Solving Five Causes of Downtime in a Robotic Welding Operation

Ensuring a robotic welding cell stays productive and consistently generates a positive return on investment is determined, in large part, by the amount of downtime it incurs. Since robotic welding systems are built for speed, accuracy and repeatability, the cost of arc-off time spent addressing issues is exponentially higher than in a typical welding cell. Having welding operators and robotic weld cell supervisors who can quickly troubleshoot and solve problems makes all the difference when it comes to keeping costs down, generating high-quality results and maintaining optimal efficiency. 

Here are five common causes of downtime that can occur in a robotic welding operation, along with ways to prevent and address them. 

Cause No. 1: Poor cable management and/or incorrect cable selection 

If a power cable rubs against the robot, on parts or against tooling, it can prematurely fail and cause unnecessary downtime. In some cases, the cable may even catch on components and wear them out, too. 

Cables that are too long or too short create excessive strain by either being pulled too tight or flopping around too much and creating strain at the front housing — both of which lead to premature cable failure. These issues are common with conventional style robots, where the power cable connecting to the robotic MIG gun is external to the robot arm. The goal is to set cable length to allow it to exit the front housing with a smooth arc, resulting in minimal strain. 

Alternately, in the case of a through-arm robotic welding system, downtime often occurs due to improper installation of the gun and/or improper cable length.

Solutions:

By adding cable tensioners, which are essentially spring-loaded cable devices that hold the power cable, operators can ensure the cables stay properly supported on a conventional robot. Programming the robot so that it doesn’t accelerate or decelerate too quickly or abruptly can also protect against premature cable failure. 

In some cases, if the work envelope is quite small, cable rubbing may be unavoidable. Using a protective wrap to shield the cable from rubbing can help. These are available in the marketplace as either a leather or woven nylon cover, or a plastic spiral wrap. 

When installing a through-arm robotic MIG gun, be sure to position the robot with the wrist and top axis at 180 degrees, parallel to each other. Then install the insulating disc and spacer the same as with a conventional over-the-arm robotic MIG gun. Always be sure the power cable position is correct and has the proper “lie” with the robot’s top axis at 180 degrees, and ensure the power cable has about 1.5 inches of slack when installing it, so it is not too taut. 

Cause No. 2: Premature consumable failure 

Although consumables may seem like a small part of the robotic welding process, they can have a big impact on how productive and effective an operation is. Nozzles, contact tips, retaining heads (or diffusers) and liners can all fail prematurely or perform poorly for a variety of issues, including spatter or debris buildup, loose connections and improper installation. Issues with the contact tip — especially burnbacks and cross-threading — are also relatively common, and are often caused by a liner being trimmed too short. 

Solution:

Choosing durable, easy-to-install consumables is key to minimizing both planned and unplanned downtime in a robotic welding operation. Longer lasting consumables require less frequent changeover. Plus, designs that help less experienced welding operators install consumables correctly result in less troubleshooting.

Contact tips with coarse threads and a long tail ensure the tip aligns concentrically in the gas diffuser before the threads engage. These features help minimize the risk of cross-threading. Also, contact tips with greater mass at the front end and that are buried further down in the gas diffuser better withstand heat from the arc to help them last longer.

For pulsed welding operations, contact tips with a hardened insert help the tip last 10 times longer than those made of copper or chrome zirconium. That is important since the pulsed waveforms are especially harsh on contact tips and cause them to wear prematurely. 

Operators should always inspect consumables for signs of spatter or debris buildup during routine breaks in production and, if signs of either are present, replace or clean them. They should also ensure their nozzle cleaning station or reamer is working properly, if one is present, and that it is programmed to ream at a rate that is appropriate for that specific application. It may be necessary to increase the frequency of the anti-spatter spray application or reaming throughout the programmed welding cycle. 

Check that all consumable connections are clean and secure, as loose connections can generate additional heat through increased electrical resistance, shortening consumable life and/or causing them to perform poorly. Consumable designs that are tapered can also help minimize heat buildup and extend consumable life by offering better electrical conductivity.

Welding operators should always follow the manufacturer’s instructions for liner trimming and installation, as a liner can cause inconsistent feeding if cut too short. It is a good idea to use a liner gauge to confirm the correct liner length. There are also spring-loaded modules that work in conjunction with a front-loading liner to help minimize issues if the liner is cut to an incorrect length. These are housed in the power pin and apply forward pressure on the liner after it is installed. They typically allow up to 1 inch of forgiveness if the liner is too short. It is also important to replace liners frequently enough, as a clogged liner full of debris and dirt will not feed properly, and may cause premature contact tip failure. 

