Overview of welding processes

The most common processes are MIG, TIG and stick. Each has benefits and limitations for certain applications. There’s no one-size-fits-all approach.

  • MIG/Gas Metal Arc Welding (GMAW) — MIG welders use a wire welding electrode on a spool fed automatically at a constant pre-selected speed. The arc, created by an electrical current between the base metal and the wire, melts the wire and joins it with the base, producing a high-strength weld with great appearance and little need for cleaning. MIG is an easy process to learn and can be used on thin or thick metals. It can also create extremely clean welds on steel, aluminum and stainless steel.

    Similar to MIG, flux-cored arc welding (FCAW)* is a wire-feed process but differs in that self-shielded FCAW does not require shielding gas. Instead, flux-cored wire shields the arc from contamination. This is a simple and efficient approach, especially when working outdoors, in windy conditions or on dirty materials. FCAW is widely used in construction because of its high speed and portability.

    Both MIG and flux-cored have the capability to join materials as thin as 26 gauge.

    *The FCAW process is offered through Miller® MIG machines.
  • TIG/Gas Tungsten Arc Welding (GTAW) — This process uses a non-consumable tungsten electrode to produce the weld. The weld area is protected from atmospheric contamination by shielding gas (usually argon) and filler metal, though some welds, known as autogenous welds, do not require it. A constant-current power supply produces energy that is conducted across the arc through a column of highly ionized gas and metal vapors known as plasma.

    TIG welding is most commonly used to join thin sections of alloy steel, stainless steel and nonferrous metals such as aluminum, magnesium and copper alloys. The process grants the operator greater control over the arc, allowing for strong, high-quality welds. TIG is comparatively more complex and difficult to master than other processes and is significantly slower.
  • Stick/Shielded Metal Arc Welding (SMAW) — Stick for many years has been the most popular method for most home-shop work. This process uses an electric current flowing from a gap between the metal and the arc-welding electrode. Stick is effective for welding most alloys or joints and can be used indoors and outdoors or in drafty areas. It’s also the most economical method and provides the ability to create a good bond on rusty or dirty metals.

    However, it is limited to metals no thinner than 18 gauge, requires frequent rod changing, emits significant spatter and requires that finished welds be cleaned. Stick is also more difficult to learn and use, particularly the ability to strike and maintain an arc. Arc welders are available in AC, DC or AC/DC, with AC being the most economical. It’s used for joining thicker metals of 1/16 inch or greater. Consequently, these machines are a good choice for farmers, hobbyists and home maintenance chores.

MIG Welding

  • Easiest process to learn
  • High welding speeds possible
  • Better control on thinner metals
  • Clean welds possible with no slag to clean
  • Same equipment can be used for flux-cored welding

TIG Welding

  • Provides highest quality, precise welds
  • Highly aesthetic weld beads
  • Allows adjustment of heat input while welding by use of a foot control

Flux-Cored Welding

  • Works as well as stick on dirty or rusty material
  • Out-of-position welding
  • Deep penetration for welding thick sections
  • Increased metal deposition rate
  • More forgiving when welding on dirty or rusty material

Stick Welding

  • Better suited for windy, outdoor conditions
  • More forgiving when welding on dirty or rusty metal
  • Works well on thicker materials

What process best fits your needs?

The type of equipment you purchase should be suited for the specific functions you require as well as the projects you will work on the most. So, think about your end goal and consider opportunities to expand the usefulness of your equipment. Will you want more power or amperage in the future? Will you ever want to learn or use additional processes?

It is important to take note of the varying amperage and power requirements as well as the duty cycle necessary to achieve the most effective and economical operational results for the projects you’re looking to complete. 

In addition to the cost of the welder itself, don’t forget to include costs for the accessories and supplies you’ll need to operate your new welder. This includes welding protection (helmet, gloves, jacket, etc.) as well as gas and consumables.

Don’t feel rushed into making a purchasing decision — take some time to define your needs. If you have questions or something is unclear, an expert at Atlas Welding Supply can answer any questions you have about processes, benefits, limitations and machine operation. When you’re ready to match a specific model with the task, hobby or business — We can suggest the model or product that is the best for you.

Miller has provided quality welders since 1929.