There are many welding processes to choose from — but no single process is suitable for all applications. Therefore, it is critical to consider your skills, the basic processes available, and the capabilities and advantages of each to determine which process is best for your needs and applications. From there, you can determine which welder is best for you.
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.
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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.
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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.
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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 TIG Welding
- Easiest process to learn • Provides highest quality, precise welds
- High welding speeds possible • Highly aesthetic weld beads
- Better control on thinner metals • Allows adjustment of heat input while welding
- Clean welds possible with no slag to clean by use of a foot control
- Same equipment can be used for flux-cored welding
Flux-Cored Welding Stick Welding
- Works as well as stick on dirty or rusty material. • Better suited for windy, outdoor conditions
- Out-of-position welding • Forgiving when welding on dirty or rusty metal
- Deep penetration for welding thick sections • Works well on thicker materials
- Increased metal deposition rate
- More forgiving when welding on dirty or rusty material
What process best fits your needs?
Identify the types of projects and materials you will weld most of the time. Are you creating metal sculptures? Do you intend to restore an old muscle car in your garage? Does the motorcycle you bought years ago require some fabrication? Or maybe you need to do basic repair on farm equipment.
What process best fits your needs?
Identify the types of projects and materials you will weld most of the time. Are you creating metal sculptures? Do you intend to restore an old muscle car in your garage? Does the motorcycle you bought years ago require some fabrication? Or maybe you need to do basic repair on farm equipment.
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Possible Projects |
Average Material Thickness |
|
Auto body |
3/16 inch or less |
|
Trailer frames and fencing |
1/4 inch to 5/16 inch |
|
Farm, ranch and landscape |
5/16 inch to 3/8 inch |
|
Thick structural components |
Over 3/8 inch |
|
Bicycles, lawnmowers or tube frames |
1/16 inch |
|
Boats, cars and motorcycles |
1/16 inch to 1/8 inch |
|
Hunting stands and utility trailers |
1/16 inch to 1/8 inch |
|
General to heavy repair |
3/16 inch to 1/4 inch |
Taking the time upfront to identify the projects that will occupy the biggest percentage of your activity will help you determine the specific metal thickness you will likely work with most often — and ultimately help you select the most suitable equipment.
Now, it's time to get a bit more specific and take a look at what process you can use for each metal type. Keep in mind that many of these materials are also processed using varying combinations of two or more metals to reinforce strength and functionality.
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Metal |
Weld Process |
||
|
|
MIG |
Stick |
TIG |
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Steel |
X |
X |
X |
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Stainless Steel |
X |
X |
X |
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Aluminum Alloys |
X |
|
X |
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Cast Iron |
|
X |
|
|
Chromoly |
|
|
X |
|
Copper |
|
|
X |
|
Brass |
|
|
X |
|
Exotic Metals (Magnesium, Titanium, etc.) |
|
|
X |
What factors should you consider when buying a welder?
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, Miller 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 — Miller can suggest the model or product that is the best for you.
Miller has provided quality welders since 1929. When you’re ready to buy, we’d be honored if your first welder was from Miller.
Top questions about selecting your first welder according to Miller service technicians
How much amperage do I need for welding?
Amperage measures the amount of electricity flowing and is the same as current, which is the heat. As a guideline, each .001 inch of material thickness requires 1 amp of output, so welding a base material that is .125-inch thick requires 125 amps, while welding material that is .250-inch thick (1/4 inch) would require 250 amps.
What is duty cycle in welding?
A power source’s duty cycle is the number of minutes out of a 10-minute period that it can operate continuously before it overheats. Therefore, a machine that’s rated with a 40% duty cycle can operate for four minutes and then must rest for six minutes. Duty cycle ratings are included in a machine’s product specifications and are typically based on the amps and the process being used. When welding at lower outputs, duty cycle increases and vice versa. For example, the Multimatic 220 AC/DC is rated at a 60% duty cycle when MIG or flux-cored welding at 105 amps and a 20% duty cycle when MIG or flux-cored welding at 200 amps.
How much duty cycle do I need in a welder?
The duty cycle rating you need in a power source depends on the type of work you will do most frequently. For example, in a shop or garage setting, a machine with a lower duty cycle rating will typically cover most jobs. The operator is likely using lower amperages and stopping more frequently, giving the machine a chance to cool down. Operators working in a light manufacturing or fabrication production environment are welding at higher amperages and more frequently, so they typically are using a machine with a 60% duty cycle.
What is the best welder for welding outside?
What is the best welder for welding in a shop?
But if you know you will be strictly MIG welding in the shop, the Cyclone 140E features a new, easy-to-read LCD screen that displays both voltage and wire feed and includes a PowerSet mode for easy setup, making it user-friendly for both beginners and professional welders alike.