Cause No. 3 Excessive spatter buildup in consumables

Excessive spatter buildup in consumables can be caused by a nozzle cleaning station that isn’t operating properly and can easily cause unnecessary downtime. Issues related to nozzle cleaning stations can be caused by an incorrect position between this peripheral and the robotic MIG gun nozzle; poor anti-spatter compound coverage; or a dull or improperly sized cutter blade. 

Solution:

If a nozzle cleaning station doesn’t appear to be working properly, first check that the robotic MIG gun is concentric to the cutting blade on the reamer. Misalignment of the nozzle can lead to partial cleaning and excessive spatter buildup. 

Also check that the anti-spatter sprayer, if present, is full, correctly positioned and properly coating the nozzle during spraying. The nozzle should be slightly damp on the inside and outside, and covered up to three-quarters of an inch from the bottom of the nozzle.  Note that over-spraying anti-spatter compound can cause nozzles to deteriorate prematurely, so it should never be sprayed for more than half a second. 

Be sure that the cutter blade matches the diameter of the nozzle bore, so that it can effectively clean during the ream cycle without hitting the nozzle or the gas diffuser. It is also important to have a sharp cutter blade and to make sure that the nozzle is at the correct depth within the jaws of the nozzle cleaning station.

Finally, adding an air blast feature to a robotic GMAW gun can help support the nozzle cleaning station’s overall effectiveness. An air blast feature blows high-pressure air through the gun’s front end, which helps remove spatter, debris and other contaminants. This feature can help reduce how often a nozzle cleaning station needs to be used and, ultimately, boost productivity. 

Cause No. 4: Collisions

Collisions can occur as the result of tooling that hasn’t been secured properly, an item inadvertently being left in the weld cell or poor part fit-up. Unfortunately, not only can collisions create unwanted downtime, but they can also damage the robot arm, the robotic MIG gun and/or front-end consumables. 

Many newer robots are equipped with collision detection software that serves the same function as a shock sensor, but some companies still use a shock sensor as a backup safety measure. 

Solution:

For robots that don’t have built-in collision software, a shock sensor can act as a safety device to protect the robot arm and gun from damage if the robot crashes. In the event of a collision, the shock sensor sends a signal back to the robot to alert it to shut down.

In order to determine that the shock sensor switch is working properly, operators should conduct a continuity check in the open and closed position of the switch using a multimeter or manually trip it by bumping the neck with their hand. If the sensor is working properly, it will send a signal back to the robot indicating there is a problem. 

Always reset the shock sensor to its home position and recheck the tool center point (TCP) after a collision, and confirm that both the TCP and clutch are correct.

If welding operators are using a newer robot with collision detection software, they should make sure it’s set up correctly and that both the TCP and center of mass or balancing point have been programmed according to the gun manufacturer’s specifications. Doing so helps ensure the robot will react properly in the event of a collision.

Cause No. 5: Poor wire feeding

Poor wire feeding in a robotic welding system is usually caused by one of three things: 1) issues with the liner, such as a clogged liner, 2) a wire feeder that isn’t functioning properly or 3) power cable kinking. Regardless of the cause, the result is poor arc stability and weld quality. 

Solution:

As previously mentioned, regularly changing the liner and using a robotic MIG gun with an “air blast” feature help eliminate debris in a liner. If an air blast feature is not available, welding operators can also manually blow compressed air through the liner periodically.

If it is suspected that the wire feeder’s drive rolls are the culprits of the poor wire feeding, there are two ways to further investigate and assess the situation. One is to visually inspect the drive rolls for signs of wear, and the other is to conduct a “two-finger” test. The latter involves disengaging the drive rolls, grasping the welding wire and pulling it through the gun. The wire should be able to be pulled easily with two fingers.

Lastly, look for kinks in the power cable, which can also lead to poor wire feeding, and then straighten or unwind the cable, if necessary.

Remember, knowing how to troubleshoot common problems in a robotic welding operation can make the difference between costly downtime and consistently productive, arc-on time. And making the effort to address potential issues up front can actually save time and money in the long run. 

