AccuLock R Consumables Reduce Downtime in Robotic Welding

In many cases, equipment-based solutions can be a means to gain success in the robotic welding operation. They can mitigate costly risks and eliminate issues that lead to inefficiencies. And often, these issues are related to a small but significant part of the robotic welding process — the welding consumables.

Changing over consumables can be a time-consuming part of maintaining the welding cell, especially if it is done multiple times during a shift. Changeover can also negatively impact productivity and quality if the consumables are installed incorrectly. Unfortunately, given the industry’s current lack of skilled welders, that may be a common occurrence. Welders simply have less experience with proper installation processes. To address this problem, many companies tend to spend more time and money on training and troubleshooting. They may even have to find workarounds to problems in the weld cell as employees get up to speed. All of this occupies resources.

Consumable challenges

Welding consumables — the contact tip, gas diffuser and nozzle — can be a major source of downtime in robotic welding operations, unplanned or planned.

During installation, cross-threading of contact tips by less experienced welders is a common occurrence that can result in unplanned downtime. Cross-threading leads to multiple problems beyond the lost productivity for contact tip changeover.

First, it can negatively affect tool center point (TCP), causing the robot to weld off-seam and create quality issues like lack of fusion or poor penetration. Personnel overlooking the robotic welding cell then need to stop production to address rework and/or scrap the part.

Cross-threading can also create a keyhole, or uneven wear, in the bore of the contact tip. A keyhole the size of only half the diameter of the wire can result in the robot welding off-seam.

Many times, a cross-threaded contact tip will stick inside the welding gas diffuser. Without another gas diffuser readily available, the operator has to make a trip to the tool crib for a new one. Meanwhile the robot is offline and not producing parts. Plus, a company incurs costs for both the contact tip and the diffuser’s replacement.

Companies that invest in power sources with a pulsed waveform capability — particularly in the automotive industry — often schedule planned downtime. Pulse waveforms improve productivity and quality by increasing travel speeds, providing a more consistent arc and reducing spatter. However, the pulsing action of the arc electrically and mechanically erodes the contact tip, leading to faster wear. It is necessary to plan downtime as a preemptive strike against contact tip failures before the chance of associated weld quality issues arise.

Both unplanned and planned downtime cost money and occupy available labor for non-value-added activities — tasks that don’t support throughput and productivity.

There is a new welding consumables technology that can help.

A new consumables solution

To address the issue of cross-threaded contact tips, Tregaskiss designed its AccuLock™ R consumables. The design is intended to support higher throughput, provide a long service life and ensure good weld quality.

The AccuLock contact tip features a long tail that concentrically aligns within the diffuser before the threads engage. The threads are also coarse, so they require minimal rotations to install. This design virtually eliminates the risk of cross-threading and provides three key benefits to the robotic welding operation:

1. It decreases the length of unplanned downtime for retrieving a replacement welding gas diffuser after cross-threading.
2. It reduces quality issues from cross-threading, such as off-seam welds or poor joint penetration.
3. It lessens unplanned downtime for troubleshooting.

The contact tips also have greater mass at the front compared to other designs, along with a taper that mates securely with the gas diffuser. The tapered surfaces ensure optimal conductivity, reduce heat and keep the consumables locked in place. These features — combined with the fact that 60% of the contact tip is buried in the diffuser, away from the heat of the arc — make the consumables last longer. Extending the product life means there is less need for changeovers.

AccuLock R consumables can also address the accelerated wear of contact tips caused by pulsed waveforms. In addition to offering the contact tips in copper and chrome zirconium, Tregaskiss has an AccuLock HDP option. The HDP contact tips last more than 10 times longer than copper tips in pulsed MIG welding applications. As a result, companies can reduce unplanned downtime for contact tip changeover — and make those changeovers faster because of the easy-to-install design.

AccuLock R consumables can be implemented easily. Switching from many other consumables typically doesn’t affect TCP or robotic programming; however, it is best to consult directly with Tregaskiss to confirm this is the case.

