tig welding

TIG Welding Explained

What is TIG Welding

Tungsten Inert Gas is commonly known as TIG welding is a process of  welding or blending together reactive metals. Aluminium and magnesium being the most notable. The TIG welding process came into common useage in the early 1940s in the US during the second world war and allowed for the increased use of aluminum for structural processes. For other metals TIG welding is chosen for its strength and results. When TIG welding, an arc is formed between a pointed tungsten electrode and the area to be welded that has been earthed back the the welder. The tungsten electrode isn’t a consumable (though it might be when you first start welding TIG) and is able to endure the temperature normally produced during the welding process. As you weld the TIG welding torch releases a shielding gas around the pointed tungsten tip and the ARC. For aluminium the gas should be pure Argon (>99.998% pure) and for absolute optimum results a Argon Helium mix. This will give faster welds and deeper penetration due to the higher voltage achievable. For stainless steel the most common gas is Argon though depending on the type of stainless steel you are using there are a number of mixes you can use.  Because of the gas shield, a clean weld is made. This stops oxidization from occurring due to contamination from the atmosphere.

Clean the Weld Surface

It is very important that the area to be welded is free from dirt, oil, oxidation or other contaminants so as to achieve clean, uniform and splatter free beads. Sanding with a flap sander or sanding with sandpaper will take away larger contaminants while alcohol is very effective at removing grease and oils. There are special chemical etching cleansers available for removing the oxidation layer. Be careful when using a flap sander as you can re-embed the oxidation that you just removed. The melting point for aluminium is 660C and for the oxidation layer is 2000C. Removing this layer will prevent the absorption of hydrogen into the weld. Remember to clean the underside of the piece as well and any filler rods you are using.  It is good practice to mark up your cleaning and scrapping tools so as to identify for use with only one type of metal. Many fabrication shops will designate one TIG welder for aluminium and another one for stainless steel. These will be set up in separate areas with separate tools to prevent any cross contamination. TIG welding will likely be smoke and fumes free when the surfaces are fully clean.

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Example of TIG Welding

What Can TIG Weld?

With TIG you can weld many types of metals. Steel and aluminum, however, are the two most common metals. Other metals used are copper, titanium and magnesium. The filler rod is another critical facet of TIG welding. Usually made up of the exact material as the base metal to be welded, it is usually used for reinforcing joints, filling and building gaps and welding heavy metals. A worn part can have its surface area built up before re-machining to a like new condition.

What is TIG Welding Used For?

There are various several types of joints meant for use with TIG welding. Included in these are butt joints (end to end), lap joints (overlapping pieces), corner joints and t-joints. The butt joint can be welded without the use of a filler rod if need be. With this type of joint, two metal components are pressed together along side the seams. By using a lap joint, the top edge is welded with the bottom piece in an area between the two overlapping metals. A weld on the rear side if possible will give  super strong joint.  A corner joint involves welding one piece of metal at a right angle to the side of another bit of metal so as to form a corner. A filler rod can be used on the inside of the joint. To create a t-joint, a filler rod is required. The t-joint is made by placing one piece of metal perpendicular to another component of metal to create a T shape. This sort of TIG welding is performed along each side of the perpendicular seam if both sides are accessible..

Where is TIG Welding Used?

TIG welders are utilized in the panel beating and motor bike sectors quite extensively due to the fact of it’s high quality welds which are essential for this sort of work. Nonetheless, any shop that requires high quality welds in aluminum, copper, manganese, titanium, steel or another reactive metals find this kind of welder essential. It is particularly suited for welding thin metals even that from different types where a excellent finish is essential. Welding of car panels, repairing parts, mending and manufacturing bicycles and also for repairing and manufacturing aircraft along with their parts are some the areas that TIG welders are ideal for.

Buying a TIG Welder

Exactly what to pay if you are buying a TIG welders depends upon what you would be welding with it and what duty you require of it. Stay away from the base end unless you don’t typically use what you buy. Find a mid range TIG welder for sale even for hobby or personal use along the lines of from the green range from SIP.

TIG Welding Advantages

  • Light and easily portable
  • Clean Smoke and fume free
  • Nicest welds you can obtain
  • Commonly doesn’t need a filler rod
  • Can weld unique metals
  • Can weld any reactive metal

TIG Welding Disadvantages

  • Much slower than MIG or ARC welding
  • Much harder to grasp
  • Not suitable for heavier metal

 

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One Response

  1. John horan
    John horan at |

    I did not realise about using the flap sander. Will try that tomorrow. That could cure a problem. Thanks

    Reply