Gain Efficiencies and Extend Consumable Life with Anti-Spatter Compound 

When it comes to robotic welding operations, uptime is key. Minimizing air movements and ensuring consistent workflow are just as important as selecting the right robot, power source and robotic gas metal arc welding (GMAW) gun. Everything should work in conjunction to bring about the greatest efficiencies. The result can be higher productivity, better weld quality and an improved bottom line — not to mention, the potential for a competitive edge. 

A nozzle cleaning station (also called a reamer), along with a sprayer for delivering anti-spatter compound, can be simple and effective additions to the robotic weld cell — and ones that offer a good return on investment. Anti-spatter compound can also be delivered from a single large drum via a multi-feed system to numerous robotic weld cells. 

Anti-spatter compound protects the front-end consumables on a robotic GMAW gun from excessive spatter accumulation, which can restrict shielding gas flow, increasing the risk for porosity. This compound also helps prolong the life of the nozzle, contact tips and gas diffuser, and can reduce downtime for consumable changeover. In addition, it can lower the cost for consumable inventory (and its management), and reduce operating costs by improving weld quality and lessening rework by way of consumables that operate at peak performance. All of these factors contribute to a more productive and profitable welding operation.  

The what, when and where of anti-spatter compounds
Although it resembles water in its consistency, anti-spatter compound (when applied correctly and in the appropriate volume), will not drip like water.  It simply creates a sacrificial barrier between the nozzle and any spatter generated during the welding process; the spatter easily falls off when the nozzle cleaning station performs the reaming cycle, thereby leaving the nozzle and other front-end consumables clean. The compound must be reapplied frequently to help maintain that barrier. tt

Constant-voltage (CV) applications and those utilizing solid wire and/or the welding of galvanized steel tend to produce high levels of spatter, and therefore, often benefit the most from the use of anti-spatter compound. However, the application of anti-spatter compound is ideal for any high-volume, high-production environment seeking to minimize potential weld quality issues, extend consumable life and also reduce downtime. Its application can easily be programmed so that it is sprayed onto the consumables after each ream cycle, during routine pauses in production for part changeover. 

When selecting an anti-spatter compound, be certain that it is capable of providing uniform coverage to protect the entire nozzle, that it cleans up easily and leaves no residue, and that it is compatible with the nozzle cleaning station being used. Water-soluble anti-spatter compound is the most popular option, and is typically non-toxic and eco-friendly. Oil-based anti-spatter compound is also available in the marketplace, but is generally less desirable to use because it is more difficult to clean up if it settles on fixtures or elsewhere in the weld cell. It is also important to note that oil-based anti-spatter compound is not always compatible with all nozzle cleaning stations and it can clog up this equipment. 

Despite the fact that the more popular water-based anti-spatter compound is non-toxic, welding operators and/or maintenance personnel should still take care when handling and using it. They should avoid breathing in spray mists and always wash their hands after coming in contact with the compound (for example, when filling the sprayer). The use of a NIOSH certified (or equivalent) respirator during spraying is recommended. Also, personnel should wear Nitrile or Butyle gloves and wear chemical safety goggles for the best protection. Local exhaust ventilation near the sprayer is also important. Store anti-spatter compound containers according at the temperatures recommended by the manufacturer. 

Best practices for anti-spatter compound use
Positioning the robotic GMAW gun and front-end consumables in the correct location for the ream cycle and anti-spatter application helps the compound to be applied uniformly. To gain optimal spray coverage, always follow the manufacturer’s instructions for proper setup based on the nozzle bore size. If the sprayer is too far away from the nozzle, it will not provide adequate coverage to prevent spatter buildup. If the nozzle and sprayer are too close, too much spray may saturate the nozzle insulator, which can lead to premature failure.

Spraying for about a half-second is the standard recommendation. If a company finds that it is necessary to spray the anti-spatter compound any longer, that usually means the sprayer is too far away. In fact, anti-spatter compound should never be sprayed for three or more seconds. In addition to causing harm to the consumables, excess spraying can leave a residue of the compound in the weld cell that could lead to safety issues, such as slick floors and slipping hazards. Over-application of anti-spatter compound may also damage equipment, such as power sources, by adversely affecting electrical circuits it comes in contact with. 