For companies that have both robotic welding and semi-automatic welding operations, the AccuLock R consumables can simplify complex inventories. The contact tips are part of a Common Consumable Platform™ and can be used across a wide range of Tregaskiss® robotic and fixed automatic MIG guns, as well as with Bernard® semi-automatic MIG guns (ranging from 200 to 600 amps). This common contact tip can reduce inventory costs and lessens the opportunity for operators to install the wrong consumable. The AccuLock R gas diffuser also has a blue o-ring to distinguish it from other diffusers.

Making the change

When companies find equipment solutions, like the AccuLock R consumables, that help reduce troubleshooting and downtime in their robotic welding operations, opportunities can increase. The ability to improve productivity and quality is at the forefront of those. But there may also be more time available to optimize the weld cell, make positive changes to workflow or material handling and seek out cost savings.In some cases, companies may also uncover issues in the weld cell that were previously masked by frequent contact tip changeovers. Now, however, there is more time address those to generate greater efficiencies in the operation.

In short, with the right consumables, there is more time to focus on reaching improvement targets and increasing throughput — and on implementing training that can help achieve those goals.

Selecting the Right MIG Welding Consumables

MIG welding gun configurators, like the Bernard® BTB semi-automatic air-cooled MIG gun configurator, allow you to choose specific styles or types of consumables to match the demands (amperages and waveforms) of your application.

Selecting contact tips

Know the wire size and type when choosing the size and style of contact tip.

1. Contact tips with coarse threads help speed replacement since they require less turns and they minimize cross-threading.
2. Some consumable systems also feature a contact tip that is buried in the gas diffuser, which keeps it cooler and helps it last longer.
3. For more aggressive welding waveforms, like pulsed MIG welding, choose a more durable contact tip. Chrome zirconium is a good option.

Welding nozzle options

Joint access, operating temperatures and arc-on time are important considerations in choosing the right welding nozzle.

1. Brass nozzles are good for reducing the spatter adhesion in lower amperage applications, but do not perform well at higher temperatures.
2. Copper nozzles are a better choice for higher amperage applications.

MIG gun liner selection

Having the right MIG gun liner helps minimize downtime to address wire feeding issues. It is important that you always trim the liner to the proper length. Consider these tips:

1. Liners are available that require no measurement for error-proof replacement. These liners lock and concentrically align to the contact tip and the power pin without the use of fasteners for smooth wire feeding.
2. When the weld cell has a wire feeder mounted on a boom, front-loading liners help make changing liners faster, easier and safer by eliminating the need to climb up to the feeder.
3. Specialty liners can aid in the feedability of the wire, especially in metal-cored or flux-cored applications.

Note, selecting the same welding consumables across multiple weld cells, when possible, can help with inventory management and can be more cost-effective.

Visit the Bernard® MIG gun configurators

This article is the third in a three-part series discussing how configuring a MIG gun can improve the welding operation, as well as what to consider in the process. Read article one, Configuring a MIG Welding Gun for Your Application and article two, How to Choose MIG Welding Gun Parts.

MIG welding consumables are a critical but often overlooked part of the welding operation. Unfortunately, without a clear understanding of the problems that can arise with consumables — and the best way to fix them — companies stand to lose productivity, jeopardize quality and increase costs. In some cases, the biggest issue is choosing the wrong consumable for the job.

Consider this real-life example: A company with 90 arcs is using five contact tips per day, per welder — that adds up to 450 contact tips a day. By simply changing to a more robust consumable system, the company could potentially use one contact tip per welder every three to four days. The savings in reduced downtime and purchasing costs in this situation is significant.

So how can companies avoid common pitfalls? A willingness to look at the impact of welding consumables on the overall operation — not just the product purchase price — is key. Training is also a vital part of success. Welding operators and maintenance personnel should know how to properly select, install and maintain consumables and troubleshoot problems when they arise. Or better yet, understand how to prevent them in the first place.

Making sense of welding nozzles

Welding nozzles play an important role in the welding operation, directing shielding gas to the weld pool to protect it from contaminants.

