Five Equipment Adjustments to Improve Weld Quality
Regardless of your skill level, you need to make sure that the equipment you use, works as hard as you do. Consider these components of your welding system to help weld conistency. Could it be time to take a good look at your equipment? Read our article published in the November issue of Fabricating & Metalworking.
Choosing Between Robots and Cobots for Robotic Welding
Learn how to recognize the key nuances between two welding-automation options, robots and cobots and how knowing these differences are essential to attain positive results. Have you ever wondered about the differences between robots and cobots? Learn more! “Choosing Between Robots and Cobots for Robotic Welding” in Metalforming Magazine
South Louisiana Community College Chooses Bernard® Semi-Automatic MIG Welding Guns and AccuLock™ Consumables for Welding Education
South Louisiana Community College (SLCC) has made a game-changing decision to enhance its welding education program by incorporating Bernard semi-automatic welding guns and AccuLock consumables into its classrooms. This shift marks a significant departure from the MIG guns and consumables they had been using for decades.
The transition began within the last year after SLCC’s welding technology instructors began noticing some challenges the students were facing with the welding guns and consumables that they were using. They noticed it took students 20 minutes to change a liner with their current welding guns and consumables.
Enter Bernard. After meeting with the instructors and listening to their pains points and need for improvement – Bernard configured a lightweight MIG welding gun with the AccuLock S dual-locked liner consumable system to test in the classrooms. Instructors and students immediately saw the benefits.
The AccuLock S dual-locked liner system makes liner installation error-proof by eliminating the guesswork and potential errors that can occur when trimming a liner. More importantly, it maximized their limited time in the classroom. The superior performance of AccuLock contact tips stood out most. SLCC saw a remarkable 50% improvement in tip life compared to the products they were using previously. AccuLock contact tips lasted twice as long.
The school found the benefits of using Bernard’s MIG welding guns and AccuLock S consumables for instructional purposes were clearly evident. The lightweight and durable design, coupled with the extended consumable life delivered a substantial return on investment. Not only does the switch to Bernard provide cost savings, but it also equips inexperienced welders with the tools that can withstand the rigors of training and real-world applications.
Understand the Truth About These 7 Robotic Welding Myths
Estimated reading time: 7 minutes
Speed, accuracy, repeatability — welding automation boasts some big benefits. Using robots across a myriad of manufacturing applications has been a boon to the welding industry, but it hasn’t come without its fair share of misconceptions. Accepting those misconceptions could actually negate those big benefits — and no one has the time (or money) for that. Here are some common myths heard ’round the manufacturing floor — and where we land on them.
Myth 1: The more anti-spatter solution you use, the better the results
There seems to be a halo effect around the word “anti” — if it’s anti-“something,” it’s often assumed that the more you use, the better off you’ll be. In welding, that’s not necessarily the case. Using too much anti-spatter spray can actually cause more problems than it solves. When applying it to hot consumables, spraying just enough for it to dry on contact will create a sacrificial barrier that spatter won’t stick to as easily. If the solution is applied to the point where it’s dripping from the torch, it’s too much — and the excess spray will leak all over the parts and weld cell, leading to compromised weld quality, a messier weld cell and premature failure of the torch parts/consumables. Some operators will “dip” the consumables into a cup of the anti-spatter instead of spraying it, but this is also problematic because excess solution can cause the nozzle to become saturated and fail prematurely.
When welds are off location, there’s usually an underlying issue that’s causing the problem. Tip bore wear, variations in stamping batches or parts being misaligned due to tooling/spatter can all create a situation where welds are off location. Here, reassessing TCP can help determine what the root problem is rather than just blaming the torch and touching up points.
Apply only enough to get the job done. Tips to keep in mind when applying anti-spatter solution include:
- Position the nozzle at least 1 inch above the spray head
- Spray duration should be 0.5 seconds
- Adjust/reduce the spray frequency until the nozzle is perpetually wet
- The use of a spray containment unit allows the anti-spatter solution to be more effectively applied to the nozzle/consumables, while also keeping the weld cell cleaner by capturing over-spray
Myth 2: Using a contact tip that matches the size of the wire always leads to the best results
Contact tips can be the difference-maker between running an efficient welding process and accruing unwanted downtime. For smaller wire sizes in semi-automatic (or handheld) welding, using a contact tip that matches the size of the wire often leads to the desired results. However, in larger industrial operations where robotic welding is common, wire package size (vs. wire size) becomes more of the determining factor for selecting the proper tip size. Large-scale operations often use 1,000–2,000-pound drums or spools as the go-to options due to their high-volume output needs. The connection between the wire and the contact tip needs to be optimized for the tip to last as long as possible, which may require deviating from matching the tip and wire size.
Myth 3: The cheapest products will work
The adage goes, “You get what you pay for,” and that sentiment can definitely impact the quality of the work in welding. Investing in robotic welding equipment can add up quickly, so if there’s an opportunity to save a few bucks along the way, selecting a cheaper alternative seems like an appealing option. However, those savings often come at the expense of sacrificing product performance and weld quality, while creating more downtime. The issues experienced during the welding process will show in the end result, along with the bottom-line burn of frequent (and costly) consumable changeovers and excessive downtime for troubleshooting issues. Selecting high-quality, long-lasting consumables over cheaper alternatives will help reduce overall operating costs in the long run because it increases throughput while reducing inventory and downtime.
Myth 4: Changing the contact tip will always solve the problem
Well … not necessarily. If the contact tip fails and you replace it, you can consider the problem “solved” for at least a short time. However, if the tip keeps failing quickly, it’s safe to say that there’s a greater issue at play. Many factors can cause a tip to fail, including feeding or grounding issues. In those cases, if you put a new tip on, you’re inevitably just waiting until it fails again because you’re not addressing the root cause. If you’re going through tips at a high rate, this is the time to assess your operation and make sure that the drive roll tension is correct and/or the liner is trimmed properly. These are two common issues that can easily cause excessive “burn backs”/tip failure.
Myth 5: Higher drive roll tension results in better wire feeding
Choosing the right drive roll style and size for the wire being used is key to smooth and consistent wire feeding. However, if the tension is too high, or too low, it can diminish productivity, quality and efficiency. Tension that’s too tight can deform the wire, resulting in arc instability or burn backs (and too little tension can cause the wire to slip). If the system constantly needs more tension to push wire through, it likely means something else within the system is failing. For example, debris buildup in the liner can inhibit the right tension setting from being effective. To help mitigate the need to crank up the tension, make sure it is set correctly each time the wire spool/drum is changed. Additionally, be sure that the inlet guides are clear/not worn and clean the drive roll surfaces with a wire brush periodically to help maintain proper wire feeding.
Myth 6: Increased gas flow results in less porosity
This is another instance where the idea of “more is better” can be misleading. You definitely need enough gas to cover the weld pool, but turning up the gas doesn’t necessarily result in less porosity — in fact, it could create turbulence and MORE porosity. Proper gas coverage is based on flow, not pressure. If a system isn’t set up properly and the nozzle gets blocked with too much spatter/debris, there won’t be sufficient gas volume (flow) to protect the pool.
Leaks in the gas system or excess air flow within the weld cell can also impact the coverage of the weld pool, regardless of how high the gas flow rate is set. Instead of just defaulting to increasing the flow, do a quick run-through of the robotic system to verify that there is a proper tip-to-work distance and that the rest of the system is configured and running correctly.
Myth 7: Off-location welds are always the gun’s fault
In many applications, weld locations are extremely important. Even though the robot is physically going where it’s programmed to go, if the wire isn’t placed in the joint properly, it could be detrimental to the end product.
When welds are off location, there’s usually an underlying issue that’s causing the problem. Tip bore wear, variations in stamping batches or parts being misaligned due to tooling/spatter can all create a situation where welds are off location. Here, reassessing TCP can help determine what the root problem is rather than just blaming the torch and touching up points.
Avoiding these common missteps in robotic welding will help you maximize uptime and throughput while minimizing costs — a win from start to finish.
Written by Ryan Lizotte (email@example.com), Technical Services Manager, Tregaskiss.
Republished with permission from Fabricating and Metalworking, (October 2023)
Self-Shielded Gun Performance
Estimated reading time: 5 minutes
Self-shielded flux-cored welding is frequently used for structural construction and other jobsite welding since it offers a significant productivity advantage compared to stick welding.
Welders using this process are likely holding their welding guns for much of the day, and they may be standing on elevated girders or lifts trying to get into tight places to complete a weld. Because of this, it’s important to choose a self-shielded flux-cored gun that is comfortable, lightweight and maneuverable to help get work done efficiently.
Here are several key factors to consider when selecting a self-shielded flux-cored welding gun and tips for properly maintaining it to optimize performance.
1. Flux-Cored Gun Options
Not every welding gun fits every application. They come in various amperages and configurations, with features that include heat shields, configurable necks and adjustable cable lengths. The key is finding a flux-cored gun that works for each welder, since many options come down to operator preference.
Guns rated at 350 or 450 amps are common in structural field welding applications. Guns rated at 600 amps are also available but used less often due to being heavier. It’s important to avoid undersizing the welding gun since it can lead to overheating and other problems.
When selecting the gun amperage, consider the wire sizes that will be used most often. Typical wire sizes for a 350-amp gun are 1/16 inch and smaller. Wire sizes for 450-amp guns are 0.72 inch and larger, including 5/64 and 3/32 inch.
3. Replaceable or Fixed Cable Liners
Some self-shielded flux-cored guns are available with either a replaceable cable liner or a fixed cable liner. The demanding environments where self-shielded flux-cored welding takes place can be hard on the gun and consumables, so replaceable liners provide benefits. They offer quick and easy cable maintenance and can extend product life, since welders can change out components that have high levels of wear. Guns with replaceable liners also tend to have a lighter weight cable and provide more flexibility to weld around edges or corners.
Guns with fixed cable liners are often larger, which can be an issue when welding in tight spaces. The cables are also typically stiffer and more rigid, so they can take more abuse. Once a fixed cable liner has reached the end of its useful life, the entire gun must be replaced.
Gun necks are available in varying lengths and bend angles. The choice for the application often comes down to operator preference or weld joint access and configuration.
A slimmer neck provides a better view of the weld pool and improved access to tight areas. A shorter neck typically provides more control compared to a longer neck. Still, operators may prefer a longer neck to increase the distance between themselves and the heat of the weld puddle — especially in higher amperage applications.
Keep in mind that lightweight, rotatable necks help reduce operator fatigue by aiding with posture and positioning, and they improve weld visibility.
In the field, triggers that get wet or covered in dirt still need to work, so it’s important to purchase a quality gun that includes a durable trigger. Look for a gun with an enclosed trigger. This protects the contacts inside a housing, so the trigger is less prone to wear and breakage. If you’re using a replaceable cable liner, it may have an internal or external trigger lead. Be aware that external trigger leads may require more maintenance because they can easily get snagged or catch on things like bolt heads. However, they are typically quick and easy to replace.
A handle needs to be rugged and durable for the jobsite, but it should also feel comfortable in the operator’s hand.
