Unfortunately, because of the time it takes to replace the liner, this is often one of the last components checked during a troubleshooting effort. Poor or erratic wire feeding, a loss of amperage or frequent contact tip burnback are all signs of liner problems. In addition to guiding the wire, the back end of the liner contains o-rings and seals to ensure the shielding gas doesn’t escape the gun cable. This occurs to a lesser degree even with cables that are not bent tightly, so it’s a good idea to periodically clear out the liner with compressed air. Eventually these tiny particles can build up and cause serious wire feed blockages. This friction makes it more difficult to push the wire through the liner, causing wear and metal fragments to accumulate inside the liner. Tight bends in the cable increase friction between the liner and the welding wire. The welding operator or maintenance personnel simply feeds the welding liner through the neck of the gun, locks it in place and cuts the liner flush with the back of the power pin. There is no liner measuring required during installation or replacement. The diffuser locks the liner in place and concentrically aligns it with both the power pin and contact tip with no gaps or misalignments (and without the use of fasteners). There are also consumables - contact tip, nozzle, gas diffuser and liner - available in the marketplace that allow for error-proof liner installation. Avoid twisting the cable when trimming the liner, as this can cause it to be too short, resulting in gaps that can lead to erratic wire feeding. Proper replacement: Improperly installing the liner can lead to wire feeding problems such as birdnesting, which results in downtime and reduced productivity. There is no liner measuring required during installation or replacement on some consumable systems. Nevertheless, bending the cable too much can cause poor wire feeding, premature liner wear and birdnesting (explained below). Most MIG gun liners are made from coiled steel wire, known as music or piano wire, which gives the liner a good balance of rigidity and flexibility and allows it to guide the welding wire through a tightly bent cable without kinking. Just make sure the liner you choose is large enough to feed the welding wire you are using. through 1/8-in., have much higher columnar strength. This in turn leads to poor wire feeding and premature liner failure due to excessive wear.īy contrast, larger diameter welding wires, 1/16-in. 045-in., have relatively low columnar strength, which, when paired with an oversized liner, can cause the wire to wander or drift within the liner. To maximize the performance of your MIG equipment, choose the correct liner size for the wire being used. This is critical because variances as small as a few thousandths of an inch can result in wire feeding problems requiring time-consuming liner replacement.

A premium quality liner maintains a consistent inside diameter throughout its length. The quality of a liner can also impact your welding performance, productivity and operator downtime. Proactive maintenance can eliminate problems before they arise and reduce operator downtime, more serious equipment failures and costly rework. There’s an old saying that prevention is the best medicine, and this holds true with MIG gun liners as well. Optimizing the Performance of Your MIG Gun Liners The following is a discussion to help you get the best performance from your MIG gun liner and troubleshoot problems when they occur.

When the wire does not feed correctly, weld quality problems may arise that lead to increased operator downtime and costly rework. If it is not performing this task properly, the gun is virtually worthless.Ī number of problems can interfere with the liner’s ability to properly guide the wire through the welding cable. Its sole purpose is to guide the welding wire from the wire feeder, through the gun cable and up to the contact tip. The liner is both one of the simplest and most important components of a MIG gun.

The liner is often overlooked as the cause of MIG welding problems, partially because it is difficult to check for problems without disconnecting the gun from the wire feeder. Dura-Flux Self-Shielded Flux-Cored Gun with Replaceable Cable Liner.Dura-Flux Self-Shielded Flux-Cored Gun with Fixed Cable Liner.

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