Incorrect contact tip recess within the welding nozzle is among the biggest problems. The more the contact tip is recessed, the longer the wire stickout, which can lead to an erratic arc and increased spatter in the nozzle. It can also negatively impact shielding gas coverage.

In approximately 90% of applications, a 1/8-inch contact tip recess provides the best shielding gas coverage with a welding wire stickout that helps support consistent arc stability.

Using the wrong welding nozzle for the application can cause downtime for changeover due to premature failure. For a standard welding application (100 to 300 amps), a copper nozzle provides good heat resistance. Copper nozzles also resist spatter buildup. For higher-amperage applications (above 300 amps), a brass welding nozzle is the better choice. Brass does not anneal as fast as copper, so the welding nozzle will maintain its hardness longer under higher temperatures.

Choosing the wrong shape and size of nozzle can be problematic. Too large of a nozzle can make it difficult to obtain the joint access needed to complete a sound weld.

Long or short tapered nozzles work well for restricted joints. However, there is an increased risk of spatter buildup due to the narrower bore, which can shorten the consumable’s life. To gain good gas coverage, use a longer nozzle when possible.

Avoiding contact tip downfalls

MIG welding contact tips provide the current transfer to the welding wire to create an arc.

Using a contact tip with an inside diameter (ID) that’s too small can lead to poor wire feeding and, potentially, a burnback. Using a tip with too large of an ID can cause the welding wire and arc to wander.

Every consumables manufacturer has proprietary formulas for gauging contact tip ID and implementing it into their design. Select a high-quality contact tip for consistent tolerances, and match the contact tip ID to the diameter of the welding wire to gain the best electrical conductivity. This happens because the contact tip ID is actually slightly larger than the specified measurement. For example, pairing a contact tip with an ID of 0.035 inch and a wire with the same diameter allows the wire to feed smoothly through the bore, connecting enough to generate a stable welding arc.

The wrong contact tip outside diameter (OD) can also cause problems. For higher amperage applications, use a contact tip with a larger OD to better withstand heat.

Pay close attention to the contact tip material to avoid premature failure. Consider these options:

1. Copper contact tips provide good thermal and electrical conductivity for light- to medium-duty applications.

2. Chrome zirconium contact tips are harder than copper ones and are good for higher-amperage applications. They are also a good option if a company experiences ongoing instances of keyholing — oblong wear on the bore that can lead to an unstable arc and premature contact tip failure.

3. Contact tips are available in the marketplace that feature proprietary materials and design. These tips cost more than copper or chrome zirconium contact tips but have been shown to last more than 10 times as long. They are designed for pulsed, spray transfer or CV MIG welding.

Cross-threading the contact tip is another issue that can lead to downtime. When a contact tip isn’t threaded properly during installation, or if the welding operator introduces dirt or debris to the threads, the gas diffuser can be damaged during installation. This will require replacement and increase costs.

To avoid cross-threading, look for contact tips with coarse threads that install with fewer turns.

Getting it straight about liners

The welding liner has a single and relatively simple purpose: to guide the welding wire from the wire feeder through the power cable to the contact tip. However, it is capable of causing significant problems if it isn’t installed properly.

Trimming a liner incorrectly is the most common installation error. A liner that is too short lessens the support of the welding wire as it passes through the length of the gun. This can lead to micro-arcing or the formation of small arcs within the contact tip. Micro-arcing causes welding wire deposits to build up in the tip, resulting in an erratic arc and burnbacks. In more extreme cases, micro-arcing can cause MIG gun failure due to increased electrical resistance throughout the front-end consumables and gun neck. It may also prompt the welding operator to increase voltage in an effort to rectify poor welding performance, which can cause the gun to overheat.

On the other hand, a too-long welding liner can lead to kinking and poor wire feeding.

When trimming a conventional welding liner, avoid twisting it and use a liner gauge to ensure the proper measurement. There are also consumable systems available that provide error-proof liner installation and require no liner measuring. The gas diffuser locks the liner in place while concentrically aligning it with the power pin and contact tip to eliminate any gaps. The welding operator or maintenance personnel feeds the liner through the neck of the gun, locks it in place and cuts the liner flush with the back of the power pin.