Adding a spray containment unit 

Some manufacturers offer a spray containment unit, which can help capture excess anti-spatter compound. This 3 to 4-inch unit fits over the spray head on the anti-spatter compound sprayer. After the spatter has been cleared from the nozzle during the reaming cycle, the nozzle docks on the spray containment unit. An opening at the top of the cylinder allows the anti-spatter to spray onto the nozzle while an O-ring seals the nozzle in place so only the outside edge and inside of the nozzle are sprayed. 

The spray containment unit also collects any anti-spatter compound runoff at the bottom of the unit so it can be easily drained into a container and disposed of properly. Anti-spatter compound cannot be reused and should be disposed of in accordance with federal, state and local environmental control regulations. 

When employing a spray containment unit, it is important to inspect it regularly, removing any spatter or debris from the bottom that could prevent it from working properly. As part of a preventive maintenance activities, clear the screen or filter inside the unit of contaminants using clean, compressed air. Doing so helps ensure that the screen can continue to fulfill its intended purpose of improving air quality.

As with any part of the robotic welding operation, when employed properly, this unit and the use of anti-spatter compound can yield positive results. Always follow the manufacturer’s recommendation for use and consult with a trusted welding distributor with any questions. 

Additional tips for effective nozzle cleaning station operation

In conjunction with anti-spatter compound, a nozzle cleaning station improves quality and productivity in robotic weld cells by helping extend consumable life and reducing downtime for changeover. Here are some tips to get the most out from this equipment.

Correct placement: Place the nozzle cleaning station in close proximity to the robot so it is easily accessible.

Match parts and sizes: Make sure the V-block inside the top of the nozzle cleaning station is the correct size for the nozzle, that the cutter blade is the correct size for the nozzle bore, and that the insertion depth of the nozzle to the reamer is adequate.

Monitor the home signal: Monitor the home signal on the nozzle cleaning station to reduce issues during the cleaning cycle and minimize guesswork regarding whether the equipment is ready for use or done with its cycle.

Clean and scrape parts: Clean the top seal on the spindle under the cutter and make sure all clamp faces are kept clean by scraping the faces and jaws on the V-block to remove debris. Buildup on these parts can push the nozzle out of position, leading to the fit-up no longer being concentric — and, potentially, to broken cutter blades. 

Tips for Optimizing Reamer Usage

A nozzle cleaning station, or reamer, is a peripheral that can be integrated into an automated welding system to maximize its performance. Reamers remove spatter from inside the gas metal arc welding (GMAW) gun’s front-end consumables — nozzles, contact tips and retaining heads — that accumulates during routine welding. In doing so, this equipment improves quality and productivity in robotic weld cells by extending consumable life and reducing downtime for maintenance.

In addition, utilizing a reamer helps prevent loss of shielding gas coverage, a problem that can lead to expensive rework to correct porosity or other weld defects. From proper installation and setup to effective operation, there are best practices to gain the highest performance, quality and long-term use from reamers.  

This article has been published as an exclusive with The Fabricator. To read the entire article, provided by Ryan Lizotte, Tregaskiss field technical support specialist, please click here.

Getting the Most Out of Peripherals

Peripherals — equipment that is integrated into the robotic welding process to make it more effective — can significantly boost the return on investment you achieve from your welding robot. And incorporating and operating peripherals successfully doesn’t have to be difficult.  To help, it is important to understand how your peripherals are intended to function and employ some best practices for using them. 

Clutches

All robotic welding systems require some form of collision detection to prevent damage to both the robotic MIG gun and the robot arm in the event of an impact. Impacts can occur when the robotic MIG gun collides with an incorrectly positioned work piece or out-of-position tooling, or when the gun strikes an item that has inadvertently been left in the welding cell. 

Some robotic systems incorporate robot collision detection software. Systems that do not have built-in collision detection, however, should always be paired with a clutch — an electronic component that attaches to the robotic MIG gun to protect it and the robot from heavy damage in the event of a collision. In some cases, you may choose to add a clutch to a system that utilizes collision software as backup protection for the robot.

Always make sure the clutch works with the weight of the load created by the robotic MIG gun and front-end consumables. If the gun is not properly supported and the robot moves rapidly to another spot on the other side of the part, the extra weight can move the clutch out of its optimal position. 

If a clutch gets triggered from a collision, reset it by pulling it towards you and letting it snap back into position. After, be sure to check your tool center point (TCP) to ensure the robotic MIG gun is properly aligned for precise welding of the joint. If it is off center, validate that the clutch is in its home position. 

