TIG Welders fall into three categories: light, industrial, and heavy duty. Most TIG welders do stick welding as easy as TIG welding, (but most stick welders don't do TIG welding.) Most TIG welder packages come with a hand and or foot pedal that lets you control the heat. TIG welders are also come with both water and or air-cooled torches. (Use a water-cooled torch for hotter welds.) TIG welding machines are available in both AC and DC current. Use AC for aluminum, not DC.)
Most light duty machines run on single or three-phase power. This is a major consideration because if you are working at home or on the farm or small repair shop, you are most likely to have single phrase power. If you get a machine that runs on three-phrase power you will need a phrase converter. New converters can cost as much or more as the TIG welder. New converters run in the $750 to $1500 range. If you need an industrial or heavy duty TIG welder for occasional use, and you don't have three-phrase power, you may want to consider using a portable outfit.
"Duty cycle" is another way of classifying a welder's "size." It reefers to how much amperage the welder can generate at a given "duty cycle." Duty cycle is the number of minutes out of a 10-minute period a welder can operate. For example, some TIG welders deliver 200 amps of power at a 60 percent duty cycle. It can weld continuously at 200 amps for six minutes, and then must cool down during the remaining four minutes to prevent overheating. Light TIG welders are usually rated at 20 % duty cycle. Industrial products are typically rated at 40 to 60 %, and heavy-duty products are 60-100 %.
Other considerations for using a TIG welder or TIG welding process are that TIG welders work on all weldable metals. The skill level required is high. TIG welds are of the highest quality, as compared to Stick welders used on regular steel where the skill level needed is medium. Stick welding is best suited for rugged outdoor conditions and used in welding repair shops. TIG welders are used in more refined conditions and applications.
TIG welders use a less intense current and produce a finer, more aesthetically pleasing weld appearance. A tungsten electrode (non-consumable) is used to carry the arc from the torch to the workpiece. Filler metals are sometimes supplied with a separate electrode that is fed manually. The gas is used for shielding. (This process is also known as GTAW, or Gas Tungsten Arc Welding.)
Most TIG welder packages includes a work cable and clamp, input power cord, TIG torch, gas regulator with hose, and foot control. You will need to get shielding gas, as it is sold separately.
Some outfits have patented technology that delivers extremely stable low amperage for starting and welding on delicate or decorative work. TIG welders have numerous manual adjustments that provide great flexibility to make great looking welds on stainless or aluminum. Some manufactures also have a "built-in "TIG pulser" that further helps you to make great welds.