A self-shielded flux-cored gun with an optional dual schedule switch allows for wire speed adjustment while welding. In some guns, this switch is integrated into the handle to keep it protected from spatter. The ability to toggle between weld parameters easily—without having to stop welding and change settings—saves time and improves productivity.
The Best Results
Beyond choosing the right gun for the job, it’s also important to use and maintain it properly. Consider these tips for optimizing gun performance.
Store and handle it properly: Jobsites can be dusty, dirty places. Be sure to store guns and cables properly when not in use. Roll the cables up and put the gun away in a clean, dry place so there’s less risk it will be damaged.
Maintain it as needed: Keep the gun and all components clean and check all connections periodically. Loose connections can cause electrical resistance and heat buildup, which can result in premature wear. Take the time to regularly blow out the liner with clean, compressed air to remove dirt and debris. Immediately address any damage to the gun components with maintenance or replacement.
Invest in quality consumables: Consumable choice often comes down to cost or operator preference. However, investing in high-quality consumables can help extend the life of the gun, provide better performance and reduce downtime for changeover.
The self-shielded flux-cored process can deliver significant benefits for productivity and efficiency. Choosing the right gun and components—and maintaining them properly—plays a key role in optimizing your results.
Written by Stephen Bennett (firstname.lastname@example.org), Mechanical Engineer, Bernard, Republished with permission from Modern Contractor Solutions (August, 2023)
Bernard® and Tregaskiss® offer welding solutions at FABTECH 2023
Tregaskiss and Bernard, manufacturer of semi-automatic, fixed automatic, cobot and robotic MIG welding guns, consumables and peripherals exhibited at FABTECH 2023, September 11-14 in Chicago. FABTECH is North America’s largest metal forming, fabricating, welding and finishing event that brings over 1,500 world-class suppliers worldwide together in one place.
This year Bernard and Tregaskiss presented its latest technology and cost-effective welding solutions to help manufacturers and fabricators improve weld quality and productivity. This year’s product showcase included:
- AccuLock™ Consumables: Enjoy more efficiency, less downtime and better weld quality in all of your semi-automatic and robotic welding operations with AccuLock S and AccuLock R Consumables. AccuLock S consumables for semi-automatic welding work to maximize productivity by reducing issues that lead to costly rework and downtime and increasing life. The available dual-locked liner system allows error-poof liner installation without measuring and is locked and concentrically aligned to both the contact tip and power pin to ensure optimized wire feeding. For welders looking to increase throughput and efficiency in their robotic welding operations, AccuLock R consumables help ensure your equipment continues to operate at its highest efficiency by reducing both planned and unplanned downtime. When used with AccuLock nozzles and diffusers, you will see no impact to Tool Center Point (TCP). The longer lifespan of AccuLock™ contact tips means fewer human interactions within your welding cells and fewer accidental errors. When AccuLock R users upgrade to AccuLock HDP contact tips they can increase contact tip life by an additional 6-10x longer in pulse welding applications.
- Bernard® Clean Air™ Fume Extraction Gun: Works to provide a cleaner, compliant work environment by reducing smoke at the source. The gun is designed with an adjustable vacuum chamber that can be adjusted to four different positions to optimize fume capture and gas flow. Welders can also benefit from the its 360-degree swivel to provide flexibility and reduce wrist fatigue when working in large weldment and confined spaces.
- Bernard® Self-Shielded Flux-Cored Guns: Bernard offers two self-shielded flux-cored welding guns, one with a fixed power cable liner and the other with a replaceable power cable liner. The Dura-Flux™ Self-Shielded Flux-Cored Gun is built for harsh and demanding environments. Its replaceable liner allows for quick and easy power cable maintenance; and the trigger is protected from dirt and dust to promote a long-lasting work life. Welders like this gun because it is extremely durable and comfortable to hold. The NEW Bernard IronPro™ 450 Self-Shielded FCAW Gun is designed for Miller® XMT® 650 ArcReach Miller® Systems this gun is ideal for outdoor environments. Its short handle and maneuverability make it an excellent choice for hard-to-reach weld joints. The gun’s sealed trigger remains slag and spatter free and is a contributing factor to the extended life of the gun.
- Bernard® Semi-Automatic Air- and Water-Cooled MIG Guns: Designed specifically to accommodate a variety of welding styles, preferences and applications, while keeping related parts and consumables to a minimum. BTB Air-Cooled Guns optimize productivity, welder ergonomics and weld access. Operators can customize this gun line with a variety of necks, handles and trigger styles. Its industrial-grade performance and reliability withstands demanding and abusive environments. TGX® XS Series Air-Cooled Gun is perfect for low volume, light- to medium-duty welding. TGX MIG guns are durable, and ideally suited for lower amperage welding applications and shorter arc-on times.BTB Water-Cooled Guns are engineered for superior performance in production environments requiring extremely high-heat applications. W-Gun Water-Cooled Gun offers heavy duty necks in multiple length and bend configurations to allow for optimal weld accessibility and improved operator comfort. A flexible cable assembly with reinforced synthetic rubber hoses prevents water leakage, provides increased water flow, and reduces gas leakage. T-Gun™ Water-Cooled Gun features a straight handle, and an insulated and armored stainless-steel neck to withstand abuse.
- Tregaskiss® BA1 Cobot Air-Cooled MIG Gun: Designed for Miller® Copilot™ and other collaborative welding systems the cobot gun is fast and simple to install and consistently delivers high-quality welds. The BA1 cobot MIG gun is built for exceptional durability and uses long-lasting AccuLock™ R consumables — together, they minimize downtime, make maintenance easier, and increase productivity.
- Tregaskiss® TOUGH GUN® TA3 Robotic Air-Cooled MIG Gun: TheTOUGH GUN® TA3 robotic air-cooled MIG gun feeds through the robot arm and provides outstanding precision and reliability, featuring a unique and durable LSR+ (low-stress robotic) unicable with SmoothTurn(TM) technology
- Tregaskiss® TOUGH GUN® TT4 Reamer: Power through the toughest spatter with the TOUGH GUN TT4 reamer. Available in analog and Ethernet models, this robotic nozzle cleaning station is a reliable solution with superior cleaning performance and high durability components that allow for quick and easy maintenance. The reamer offers the following standard features:
- Anti-spatter reservoir with increased fluid capacity, featuring a tethered cap, removable easy-to-clean filter, and a low fluid level indicator
- Dedicated motor lubricator
- Spray containment unit
Additional options include nozzle detect and wire cutter, and installed on the TOUGH GUN® reamer stand. , plus all TOUGH GUN TT4 reamer robotic nozzle cleaning stations come with an industry-leading 2 year warranty that can be extended to 3 years with exclusive use of TOUGH GARD anti-spatter liquid.
Best Practices For Weld Cell Layout
Today, even the smallest weld shops are making the jump to robotics, and even the largest, highly automated OEMs likely have semiautomatic weld cells for repairs or for welding parts that don’t lend themselves to automation. In automotive manufacturing, these manual cells may be midway through the line for welding frames or at the end for minor rework. If you’re in heavy equipment manufacturing, you might automate multipass welding on thick parts and reserve semiautomatic welding for tacking the parts or adding specialized components.
No matter your industry or your level of welding automation, an effective weld cell layout can help. Work needs to flow in an orderly fashion. Power, grounding, and wire feed cables need to be properly managed. And, of course, you need to ensure welders can work safely, consistently, and with good ergonomics. Proper layout supports high productivity and quality, along with cost savings.
The Big Picture
Whether robotic or semiautomatic, a well-designed weld cell makes efficient use of available space, where every component—the power source, welding gun, weld table, cables—ensures parts can be produced with little interruption. Streamlining workflow is a good first step. This involves setting up equipment in a way that helps operators avoid handling parts multiple times. Double handling of parts adds non-value-added seconds to the overall manufacturing cycle time and reduces the capacity for completed parts sent out the door. Think with an assembly line mentality.
Look beyond the weld cell to how parts are being delivered. For example, when an operation requires that parts receive semiautomatic tack welds before robotic welding, work must flow at a consistent pace to prevent the welding robot from sitting idle. To ensure a steady supply of parts and prevent bottlenecks, the cell should have a single point of entry. For optimal workflow, parts should move out of the weld cell in the same direction.
Minimize the distance a part needs to travel by keeping assembly points close together. Weld cells contributing to the completion of a single weld assembly should be in the same area of the facility. This proximity not only reduces time for moving a part, but it also lessens the number of footsteps operators need to make. Excessive movement in a welding cell is considered non-value-added work.
If you notice bottlenecks or operators or welding robots standing idle, or operators walking too far between weld cells, you might consider performing an audit. Any idle operation results in a failure to capitalize on the investment of that process. An audit can help you identify the causes behind these problems and implement solutions. The aim is to balance out the operations so that every aspect contributes to value-added work and high productivity.
The Semi-Automatic Weld Cell
Welding ergonomics are at the center of a semiautomatic welding cell layout. A more comfortable, healthier welding operator is a more productive one. Setting up the weld cell in a way that minimizes the need to reach repetitively or move awkwardly can reduce the risk of work-related musculoskeletal disorders.
Try to position the workbench or workpiece between the welding operator’s waist and shoulders, since this promotes a neutral posture that reduces stress on the body. When welding large components, use positioners or weld tables that move or rotate the part to the correct height and angle.
The same holds true when providing operators with a MIG gun that suits them, whether it be a curved or straight handle. Locking triggers help support comfort, as do rubber mats to stand on.
Strategically locating the power source and wire feeder can make the cell more efficient. Keep the two pieces of equipment as close as possible, so the operator can easily access them. Close proximity allows for shorter power cables for smoother wire feeding and also reduces electrical resistance drops so welding parameters remain more consistent.
Keep ground cable connections to a minimum. Some companies string together welding cables between weld cells for the same power source. This practice is inefficient, however, and can lead to problems. The multiple junctions can wear out easily, which causes electrical resistance and poor weld quality over time. The electrical resistance also can shorten consumable life, resulting in erratic arcs and burnbacks, leading to more downtime for contact tip changeovers.
The Robotic Weld Cell Layout
Implementing an effective robotic welding cell layout requires careful planning and attention to detail. One of the best approaches is to test the layout through virtual modeling or 3D simulation. These software programs can simulate the welding gun configuration—neck length, nozzle, and mounting (solid versus clutch)—to ensure it will operate properly within the work envelope. They also consider weld sequencing, robot arm movement, fixturing, and the parts to be welded so that you can be confident everything will work as planned.
Take the time to simulate the weld cell layout and process before equipment integration to avoid issues once the welding robot is in service. Simulations help prevent downtime during mass production for troubleshooting and potential expenses for revamping tooling or replacing components.
They also can model another key factor—welding robot reach. Be sure to match the size of the part with the reach of the robot. The robot must be able to reach all weld joints on the part; otherwise, you might need multiple robots for the application. A single, small welding robot won’t suffice for welding on a large part. If you have a weld on the edge of the reach envelope, you might not be able to achieve the optimal welding gun angle to create quality welds. This can add costs for rework, and you’ll likely need to replace stretched power cables that fail prematurely.
