temperature is 450 degrees Celsius, but note that some metals need to be soldered at much higher temperatures. In industrial brazing, the highest temperatures are used. This type of work requires an oxy-acetylene torch, a brazing lamp or a forge fire. Alternatively, induction brazing using electric current can also be used. Silver alloy is one of the most commonly used hard alloys. It allows the joining of most metals, except aluminium and magnesium. Copper-phosphorus solders, on the other hand, are useful for soldering bronze, copper and brass. For joining stainless steel, nickel is ideal. For joining steel, nickel and brass-tin alloys, copper solder is best. Brazing is very common. It is used in refrigeration, automotive and other industries.