Copper Sleeve 3/8 Solder Union With Valve Obus Plug

Types of blowtorch welding: soft soldering and hard solderingIn this article you will see everything you need to know to carry out welding of copper pipes or other metals using a blowtorch, very useful if you want to repair a leak in a copper pipe or if you want to install a radiator, a sink, etc. Welding copper or other metals with a blowtorch consists of joining copper parts with the help of a second metal that melts between them. The melting temperature of the filler metal rod must be lower than that of the copper or metal to be welded. The piece to be welded does not melt, therefore it is not a fusion welding of the base material. This type of welding is used when you want to join different materials, or those with poor weldability and high strength is not required. It is the easiest welding technique to perform, even for DIY beginners.There are two types of welding with regard to the melting temperature of the filler material: soft soldering and hard soldering. Soft soldering requires reaching temperatures below 450°C, whilst hard soldering uses temperatures above 450°C. For example, filler materials made of silver and copper require temperatures of 600°C and 900°C. The higher the melting temperature of the filler material, the greater the strength of the joint. In electronics, the filler material consists of 60% tin and 40% lead and the temperature required for its melting is only 190°C. Previously with lead pipes, a large proportion of lead was used in the filler material, but nowadays with copper piping it has been removed from the filler material and replaced by copper and a higher proportion of tin. The filler material used in hard soldering is generally an alloy of copper, copper phosphate and zinc, or copper and silver. The melting point is between 600°C and 880°C. Alloys with a high proportion of silver (40%) are recommended for making welds with high mechanical strength and are those used for copper and brass gas pipe joints. Brass is used for joining steel parts. The filler metal or flux is used with a flux, which is responsible for removing impurities from the joining surface and also oxides so that the flux adheres well.Choice of the appropriate blowtorch depending on the type of welding to be carriedThe soldering lamp: it is powered by a butane or butane/propane cartridge. It is ideal for carrying out soft soldering (with tin wire). Soldering blowtorch: it is powered by butane or propane gas cylinders and provides a larger flame, they usually come with various nozzles for different applications. This blowtorch is suitable for welding different metals and alloys: tin, copper, brass, aluminium and zinc. Its use is not recommended for ferrous metals as it offers poor mechanical strength in joints. Bi-gas blowtorch: it is powered by a GPL or acetylene cartridge, mixed with oxygen under pressure, coming from another tank. It is ideal for carrying out hard soldering of large diameter pipes and also for ferrous metals. Professionals usually use this type of blowtorch for all hard soldering as it greatly facilitates their work as it provides a higher temperature. Choice of filler metal or flux The choice of filler metal will depend on the type of material to be welded and the strength required for the joint and will influence the type of blowtorch to be used. The more resistant the filler material, the higher its melting temperature. Type of welding Mechanical strength Application Soft soldering (tin) Weak: 5 kg/mm2 Installation of taps, extension of water lines. Hard soldering (copper/phosphorus) 50 kg/mm2 Cold and hot water pipes, radiators, water circuits. Copper/silver 6% and 20% 60 kg/mm2 It facilitates professionals in achieving resistant and watertight joints. The silver content helps to turn the pieces whilst they are being welded ensuring a good seal. Copper/silver 40% 40 kg/mm2 Copper pipe for gas. Procedure for welding with a blowtorch You must prepare the material to be welded very well, sanding the two surfaces to be joined with sandpaper. Then, with a soft cloth we remove the dust and finally with a brush. Apply the flux to the joint that will receive the filler metal and fit the pieces in their final position. The pieces to be welded must be held (if necessary) with clamps as copper and its alloys are good heat conductors. If you are going to weld against a wall, there are special fire