As with contact tips, remember that quality matters when it comes to welding liners. Always select a stiffer liner, so it is capable of supporting the wire as it feeds from the spool through the power pin and the length of the gun.

Final considerations

Paying close attention to MIG gun consumables is important to gaining good welding performance. That means looking at the overall quality of the products being purchased; the manner in which they are inventoried, stored and handled; and how they are being installed. Always follows the consumable manufacturer’s recommendations, and when in doubt, contact their customer service or a trusted welding distributor for help.

MIG Welding Consumables Reduce Wire Feeding Issues and Downtime

New HDP Contact Tips Provide Robotic Pulsed MIG Welding Benefits

Optimizing the robotic weld cell helps improve productivity, allowing a manufacturing facility to save time and money. It can be especially beneficial in applications that use pulsed gas metal arc welding (GMAW-P), a process that results in rapid wear to the welding gun’s front-end consumables.

While the choice of contact tip for the GMAW gun may seem like a small factor in the entire operation, consider how much time it takes for an operator to enter the weld cell and change the contact tip — and how many times per day the tip is changed in most robotic welding operations. For example, copper contact tips are changed on average four times per shift. In a three-shift operation averaging 10 minutes per tip change, that equates to spending two hours per day changing contact tips. What else could a welding operator be doing with this time to create value in the manufacturing operation?

There are contact tip innovations that help significantly reduce the downtime spent on changeover — time that can be spent on other tasks in the operation, such as increasing production up-time. In addition, when the operator spends less time in the weld cell, it reduces the potential of health and safety incidents and the possibility of weld quality issues through altering weld settings and parameters such as tool center point.

For these reasons, it’s important to consider the total cost of ownership when selecting the right contact tip for a robotic welding operation.

Demands of GMAW-P

As more manufacturing applications use thinner, lighter and more corrosion-resistant materials to meet industry demands, this increases the use of GMAW-P processes, which offer benefits for welding thin-gauge materials. Pulsed waveform technology continues to develop, offering faster travel speeds, reduced spatter levels and high weld quality in many robotic applications.

However, pulsed processes typically require a higher frequency of contact tip changeover due to the energy of the process. Faster contact tip deterioration is caused by peaks in pulse waveforms where the energy/heat is five times greater than in traditional constant voltage (CV) GMAW.

Because of this, arc erosion is a common failure for contact tips in GMAW-P. Contact tip failure increases an operation’s costs, due to the increased frequency of downtime related to tip changeover.

A new contact tip design has resulted in tips with improved resistance to arc erosion that last much longer in pulsed welding.

Contact tip advancements

Contact tips made from copper or copper chrome zirconium are commonly used in many welding applications. However, adoption of a GMAW-P process can double contact tip replacement frequency and related downtime when using copper or chrome zirconium tips.

A new innovative technology on the market today can significantly extend the time between contact tip changeover, thanks to a combination of proprietary materials and tip design. HDP contact tips from Tregaskiss last more than 10 times longer than copper or chrome zirconium tips, allowing operations to go from changing contact tips two to four times each shift to only changing the tips once every third shift or longer.

HDP contact tips are engineered to resist wear better than other materials and designs previously used for contact tips, providing increased resistance to arc erosion in pulsed welding, as well as spray transfer and CV GMAW. The precise fit between the tip and the wire also results in good arc stability to help produce high-quality welds, and because the degradation of welding current from the power source to the contact tip is reduced, it provides a truer representation of the pulsed waveform program.

The tips currently come in .035, .040 and .045 sizes and can be used with standard nozzles and TOUGH LOCK® retaining heads as well as with air-cooled guns or water-cooled guns. HDP contact tips can be used with Tregaskiss guns, as well as guns from other MIG welding gun manufacturers.

Because the tip bore is sized so tightly to the welding wire, it’s best to use the HDP Contact Tip with good-quality welding wire that has a large cast. A high-quality wire typically has a consistent wire diameter, which promotes better feeding and optimized performance.

