Feedability in GMAW Welding of Aluminum

Feedability is one of the most common challenges encountered when moving from GMAW welding of steel to GMAW welding of aluminium. Operators frequently experience equipment problems such as fusion of the aluminium welding wire to the contact tip, which requires the feeding system to be stripped down and the tip replaced. These interruptions are both time-consuming and costly. This article covers the main feedability issues associated with GMAW aluminium welding and how to address them effectively.

What Is Feedability?

In this context, feedability refers to the ability to consistently feed spooled welding wire through the system during GMAW welding without interruption.

Feedability in Steel vs Aluminium

Feedability is a significantly greater challenge with aluminium than with steel, primarily because of the difference in mechanical properties between the two materials. Steel welding wire is rigid, can be fed over greater distances, and is far more tolerant of mechanical stress during feeding. Aluminium wire, by contrast, is softer and more susceptible to deformation and shaving during the feeding process. This requires considerably more care when selecting and configuring a feeding system for aluminium GMAW welding. Feedability difficulties are compounded when using smaller diameter wires and softer aluminium alloys such as 1100 and 4043, compared to harder alloys such as 5356.

Understanding the Feeding System

Feedability problems most commonly appear as irregular wire feed or as burn-backs — the fusion of welding wire to the inside of the contact tip. Preventing these issues requires a thorough understanding of the entire feeding system and how each component affects aluminium wire behaviour.

Spool — Starting at the spool end of the system, brake setting tension should be reduced to the minimum level needed to prevent the spool from free-wheeling when welding stops. Any brake pressure above this threshold increases the risk of feeding problems and burn-backs. Electronic braking systems, and combinations of electronic and mechanical braking, have been developed to provide greater sensitivity and are particularly beneficial for aluminium wire feeding.

Inlet and Outlet Guides and Liners — Inlet and outlet guides, as well as liners, are typically made from metallic materials for steel welding. For aluminium, these must be replaced with non-metallic alternatives — such as PTFE (Teflon) or nylon — to prevent abrasion and shaving of the softer aluminium wire. ESAB's RobustFeed Edge DX is configured with aluminium-compatible liner options specifically to address this requirement.

Drive Rolls — Drive rolls designed specifically for aluminium should always be used. These typically feature U-groove profiles with chamfered, smooth edges rather than sharp ones. Drive rolls with sharp edges will shave the soft aluminium wire, and the resulting shavings can accumulate within the feeding system and cause blockages and burn-backs. Excessive drive roll pressure or misalignment deforms the wire and increases friction drag through the liner and contact tip. ESAB's aluminium-optimised drive rolls for the RobustFeed Edge DX are designed to minimise these risks.

Contact Tip — Contact tip bore diameter and quality are critical. Only use contact tips made specifically for aluminium wire welding. Tips must have smooth internal bores and no sharp burrs at the inlet or outlet that could shave the softer alloys. The contact tip bore diameter should be approximately 10–15% larger than the electrode diameter to allow for the thermal expansion of aluminium wire during welding.

Feedability Chart

The Importance of Welding Wire Quality

The quality of the welding wire itself has a direct influence on feedability. Surface smoothness, diameter consistency, and the final treatment of the wire during spooling all affect how easily it travels through the feeding system. Selecting aluminium welding wire with consistent quality characteristics — such as ESAB's OK Autrod aluminium wires — is an important step in minimising feedability problems before they arise.

Aluminium Wire Feeding Systems

There are four recognised feeding systems used for aluminium GMAW welding:

• Push feeders
• Pull feeders
• Push-pull feeders
• Spool-on-gun feeding systems

Push Feeders and Pull Feeders

For aluminium welding, both push and pull feeders have recognised limitations that depend on the application and feeding distance. These systems are generally practical up to a cable length of approximately 3.5 metres. With push feeders, the distance limit is a consequence of aluminium wire's flexibility and its tendency to buckle and kink in the liner. With pull feeders, friction drag increases rapidly along the liner — particularly where there are bends in the conduit.

Push-Pull Feeders

Push-pull feeders were developed specifically to overcome the limitations of single-motor systems and represent the most reliable method of feeding aluminium welding wire. Push-pull systems improve feedability across a wide range of applications and are often essential in more critical or specialised operations such as robotic and automated welding, where consistent, uninterrupted wire delivery is non-negotiable.

ESAB's PP 350w Inline Push-Pull Torch, used in combination with the RobustFeed Edge DX and Warrior Edge DX power source, provides a fully integrated push-pull solution designed for demanding manual aluminium applications — including long seam welding on tanks, structures, and fabrications common across oil and gas, marine, and construction sectors.

Spool-on-Gun Feeding Systems

Spool-on-gun systems are typically designed to use small 0.45 kg spools mounted directly in the gun. These guns are usually air-cooled and limited to smaller wire diameters and light-duty applications. Their relatively low current rating makes them unsuitable for heavy-duty continuous production welding, but they can be effective for tack welding and other intermittent light-duty tasks.

The most appropriate feeding system for any given application depends on factors including the duty level (light or heavy), electrode diameter and alloy, the need for a long flexible conduit, and the importance of minimising wire cost — larger diameter wires are generally lower in cost per kilogram than smaller diameters.

Recommended ESAB Aluminium Feeding System

For fabricators requiring a reliable, production-ready aluminium GMAW feeding solution, ESAB's integrated system — comprising the Warrior Edge DX power source, RobustFeed Edge DX feeder, and PP 350w Push-Pull Torch — is engineered to minimise feeding issues and deliver consistent aluminium arc performance across shift-length production runs.

Summary

Welding applications vary considerably in their demands, and feeding system costs vary accordingly. The cost of downtime caused by feedability problems — and the replacement parts required to resolve them — can be significant. For this reason, selecting a feeding system that is genuinely suited to your application and setting it up correctly from the outset is the most effective way to protect both productivity and weld quality.

For further guidance on aluminium wire feeding and system configuration, explore the related articles below or visit ESAB's aluminium welding resource hub.

Explore ESAB's Aluminium Welding Solutions