Welder Maintenance
The First Step to Successful Welding: Properly Maintaining Your Welding Equipment
By Scott Skrjanc, The Lincoln Electric Company
One of the most important – and simplest – ways to create strong welds is to properly maintain your welding equipment. Taking care of your welder does not require a great deal of effort, and it can save you significant time and money in the long run – both in equipment longevity and in weld quality and performance. Proper short term machine maintenance will help you to avoid some common welding errors and help you avoid paying for costly repairs on improperly maintained or neglected equipment.
Depending on the type of welding equipment you’re using, the maintenance required will be different. Stick (SMAW) welding equipment requires very little maintenance, while MIG (GMAW) and TIG (GTAW) welders need a bit more care and attention to stay in proper shape.
Caring for your Stick (SMAW) Welding Equipment
Because the majority of the equipment components are contained inside the welder, stick welding equipment requires the least amount of machine maintenance.
The only elements not contained inside the equipment are the electrode holder and the ground clamp. However, these elements do not require a great deal of day-to-day maintenance; rather, these parts have a tendency to wear over time, so it’s good procedure to monitor their condition and replace these parts when needed.
Long term, you will want to have a qualified technician check inside the machine for buildup of dirt, dust and grime on cooling fans, wiring, transformers and PC boards. Servicing the machine in this way will help to cool the components and prolong the service life of the unit. Be sure you always unplug the machine before performing any maintenance tasks.
The most significant maintenance concern in stick welding relates to your electrodes. When the steel electrodes used for the SMAW process are left out in the open, they tend to collect moisture, creating a risk of rust.
Make sure to care for your rods by properly storing them in a closed container and sealing the lid tightly. You also can use a rod oven, such as Lincoln Electric’s HydroGuard™ Rod Oven, to keep your electrodes at the correct moisture level. Put electrodes into a rod oven as soon as the container is opened to prevent moisture from entering and ensure that the electrode’s moisture content stays at the proper level. If you only weld occasionally, there’s no need to purchase a rod oven – simply purchase rods that come in a re-sealable container.
Finally, always store your electrodes in an upright position to prevent damage that can occur when rods bump against one another, as dented rods or electrodes missing the extruded coatings can negatively impact the welding performance.
Maintaining MIG (GMAW) Welders
Unlike stick welders, wire welders (MIG and/or flux-cored welding) include many more peripheral items – including the gun liner, gun contact tips and the shielding gas hose – and therefore require much more regular care and attention. Again, always unplug the machine before performing any maintenance tasks.
Steel drive rolls typically do not experience a great deal of wear. However, when the wire runs across them, it can introduce a great deal of dirt and dust that can build up on the drive rolls. To combat the buildup of grime, it’s a good idea to blow out the inside of the feeder section of the machine with compressed air at least once a week to keep the drive rolls clean and in the best shape for feeding thin .025 - .035 inch welding wire. Alternately, you can remove the rolls and clean them with a wire brush. Most important – no matter which method you opt to use – always make sure the wire feeder is powered off before inspecting or cleaning the drive rolls.
Because the wire runs through the drive rolls and into the gun liner, it can create dirt and dust buildup in the liner. Again, it’s good practice to blow out the liner with compressed air from the contact tip end of the gun approximately once a week to remove accumulated dust and dirt, especially if you’re not using your welder on a regular basis.
Next, always ensure that the liner is cut to the proper length – if it’s too short, dirt and dust can build up between the liner and the retaining head, causing problems with your wire feeder. And, to make sure your gun liner is always protected and maintained, never drive or roll anything heavy over the gun cable – it will flatten the liner, and you’ll typically have to replace it.
Often overlooked areas in welder maintenance, the gun contact tips, cone and diffuser are essential to maintain for trouble-free welding performance. Because these components work together to facilitate the necessary electrical conductivity and gas dispersion for the MIG process to occur, you won’t be able to weld properly if these elements of your system aren’t kept in top shape.
While welding, the gun nozzle, which helps to shield the weld, often becomes filled with spatter. Make sure to keep the nozzle clean in order to avoid inhibiting the flow of gas and preventing your ability to weld. Using nozzle dip will help keep the nozzle clean. Similar to the consistency of jelly, a product referred to as nozzle dip can help prevent spatter from sticking to the nozzle. Simply dip the nozzle in the product every once in awhile while welding to reduce the buildup of spatter. However, don’t fully submerge the entire nozzle, as doing so can damage the porous insulator in the nozzle’s interior – just dip the tip. Also, store the nozzle in the manufacturers packaging to prevent damage – if you toss it in a bin or other container, it may get dented or scratched, creating defect areas that can collect spatter.
The diffuser screws into the gun tube inside of the nozzle and disperses the shielding gas required for MIG or gas-shielded flux-cored welding. Like on the nozzle, the buildup of spatter on the diffuser also will inhibit the flow of gas. On a regular basis, remove the cone and check the diffuser to ensure that it’s not clogged. If there is spatter in the diffuser, use a wire brush or rag to wipe it clean.
To ensure that your gun contact tips stay in the best shape, try not to touch the tip to the work piece. Every time you make unwanted electrical connection between the tip and the work piece, the tip is damaged. Often, it is possible to burn the tip enough to modify the path of the wire through the tip and affect weld quality. Also, for best performance, be sure to change the tip to a model with the correct hole size every time you change the wire diameter size.
Still, despite a welder’s best efforts, gun contact tips do eventually need to be replaced. After significant use, the hole diameter in the tip will elongate, affecting wire placement in the joint.
Also, tips will wear out and become covered in spatter. This signals that it’s time to purchase a new one, such as the Copper Plus® tips offered in Lincoln Electric’s Magnum® PRO gun line.
Other concerns when MIG welding include paying attention to the shielding gas bottle – make sure it is always chained up, either to the machine or somewhere in the shop. If it falls over with a regulator on it, the gas will try to escape and the gas stream could potentially hurt someone. To prevent the escape of gas when not in use, remove the regulator and fasten a threaded protector cap to the top of the bottle to keep the valve system safe and help prevent a rupture.
To keep your shielding gas hose in good shape, coil it loosely and store it off the ground to prevent it from twisting or kinking, which may cause damage. Also make sure to examine it regularly for any holes or potential leakage spots. Store it somewhere cool and dry.
Perhaps the simplest tip for maintaining your MIG welder is to prevent dust by keeping a cover on top of the machine when not in use. And, it’s good practice to have a certified technician service/inspect your guns periodically.
Though MIG welding has many more machine maintenance requirements than stick welding, one maintenance benefit of the GMAW process is that the wire is generally copper coated, which means it’s less likely to rust, eliminating the need for a rod oven.
While caring for MIG equipment has many elements, there’s an easy way to spot a potential maintenance problem – visible porosity holes in your weld. With any gas-shielded process, visible porosity in the weld indicates a procedural problem or a shielding gas problem – it signifies that you’re out of gas, the nozzle is clogged or there’s a hole in your shielding gas line. So, pay attention to your weld quality – it’s an easy barometer of whether or not your machine maintenance is up to date.