MIG gun consumables are critical to welding performance and quality. They can also affect the productivity of a welding operation and should be cared for the same as any other piece of welding equipment.
MIG gun consumables comprise the front-end part of the gun — the nozzle or shield, gas diffuser and contact tip — plus the liner. Together, these components are responsible for feeding the welding wire and gas through the MIG gun and for establishing the electrical conductivity necessary to create the arc. Fortunately, you can extend the life of these components and positively affect the efficiency and profit of your welding operation with a few basic tips.
Opening your consumables and haphazardly placing them in a bin can lead to scratches or dents that allow spatter to adhere and will ultimately shorten the products’ life. Similarly, storing your consumables in open or dirty containers can cause dirt and oil to accumulate in the threads, which can prevent them from properly seating together.
Keep MIG consumables in their original packaging until they are ready for use. Also, welding operators should use clean gloves when handling or replacing contact tips, nozzles and diffusers to prevent dirt, oil or other contaminants from adhering to them. Remember, proper storage and handling doesn’t just lower your actual costs for consumables, it can also prevent weld defects that require costly rework.
The position of the contact tip (extended or recessed in the nozzle) can affect how long consumables last, along with how clean they stay. This also extends to the nozzle. The farther the contact tip extends from the nozzle, the closer it is to the arc and the more prone it is to reflective heat. This can result in an increase in spatter and a greater opportunity for burnbacks.
Using a recessed contact-tip-to-nozzle relationship when possible can minimize this problem and provide better shielding gas coverage at the same time.
Good conductivity results in better weld quality and can help the components last longer. The diffuser or retaining head forms the connection between the nozzle and the MIG gun neck, holds the contact tip in place and also carries the electrical current to the contact tip to create an arc.
Look for consumables with a tapered design that locks conductive parts — like the contact tip, gas diffuser and MIG gun neck — together. If the connection between the retaining head and contact tip is not secure, electrical resistance can occur and cause the components to overheat and fail.
A MIG gun liner spans the length from the front of the MIG gun through to the feeder connection and is the conduit through which the welding wire feeds. Properly trimming your MIG gun liner significantly increases the longevity. The wrong liner length can cause poor wire feeding and premature failure of both the liner and the contact tip. Too long of a liner can cause compression, resulting in kinking, while cutting it too short allows debris to build up between the liner and the gas diffuser.
Trim your MIG gun liner according to the manufacturer’s recommendations, using the proper tools and cutting it to the correct length. After trimming the liner, make sure there are no raised or sharp edges.
Using an anti-spatter compound can help keep MIG consumables clean on both semi-automatic and robotic welding applications; however, it must be used sparingly. Using too much can cause build-up on the consumables and/or cause debris to accumulate and clog the nozzle, leading to poor gas coverage, inconsistent electrical conductivity or shortened consumable life.
Another way to combat spatter is to inspect the nozzle for build-up on a regular basis and clean it with a soft wire brush or nozzle-cleaning tool as needed. Welding operators should never hit the nozzle against the tooling or work piece to loosen spatter. Doing so can dent, misshape or compromise the smooth surface finish of the nozzle, which creates greater areas for spatter to adhere to and reduces the life of the consumable.
Whenever possible, purchase MIG guns and consumables that are backed by a reliable manufacturer’s warranty, and use all guns and consumables as intended. Also, consider the upfront cost versus the long-term savings of purchasing sturdier and more expensive consumables. They will likely last longer, reducing downtime associated with changeover and the cost of the consumables themselves.
Consumables are vital to the welding process and should be purchased, installed and maintained with care. Doing so not only prevents the cost of downtime for changeover, maintaining excessive inventory and rework but can affect your bottom line. Linde Gas & Equipment offers a supply of premium quality robotic and manual MIG guns and consumables to help you maximize throughput and reduce costs. Contact your Linde productivity specialist or call us at 1-800-225-8247 to learn more.