TIG Welder Buyer's Guide

Buying a TIG welder? There are many things to look for to assure yourself of buying the proper welding machine that will handle your needs. The first step is to identify your welding demands; such as thickness of metal and how much welding need to be done at one time (the duty cycle). When shopping for a TIG welder, features that increase versatility and durability are key to getting the most out of one. While some of these features may increase the price of your welder, many will end up saving you more money in the long run.

Amperage Range and Low Amp Arc Stability

Always go for the widest range available for your price range. A TIG welder with a 5 to 230 amp range is a great choice that will allow you to work with a variety of materials and thicknesses. A welder with good arc stability below 10 amps will help you work with thinner materials without warping, as well as give you better crater fill ability at the end of the weld.

A TIG torch set on 100 to 150 amps should be the high end for any general purpose TIG weld. Only specialized industrial applications would ever require a higher setting. Generally speaking you will probably be operating in the 75 to 95 amp range for most projects. Most welders operate in this range without fault.

Duty Cycle

Duty cycle is the amount of time you can actually weld with your machine without overheating it and causing damage. For example, a welder with a 25 percent duty cycle can safely be operated 15 minutes out of every hour. A machine with a 50 percent duty cycle can weld 30 minutes out of every hour and of course a 100 percent duty cycle machine allows continuous operation. Most individuals do not need a 100 percent duty cycle machine, but you must make that decision for yourself.

Cooling Systems

The simplest and most economical is an air cooled torch, which is cooled by the inert gas flowing through. The gas shields the weld from contamination but also serves the dual function of keeping the torch head cool. High amperage or constant use will soon have this torch-head heating up to the point of requiring the welder to wear a very well insulated glove on his torch hand. The other option is a water cooled torch, which usually has a pump and reservoir circulating a coolant through a small line in the torch head keeping it cool. These are much more expensive and usually intended for an industrial purpose.

AC and DC Settings

To increase the amount of materials you can weld, looking for a welder with both an AC and DC setting is essential. Manual control of the AC balance, or the time the current spends in the negative half versus the positive half of the cycle is also important. This allows adjustment of both cleaning and penetration. A durable foot pedal to control amperage can be indispensable when working with aluminum.

Quick Change Tips and Stick Welding Ability

Look for a welder with tips that are interchangeable, as permanent tips not only limit your welding, but may require servicing should they become damaged or worn out. The ability to stick weld will allow you to perform heavy duty welds when needed.

Quality Design and Durability

An important feature that's often overlooked is fan control. Look for a fan that's triggered when you strike an arc, as it can help prevent much of the dust found in full time and thermostatically triggered fans. Also, make sure to avoid wooden transformer windings when possible, as they can swell and shrink with humidity, leading to reliability problems.

Using a TIG Welder

A TIG welder, also known as tungsten inert gas welder, works through the creation of an arc between the metal being bonded and the tungsten electrode. The arc creates the weld, which is sealed and protected from elements by gas being fed to the arc. A TIG weld generates a lot of heat and electricity, and the welder must wear a protective shield to cover his or her eyes.

The Difference between TIG and MIG Welding

TIG welding uses tungsten electrodes. The electrodes do not burn off or dissolve during the welding process. MIG welding, which is metal inert gas welding, uses a wire, which dissolves upon the completion of the weld. MIG welding was developed in the 1940s as a way to bind aluminum and non ferrous metals, while TIG welding is used with thin layers of stainless steel, aluminum, copper and magnesium alloys. Here are three best practices for using a TIG welder.

Observing Safety Procedures

TIG welding requires two hands on the material being bonded. The welder must maintain a short arc in order for the weld to be effective. Wearing a safety shield and ear plugs and not wearing loose, combustible clothing are ways to maintain a safe working environment when using a TIG welder. The ultraviolet light created by the arc requires you to wear an apron or other protective clothing and gloves, to cover exposed skin and prevent "sunburn".

Feeding the Metal for the Weld

The metal being bonded with a TIG welder should be carefully guided under the tungsten electrode. While welding the piece, care should be taken not to touch the metal with the electrode. Contact will produce a crater and weaken the weld point. When the arc is struck, a welder moves the metal in a circular motion as it is fed forward, in order to produce the weld. You might need to practice on several scrap or discarded pieces to develop a technique for properly applying the weld.

Shutting Down and Cleaning Up

Upon completion of the welding process, the TIG welder should be shut down immediately. Hands and other exposed skin areas should be kept away from the welder during this process, and the machine should be allowed to come to a complete shutdown before any component, such as the tungsten electrode, is handled. Approved cleaning methods should be observed to remove any particulates that might have accumulated during the welding process.