Significant productivity gains

Typically, operations conduct contact tip changeovers on a preventive maintenance schedule to avoid unplanned downtime in the manufacturing process. The necessary frequency of contact tip changeover varies based on many factors including application, wire type and quality, waveform and base material.

Many robotic welding operations have 100 welding arcs or more and run three shifts per day. In robotic welding operations, copper tips are changed on average four times per shift — or 12 times per day. Chrome zirconium tips are changed about half as often, or six times per day. A scheduled contact tip change typically takes 10 to 15 minutes to complete.

Compare this to real-world results from several manufacturing operations using HDP contact tips. For example, one manufacturing operation converted to HDP contact tips in a solid wire GMAW-P application. The operation produces 600 parts per shift, and the previous chrome zirconium contact tip required changeover every 60 to 80 parts — or about 10 times per shift. In the company’s trial, one HDP contact tip was still running after 2,500 parts under the same parameters.

Another manufacturing operation running a standard GMAW process tried HDP contact tips on a line of 18 robots. Where previous contact tip usage for the operation was 216 per day — or about 1,500 tips per week — one HDP contact tip lasted an entire week on each cell, totaling 18 tips per week.

Additional benefits

In addition to the significant productivity gains the new contact tip design provides, there are other benefits for arc stability, productivity and operator safety.

Reduced frequency in contact tip changeover not only increases throughput while saving time and money due to downtime, it also reduces the risk of safety incidents, since every time an operator enters the weld cell it increases the risk of injury.

Also, each time someone touches the welding gun, there is the risk putting it out of alignment. The less frequently an operator must enter the cell, the less chance there is for human error that can disrupt tool center point that reduces part quality.

Frequently changing the contact tip can cover up other issues within the weld cell. When the contact tip is changed less often, other issues such as wire feeding problems, wire routing or a loose ground can come to the forefront. With standard contact tips, changing the tip out is often the first go-to fix when there is a problem in the weld cell — even if something else is the root cause. With a longer-lasting contact tip that is not changed as frequently, other issues that may not have been noticed before can now be fixed to improve the overall efficiency of the weld cell.

Return on investment

It’s important to consider total cost of ownership when evaluating contact tips and other consumables. The upfront cost of a contact tip is just one factor in total overall costs. A longer-lasting contact tip may be more expensive upfront, but it can provide significant payback in time and labor savings and reduced downtime.
Be sure to look at the big picture in terms of productivity and efficiency improvements for the entire operation.

In considering a switch in consumables, an operation should also be sure there is time to conduct a trial, which should always be part of changing the type of consumable or contact tip. The numbers will often speak for themselves when vetting the option and analyzing return on investment.

Improve productivity and efficiency

An operation may think the welding process is optimized, but that may not be the case if operators must frequently enter the weld cell to change the contact tip. As manufacturing operations look for ways to improve production efficiency and throughput in automated welding, choosing the right contact tip for the gun is one solution.

A contact tip designed to provide significantly longer tip life saves time and money in necessary changeover and reduces the frequency of people entering the weld cell. New contact tips on the market can last days in GMAW-P applications compared to standard copper tips that may only last a few hours.

 *Other parameters: 450 ipm wire feed speed, 40-45 ipm travel speed, 90/10 mixed gas, 240-260 average amps on a Tregaskiss robotic MIG gun with a 22-degree neck.

What MIG Gun Neck is Right for You? 

Optimizing MIG welding gun performance in specific applications can be a matter of choosing different components for the gun. Selecting the right MIG gun neck improves access to the weld joint, increases operator comfort and can reduce costs in the operation. 

The biggest factor when choosing a gun neck is to ensure it provides proper access and visibility to the work. In some applications, the weld joint may be difficult to reach, or it may require you to reach down into a groove. A gun neck should provide optimal access to the weld joint — so you can do your best work while maintaining proper ergonomics.

In addition to joint accessibility, several other factors play a role in the decision, including the welding process and parameters, the welder’s height and whether the gun has a curved or straight handle. Keep the following considerations in mind to choose the right MIG gun neck for your application. 

