When choosing the right MIG gun for a semi-automatic welding application, there are many factors to consider — from the material being welded and the filler metal type to the weld cell layout and expected arc-on time.
Customizing a MIG gun for the specific needs of the application, in addition to choosing the proper consumables, can pay off in greater productivity, better comfort and improved quality in the completed welds.
There are easy-to-use tools, such as online configurators, available to help users customize a MIG gun. In addition, keep some key factors in mind to help configure a gun that best suits the application needs.
Customizing a MIG gun offers numerous benefits compared to using a standard gun out of the box. Customization can maximize efficiency and productivity in a welding operation, and provide greater comfort — which can improve safety and offer longer arc-on time. Essentially, customization ensures that the welding operator has the exact MIG gun for the application.
Also, some standard MIG guns may require extra time for assembly right out of the box or require extra components be added before welding can begin. This is not the case with customized MIG guns, which are ready for welding immediately.
Customizing a MIG gun can be viewed as a pre-emptive strike against issues or challenges that otherwise would add time and money to a welding operation.
To choose or customize the right MIG gun, look at several aspects of the welding operation. Like a decision tree, one answer impacts the next choice.
First, consider the type and thickness of the base material, since both impact the filler metal selection. Once the material and filler metal are known, these dictate the welding parameters for the application.
Understanding the welding parameters is important because the gun selected must meet the amperage and voltage requirements. While it’s important to choose a gun with enough amperage for the job, the larger the gun, the heavier it is, which impacts operator comfort.
Next, think about the expected arc-on time and length of the welds. In addition to impacting the necessary amperage of the gun, these factors also play a role in ergonomics. For example, what length of gun is best for the physical space and length of the welds, and what handle style does the operator prefer?
These factors come together in building the right gun for the job.
Consider the Welding Cell
The physical space of the welding cell is also an important factor. If there are fixtures or jigs to work around, consider these when configuring the gun and selecting consumables.
For example, space limitations in the welding cell can impact cable length — the goal is always to have the shortest cable possible that still meets the needs of the application to avoid unnecessary coiling. The length and bend angle of the gun neck are also factors based on the available workspace and joint access. Remember, it is easier to make design choices like these up front rather than make changes to the gun after it’s purchased.
Also consider if the application requires table welding or out-of-position welds. For flat welds at a table, the operator may repeat the same motion over and over. In this case, comfort and repeatability is key and a gun with a shorter cable can likely be used, which helps reduce overall weight.
For out-of-position welds, the operator may need to move around a lot to complete the welds. Choosing a longer cable is helpful. Be aware, however, that a cable that is too long can be a tripping hazard for the operator or it can curl and tangle, causing wire feeding issues.
Choosing the Cable
There are two main options when choosing a MIG gun cable: steel mono-coil or industrial-grade cables. Industrial-grade cables are more commonly used.
Steel mono-coil cables are well-suited for heavy-duty applications in harsh environments. These cables offer more rigidity and support to minimize feeding issues in applications where the wire must travel through a longer cable. Steel mono-coil cables are also used in applications where there is a risk they may get run over by equipment, such as a forklift.
Cable lengths can vary greatly — from 10 feet to 25 feet or longer. While a longer cable may be necessary in applications that require the operator to move around, again, try to use the shortest cable possible that will get the job done.
Smaller filler metal wire sizes typically call for a shorter cable, since it’s more difficult to push a smaller wire over a greater length. As wire size increases, the cable length can also increase.
Neck & Handle Options
Deciding the best gun neck and handle choices for the application depends on several factors, including operator preference and comfort, as well as weld cell space limitations or fixtures. The type of filler metal being used also plays a role. For example, necks with less bend reduce the chances for bird-nesting or other feeding issues with thicker wires and softer wires.
Neck options are available with bends ranging from 30 degrees up to 80 degrees for applications where an extreme angle is needed to reach the weld joint. The choice of neck angle is often tied to the style of gun handle being used.
Gun handles are available in straight or curved options, and the decision typically comes down to operator preference. For a straight-handled gun, a neck with a 60-degree bend is a frequent choice, whereas pairing a curved-handled gun with a 45-degree neck is a popular combination.
Gun necks are also available in fixed or rotatable options. A rotatable neck makes it easier for the operator to change angles to access the weld joint without having to change out the gun. Straight handles are often paired with fixed necks, while curved handles are often paired with rotatable necks. Other features, such as trigger locking on the handle, which eliminates the need to hold the trigger during welding and increases comfort, can also be added when choosing the gun neck and handle.
The bottom line: Choose the option that makes it easiest and most comfortable for the operator to reach the weld joint.
Matching Consumables to the Gun
Some MIG gun configuration tools also allow users to choose specific styles or types of consumables. Consumables must be able to handle the amperage of the application; some higher amperage applications may require heavy-duty consumables. Inventory management may be another factor — selecting the same consumables across multiple weld cells, when possible, is typically more convenient and cost-effective. The three key consumables to consider are contact tips, nozzles and liners.
- Contact tips: Know the wire size and type when choosing the right size and style of contact tip. Some tips have finer threads, while others are designed for quick installation with a quarter or half-turn. Contact tips that “drop” into the nozzle are good for flat and horizontal welding, but they may not offer as good of performance out of position.
- Some styles offer longer life than others, too, so keep that in mind when making the choice. Pulsed MIG welding, for example, is a more aggressive mode of metal transfer that is tougher on consumables. Therefore, choose a more durable contact tip made of chrome zirconium to help extend contact tip life in these applications.
- Nozzles: Joint access, operating temperatures and arc-on time are important considerations in choosing the right nozzle. Brass nozzles are good for reducing the spatter adhesion in lower amperage applications, but does not perform well at higher temperatures. Therefore, copper nozzles are a better choice for higher amperage applications due to the ductility of the material.
- Liners: When the weld cell has a wire feeder mounted on a boom, front-loading liners help make changing liners faster, easier and safer. Specialty liners also exist that can aid feedability of the wire, especially in metal-cored or flux-cored applications.
Choosing the Right MIG Gun
Consider the challenges or needs of a specific welding application — and the preferences of the welding operator — when selecting the right MIG gun for the job.
A customized MIG gun can improve operator comfort, extend the longevity of consumables and offer greater productivity and efficiency in the operation.