Regarding tooling, you might be tempted to purchase less expensive options—though such tooling might not have the features you need, such as the appropriate number of clamps or location pins. This can lead to inconsistent part fit-up or locating that requires multiple passes to fill the weld joint, adding to cycle time. You might experience more downtime as you reprogram the welding robot to accommodate the gaps, or you may end up needing to invest in touch sensing to locate the joint. Even worse, you might need to upgrade your tooling after the initial design phase—a costly step.
Also consider the positioners. Their size and weight capacity must account for both the weight of the part and the tooling. Design the robotic cell for the heaviest part to be welded.
Where you place the power source and wire feeder matters as they both impact power cable management and grounding. If space is at a premium, you may want to place the welding power source above the robot cell on a mezzanine. This way, you can run the power cable and ground leads down channels in the cell’s back wall directly to the tooling and welding robot.
These leads are stationary—except for the ones on the robot, so be sure to account for the robot’s air movements to minimize wear on the cables. Placing a junction power block at the base of the robot and running a high-flex power cable from that base up to the wire feeder can help save time in repairs, and it can save money. If the high-flex cable becomes worn, you just replace that shorter piece instead of the entire cable. The same approach works for the grounding leads.
Finally, determine the best location for the nozzle cleaning station or reamer. This peripheral cleans the nozzle of spatter during routine pauses in welding. It helps extend consumable life and reduces downtime for changeover.
The reamer needs to be close enough for the robotic welding gun to engage fully for the ream cycle. If you’re operating two robots close together, you can program them both to use the same reamer. Avoid mounting the reamer anywhere but a flat surface, since positioning it at an angle can cause anti-spatter to leak over equipment or fixtures.
Avoid interrupting the weld cycle by cleaning the nozzle during robot idle time. For example, consider cleaning the nozzles while parts are being transferred in and out of the fixture or while components are being loaded into a weld cell.
Small Moves, Big Impact
If you’re experiencing bottlenecks or missing productivity or quality goals, take a look at the welding cell layout. In a semiautomatic setup, never overlook welder comfort and safety. In a robot cell, moving power cables, power sources, wire feeders, or anything else can change how much that cell can produce over a shift.
The little things matter, and missing just one detail can snowball into bigger problems down the road. Small changes can make a big impact on the efficiency you can achieve.
Written by Justin Craft (email@example.com), Field Technical Services Specialist, Tregaskiss and Bernard, Republished with permission from The Fabricator (August, 2023).
Proper Robotic Welding Gun Configuration
Estimated reading time: 6 minutes
The welding gun is a vital piece of equipment in a robotic welding system, serving as the conduit for the welding wire, gas, and power. However, it can sometimes be an afterthought when companies implement an automated welding solution. Unfortunately, this oversight can lead to a host of problems, not to mention frustration. That is especially true for first-time users making the investment.
The wrong robotic welding gun can also cause issues for those more experienced with robotic systems. It’s not uncommon for companies to purchase the same gun for a new robot and tooling when, in fact, it may not be the best option.
Companies also need to determine their welding amperage and arc-on requirements for the application. This ensures that they purchase a robotic welding gun with the proper duty cycle — the amount of welding that can occur at a rated output over a period without causing damage to the gun.
Robotic welding guns are available in a variety of ratings, including air-cooled models that operate at 350 or 385 A at 100% duty cycle.
Today, most robotic welding systems are through-arm models in which the power cable runs through the casting of the robot arm. As a first step in configuring a robotic welding gun for these systems, it’s important to know the make and model of the robot, power source, and wire feeder. Each equipment manufacturer has a different interface that dictates how each piece of equipment connects with one another.
There are higher amperage water-cooled options, which are typically 400 A and above, available in the marketplace. Some of these may be rated at 100% duty cycle, while others are rated at 60%. Don’t be fooled by high amperage unless it’s at 100% duty cycle.
Hybrid options are available for companies that want the simpler construction of an air-cooled robotic welding gun with the added cooling capacity of a water-cooled one. These guns have external water lines that circulate water around the nozzle to keep the front-end consumables cooler.
For a robotic welding gun to access the weld joints, it’s critical that the work envelope is adequate. Companies need to consider not just the size of the gun but also the space that is available when the tooling, fixtures, and parts are all in place. Joint design and weld sequencing also factor into the equation. It’s important that there is room and time for the welding gun to weld the joints in a sequence that keeps heat to a minimum. Companies should avoid heat soaking the parts, so they don’t become distorted.
A robot integrator can conduct a 3D simulation using models provided by the robotic welding gun manufacturer through computer-aided design (CAD) to make sure the gun and neck have the proper access and reach within the given space. The CAD model can also show whether the selected gun has the correct tool center point (TCP) and can extend to the nozzle cleaning station for reaming or to a service window for consumable changeover. A service window supports safety in the operation by eliminating the need for an employee to physically enter the cell.
Configuring the Gun
Some robotic welding gun manufacturers offer online configurators that allow companies to customize the equipment for their exact application. These configurators guide the user through a step-by-step process, providing options to choose from for each component. With or without this tool, companies need to consider what their needs are based on their upfront assessment.
Gun mount: There are two mounting options for a robotic welding gun to protect it in the event of a collision — a solid arm mount and a clutch. If the robot or end user’s safety procedure requires external collision detection, a clutch can be added to the system. This component functions both mechanically and electrically by recognizing a collision and sending a message to the robot controller to stop the system. If procedures allow for reliance on only the robot’s collision detection, then a solid mount will suffice.
Neck: The neck length and angle must provide the approach angle to weld parts properly and to allow for smooth wire feeding. Standard neck angles are 22, 45, and 180 deg. Through-arm robots generally use a 45-deg neck; however, that should be verified with the CAD model/simulation before implementing. Companies will also need to take into consideration the welding wire they are using. For example, aluminum wire requires a straighter neck to feed through properly since it is so soft.
Welding cable: For through-arm robots, the make and model dictate the cable length. For conventional robots (where the cable assembly runs outside the robot arm), the gun cable length also depends on the robot make and model along with the location of the feeder. It may be remotely mounted or mounted on the robot itself. There is more flexibility with cable length for these robots, but it’s important not to use too long of a cable since this can lead to wire-feeding issues. Conversely, a cable that is too short can stretch and break down quickly.
Welding consumables: When choosing contact tips for the robotic welding gun, look at the welding process. Pulsed gas metal arc welding (GMAW-P), for example, is quite hard on contact tips due to its high-frequency waveforms. This process requires a harder tip or a contact tip specifically designed for pulsed welding.
The chosen nozzle needs to allow proper access to the weld joint. A tapered nozzle works well when using smaller-diameter wire and contact tips. Higher-premium consumables are a good choice since these last longer and reduce downtime and labor for changeover.
Welding supervisors and operators should schedule time to perform preventive maintenance, such as checking connections and visually inspecting consumables for spatter, during routine pauses in welding.
Liners are another factor to consider, and the welding wire being used affects the choice. Flux- and metal-cored wires tend to be stiffer and harder to feed than solid wires. They require an extra-heavy-duty liner to support the wire and gain smooth feedability as it moves toward the contact tip. A D-wound galvanized wire works well. Companies can also use this liner for solid wire with good success.
Companies invest in robotic welding systems to increase quality, productivity, and cost savings through a fast, repeatable process. To gain those benefits, every part of the system needs to be functioning optimally. Ensuring that the robotic welding gun has been configured properly before implementing the system can prevent downtime and extra expenses.
This article was written by Ryan Lizotte (project manager, Tregaskiss, Windsor, Ontario, Canada) for the American Welding Society.
MIG Welding FAQ: Best Practices for MIG Success
Estimated reading time: 6 minutes
MIG is the most frequently used welding process in general manufacturing and fabrication, thanks to its ease of use, versatility, and productivity benefits.
While MIG is widely used, some operations may still run into issues that require troubleshooting. Understanding the basics of MIG welding and following best practices for operator technique as well as gas and consumable selection can help optimize results with the process.
Q: What are the main advantages of MIG welding?
MIG offers productivity benefits when compared to some other welding processes such as TIG and Stick, thanks to its higher travel speeds and deposition rates. MIG is also considered easier for new welders to learn, so it can be a good option for operations that struggle to find skilled welders.
MIG could be utilized with either solid filler wires or tubular wires such as Metal Cored and when used with Flux Cored wires it is referred to as Flux Cored welding. Tubular wires in general can be run at higher speeds and deposit more weld metal, so they even offer higher productivity gains than Solid wires.
Q: What are the differences between MIG and TIG welding?
There are many factors to consider when choosing the right welding process for your application. These include base material type and thickness, weld appearance requirements, productivity requirements, the welding environment and available skilled labor.
TIG welding is generally used in niche applications, such as those that require high-precision welds or extremely high aesthetic quality. TIG is frequently used with special-grade materials like titanium or stainless steel. In comparison, MIG can be used in higher production applications where increased throughput is important, and it’s a good option for a wide variety of metals.
A typical travel speed in TIG welding is 4-6 inches per minute. With MIG welding, travel speeds are much higher; 6 inches per minute are considered slow, and 15 to 20 inches per minute are common. Deposition rates are also much higher with MIG welding.
Regarding training, TIG is considered the most difficult welding process to learn and master since it uses both hands. An operator may take a few months to become proficient in TIG, while a new welder could be proficient in MIG within a week or two.
Q: What is the right shielding gas for MIG welding?
Shielding gas plays an important role in determining weld penetration profiles, arc stability, mechanical properties of the finished weld, the transfer process you use and more.
The filler metal manufacturer often provides shielding gas recommendations for the type of wire being used, so it’s a good idea to first consult the wire specification sheet.
When using flux-cored wire, 100% CO2 or an 80/20 Argon/CO2 mix are common choices. When it comes to solid wire or metal-cored wire, the right gas is dependent on the transfer mode being used. A short-circuit transfer mode works with 100% CO2 gas in most cases but can still run on mixed gas. While using a pulse or spray transfer, a higher Argon content is needed, and an 80/20 Argon/CO2 is the right choice.
The base material also plays a role in choosing the right gas. Aluminum requires 100% argon, while stainless steel requires at least 98% argon.
Q: Which is better: a push or a pull technique?
The technique choice may come down to operator preference in most cases, but there are some best practices. For example, when welding aluminum, a push angle is generally better because it helps the cleaning action of the oxidation layer on aluminum, similarly uphill position, a push angle is good for visibility and penetration. While if you use Flux Cored wire to weld carbon steel then a pull angle is going to work better in this case to give enough time to the slag not to be entrapped in the weld metal.
Q: What is the proper wire stick-out?
Maintaining a proper stick-out is important to achieving the best results in MIG welding, a too-long or a too-short stick-out will affect the weld quality and appearance. A 3/8-inch stick-out is a good starting point, but operators can deviate from that based on preference, wire diameter and accessibility to the weld.
Q: What amperage MIG welding gun is needed?
To choose the right MIG welding gun, consider the specifics of the application. The wire feed speed and wire diameter are two of the most important factors in determining proper gun amperage. Are you welding heavy wall materials, like heavy equipment or heavy steel structures? Those jobs will likely require a high deposition, hence a high-amperage welding gun — such as an Air-cooled 400-amp gun with at least a 60%-80% duty cycle or above, and in some cases a water-cooled gun. If you weld lighter walls and shorter beads, you may consider a 200 to 300-amp gun.