Feeling the heat

Certain welding processes and filler metals generate much greater heat during welding, so take that into account when choosing a gun neck. Pulsed welding processes, the use of metal-cored wires and even certain materials, including stainless steel and aluminum, all generally create more heat during welding. 

The welding parameters — including amperage, volts, joint configuration and distance from the welder to the joint — also impact the amount of heat produced and felt by the welder. 

In applications with high heat, a standard short gun neck can cause the heat to radiate through the glove and into the welder’s hands. It’s recommended to use a longer gun neck in these situations to keep the heat farther away. Another good rule of thumb to remember is the larger the wire diameter being used, the longer the gun neck should be.

Standard necks

Standard necks for MIG guns are available in a range of options, with varying angles and material types. 

• Aluminum armored necks can withstand abuse and offer outstanding heat dissipation. They are typically available in fixed and rotatable styles, and some models require no tools to rotate. These necks, which come in 30-, 45-, 60- and 80-degree angle options, are a good all-purpose choice for many welding applications.

• Black polymer armored necks, available in a 60-degree angle, contain a thick copper wall with a conductor tube interior, so they don’t radiate or reflect heat as quickly. This insulation from the heat makes them a good choice for higher-amperage welding applications. Be aware that black polymer armored necks can become brittle and break since the high temperatures, over time, can break down the exterior tube. 

Choosing between these standard neck options is often a balance of application requirements and welder preference. The same is true for choosing a neck angle. The style of the gun handle, however, is also a determining factor in selecting the right neck angle. When using a curved handle, it’s often more comfortable to use a 60-degree neck than a 45-degree neck. With a straight handle, a 45-degree neck is typically better suited due to natural hand placement. A welder’s height also impacts proper neck angle: A taller welder may want to use a 60-degree neck, while a shorter welder may prefer a 45-degree neck for comfort. 

A neck coupler is an accessory that allows a flex neck to be added to the top of an existing standard neck. This can be used when a longer neck with flexibility is needed to get into hard-to-reach areas. to-reach or narrow areas. Some flex necks have a bend radius up to 80 degrees. These necks are typically available in 6- and 8-inch lengths for straight and curved handles. Because flex necks can be changed, rotated or bent without tools, this saves time and labor. 

Flex necks

In applications where a standard neck can’t provide proper access to the weld joint, consider using a flex neck, which can be bent into a desired shape or angle to access hard-to-reach areas. 

Some flex necks can also be used with an easily removable jump liner for quick changeover. Jump liners replace only the most commonly worn and clogged liner area in the neck bend, to reduce downtime for liner changeover. A jump liner connects the standard liner at the back of the neck and runs through the neck up to the contact tip. 

Because a jump liner allows for quick and easy neck change-out, the gun can be easily adapted to fit multiple applications. For example, flex necks and rotatable necks are frequently used in shipbuilding. A welder may be in the ship’s hull and need multiple neck styles to access different weld joints. Instead of bringing several welding guns to the work area, a jump liner allows the welder to quickly unscrew one neck and thread another one on without changing or trimming the liner. An operation can also reap cost savings, since jump liners are less expensive than standard liners and quicker to install.

Specialty necks

When available standard or flex necks don’t provide proper weld joint access, specialty necks can be created. Multiple lengths and bends are available for limited access positions and improved operator comfort. These necks are specially designed by manufacturers to fit the specifications of the application. Because producing a quality weld hinges on optimal access to the joint, in some cases a custom neck can provide the best accuracy and results. 

Final thoughts

Many neck options are available for MIG welding guns, including rotatable, flex, various bend angles and lengths, neck couplers and custom necks. Choosing the right style can improve your comfort and maneuverability — especially with hard-to-access welds. When you’re unable to reach your weld joints comfortably using a standard neck, consider adding a specialty or custom neck to your toolkit. 

Steps for Proper MIG Gun Liner Installation

A MIG gun liner is an important consumable because it can make a significant difference in gun performance and the time and money an operation spends in unplanned downtime. Proper installation of the liner is critical to its ability to guide the wire through the welding cable and up to the contact tip.

