Successful Soft Soldering Process

Method of Soft Soldering To carry out successful soft soldering, the following process is to be adopted: (a)          Clean the parts thoroughly. (b)          Tin the parts to be joined, if necessary. (c)          Assemble the job in proper position. (d)          Apply flux slightly. (e)          Melt the solder between the joints with a hot, clean and tinned soldering iron. (f)           Allow the solder to get completely cooled. (g)          When it is cooled, wash it properly with clean water (normally warm soapy water). (h)          Remove all the traces of the flux, which will…

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Hard Soldering Process and Flux

Soldering Process A large number of joining processes are used in industry to make the finished products like aeroplanes, ships, cars, vehicles, radios, televisions, computers, machine tools and domestic appliances. Different methods used for joining components are riveting, brazing, welding, screw fastening devices, etc. In the engineering industry, for instance, soldering finds applications in making turbine blades and discs, pipelines, radiators, fins, in air-cooled engines, bicycle frames, industrial receptacles, gas equipment, etc. Soldering is the process of joining two or more similar or dissimilar pieces of metal by the application…

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Hard Soldering an Alternative to Brazing

Hard soldering (silver soldering) is an alternative to brazing. It specially implies the use of the filler materials containing silver, which have lower melting point than brazing spelter and therefore associated with greater ductility and often greater strength. Hard soldering is general term used to cover brazing and silver soldering. However, hard soldering can be defined as an intermediate stage between low temperature soft soldering and high temperature brazing. The operation of brazing and hard soldering are almost identical and the two terms are used synonymously. Hard soldering normally means…

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Advantages, Disadvantages, Precautions in Brazing

Advantages of Brazing Following are the advantages of brazing: (a) Brazing is used to join a large variety of dissimilar metals. (b) Properly brazed joints are pressure tight. (c) Pieces having great difference in cross-sectional areas can be brazed. (d) Thin sheets, pipes and gauges that can’t be joined by welding can be joined by brazing. (e) Complex assemblies can be fabricated by this method. (f) A brazed component has ability to preserve protective metal coating. (g) Brazing can be done on cast and wrought materials. (h) Corrosion resistance joints…

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Brazing and Its Applications

Brazing is defined as a process of joining similar or dissimilar metals in which molten filler metal is drawn by capillary action into the space between closely adjacent surfaces of the parts to be joined. In general, the melting point of the filler metal lies above 5000C but below the melting point of the parent metals being joined. The brazing alloy is often called spelter and can be plain brass (50% copper and 50% zinc). Increasing of the zinc content decreases the melting point of the spelter. Borax is used as a…

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Methods of Brazing

Torch Brazing. This method requires very little equipment and is more frequently practiced. It involves the use of a type of gas blowpipe fitted with the combination of air and gas regulators by means of which both the size and nature of the flame can be adjusted to suit the work. The gas combinations used and the temperatures obtained from them are given below: Torch Brazing (a) Compressed air-coal gas : 10000C to 11510C (b) Coal gas-oxygen : 21000C to 22000C (c) Hydrogen-oxygen : 24000C (d) Oxy-acetylene : 32000C In general,…

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Brazing Various Metals

Brazing of Aluminium Pure Aluminium and certain aluminium alloys can be joined by aluminium brazing. A filler material or a brazing rod, usually, an alloy of Aluminium and Silicon of a lower melting point than that of parts to be brazed is used for aluminium brazing. One of the filler materials contains 10 to 13% silicon and melts at 5750C. This is 850C below the melting point of aluminium. It is clean and smooth flowing in action with a good penetrative and wetting power, which causes it to flow into and…

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Metals That Can Be Brazed

Practically all metals and alloys can be brazed or hard soldered satisfactorily with the exception of alloys having zinc, tin, lead or magnesium as base and aluminium alloys containing more than 2% magnesium. Cleaning of Components before Brazing Mechanical cleaning methods are filing, scraping, grinding, polishing and sandblasting. The cleaned parts should not be touched with bare hands. Alloys, on which oxide films grow rapidly, should be brazed soon after cleaning. For chemical cleaning, components should be degreased as suggested below: (a) Steel and Iron. Oxide or scale can be…

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Sheet Metal Thickness Measurement

Many engineering components are produced from a sheet of metal, which is cut to shape and then folded to form the finished article. The edges are then secured by various methods such as welding, brazing, soldering, riveting etc. The term ‘sheet metal’ is normally used to describe metal sheets with a maximum thickness of 2mm. Above this thickness, it is usual to use the term ‘plate’. The sheets of very low thickness (30 to 50 SWG) are known as foils. The thickness of metal sheets is identified by a series…

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Classification of Metal Sheets and Their Uses

Sheet metal work has its own significance in the engineering work. Many products, which fulfill the household needs, decoration work and various engineering articles, are produced from sheet metals. Common examples of sheet metal work are canisters, guards, covers, pipes, hoods, funnels, boxes, etc. Various types of metal sheets are used in aircraft structural work including iron, steel, copper, brass, aluminium, duralumin, etc. Metal sheets are classified on the basis of the material out of which these are made of. For the same metal, sheets are classified according to their…

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