The most common amperage choice in the industry is a 300- to 400-amp, air-cooled MIG gun. This gun can address the majority of the MIG welding applications and can run the most common wire sizes such as 0.045” and 0.052”.
A good starting point would also be the welding procedure in place that specifies the amperage needed for the weld, which would help in choosing the gun’s amperage. Another easy way is to match the welding machine amperage output, a 400-amp welder would run well with a 400-amp gun in most cases, but this might not be the most effective way to select the right amperage gun when compared to the other methods mentioned above.
Q: How can an operation make consumables last longer?
Using the OEM consumables designed to be used with a specific MIG gun and welding system is important. Because these consumables are machined to very tight tolerances and go through high-quality measures which in turn is translated into higher quality welds and longer consumable life.
Be sure to choose a contact tip that is the appropriate size for the wire diameter — an oversized or undersized contact tip will wear faster and result in poor performance. In addition, follow the gun manufacturer’s recommendations for consumable installation and changeover, check connections regularly, install and trim to the right length, select the right nozzle material, size and recess/extension, and finally clean your consumables regularly and change them when needed.
Written by Mostafa Hanafy (firstname.lastname@example.org) , Market Segment Manager, Tregaskiss and Bernard. Republished with permission from Fabricating and Metalworking (August 2023).
Upfront Cost vs. Total Cost of Ownership of MIG Guns and Consumables
Estimated reading time: 4 minutes
While it may be tempting for companies to purchase MIG welding guns and welding consumables based on price, lower upfront costs don’t always add up to savings. Less expensive products often lack in quality and bring risk to the profitability of the welding operation. This can come in the form of:
- Downtime for troubleshooting
- Shortened product life span
- Missed production goals
- Poor MIG gun and consumable performance
- Poor quality welds and associated rework
For these reasons, it’s important to look at MIG guns and consumables as more than simple commodities. Welding engineers, production managers and purchasing agents, along with other stakeholders, should instead look at the total cost of ownership of these products. Those with a higher upfront cost can help reduce risks and save money in the long term.
A look at MIG welding guns
When considering the total cost of ownership of a MIG gun, there are several factors to keep in mind. For example, less expensive guns may require more maintenance and repairs over the life span of the product. Parts like necks, handles and triggers may need frequent attention, resulting in increased expenses for replacement and downtime for changeover. With labor being the largest expense in a welding operation, time spent on activities other than welding come at a price.
Lower quality guns may also require more downtime for troubleshooting issues like poor wire feeding. This not only stops production, preventing parts from moving out the door, but it also keeps welding supervisors or others from more important tasks. When an employee’s job is to keep the weld cells running smoothly, any distraction for troubleshooting can negatively affect the productivity and profitability of the welding operation.
To lower the total cost of ownership of a MIG gun, companies should look for quality products with a long life span. Guns that offer the ability to repair the power cables are a good option. In this case, the downtime and cost for replacement is a benefit. It is less expensive to repair the cable than to buy a brand-new gun. Companies should also look at a gun’s warranty.
With heavy industrial use, a high-quality MIG welding gun typically lasts one to two years and those, like Bernard® BTB guns, include a one-year warranty. Some Bernard guns also have a lifetime warranty on triggers, switches and handles.
Considerations for consumables
Poor quality, cheaper consumables — contact tips, gas diffusers, nozzles and liners — can lead to a host of problems that increase downtime and costs. These include an erratic arc, burnbacks, birdnests and a short life span (particularly for contact tips) that can lead to rework. Such issues also increase instances of troubleshooting and make less expensive consumables pricier in the long term.
Cheaper contact tips can be prone to keyholing, or an uneven wear of the bore, and may not be as consistent in terms of electrical conductivity. Both can affect welding performance and shorten product life.
Conversely, premium consumables can lower the total cost of ownership in a welding operation. The longer they last, and the easier they are to install, the less downtime for changeover and the less expense for replacement. AccuLock™ contact tips feature a coarse thread that eliminates cross-threading and 60% of this consumable is buried in the diffuser, so it is away from heat during welding. As a result, these contact tips last two to three times longer than competitive ones. For robotic applications, AccuLock HDP contact tips last six to 10 times longer. This extended life can help increase production by reducing the number of scheduled changeovers.
QUICK LOAD™ liners are also a good option for robotic applications, as they load from the front of the robotic welding gun — safely out of the weld cell — in less than half the time needed for a conventional liner. The liner in the AccuLock S consumable system offers error-proof liner trimming without measuring, to prevent issues with wire feeding.
MIG gun and consumables trials
When it comes to MIG guns and consumables, time is money. Repairs, replacements and rework all add up and affect the total cost of ownership of these products — not to mention the company’s bottom line. Making a conversion to higher quality options can yield good results and the benefits can be verified with a MIG gun and consumables trial prior to implementation. These trials help establish a baseline for improvements and provide data that allows companies to assess the upfront cost of products compared to the cost of downtime. With this information in hand, companies can make an informed decision about alternative MIG welding guns and consumables.
Employee Training: Best Practices for Preparing New Welders
Estimated reading time: 4 minutes
Given the industry statistics regarding the number of experienced welders who are retiring from the field, many companies are likely training more new welders than ever before. By 2023, the nation’s workforce will need over 375,000 welders to satisfy the demands of several industries. 
Proper new welder training is essential to help companies meet quality and productivity goals. Consistent, thorough training also helps get welders onto the production floor as quickly as possible, allowing operations to meet throughput targets and customer timelines. Underscoring the importance of employee training, a study by the National Center on the Education Quality of the Workforce shows a 10% increase in workforce education can lead to an 8.6% increase in total productivity. 
There are various techniques and solutions for training new welders and resources available once training is complete.
3 primary learning styles
Welding is obviously a hands-on skill, but the best type of welder training for new employees may vary based on their learning style. Understanding the differences in learning styles can help companies tailor their training to best fit the way each individual learns. The three main learning styles are: 
People who have a visual learning style prefer to absorb new information by seeing the material being presented. They tend to remember things that are written down. Tips for reaching visual learners include turning notes into pictures, charts or maps; color coding parts of new concepts in any notes; focusing on learning the big picture first before drilling down to the details; and avoiding distractions.
Learners who fall into this category prefer to learn through listening; they retain information best through hearing and speaking. Tips for reaching auditory learners include having them repeat the material out loud and in their own words; discussing the material in small groups; and having them read any new information or instructions out loud.
This type of learner prefers to learn by hands-on training. They would rather have a demonstration of how something works than a verbal explanation. Tips for this style of learner include taking frequent training breaks; have them learn new information while doing something active; and focus on hands-on demonstrations or lab work.
Covering the basics of welding training may differ for each type of learner. For example, a visual learner may want charts and graphics showing the different welding processes or parameters they will be using, while an auditory learner may want the trainer to explain those processes and parameters to them out loud. A kinesthetic learner may want to use a virtual reality or augmented reality welding training system to learn the skills in a hands-on manner.
No matter what learning style is used in training, there are many solutions and welding technologies available that can help reinforce the information with welders once they are on the production floor.
Many of today’s welding power sources include technologies such as automatic presets and parameters windows that help ensure operators are using the best settings for the application. Weld data monitoring technology is another solution that can provide guidance to welders who have less experience. For example, some systems guide welders through the weld sequence in real time and will provide alerts if a weld is missed or outside of acceptable parameters.
Choosing welding equipment and consumables that are easy to install and use is another step companies can take to help welders of all experience levels produce high-quality welds. AccuLock™ welding consumables are designed to address common challenges in semi-automatic and robotic MIG welding applications. Simplified welding consumable replacement helps increase accuracy and reduce employee training requirements.
Resources for support
Many welding manufacturers also provide resources that companies can use to support welders after the training process. These resources include training manuals and welding guides found online, and how-to videos for welding equipment and consumables that are available on manufacturer websites or YouTube channels. QR codes on the welding equipment itself can be used to access how-to guides, training or machine updates.
These resources, coupled with the capabilities and ease-of-use engineered into today’s welding equipment and technologies, can help companies train new welders faster and support them once they are in production.
 American Welding Society: https://www.aws.org/foundation/page/workforce-development
 National Center on the Education Quality of the Workforce https://onlinemba.wsu.edu/blog/the-four-benefits-of-employee-training/
 Missouri State University: https://www.missouristate.edu/Assets/busadv/p-30.pdf
Making a MIG Gun Last in Harsh Manufacturing Environments
Whether it’s a high amperage application, high or low ambient temperatures, or humidity, harsh manufacturing environments can be tough on welding equipment — including MIG guns and consumables. Confined, cluttered or dirty weld cells can also negatively affect this equipment.
Cleaning and organizing the weld cell, plus areas upstream and downstream, can help prevent some issues — for example, damage to welding gun cables caused by forklifts running over them. However, operators can’t change factors such as heat or cold or the amperage required for the job. For that reason, it’s important to look for a durable MIG welding gun and consumables and know how to protect them. Not only does that help minimize costs for replacement, but it also supports productivity by reducing downtime for changeover.
What to look for
One of the best defenses against the elements in a harsh manufacturing environment is to choose a MIG gun with robust components and make certain it’s the best option for the job. Consider these factors.
This is the most important factor in selecting a MIG gun for any operation, but especially in a harsh environment. Duty cycle is the amount of arc-on time within a 10-minute period that a gun is capable of being used. Manufacturers in the U.S. rate their MIG welding guns according to the National Electrical Manufacturers Association (NEMA), with the rating reflecting the temperatures at which the gun or cable becomes too warm for use. For example, a gun may be rated at 400 amps and 100% duty cycle, meaning it can weld the entire 10 minutes at 400 amps (or even longer at a lower amperage) without discomfort to the operator.
In areas of high heat and humidity, it is helpful to use a MIG gun offering 100% duty cycle and higher amperages than needed for the application. If a welding shop is experiencing 80% humidity and it is 100 degrees F outside, that ambient temperature will reduce the duty cycle — a 400-amp gun may drop from 100% duty cycle to a 60% duty cycle range.
MIG gun handles should be manufactured with materials designed to withstand heat. Those with added glass in the plastic mold material are particularly adept at resisting wear in harsh environments. Tubular handles are also an option, as they tend to be a bit larger, and they have a slight air gap between the handle and the power cable that adds to its durability and heat tolerance. However, each handle material and design can have its own pros and cons. High glass content will create a more brittle handle, while more malleable materials may withstand less heat but not break as easily if abused.
Trigger designs vary by manufacturer. The best option to protect against harsh elements is a micro-switch trigger, which is sealed. MIG guns with straight handles typically have a trigger that is enclosed to protect against dirt and debris. Avoid contact triggers, as these feature a spring and two contacts that touch each other when the operator presses down on it. Dirt can get inside of these triggers and break the contacts, preventing good electrical connections.
A MIG welding gun neck with aluminum armor on the outside is a durable choice. This type of neck is also lightweight, so it is more comfortable for the operator. MIG gun neck grips can also increase comfort, as well as control.
