How to TIG Weld - Learning How to TIG Weld
What is TIG Welding?

TIG welding is similar to MIG welding, but it can weld a wider variety of metals and does not feed the metal through the welding torch. TIG welding is used to weld steel, stainless steel, chromalloy, aluminum, nickel alloys, magnesium, copper, brass, bronze, and even gold. View a diagram of the TIG welding process here.

Applications for TIG Welding

Common uses for TIG welding include: home repairs, welding items for indoor/outdoor use, art work, farm tools and machines, and automotive work.

About This Article

This is not an exhaustive guide to every TIG welding scenario, procedure, and consideration. If you are new to welding and unsure about your material, equipment, or technique, please consult an expert. The following article is a series of guidelines that will provide basic welding information and links, but is not a substitute for an expert's on-site advice. Additional resources are included at the end of this article for those ready to take the next step.

Why Use TIG Welding?

TIG welding creates a high quality, clean weld, which makes it ideal when appearance counts. There is no need to worry about splatter because it only uses the necessary amount of filler metal needed in the welding puddle. Because the Argon gas used during TIG welding (most common gas used), there is no slag to block the view of the weld puddle. Argon gas can weld any metal at any thickness with TIG welding, and therefore there is no need to change the gas depending on the project.

For a comprehensive overview of the various factors to consider for TIG welding, see Miller's list of possible scenarios.

Accessories and Consumables needed for TIG Welding 

Setting Up

As long as the metal you are welding is free of any oil, grease, paint, zinc, or lead, TIG welding does not create any harmful fumes or smoke. However, for a good weld the metals do need to be clean prior to welding. Like MIG welding, TIG welding can be done in a variety of positions, but it is often safer than MIG welding.

Invest in a helmet, gloves, jacket, boots, clamps, and any other safety gear your project may require as listed above. Welding produces sparks (though TIG produces far less than MIG welding), static electricity, and possibly toxic fumes. Consult a professional if unsure about the proper safety measures for your welding project.

Once all safety concerns have been addressed, select the appropriate electrode. There are a number of tungsten alloys (use a respirator when using thoriated tungsten: it is radioactive) which are suited to welding different alloys of metal.

Tungsten comes in 5 commonly used grades that are color coded:

  • The pure grade is color coded green and provides good arc stability for arc welding and is the least expensive.
  • Ceriated is color coded orange and also permits easy arc starting, good arc stability, and longevity.
  • Thoriated is color coded red and has a higher current capacity than Ceriated and has a high resistance to weld pool contamination, however it is more difficult to maintain a balled end on AC.
  • Lanthanated is color coded gold and works much like the thoriated.
  • Zirconiated is color coded brown and is probably the most preferred over all of them. It is excellent for AC welding. The higher quality tungsten will always give the best results. 

If there any questions during the set up process, see Miller's thorough introduction to setting up a welder. Setting up the TIG welder includes: assembling the torch and then connecting the torch to the welder, the remote control, and the work clamp to the welder. Use this guide in order to select the correct polarity settings. This guide will also suggest the best gas.

Once the welder is set, grind the tungsten to either a ball or a point depending on the nature of the project. A balled tip typically works well for AC welding and a pointed tip for DC welding. A pointed tip results in a smaller, more directed arc. The arc will tend to dance around when the tip is rounded.

When the tungsten has been installed into the torch (see this video on how to install the electrode), plug in the welder, making sure it's plugged into the correct power outlet. When ready to begin, turn on the gas. Welding heats metals to particularly high temperatures where the metal can rust. Gas prevents rust while welding. One welder recommends using pure argon for aluminum and an argon/carbon/dioxide mixture for steel.

Basic Welding Tips

Those new to TIG welding should practice on scrap metal in order to learn both proper pedal movement, welding techniques, and how to feed the metal rod into the welding puddle.

While welding, hold the torch at a 70deg- 80deg angle. Keep the torch off the work surface so that the tungsten never makes contact with it - aim for a space of 1/8 to 1/4 of an inch. The tungsten is not consumed during the welding process, but rather produces heat. If the tungsten touches the work piece, it will contaminate the material and ruin the tungsten's tip. If this happens, regrind the tungsten before proceeding.

The foot pedal regulates the heat. Therefore beginners should practice controlling the heat in order to learn how the weld puddle increases and decreases. Experts suggest making a weld puddle that is about 1/4 inch wide. Learn to control the pedal so that the puddle size stays consistent while welding, rather than shrinking to an ineffective size or spreading too far.

Though small gaps can be filled without additional metal, larger gaps may require a filler metal that is typically a 3-foot-long rod. Holding the filler metal in the free hand, make sure it rests horizontally at a 15deg angle (not pointed down) from the material. After heating; the base metal into a puddle, gently dab the filler into it. In order to avoid large deposits of filler, dab the filler quickly.

While welding it's important to keep the TIG rod moving toward the pool of melted metal. Before beginning a welding project, practice holding the TIG rod in one hand and feeding it with a steady rhythm. Watch this tutorial video in order to learn how to hold a TIG rod and move it faster.

For tips on welding technique, see the Tips by Tom Bell. They include extensive information, diagrams, and advice for a variety of scenarios, especially welding aluminum. For illustrations of basic TIG welding techniques, see Miller's TIG Guide. 

Correcting Common Mistakes

Some common problems that TIG welders come across are fairly simple to correct.

In order to prevent the metal from warping, avoid welding in one straight line. Rather, weld part of one side and then switch to the other so that each side has a chance to cool and hold the metal in place while welding.

If the tungsten is burning too quickly, it could be due to one of the following: inadequate gas flow, the electrode operating as a positive rather than a negative, using the wrong size tungsten for task, or using gas containing oxygen or CO2 instead of Argon gas. In order to correct the gas flow, check the hose, gas valve, and torch to make sure they are not restricted or kinked. Check the tank to make sure it is not out or close to running out of gas. For most TIG welding the gas flow should be set at 15 to 20 cfh. The tungsten size used for general-purpose welds is 3/32 at 220 amps maximum.

For a list of other potential problems and solutions, see Miller's Troubleshooting.

Additional Articles and Resources

Written Exclusively for Baker's Gas and Welding by Ed Cyzewski