Guilbert Express - Air-conditioning / Plumbing / Heating - Electric Soldering Irons Catalogue

There are a number of techniques that can be used to join metal parts. The soldering of metals is a joining process that creates a metal bond between the parts. Unlike welding, there is no fusion of the joined edges. In order to perform soldering, a strong heat is applied to the basemetals. The fillermetal is then placed in contact with the heated parts. It is instantly melted by the heat of the base metals and is then completely drawn into the joint by capillary action. Soldering is known as ‘ soft soldering ’ or ‘tin soldering’ when the melting temperature of the filler metal (usually tin wire) is below 450°C - 842 °F. ‘Hard soldering’ is done using sticks of copper/phosphorus, with or without silver. It requires higher temperatures than soft soldering, between 600 °C - 1112 °F and 850 °C - 1562 °F. Braze welding is a process used to join two metal parts, of the same or of a different nature. It is performed using a brass-based filler metal, which has a melting point that is lower (850 to 920 °C - 1562 to 1688 °F) than that of the two parts to be joined. This involves no capillary action, as in soldering, and no melting of the base metal. The filler metal attaches firmly to the base metals through diffusion or infiltration into the upper layers of the metal to be joined. Autogenous welding is a process used to join two parts of the same nature (steel or iron) by melting them at a very high temperature (> 1400 °C - 2552 °F) so that they fuse together. It is used for very many applications, ranging from central heating systems to ironwork, metalwork and even certain types of furniture production. With practice, it is possible to produce a quality weld that is smooth, straight and even. There will, however, often be slight excess thickness at the point where the parts meet. 1. Firmly attach the parts to be welded in order to ensure their stability during the process. 2. Clean them carefully before heating them to the required temperature. 3. As soon as the parts begin to melt, they will join together. However, because dripping at the point where they meet can weaken the joint, it is advisable to use some filler metal to strengthen it. This filler metal must be of the same nature as the parts to be joined or very similar. This is why it is known as ‘autogenous’ welding. HOW TO PERFORM AUTOGENOUS WELDING SOLDERING SOLDER I NG T I PS AUTOGENOUS WELD I NG 1 . Choose the appropriate soldering tool, filler metal and flux for the type of joining to be performed. 2. Cut the pipe and deburr it, in order to remove any remaining imperfections that prevent diffusion of the filler metal. Use a deburring pen to smooth the inside of the tube. Clean the parts to be joined using an emery cloth, in order to remove any oxidation, until the pipe shines. The filler metal will be able to form an even layer, which will avoid leaks. The aim is to allow the filler metal to spread by capillary action. 3. Apply flux (or flux gel) on the parts to be joined, in order to protect them from oxidation. 4. Place the ends of the parts to be joined as close together as possible. 5. Heat the parts to be joined (not the filler metal) with the tool. 6. Remove the soldering tool. Apply the filler metal to the joint, where it will melt in contact with the heated parts to be joined PERFORMING SOFT SOLDERING Go round with the tin wire one or several times, according to the size of the joint. It will spread over the heated parts by capillary action. Once it has cooled down, either naturally or by dipping the joint in water, the work is complete. PERFORMING HARD SOLDERING Spread the flux directly on the stick of solder. Place a drop of the filler metal where the parts to be joined meet. When it liquefies and spreads, this means that the parts have reached the correct temperature. Apply the stick of solder around the joint and then reheat it to make sure that an even material is formed. 7. Before moving the parts, wait for the filler metal to solidify and the parts to cool down. 8. Clean the joined parts with a damp cloth in order to remove any remaining flux. 2 5 3 6