Look for a power cable with a thick rubber outer jacket. While this type of cable may add some to its stiffness and weight, it will last longer. It can better take the abuse of being dragged on the floor, run over edges and exposed to hot materials. There are also power cable jackets that further protect power cables in harsh environments. A good jacket option is one with a tubular design versus one with Velcro or buttons. A power cable with higher-quality grades and higher amounts of copper adds to its durability and performance, as well.
Welding contact tips, nozzles and gas diffusers made from quality copper or chrome zirconium are reliable complements to a sturdy MIG gun. Typically, higher-quality welding consumables cost more upfront; however, they last longer. Having fewer changeovers during shifts can save money for labor and replacement consumables in the long run. Contact tips, like those in AccuLock™ S consumable systems, have 60% of the tip buried within the gas diffuser. This keeps heat from the weld away from the tip, so it lasts longer. Shielding gas also cools the contact tip tail to protect it.
Maintain and protect
Preventive maintenance is critical in any welding operation, but especially in harsh manufacturing environments. Purchasing a gun that is repairable and can be maintained versus thrown away is a smart investment. In the long term, operators and maintenance personnel can gain more life from the gun even when exposed to heat, humidity and other elements.
Periodically, remove the welding gun liner and blow out any dust or debris that accumulated with compressed air. Take care not to drag the liner on the ground, where it can pick up more dirt or inadvertently become damaged.
At the start of every shift, especially when operators share MIG guns, check all connections. Tighten connections along the length of the gun — between the welding contact tip, gas diffuser, neck, power cable and power pin. Also check that the screws on the handle are tight and the trigger is functioning. When using a MIG welding gun with a rotatable neck, be certain to tighten it to avoid wire feeding problems.
The best defense to protect a MIG gun used in a harsh manufacturing environment is to make sure to select a durable one in the first place. Look for quality components and take care to schedule preventive maintenance. Treat the MIG welding gun just like any other piece of equipment in the welding operation, caring for it with regular inspections. Doing so can increase its lifespan and help prevent downtime and the cost for replacement.
Using Root Cause Analysis to Address Welding Consumable Issues
Estimated reading time: 4 minutes
Troubleshooting problems with welding consumables can be time-consuming and expensive. From the associated downtime to the cost of replacing contact tips, diffusers, nozzles and liners, companies stand to lose productivity and potentially miss production goals.
Applying root cause tools can help expedite the process. These are structured methods to narrow down the true cause of a problem and determine an exact solution.
At a high level, root cause analysis follows several key steps:
- Defining the problem
- Collecting information
- Identifying issues that are contributing to the problem
- Determining the root cause
- Recommending and implementing the solution
To successfully implement root cause tools, it’s important to keep an open mind about possible causes that are contributing to welding consumable problems and to be patient, as it may take time to determine a cause and solution. Analytical thinking, along with being thorough and unbiased in the assessment, is a must.
The 5 Whys
The 5 Whys is a common and simple root cause tool to apply to welding consumable issues. It involves asking “Why?” five times, and providing answers, to drill down to the root cause. In some instances, the solution may become apparent after fewer than five questions. Other times, it may take more. It is also possible that the questioning may become circular and require branching off into another line of questions. Once the root cause is identified, companies can home in on the right solution and determine ways to prevent further problems.
For example, companies may ask the following if there are issues in a semi-automatic welding operation:
- Why do we have an erratic arc? Because the welding wire is feeding poorly.
- Why is the welding wire feeding poorly? Because the wire feeding path is blocked.
- Why is the wire feeding path blocked? Because the liner is kinked up.
- Why is the liner kinked up? Because it was trimmed incorrectly.
- Why was the liner trimmed incorrectly? Because welding operators didn’t measure it properly
Knowing this information, companies may determine they need to train welders to use a liner gauge during trimming and installation. AccuLock™ S consumables are another option, as these have a liner that eliminates liner trim length errors without the need to measure. The liner locks and aligns at the front and back of the gun to provide a flawless wire feed path.
To gain the best results from The 5 Whys, engage employees who have hands-on experience with the welding process. Quality engineers are also great resources to include.
Failure Modes & Effects Analysis (FMEA)
FMEA assesses how a failure could occur, its causes and what the potential consequences of a failure would be. FMEA follows the same logic as The 5 Whys to drill down to a root cause. Engineers use this tool proactively during the design of components like welding consumables. Companies can also use FMEA over the course of using these products as a troubleshooting method.
Keeping with the example of welding consumables, a FMEA for troubleshooting may look like this in a robotic welding operation:
- Failure mode: Off-location welds.
- Potential consequence: Non-conforming parts.
- Potential cause: Cross-threaded contact tip.
- Current process controls: Train employees to install contact tips correctly.
Potential solution: Use a contact tip that can’t be cross-threaded. These can be found in the AccuLock R consumables system.
When using FMEA or The 5 Whys to troubleshoot welding consumables issues, it’s important to look at all aspects of the situation to accurately determine the root cause. While it may seem time-consuming, investing in the use of these methods can actually save time in the long term — not to mention frustration and costs.
Welder Training Tips To Help Improve Productivity
Estimated reading time: 6 minutes
Improving productivity in semi-automatic operations isn’t simply about welding faster and working harder. Instead, there are ways to create consistency in the process and support quality so that companies can avoid downtime that adversely affects throughput.
When training new welders, it’s important to provide a solid foundation of knowledge to achieve the best results. Taking the time to establish and expand welders’ skill sets shows welders companies are invested in them, and as welders gain more experience, they become more confident. The aim is to empower them and provide all the information necessary to be productive.
To instill good habits from the start, consider some key training tips.
Put safety first
A safe welder is a productive welder. By training new welders to follow welding safety protocols, there is less risk of lost productivity due to injury. Wearing the appropriate personal protective equipment (PPE) is important. This includes a properly fitted helmet, safety glasses, flame-resistant jacket or sleeves, welding gloves and steel-toed, rubber-soled boots. If the process is prone to higher levels of fume generation, correct use of a respirator is necessary. Train welders to read and follow all equipment labels and their owner’s manual carefully before operating welding equipment. Training also includes checking the power source ground, securing workpieces in the best possible manner and keeping their heads out of the weld plume when welding.
Establish consistent weld prep
Following best practices for weld prep supports high weld quality, reduces rework and scrap, and improves productivity. As part of new welder training, welders should understand their power source settings, type and levels of the shielding gas being used, and how to clean the base material. Checking that all welding consumable connections are tight can minimize electrical resistance that could lead to burnbacks (the formation of a weld in the contact tip) and downtime for tip changeover.
Install welding consumables correctly
Downtime to address liner issues is common in semi-automatic welding operations and is typically caused by incorrect installation. This can lead to bird-nesting (a tangle of wire in the drive rolls), poor wire feeding, an erratic arc, wire chatter, burnbacks and more. Always use a liner gauge when trimming a liner; or consider a consumable system like AccuLock™ S, which provides error-proof liner installation without measuring. The liner locks and is aligned to the power pin and the contact tip to ensure proper wire feeding. New welders should also learn to install and tighten contact tips according to the consumable manufacturer’s recommendation.
Focus on comfort
Training welders to pay attention to their posture and the angle they hold their MIG welding gun can help reduce fatigue and the risk of welding-related musculoskeletal disorders that lead to lost productivity. Whenever possible, welders should position themselves so they are welding the workpiece in the range between their waist and shoulders. This may require a work stool or adjustable chair. Welders should also keep their hands and welding gun at or slightly below elbow height. Gaining good visibility to the weld joint can encourage proper posture.
Follow welding procedures
Welding procedure specifications (WPS) are a means to create consistency in the welding operation by taking the guesswork out of the process. This document outlines welding parameters, filler metal type and diameter, wire feed speed (WFS), weld pass sequence and more. Training new welders to follow the details in a WPS can help ensure that they produce quality welds and remain productive.
Use the right equipment
New welders should be trained to use the best equipment and tools for the job — and ones that best suit them. A MIG welding gun that fits the welder’s hand comfortably will help maximize their time when welding. Using a hammer for repositioning a part, as opposed to the MIG gun itself, can prevent damage to the gun that leads to downtime for repairs or replacement.
Likewise, having the correct wrench for installing gas diffusers or welpers for tightening contact tips helps ensure snug connections and lessens the opportunity for issues. Using the wrong tools or not tightening parts properly leads to loose connections that cause electrical resistance. This, in turn, increases heat and wears out the equipment prematurely.
Employ proper techniques
Welding techniques vary according to the process, the welding position and the thickness of the base material. For example, when MIG welding with solid or metal-cored wire, welders need to learn to use a push technique, while a flux-cored process requires a drag technique. Train welders on the proper gun angles for flat, horizontal and out-of-position welding applications so they are able to fill the joint with the appropriate amount of weld metal and avoid issues like lack of fusion.
Recognize signs of trouble
Training new welders to quickly identify issues in the welding process can minimize downtime for troubleshooting. They should be given the guidance to identify the causes of common problems like porosity, burnbacks, poor deposition and more, along with their solutions. Welders should also be able to recognize signs that equipment needs to be repaired or replaced — for example, a welding contact tip that is keyholing (wearing at the bore unevenly) or a gun that has nicks in the power cable. Companies can provide troubleshooting cards with quick checklists to keep in the weld cell as reminders.
Keep communication open
Clearly communicating expectations to new welders and having supervisors who are responsive to questions are vital parts of training. It is about both learning and listening. As training continues and welders grow their skill sets, it’s important to establish two-way feedback. This way everyone can find common ground on what best practices could be. In some cases, new welders may identify a way to improve the operation based on experience they have from another job.
Successful new welder training
When companies commit to providing thorough new welder training, the aim is to establish skills that lead to consistency in quality and reduce downtime. The more they can avoid secondary work or additional processes, the better productivity will be. Plus, supporting the comfort and safety of welders can help make sure they perform their best every day, build confidence and help retain them as employees.
At a Glance: Cobots and the BA1 Cobot MIG Gun
Estimated reading time: 4 minutes
Companies today continue to face a shortage of qualified welders, but the demand for product has stayed the same — or in many cases, increased. Turning to new solutions to keep up with production can help keep the welding operation running smoothly and quickly.
For many companies producing a high mix and low volume of parts, investing in a cobot can be a smart business decision. A cobot, or collaborative robot, relies on interaction from a welding operator but provides faster speeds than semi-automatic welding. Cobot welding is also a less expensive alternative to robotic welding and takes up less space.
To operate the cobot, the welding operator uses a tablet to program the desired weld and moves the cobot welding gun to the beginning of the joint. While the cobot is welding, the welding operator can work on other activities, helping companies make the most of the available labor.
Tregaskiss BA1 cobot air-cooled MIG gun
Tregaskiss designed its BA1 cobot welding gun to help companies gain the most from their cobot. It provides several key benefits.
The BA1 gun is designed and engineered with the same trusted and robust components as other Tregaskiss guns and is proven to last in high-volume welding operations.
Combined with AccuLock™ R consumables, the BA1 welding gun can help ensure greater productivity. The contact tips last longer so there is less downtime for changeover. When routine changeover is necessary, it can be done quickly and easily so the cobot and welding operator spend more time producing parts.