Improper liner installation — which includes trimming the liner too short or having a liner that is too long — can result in a number of problems, such as birdnesting, wire feeding issues and increased debris in the liner. These issues can result in costly rework and operator downtime for maintenance and repairs, which impacts productivity. Also, wasted wire due to issues like birdnesting can drive up costs for a company.

Step-by-step installation

The installation process is somewhat similar for all types of MIG gun liners, with some variations. Here are some general steps to consider when installing a new MIG gun liner. 

1. Before removing the consumables, make sure the gun is straight and the cable is flattened. This makes it easier to feed the liner all the way through. 
    
2. Trim the wire at the front of the gun to remove the bead of molten wire that often forms after welding.
    
3. Remove all of the front-end consumables so the liner can be fed through the gun.
    
4. For a conventional liner installation, remove the power pin from the feeder at the back of the gun and cut the wire. This allows the wire and the old conventional liner to be removed from the back of the gun.
    
5.  If using a conventional liner, feed the liner through the back of the gun, threading it into the power pin. Reinsert the power pin back into the feeder, and feed a few inches of wire through the back of the power pin.
   That way, once all of the consumables are back on at the front of the gun, the wire is already in the gun and ready to be pulled through.
    
6. Because the liner is longer than the gun (designed to accommodate varying gun and cable lengths), there will be liner sticking out the front of the gun, so it’s necessary to trim the liner to the correct length. Conventional liners and front-loading liners may come with a plastic liner trim gauge. This can be fed over the top of the liner and pressed up flush against the neck, so the liner can be trimmed to the end of the gauge. If no gauge is provided, please consult your MIG gun manual or manufacturer’s website for the correct trim length.
    
7. Hit the trigger to pull the wire up, and at the same time purge the gun with shielding gas.

Installing a front-loading QUICK LOAD Liner 

There are some variances in the installation process, depending on the type of liner being used. Follow these steps when installing a front-loading liner.

1. Unravel the liner (which comes coiled) and stick the brass end — the end that goes into the receiver at the back of the gun — over the wire and through the neck.

2. Feed the liner through the front of the gun using short strokes, to avoid kinking the liner. The front-loading liner will click or snap into place once it hits the receiver in the power pin.

3. Once that is complete, put the liner gauge on top of the liner and follow the standard installation steps above.

Installing a front-loading liner with the spring-loaded module

The only difference in this installation process is that there is no receiver in the back of the power pin. The receiver is built into the module pin.

1. Feed the front-loading liner into the gun using short strokes. The liner will engage with the receiver inside of the module’s power pin. When this happens, the welding operator can feel the liner spring back toward the front of the gun. This is a good sign, because it means the liner is properly engaged.
    
2. Place the liner trim gauge over the front-loading liner until it is flush against the neck.
    
3. Push the liner back into the gun until it bottoms out against the spring-loaded module, then trim the liner flush to the end of the liner trim gauge.
    
4. After trimming, remove the liner trim gauge and release the liner. Note that the liner will spring back and stick out of the neck by approximately 1-3/4 inch, which is normal, as installing the consumables will compress the liner into its proper position.

Retrofitting a gun

The installation process also varies when retrofitting a gun from a conventional liner to a front-loading liner. Here are a few additional things to remember:

1. When retrofitting a gun from a conventional liner to a front-loading liner, the first installation will be from the back of the gun, since a receiver is needed on the back in order to accept the front-loading liner.
    
2. After following the standard steps above and removing the conventional liner and wire from the gun, install the end of the front-loading liner with the O-rings on it into the receiver and unravel the liner.
    
3. Feed the front-loading liner in, just as with a conventional liner, through the back of the gun, and thread the receiver into the power pin.

Proper liner installation can help optimize performance

The quality of the liner also can impact welding performance, productivity and operator downtime, so it’s important to buy quality liners from a trusted manufacturer. Choosing the correct size of liner for the wire being used is another way to help maximize performance.

While liners may seem like a small part of the welding operation, it’s important to be mindful of the impact they can have on quality, performance and costs. Liners perform a vital function in the MIG welding process, and the proper installation and maintenance of liners can help reduce costly rework, operator downtime and wasted wire.