Well Known Problems in TIG Welding

Published: 30th March 2012
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Welding, as is known to many, is the process used for fusing metals. There are different types of welding processes like arc welding, gas welding and resistance welding. TIG or Gas Tungsten Arc may be described as a type of gas metal arc welding. In TIG welding, consumable electrodes are fed through a welding gun.

There should be constant voltage regardless whether AC or DC electric current is used. The three most common problems encountered by the operator in TIG welding are erratic arc, high electrode consumption and porosity of the weld. But if you can only identify and rectify the problems, you will save enormous time and money and the weld can be achieved faster.

One of the chief problems of TIG welding is porosity. Porosity may be described as gas pockets formed in a metal weld. The reason for porosity may be due to improper coverage of shielding gas, the use of inappropriate shielding gas or filler metal, too much heat and a base material that is not cleaned properly.

Lack of fusion is another major problem that can occur in TIG welding. If the weld does not join with the base material then it will lead to a weak joint. Experts suggest that to have the best TIG weld, you should use 10 amps for every thousandth of an inch of material.

To avoid TIG welding problems, take care to tighten all torch fittings and examine all the holes for possible leakages. If a hose is weak or damaged, it is best to replace it forthwith.

Please know that the shielding gas flow rate must be 10 to 20 cubic feet per hour. If the rate is higher it will lead to weld puddle turbulence and if it is lower it will not protect the weld puddle. Incorrect rate of flow will result in porosity.

The appropriate filter rod should be selected for the base material. Use argon gas shielding and not CO2. This will also prevent porosity. TIG welding is best performed using argon gas instead of a gas mixture or carbon dioxide.

Excess heat can also cause porosity. You have to remove dirt, grease and surface oxides from the surface of the material using a stainless steel brush to avoid porosity.

Undercutting is yet another common problem with TIG welding. This happens when a groove is made along the edge of the weld and then you fail to fill the place with weld metal.

When welding a joint create a space between the joints or bevel the pieces that form the joint. This will facilitate proper fusion of the joint.

If the welding arc is unduly long, you may obviously be holding the tip of the torch far away from the metal. Make sure to keep the torch tip less than 1/4 inch from the metal. Do not to touch the tungsten tip to the metal.

Here are some more useful tips to prevent possible problems in TIG welding:

1. Know the right use of an air-cooled / water-cooled torch
2. Learn the proper procedure for cleaning base metals
3. Know the occasions when you should use gas lens
4. Know the causes of an unstable arc and learn to remedy them
5. Find out all about excessive electrode consumption
6. Learn to prevent tungsten contamination and discoloration
7. Find out the causes porosity in a GTAW bead, and learn how to prevent it
8. Know the types of tungsten you should use

Oleg Gladshteyn is a professional writer working with Everlastgenerators and he writing many articles about Plasma cutter, Tig welding, Welding helmets. For more information, visit our website.

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