Wire cutters

If you have robotic welding applications that require consistent welding wire stick-out — the distance the wire extends from the end of the contact tip — a wire cutter is a recommended peripheral. As the name implies, a wire cutter cuts the welding wire to a specified length or stick-out and also removes any balling at the end of the wire. 

Most wire cutters can cut a range of different types of welding wire, including stainless steel, flux-cored and metal-cored, usually up to 1/16-inch diameter. They can often be mounted on a nozzle station or used remotely as needed.

In conjunction with a wire brake, the wire cutter can ensure that the stick-out remains consistent for robots with touch sensing capabilities that help locate the joint. 

Neck inspection fixtures

Another key peripheral is a neck inspection fixture, which tests the tolerance of a robotic MIG gun’s neck to the TCP so you can re-adjust it after an impact or after bending due to routine welding. 

The advantage of adding a neck inspection fixture to a robotic weld cell is twofold. One, it ensures the neck meets the specifications to which the robotic welding system has been programmed and, once the tolerance has been determined, you can simply adjust the neck accordingly. This can prevent costly rework due to missed weld joints and can also prevent downtime required to reprogram a robot to meet welding specifications with an existing bent neck. Second, a neck inspection fixture can save you time, money and confusion when exchanging necks from one robotic MIG gun to another. Having this ability is especially advantageous if you maintain a large number of welding robots. You can simply remove a bent neck and change it with a spare that has already been inspected and adjusted, and put the robot back in service immediately.  

Nozzle cleaning stations and sprayers

One of the most important peripherals you should consider for your robotic welding system is a nozzle cleaning station or reamer. A nozzle cleaning station removes spatter from the robotic MIG gun nozzle and clears away the debris that accumulates in the diffuser during the welding process. This helps lengthen the life of the robotic gun consumables, as well as the gun itself. A clean nozzle also reduces problems that could lead to rework and helps the robot create better quality welds.

During installation, be sure your reamer is on a sturdy base or otherwise securely fastened and not moving around during the reaming cycle. Ideally, the nozzle cleaning station should be placed in close proximity to the welding robot so it is easily accessible when cleaning is necessary. You should program the reaming process to run in between cycles — either during part loading or tooling transfer — so it does not add to the overall cycle time per part. 

Always keep the covers on your reamer. The electronics within a reamer can be easily ruined by moisture from the atmosphere. Also, remember to use clean, filtered and lubricated air in your reamer. If “dirty” air goes into the reamer, it will clog up the valves. If you don’t have a lubricator installed on the reamer, use an alternative method to lubricate the air that goes through the motor. 

It is important that your reamer matches the diameter of the nozzle and that the blade does not hit the diffuser or nozzle when it goes through a ream cycle. Be sure you are using the right blade for the nozzle you have and that your nozzle is set at the correct depth within the jaws of the reamer. 

A reamer can be used by itself or in conjunction with a sprayer that applies an anti-spatter compound to protect the nozzle, diffuser and work piece from spatter. Make sure the nozzle is the correct height away from the spray block and that the duration of the spray is about a half a second. Too much anti-spatter compound can ruin the insulator on your nozzle, and can lead to unnecessary costs for replacement. The compound may also build up on the nozzle, the robot and the parts being welded, resulting in additional cleanup.

Frequently check that the sprayer and sprayer head is free of debris; if spatter gets inside the sprayer head, it will cause the spray plume to be distorted, which will create inconsistent coverage. 

If you are using a multi-feed anti-spatter system, be sure you have a good quality hose, such as a urethane hose, and that it is protected from any spatter that may hit it and create a hole. Also, securely fasten the hose with clamps at every connection to prevent leaks. 

You may consider using a spray containment unit to capture excess anti-spatter compound. If so, weekly inspections are recommended; remove any spatter or debris that may have fallen to the bottom. Failing to do so can prevent the unit from draining, which will cause the containment unit to overflow and create a mess. 

No peripheral decision

The decision to invest in robotic welding equipment is significant. It requires time, knowledge and a trusted relationship with a robotic welding equipment manufacturer to find the right system. The same holds true for peripherals. 

Although these devices do add to the initial cost of automating, they can lead to measurable cost savings and profits in the long run. But remember, the goal in robotic welding is repeatability and increased productivity, and any additional equipment that can help achieve these results may be worth your investment.

