The Importance of Cutting a Welding Liner Properly

Installing a welding liner correctly is, first and foremost, a matter of proper training. For traditional systems, it’s critical that welding operators understand how to measure and cut the liner to the required length for the gun. 

A welding liner that has been cut either too short or too long can lead to a host of issues, most often poor wire feeding. That, in turn, can lead to weld quality issues and rework — both factors that contribute to unnecessary and costly downtime. 

The Bernard® AccuLock™ S Consumable System can help eliminate installation issues. First, however, it’s important to understand the pitfalls of standard liner installation to understand the value of this solution. 

The problem
The position of the gun and power cable factors significantly into whether liner installation is successful. If the gun and power cable are twisted or coiled before the welding operator trims the liner, the liner can end up either too long or too short, due to how the cable is constructed. 

Inside the power cable is copper that is wound around a central conduit in a helix or spiral. If the cable is twisted or coiled, it will grow or shrink based on how the copper helix is also twisted. Think of a spring — if it is twisted one way, it grows; if twisted the other way, it shrinks.  

For this reason, it’s important to lay the gun and cable straight to avoid any kinks that would lead to an incorrect reading when trimming the liner. Generally, longer power cables are more prone to twisting, so welding operators must take even more care when installing liners in them. 

Welding operators may experience the following due to an improperly trimmed liner:

• Poor wire feeding
• Erratic arc
• Birdnesting
• Burnbacks
• Wire chatter

A new solution

The Bernard® AccuLock™ System eliminates the need to measure the liner for replacement. The liner locks into place so it can then be trimmed flush with the power pin cap at the back of the gun and power cable. It is still important to lay the gun and cable flat, avoiding twists. 

The welding operator can conduct a visual check to determine the liner is in the proper place. This check isn’t possible with a traditional liner if it has been cut too short; the liner will be hidden under the nozzle and gas diffuser, and not visible to the welding operator. 

The AccuLock System reduces wire feeding issues through the gun, as well, since the liner is locked and concentrically aligned at both the power pin cap and contact tip. This dual lock helps ensure the liner won’t extend or contract as the welding operator changes positions and the power cable naturally bends. The result is the elimination of gaps or misalignments at the front and back of the gun for a flawless wire-feeding path. 

As an added benefit the concentric alignment of the liner reduces mechanical wear on the contact tip that could lead to burnbacks or keyholing, both of which shorten the contact tip life. 

For more information please visit the AccuLock S consumables product page.