The BA1 cobot MIG gun has metal-to-metal keyed connections to hold it in place in the mounting arm. These also keep the aluminum-armored neck firmly connected to the gun, so users can depend on the gun to perform consistently.
The gun is easy to maintain when needed — necks can be changed with one tool by loosening a small number of fasteners. Operators can also easily install QUICK LOAD® liners from the front of the gun. For operations that have semi-automatic welding, companies can streamline inventory by using the same AccuLock contact tip on their MIG guns.
The BA1 cobot gun is compatible with cobots from FANUC®, Yaskawa® Motoman® and Universal Robots (UR) and most welding power sources. Power pin options are available for machines from Miller®, Lincoln®, Fronius®, Tweco®, Panasonic® and more.
Tregaskiss offers customizable options according to style and neck, consumables, cable length, wire size and power pin through the online configurator.
Cobot welding best practices
Along with having a reliable cobot MIG gun, there are some best practices to consider for cobot welding.
- Provide welding operators with proper training. Programming is relatively easy using a simple tablet interface, and training can be done quickly. In many cases, welding operators are able to share their knowledge with other employees to expedite training.
- Follow safety precautions and use proper Personal Protective Equipment (PPE). Read and follow the cobot and cobot gun owner’s manuals. The cell where the cobot is located should be surrounded by welding curtains to protect the operator and others from arc flash.
- Tooling, fixtures and other equipment added to the robotic cell after delivery may change the type and number of hazards present in and around the cobot system. Conduct a safety review and perform another risk assessment after the installation of any additional equipment to the robotic cell.
- Understand the rating of the gun and make sure that it is appropriate for the application and prevent overheating. The BA1 cobot gun offers 385 amps at 100% duty cycle with mixed gases.
- Be sure the robot and gun can move freely and that the power cable doesn’t interfere. Operators should also stand clear of the moving cobot.
- Understand the tool center point (TCP) and how far the cobot and cobot gun can reach to ensure quality.
As with any welding application, contact a trusted cobot welding gun or cobot manufacturer with questions or reach out to a local welding distributor.
5 Tips for Improving Weld Quality
Estimated reading time: 7 minutes
Establishing consistent levels of weld quality is important for attaining production goals and a better bottom line in semi-automatic welding operations. However, there are many factors that can negatively impact those efforts, including a lack of skilled labor, inadequate or aging equipment or using the wrong welding consumables.
To avoid costly rework associated with poor weld quality, it’s critical to implement proper welder training. Evaluating the welding operation on a regular basis for issues can also help, along with following these key tips.
No. 1: Size contact tips correctly
Welding contact tips are available in a range of diameters — typically 0.023 to 1/8 inches — to accommodate different welding wire sizes. The wire packaging, in part, determines what size contact tip is appropriate to support good weld quality.
Welding wires in larger drums — 500 pounds or more — have a larger cast and are flatter so there is less degree of arc. This means there is less opportunity for the wire to make consistent contact when feeding down the bore of the contact tip, resulting in an erratic arc and weld quality issues. To avoid problems when using copper and chrome zirconium welding contact tips (with Bernard and Tregaskiss consumables), undersize them for the diameter of wire. For example, match an 0.045-inch wire to a 0.039-inch contact tip. For other manufacturers’ contact tips, request recommendations.
Copper and chrome zirconium contact tips can be matched size for size with wire on spools or in drums less than 500 pounds since the wire has a tighter cast.
For AccuLock™ HDP contact tips, the wire and tip size can be matched regardless of the welding wire drum or spool size.
No. 2: Size and change over liners properly
As with contact tips, welding liners are available in various diameters and ranges, from 0.035 to 0.045 inch or from 0.045 to 1/16 inch. To avoid issues like burnback (the fusing of a weld in a contact tip), poor wire feeding and an erratic arc that can be detrimental to weld quality, match the diameter of welding wire to that of the liner. This supports the wire as it feeds through the liner.
It’s equally important to trim the liner properly. A liner that is too short can create wire chatter, an erratic arc and bird-nesting (a tangle of wire in the drive rolls). If the liner is too long, it can cause the wire to weave. Both situations can cause poor welds and, potentially, rework.
Always use the gauge provided by the manufacturer to ensure that the liner is trimmed correctly. The AccuLock S consumable system is also a good option, as it provides error-proof liner replacement. The liner loads through the neck at the front of the gun and is locked and trimmed flush with the power pin at the back of the gun, which eliminates the need to measure.
No. 3: Keep electrical resistance low
Electrical resistance — or interference with the flow of electricity in a semi-automatic MIG gun’s circuit — generates heat and can impede weld quality by negatively impacting the gun’s components. There are several causes that can be rectified to prevent issues such as inconsistent weld appearance or an erratic arc.
Through ongoing use, connections begin to wear and loosen, leading to electrical resistance. Address this problem by tightening connections between the gas diffuser, gun neck and handle, as well as the connections from the power cable to the power pin and wire feeder.
Power cable wear that results in hotspots can also lead to electrical resistance. This wear may not always be visible, so as a course of troubleshooting, operators should consider this problem as a cause of poor weld quality. Replace the cable as necessary to prevent issues. Likewise, increased electrical resistance can occur in the gun handle, since it is an area of high use and bending. Look for signs of wear and replace as needed.
No. 4: Be mindful of cleanliness
There are various aspects of cleaning and weld prep that can help support good weld quality. Always follow proper procedures for cleaning the base material to prevent defects like porosity that can be caused by welding through dirt, oil and debris.
It’s also important to be proactive about cleaning consumables. For example, weld spatter buildup in the nozzle or in the ports in the gas diffuser can hinder shielding gas coverage, which also leads to porosity. Clean or replace these consumables when excessive spatter is evident. Operators can also apply anti-spatter compound to the consumables by dipping the front inch and a half of the nozzle into the liquid. Use the anti-spatter compound sparingly to avoid damaging the nozzle insulator.
Storing consumables in a clean area minimizes the opportunity for dust, oil or other contaminants to adhere to the surface of the welding contact tip, nozzle and diffuser and adversely affect weld quality. A covered container with compartments for each welding consumable is a good option to protect them.
Also consider how to handle the welding liner during changeover. Be careful not to drag the liner on the floor while feeding it into the gun, since doing so can cause debris to collect on it and be pulled into the gun.
No. 5: Plan for inspection and maintenance
Preventative maintenance and ongoing care of the MIG gun and consumables can go far in supporting high weld quality. Set a schedule to inspect, maintain and repair the components.
Although often overlooked during regular inspections, the O-rings found throughout the gun are important to assess. If they start to degrade or break, they can cause shielding gas leaks that lead to porosity and potentially extra costs for shielding gas if the operator increases gas flow to compensate for the leak. Check O-rings on the power pin, gas diffuser and liner during routine preventive maintenance and replace these components as needed.
Look for damage to the power cable, such as nicks or tears that can impede gas flow. Visually inspect the gun handle for cracks or missing screws and the trigger for sticking or malfunction. Repair or replace as necessary.
Last, inspect the welding contact tip for keyholing (an oblong wear of the bore); this can cause drifting wire and arc start failures that affect weld quality.
Improving weld quality is a matter of ongoing evaluation. Supervisors and managers overseeing semi-automatic welding operations should regularly consult with welding operators to make sure they are following best practices. Ongoing training and quickly troubleshooting issues can also support good weld quality and prevent costly downtime and rework.
Is a Water-Cooled Robotic Welding Gun Necessary?
Robotic welding operations can be tough on equipment. The heat from the welding arc, along with reflective heat from the base material and resistive heat from the electrical components, can wear on consumables and the robotic welding gun. In some cases, implementing a water-cooled robotic MIG gun is the answer, but many times an air-cooled model can handle the job.
Water-cooled robotic welding guns are designed to handle high amperage applications, typically above 400 welding amps at 100% duty cycle. They are used for longer welds and multiple passes on thicker material with larger welding wire diameter (above 0.052 inch), such as those found in heavy equipment manufacturing.
That said, water-cooled guns are more expensive upfront compared to their air-cooled counterparts and require the additional expense of a water cooler. These guns operate by circulating a coolant from the water cooler through hoses in the power cable to the gun and neck, then returning the coolant to the cooler to release the absorbed heat. Due to the complexity of this design, there are more potential failure modes, so maintenance and repairs cost more over the life of the gun. Given the current shortage of skilled labor, it can be difficult to find welding operators who can take on these tasks. That can lead to downtime and lost productivity.
For these reasons, companies need to ask: Is a water-cooled welding gun necessary? Often, companies may be using this type of gun because it’s what’s always been on the plant floor, or they think they need the extra protection from the heat of the application. They may even be trying to protect the consumables from overheating. That doesn’t mean that a water-cooled welding gun is the best option.
When air-cooled makes more sense
Air-cooled robotic welding guns use the ambient air, shielding gas and arc-off time to dissipate heat. Their design is simple and easy to maintain since they have fewer parts than water-cooled models. A lower upfront cost and less expense to care for the guns make them an appealing alternative to a water-cooled gun. And, in several instances, these guns are a better option for a welding operation.
Duty cycle factors into using an air-cooled robotic welding gun. Duty cycle refers to the number of minutes a welding gun can operate at full capacity in a 10-minute period without overheating. If the gun can operate the full 10 minutes, then it offers 100% duty cycle. However, many applications do not require 100% duty cycle and therefore wouldn’t benefit from a water-cooled gun that offers that capacity. In this case, it is possible to use a 350-amp air-cooled gun and run it at a lower duty cycle: for example, 50%. An air-cooled robotic MIG gun will heat up and plateau at a certain temperature. The operator overseeing the application will need to be cognizant of the duty cycle and welding duration and adjust the application accordingly.
In applications with shorter weld requirements, it’s also possible to configure a robotic welding cell to use air-cooled robotic welding guns. On a robotic line, there are often multiple robots welding at the same time. If one robot only welds for one minute and a second robot welds for two minutes, then the air-cooled gun on the first robot has time to cool down as it waits for the other robot to finish its weld. In essence, the robotic welding gun on the first robot would be working at 50% duty cycle as compared to the second robot.
For companies using a water-cooled robotic MIG gun to keep consumables from overheating, a simple change of consumable type combined with an air-cooled gun is a better, and less costly, option. Consider changing from a copper contact tip to a chrome zirconium, since it can withstand heat better. Also, high-performance consumables like AccuLock™ HDP contact tips can significantly extend tip life, even in hard pulsed robotic welding applications. They can last six to 10 times longer than copper and chrome zirconium tips. While these contact tips have a higher upfront cost, the lower expense of an air-cooled robotic welding gun means the reduction in downtime and higher productivity saves money in the long term.
Simplifying the robotic welding operation
The goal of investing in robotic welding is to increase productivity, improve quality and reduce costs. Using an air-cooled robotic welding gun, when possible, can help companies gain these benefits. The lower upfront cost and total cost of ownership of this equipment means a better bottom line.
From Consumables to Communication: Reducing Human Error in Welding
Estimated reading time: 4 minutes
Human error can take its toll on welding operations, leading to downtime and lost productivity, poor quality and increased costs. It can result from a variety of factors. An operator may know how to manage a process, but periodically misses a step or forgets to complete a task. Or an operator may believe he is conducting a task in the correct manner, but it is wrong.