What You Should Know About Robotic MIG Gun Clutches

Implementing and operating a robotic welding system requires attention to detail to gain high productivity and consistent quality. It’s equally important to do whatever you can to protect your investment for the long term — from the robot to the MIG gun and more. In some cases, robotic peripherals are an additional means to help and can provide added safety, in the case of a clutch.  

As a safety device for your robotic MIG gun, a clutch attaches to the robotic MIG gun and protects it — and the robot arm — from damage. If the robot crashes, the clutch will send a signal back to the robot that alerts it to shut down. Not only does this help prevent further damage to the robotic arm, but it also protects your gun and your front-end consumables. 

While many newer robots are equipped with collision detection software that serves the same function as a clutch, older robots, which are still very commonly used, are not. Regardless of whether you’re operating a new or older robot, everyone knows your robotic welding system is only as good as the uptime it offers. It’s essential to keep as much arc-on time as possible. 

When selecting a clutch, you need to choose one that can hold whatever load is going to be on it. For example, if the front end of the gun is extremely heavy and requires significant air movement, some clutches may not be able to support it or may require an adjustment to their sensitivity settings.

Also, look for obvious size constraints and make sure the clutch fits within your molding application and tooling.  

When setting up your clutch be sure to check your tool center point (TCP). Putting on a clutch should not significantly change the TCP. If it’s off, be sure to validate that the clutch is in its home position. Also, when replacing a clutch, make sure the TCP is within specifications. Similarly, always reset the clutch to its home position and recheck the tool center point after a crash.   

If the tool center point is off, look first to make sure no other damage occurred to another component during the crash. It could indicate that the neck bent out of position, for example, and needs to be straightened with a neck checking fixture or replaced. If all components are undamaged and the deflection is still off, you’ll need to trip the clutch again by pulling it back and snapping it back into place. 

Typically, the only reason a clutch will fail is if its electrical switch inside fails. If that happens, it will no longer send a signal back to the robot, which will shut down the entire system. 

In order to ensure the switch is working properly, you can either conduct a continuity check in the open and closed position of the switch using a multimeter or manually trip it by bumping the neck with your hand. If the clutch is working properly, it will send a signal back to the robot that indicates there is a problem. 

This type of check can be done as part of your preventative maintenance whenever the robot is set up and in a stopped position. 

Remember, as with any part of the robotic welding system, knowledge is key. Peripherals like clutches serve a distinct purpose in helping make robotic welding successful. Keep in mind some of these tips to help you get the most out of this equipment.

7 Tips for Improving MIG Welding

Want to improve your MIG welding? By following these seven tips, you can take your MIG welding operation to the next level and ensure you are as safe, efficient and professional as any other shop. 

1. Remember that the best MIG welding operator is a safe one. 

Never forget that MIG welding, when done improperly, can be hazardous. Electric shock, fumes and gases, arc rays, hot parts, noise and a host of other possible hazards come along with the territory. The ultraviolet and infrared light rays can also burn your skin — similar to a sunburn but without the subsequent tan — and your eyes. This is why the best MIG welding operator knows how to stay safe.

Welding helmets, gloves, close-toed shoes and clothes that fully cover exposed skin are essential. Make sure you wear flame-resistant natural fibers such as denim and leather, and avoid synthetic materials that will melt when struck by spatter, potentially causing burns. Also, avoid wearing pants with cuffs or shirts with pockets, as these can catch sparks and lead to injuries.

Keep in mind that heavy-duty MIG welding often produces a lot of heat, sparks and spatter, and requires a lower degree of dexterity than some other forms of welding. Therefore, using thick, stiff leather gloves that provide a higher level of protection is smart. Similarly, choose leather footwear that covers your entire foot and leaves as little room as possible for spatter to fall along your ankle line. High-top leather shoes and work boots often provide the best protection. 

Finally, always be sure you have adequate ventilation per OSHA recommendations and check material safety data sheets (MSDS) for each metal being welded and filler metal being used. Use a respirator whenever required by the MSDS.

2. Do your research before you set up your equipment. 

Before you get started with MIG welding, conduct online research to see what the best practices are for the specific wire you have or contact a trusted filler metal manufacturer to improve the quality of your welding. Doing so not only tells you what the manufacturer’s recommended parameters are for your diameter wire, but also what the proper wire feed speed, amperage and voltage is, along with the most compatible shielding gas. The manufacturer will even tell you what electrode extension or contact-to-work distance (CTWD) is best suited for the particular wire. 