To reduce problems, it’s important to provide proper training to semi-automatic and robotic welding operators. This includes not only training on the welding process, but also on how to spot errors when they occur.
Companies may want to rely on principles of poka-yoke to help. These principles could be applied in several ways in a welding operation.
- Elimination: Remove or change parts of the welding process that cause problems
- Prevention: Investing in equipment or processes that prevent errors
- Replacement: Substitute consumables with ones that are more consistent
- Facilitation: Streamline operations to reduce the risk of a welding operator causing an error
- Detection: Identify errors early and correct them before they lead to costly rework
- Mitigation: Find ways to reduce the impact of errors on the welding operation
With these high-level, error-proofing ideas in mind, it’s possible to put them into action in several specific ways.
Investing in welding consumables with color-coded parts can help eliminate confusion during installation. AccuLock™ S liners and power pin caps are color coded to make it easy to identify which power pin cap is compatible with which liner. For example, power pin caps with red washers are compatible with liners that have red shrink tube and so on.
Implementing a welding procedure specification (WPS), and training operators to follow it, can help ensure consistent, high-quality welds. A WPS outlines details on the welding process and parameters, weld pass sequences, filler metal type and size, and more.
Error-proof consumables design
For operations with a mix of welding arcs or for all automated welding operations, AccuLock R consumables are designed to prevent errors associated with cross threading during installation. They feature a long contact tip tail that aligns in the diffuser prior to the thread engaging. This allows operators to install the tip easily and accurately. The AccuLock S welding gun liner also offers error-proof liner trimming with no measuring required for semi-automatic welding operations.
Consumables that last longer require less changeover, which means less interaction by the welding operator in the welding cell and less potential for errors. AccuLock contact tips offer a longer lifespan, particularly the AccuLock HDP tips. These last up to ten times longer than standard contact tips and are designed for use in pulsed MIG welding applications, where waveforms tend to be harsher on tips.
Taking steps to simplify inventory by having a lower variety of consumables can help prevent errors during changeover. The AccuLock S and AccuLock R consumable systems share a common contact tip, so the tip can be used in Bernard semi-automatic MIG guns and Tregaskiss robotic and fixed automatic guns.
Communication and reporting
Keeping open lines of communication among welding operators and with management is an important way to minimize and rectify errors. Knowing what is expected in the welding process is a good start, as is reporting errors when they occur so that they can be fixed and don’t lead to further complications.
Preventing errors in a welding operation requires attention to detail, a commitment to making improvements, and collaboration among welding operators and management. Everyone needs to take a vested interest in the process, knowing that it will help improve quality and productivity — and ultimately make everyone’s job easier.
Choosing Between Fixed Automatic, Cobot and Robotic Welding
Estimated reading time: 5 minutes
No doubt manual, or semi-automatic, welding has its place across the industries — general fabrication and manufacturing, shipbuilding and more — and it will continue to be an important process for many applications. There are times, however, when companies need to turn to welding automation to augment or replace portions of their operations. Some may benefit from fixed welding automation, while other operations lend themselves to either cobot welding or automated (robotic) welding.
At a high level, companies tend to move to one of these types of welding processes for similar reasons: to improve quality, increase welding productivity and/or lower costs. Some companies may be responding to an increase in demand from customers or want to gain a competitive edge by supplementing their operations with automation. In certain cases, companies may replace some semi-automatic welding cells, shifting welding operators to oversee the automated operation. These systems always require interaction with an operator for loading and unloading parts, programming and troubleshooting when necessary.
To implement the right solution and successfully operate it requires careful planning. A robotic integrator or equipment manufacturer can help, and they can also provide a thorough calculation to help determine the expected return on investment (ROI).
So, when is it time to add an automated welding solution? And which one is the best for a given application?
Companies that find themselves with very large parts that are difficult to weld in a timely or repeatable manner with a semi-automatic process may want to consider fixed welding automation. This process is well suited to high-volume operations with a low variety of parts, such as structural beams or railcars requiring long, continuous welds or pipe that requires circular welds. The investment in fixed welding automation equipment is relatively low, but it can provide a reliable payback by increasing productivity.
Companies can choose from two options:
- Tooling that holds the part in place combined with a fixed automatic welding gun that moves the length of the weld joint on a track. This is a good option for long, linear welds.
- A fixed automatic welding gun held in place by tooling while the part moves. This setup works well for pipe, which can be rotated.
Because there isn’t a lot of flexibility with tooling, companies investing in fixed welding automation need to consider their long-term plans and the parts they will produce.
Companies seeking greater versatility in their high-mix, low-volume operations or those needing to produce longer welds than possible with a semi-automatic process could benefit from cobot welding. Those who are interested in the faster speeds associated with welding automation but have limited space or capital to invest may also want to consider the switch. Cobot welding systems are less expensive than robotic welding systems, have a smaller footprint and don’t require the guarding that a robot would.
Since a welding operator works side by side with the cobot, he or she can be in the cell with the equipment with a relatively low safety risk. Cobots are also portable, allowing companies to address multiple applications in the facility without the need to invest in additional equipment.
Training requirements are minimal compared to robotic welding, with straightforward programming on a tablet, and setup is relatively quick. These factors are important for companies struggling to find and retain skilled labor and those seeking productivity increases.
During operation, the operator sets the cobot welding gun at the starting point to put the welding in motion. The cobot is designed to complement the work that the welding operators are doing and allows them to attend to other tasks like grinding while the cobot is welding.
When a company is falling short of its production goals, experiencing weld quality issues or facing increased customer demands, it may be time to invest in a robotic welding system. While smaller operations can benefit from this process, robotic welding systems especially excel at high-volume, low-variety applications. The facility must have the appropriate space available; robotic welding cells typically take up more room than a cobot or a semi-automatic welding cell.
An advantage of robotic welding, in addition to speed and repeatability, is the relatively quick ROI. To gain that, however, it’s important that the parts coming from upstream are consistent — gaps or poor fit-up can hinder the operation — and that there are no bottlenecks that would make the robot stay idle. An electronic CAD model of the part can help determine if a part lends itself to repeatability.
As with fixed welding automation and cobot welding, it’s imperative to have a welding operator involved with a robotic welding system. Parts need to be loaded and unloaded, and the robot requires programming. Robot integrators and manufacturers typically offer training to help ensure success.
Making the switch
Whether a company is a candidate for fixed welding automation, cobot welding or robotic welding, taking the time to carefully plan for the investment is important. Look to a trusted welding distributor, robot integrator or equipment provider for assistance and for help determining the expected payback.
MIG Welding Basics
Estimated reading time: 3 minutes
When it comes to MIG welding, it’s important for new welders to start with the basics to set a solid foundation for success. The process is generally forgiving, making it simpler to learn than TIG welding, for example. It can weld most metals and, as a continuously fed process, offers greater speed and efficiency than stick welding.
The very first consideration for new welders is welding safety. It is imperative to read and follow all labels and the equipment Owner’s Manuals carefully before installing, operating, or servicing welding equipment. Welders must wear proper eye protection to avoid arc flash burns and sparks. Always wear safety glasses and a welding helmet set to the appropriate shade level. Proper personal protective equipment attire is also critical to protect the skin from electric shock and burns. This includes:
- Leather shoes or boots.
- Leather or flame-resistant welding gloves
- Flame-resistant welding jacket or welding sleeves
Adequate ventilation is also an important safety factor. Welders should always keep their head out of the weld plume and be sure that the area in which they are welding has adequate ventilation. Some type of fume extraction may be needed. Fume extraction guns that remove the exhaust at the arc are also helpful, and are very efficient compared to floor or ceiling capture.
Welding transfer modes
Depending on base material and shielding gas, welders can weld in various welding transfer modes.
Short circuit is common for thinner materials and operates at lower welding voltage and wire feed speed, so it is slower than other processes. It also tends to produce spatter that requires post-weld cleaning, but overall, it is an easy process to use.
Globular transfer operates at higher wire feed speeds and welding voltages than short circuit and works for welding with flux-cored wire with 100% carbon dioxide (CO2) (see details on CO2 in next section). It can be used on 1/8-inch and thicker base materials. Like short-circuit MIG welding, this mode produces spatter, but it is a fairly fast process.
Spray transfer offers a smooth, stable arc, making it appealing to many new welders. It operates at high welding amperages and voltage, so it is fast and productive. It works well on base materials that are 1/8 inch or more.
Welding shielding gas
In addition to protecting the weld pool from the atmosphere, the type of shielding gas used for MIG welding impacts performance. Weld penetration, arc stability and mechanical properties depend on shielding gas.
Straight carbon dioxide (CO2) offers deep weld penetration but has a less stable arc and more spatter. It is used for short circuit MIG welding. Adding argon to a CO2 mixture allows for use of spray transfer for higher productivity. A balance of 75% argon and 25% is common.
Beyond the basics
Along with practice, knowing some key information can help new welders better understand the MIG welding process. It’s also important to be familiar with the equipment, including MIG welding guns and welding liners. Understanding how to select and maintain this equipment can go far toward establishing good welding performance, quality and productivity.
MIG Welding Glossary: Terms To Know
Estimated reading time: 3 minutes
Welders use MIG welding in many industries — fabrication, manufacturing, shipbuilding and rail to name a few. While it is a common process, it requires attention to detail, and it is helpful to know some key terms associated with it. As with any process, the better the understanding, the better the results.
The tangling of welding wire in the drive rolls of the wire feeder. This typically happens when the wire doesn’t have a smooth feeding path due to a liner being cut too short, the wrong size liner or tip being used, or incorrect drive roll settings. Resolve this issue by trimming the liner properly and ensuring that the feed path of the wire is as smooth and straight as possible.
Occurs when the wire melts inside the contact tip before reaching the workpiece. It results from incorrect contact-tip-to-work distance (CTWD) — the distance between the end of the tip and the base metal — or a too-slow wire feed speed (WFS). It can also be caused by incorrectly trimmed liner and incorrect parameters. Remedy the problem by increasing WFS, adjusting CTWD, trimming the liner according to the manufacturer’s recommendation and modifying weld parameters.
Refers to how much filler metal is deposited into a weld joint over a specified period of time, measured in pounds or kilograms per hour (lbs/hr or kg/hr).
A flaw in the structure of a weld that does not pose a risk of failure. It differs from a weld defect that can affect the integrity of a weld once in service.
Refers to the percentage of time in a 10-minute period a gun can be used at a specific amperage (arc-on time) without becoming too hot to handle or overheating. A gun’s duty cycle is affected by the type of shielding gas being used for welding. For example, a MIG gun may be rated at 100% duty cycle with 100% CO2 shielding gas, meaning it can weld the entire 10 minutes without issues; or it could have a gun rating of 60% duty cycle with mixed gases.
The distance the welding wire extends from the end of the contact tip to where the wire melts. As electrode extension increases, amperage decreases, which reduces joint penetration. Also commonly referred to as tip-to-workpiece distance.
Often referred to as HAZ, it is the portion of the base material surrounding the weld that hasn’t melted but has had its properties changed at a microstructure level due to the heat input. Cracking can occur here.
Also called lack of fusion, it occurs when the weld fails to fuse completely with the base material or a previous weld pass in multi-pass welding. Typically, it is the result of an incorrect MIG gun angle.
A cavity-like discontinuity that occurs when gas becomes trapped in the weld upon solidification of the molten weld pool. It is most often caused by poor shielding gas coverage or base material contamination.
Refers to the distance the weld fuses below the surface of the base material. Incomplete weld penetration occurs when the weld doesn’t completely fill the root of the joint.
MIG Welding Techniques: What To Know
Estimated reading time: 2 minutes
Understanding some proper techniques for MIG welding can help welders gain good weld quality and avoid the frustration and cost of rework. Everything from proper positioning of the MIG welding gun to travel angle and travel speed can make an impact.
Consider these four recommended techniques:
- While welding, hold the MIG welding gun straight, using both hands to steady it and keeping them at or just below elbow height. This approach not only makes it easier to make a quality weld, but it also helps improve ergonomics. That is particularly important for welders welding for a long period of time, so they can avoid injury.
- Welders should keep a contact-tip-to-work distance (CTWD) of approximately 3/8 to 1/2 inch for short-circuit welding and around 3/4 inch for spray transfer MIG welding.
- Use the proper travel angle. When push welding, welders should hold the gun at a 10-degree angle. This technique creates a wide bead with less joint penetration. For a pull technique, welders use the same angle, pulling the gun toward their body. This results in more penetration and a narrow weld bead.
- Maintain a consistent travel speed with the wire at the leading edge of the weld pool. Too fast of a travel speed creates a narrow bead that may not fully tie in at the weld toes and may lack proper penetration. Traveling too slow creates a wide weld, also with inadequate penetration. Both too slow and too fast travel speeds can cause burn-through on thin base metals.
As with any welding process, practice is a large part of MIG welding success. Along with good techniques, it’s also important to properly prepare and clean the base material before welding and to maintain the MIG welding gun and consumables properly. This can reduce downtime for addressing equipment issues or troubleshooting weld defects and problems such as poor wire feeding.
Solving Common Causes of Welding Porosity
Estimated reading time: 7 minutes
Porosity, cavity-type discontinuities formed by gas entrapment during solidification, is a common but cumbersome defect in MIG welding and one with several causes. It can appear in semi-automatic or robotic applications and requires removal and rework in both cases — leading to downtime and increased costs.
The major cause of porosity in steel welding is nitrogen (N2), which gets involved in the welding pool. When the liquid pool cools down, the solubility of N2 is significantly reduced and N2 comes out of the molten steel, forming bubbles (pores). In galvanized/galvanneal welding, evaporated zinc can be stirred into the welding pool, and if there is not enough time to escape before the pool solidifies, it forms porosity. For aluminum welding, all porosity is caused by hydrogen (H2), by the same way as N2 works in steel.
Welding porosity can appear externally or internally (often called sub-surface porosity). It can also develop at a single point on the weld or along the entire length, resulting in weak welds.
Knowing how to identify some key causes of porosity and how to quickly solve them can help improve quality, productivity and the bottom line.
Poor Shielding Gas Coverage
Poor shielding gas coverage is the most common cause of welding porosity, as it allows atmospheric gases (N2 and H2) to contaminate the weld pool. Lack of proper coverage can occur for several reasons, including but not limited to poor shielding gas flow rate, leaks in the gas channel, or too much air flow in the weld cell. Travel speeds that are too fast can also be a culprit.
If an operator suspects poor flow is causing the problem, try adjusting the gas flow meter to ensure the rate is adequate. When using a spray transfer mode, for example, a 35 to 50 cubic feet per hour (cfh) flow should suffice. Welding at higher amperages requires an increase in flow rate, but it’s important not to set the rate too high. This can result in turbulence in some gun designs that disrupts shielding gas coverage.
It’s important to note that differently designed guns have different gas flow characteristics (see two examples below). The “sweet spot” of the gas flow rate for the top design is a lot larger than that of the bottom design. This is something a welding engineer needs to consider when setting up the weld cell.
Also check for damage to the gas hose, fittings and connectors, as well as O-rings on the power pin of the MIG welding gun. Replace as necessary.
When using fans to cool operators or parts in a weld cell, take care that they are not pointed directly at the welding area where they could disrupt gas coverage. Place a screen in the weld cell to protect from external air flow.
Re-touch the program in robotic applications to make sure there is a proper tip-to-work distance, which is typically ½ to 3/4 inch, depending on the desired length of the arc.
Lastly, slow travel speeds if the porosity persists or consult a MIG gun supplier for different front-end components with better gas coverag
Base Metal Contamination
Base metal contamination is another reason porosity occurs — from oil and grease to mill scale and rust. Moisture can also encourage this discontinuity, especially in aluminum welding. These types of contaminants typically lead to external porosity that is visible to the operator. Galvanized steel is more prone to subsurface porosity.
To combat external porosity, be certain to thoroughly clean the base material prior to welding and consider using a metal-cored welding wire. This type of wire has higher levels of deoxidizers than solid wire, so it is more tolerant of any remaining contaminants on the base material. Always store these and any other wires in a dry, clean area of similar or slightly higher temperature than the plant. Doing this will help minimize condensation that could introduce moisture into the weld pool and cause porosity. Do not store wires in a cold warehouse or outdoors.
When welding galvanized steel, the zinc vaporizes at a lower temperature than the steel melts, and fast travel speeds tend to make the weld pool freeze quickly. This can trap zinc vapor in the steel, resulting in porosity. Combat this situation by monitoring travel speeds. Again, consider specially designed (flux formula) metal-cored wire that promotes zinc vapor escape from the welding pool.
Clogged and/or Undersized Nozzles
Clogged and/or undersized nozzles can also cause porosity. Welding spatter can build up in the nozzle and on the surface of the contact tip and diffuser leading to restricted shielding gas flow or causing it to become turbulent. Both situations leave the weld pool with inadequate protection.
Compounding this situation is a nozzle that is too small for the application and more prone to greater and faster spatter buildup. Smaller nozzles can provide better joint access, but also obstruct gas flow due to the smaller cross-sectional area allowed for gas flow. Always keep in mind the variable of the contact tip to nozzle stickout (or recess), as this can be another factor that affects shielding gas flow and porosity with your nozzle selection.
With that in mind, make sure the nozzle is large enough for the application. Typically, applications with high welding current using larger wire sizes require a nozzle with larger bore sizes.
In semi-automatic welding applications, periodically check for welding spatter in the nozzle and remove using welder’s pliers (welpers) or replace the nozzle if necessary. During this inspection, confirm that the contact tip is in good shape and that the gas diffuser has clear gas ports. Operators can also use anti-spatter compound, but they must take care not to dip the nozzle into the compound too far or for too long, since excessive amounts of the compound can contaminate the shielding gas and damage the nozzle insulation.
In a robotic welding operation, invest in a nozzle cleaning station or reamer to combat spatter buildup. This peripheral cleans the nozzle and diffuser during routine pauses in production so that it does not affect cycle time. Nozzle cleaning stations are intended to work in conjunction with an anti-spatter sprayer, which applies a thin coat of the compound to the front components. Too much or too little anti-spatter fluid can result in additional porosity. Adding in air blast to a nozzle cleaning process can also aid in clearing loose spatter from the consumables.
Maintaining quality and productivity
By taking care to monitor the welding process and knowing the causes of porosity, it’s relatively simple to implement solutions. Doing so can help ensure greater arc-on time, quality results and more good parts moving through production.
Employee Retention: Best Practices for Keeping Welders Engaged
Estimated reading time: 4 minutes
The welding industry, like many others, is challenged by a labor shortage — and one that is growing. By 2023, the American Welding Society (AWS) anticipates the welder shortage to reach approximately 375,000, as an increasing number of experienced welders reach retirement age and leave the field. With those statistics in mind, it’s more important than ever for companies to take steps to retain the welders they have.
Employee retention is critical for several reasons. It helps support quality and productivity initiatives, which in turn makes it easier to meet customer demands. It also prevents overworking welders — an issue that can lead to low morale and a poor company culture. In addition, retaining welders helps maintain the bottom line. Turnover can cost companies significantly in terms of recruiting and retraining new welders, as well as for downtime in production due to lack of a full workforce. 
Fortunately, there are some best practices that can help companies create a positive environment and keep welders interested in the job.
Provide proper welder training
Empowering welders is important to instill a sense of interest and pride in the job —and that process should start from the very beginning. It’s reported that strong onboarding and training can help companies retain 82% of new hires. 
With proper training, welders can feel confident in their ability to do the job and help train new welders. Start with establishing good welding habits and creating a familiarity with the welding process. This includes training new welders on how to set up their power source accurately and safely and on what welding parameters to use. Equally important is providing guidance on the best technique for the process and application to minimize weld defects. Establishing a comfort level with following welding procedures is also a valuable part of welder training. 
For more experienced welders, offering more advanced training opportunities can help keep them engaged. This could include training to weld on more complicated applications or complex parts, robotic welding programming and more.
Create a clean, safe environment
Along with providing appropriate personal protective equipment (PPE), such as helmets, gloves, safety glasses and jackets, it is also important that the environment is safe. That means ensuring the welding cell and surrounding areas are free of clutter and any tripping hazards. It also entails proper ventilation. Companies can achieve that by removing weld fume at the source with a fume extraction gun, or with a mobile, wall-mounted system or a centralized fume extraction system. A clean, safe welding environment is more appealing for welders to work in — and it can provide an edge over competitive companies when it comes to employee retention. Additionally, be certain to train employees on all company safety protocols and welding equipment manufacturer’s safety precautions. Doing so can help create a culture of safety in which everyone is contributing. 
Offer easy-to-use welding equipment
Complicated equipment can be difficult to use, especially for inexperienced welders, leading to frustration about errors and downtime. This holds true not only for power sources, but also MIG guns and consumables: contact tips, nozzles, gas diffusers and liners. Liners, in particular, can be troublesome to install since it’s easy to trim them too long or too short, the latter of which happens more often. When the liner is too short, it can cause burnbacks, an erratic arc and poor wire feeding. Look for a consumable system that offers error-proof liner replacement for easier installation. This leaves welders more time to hone their welding skills while spending less time on troubleshooting. In automated welding operations, it is important to have equipment that is easy and intuitive to maintain and program after the proper training. This includes teach pendants with easy-to-use controls for inputting new parameters and requirements for the application.
Provide growth and advancement opportunities
Offering welders a chance to advance and learn new skills can be a good way to retain those who are interested in those opportunities. Growth can take many forms, whether it’s stepping into a new role or shouldering additional responsibilities within a current position. Certifications are another avenue for growth. The American Welding Society (AWS) offers its AWS Certified Welder performance-based program so welders can expand their knowledge and technique — from plate to pipe welding with a variety of processes. There are additional programs that support advancement, including one for a certified welding supervisor. 
Along with these best practices, keeping open lines of communication with welders is key — as it is in any work environment. Staying involved and creating a sense of community in which everyone is contributing to the well-being of the company can go a long way in keeping welders interested and engaged.