Keep in mind that if you get too long of a stickout, your weld will be cold, which will drop your amperage and with it the joint penetration. As a general rule of thumb, since less wire stickout typically results in a more stable arc and better low-voltage penetration, the best wire stickout length is generally the shortest one allowable for the application.

3. Make sure all of your connections are sound before getting started.  

Before you start welding, make sure all of your connections are tight — from the front of the MIG gun to the power pin attaching it to the power source. Also be certain there is no spatter buildup on your welding consumables and that you have a ground cable as close to the workspace as possible. 

Whenever possible, hook the ground cable on the weldment. If that is not possible, hook it to a bench. But remember: The closer it is to the arc, the better. If you have a questionable ground, it can cause the gun to overheat, impacting contact tip life and weld quality. 

In addition, regularly clean any shavings from the welding wire or debris that collects on your consumable parts and in your liner using clean compressed air.

4. Select the proper drive roll and tension setting to effectively feed wire. 

Improper drive roll selection and tension setting can lead to poor wire feeding. Consider the size and type of wire being used and match it to the correct drive roll to improve MIG welding performance.  

Since flux-cored wire is softer, due to the flux inside and the tubular design, it requires a knurled drive roll that has teeth to grab the wire and to help push it through. However, knurled drive rolls should not be used with solid wire because the teeth will cause shavings to break off the wire, leading to clogs in the liner that create resistance as the wire feeds. In this case, use V-grove or U-groove drive rolls instead. 

Set the proper drive roll tension by releasing the drive rolls. Then increase the tension while feeding the wire into your gloved hand until the tension is one half-turn past wire slippage. 

Always keep the gun as straight as possible to avoid kinking in the cable that could lead to poor wire feeding.

5. Use the correct contact tip recess for the application.

Contact tips can have a significant impact on improving MIG welding performance since this consumable is responsible for transferring the welding current to the wire as it passes through the bore, creating the arc. 

The position of the contact tip within the nozzle, referred to as the contact tip recess, is just as important. The correct contact recess position can reduce excessive spatter, porosity, insufficient penetration, and burn-through or warping on thinner materials. 

While the ideal contact tip recess position varies according to the application, a general rule of thumb is that as the current increases, the recess should also increase. See Figure 1.

6. Use the shielding gas best suited to your wire.

Always know what gas your wire requires — whether it’s 100 percent CO2 or argon, or a mix of the two. While CO2 is considerably cheaper than argon and good for penetrating welds on steel, it also tends to run cooler, making it usable for thinner materials. Use a 75 percent argon/25 percent CO2 gas mix for even greater penetration and a cleaner weld, since it generates less spatter than straight CO2.

Here are some suggestions for shielding gases for common types of wire: 

Solid Carbon Steel Wire: Solid carbon steel wire must be used with CO2 shielding gas or a 75 percent CO2/25 percent argon mix, which is best used indoors with no wind for auto body, manufacturing and fabrication applications. 

Aluminum Wire: Argon shielding gas must be used with aluminum wire, which is ideal for stronger welds and easier feeding. 

Stainless Steel Wire: Stainless steel wire works well with a tri-mix of helium, argon and CO2.

7. Keep the wire directed at the leading edge of the weld pool. 

For the best control of your weld bead, keep the wire directed at the leading edge of the weld pool. When welding out of position (vertical, horizontal or overhead welding), keep the weld pool small for best weld bead control, and use the smallest wire diameter size you can. 

A bead that is too tall and skinny indicates a lack of heat into the weld joint or too fast of travel speed. Conversely, if the bead is flat and wide, the weld parameters are too hot or you are welding too slowly. Ideally, the weld should have a slight crown that just touches the metal around it.

Keep in mind that a push technique preheats the metal, which means this is best used with thinner metals like aluminum. On the other hand, if you pull solid wire, it flattens the weld out and puts a lot of heat into the metal. 

Finally, always store and handle your filler metals properly. Keep product in a dry, clean place — moisture can damage wire and lead to costly weld defects, such as hydrogen-induced cracking. Also, always use gloves when handling wires to prevent moisture or dirt from your hands settling on the surface. When not in use, protect spools of wire by covering them on the wire feeder, or better yet, remove the spool and place it in a clean plastic bag, closing it securely.  

As with any welding process, it takes time and practice to gain the best performance when MIG welding. Following some of these simple steps can help along the way.