Common Welding Problems and How the Right Gas Mix Can Solve Them | Pacific Gas

Welding is fundamental in fabrication, construction, and repair, but even skilled professionals can run into issues that compromise weld quality. Whether it’s porosity, spatter, or poor fusion, many common welding problems can be traced back to shielding gas choice—or the lack of it.

In this guide, we break down the most frequent problems found in MIG, TIG, arc, and aluminium welding and show how using the correct gas mix can make a measurable difference in both performance and quality.

Common Welding Problems & Gas Solutions

MIG Welding Problems & Solutions

MIG welding is known for its speed and ease of automation, but it is also prone to several recurring issues.

Typical problems include:

Porosity from poor shielding or contamination
Excessive spatter caused by arc instability
Incomplete fusion due to incorrect heat input
Burn-through on thinner materials

These issues are often caused by improper gas mixes, incorrect flow rates, or contamination of the workpiece or wire. To address them:

Use an argon-CO₂ blend like PACShield® 8020 for general steel applications.
Maintain a gas flow rate of 20–30 CFH to balance shielding without introducing turbulence.
Clean all base materials and ensure dry storage for consumables to minimise contaminants.

TIG Welding Problems & Solutions

TIG welding provides excellent control and clean welds, but its precision also makes it more sensitive to issues.

Common challenges include:

Oxidation caused by inadequate shielding
Lack of fusion from inconsistent heat input
Tungsten contamination due to contact with the base or filler

Most of these stem from shielding gas selection or gas delivery problems. Solutions include:

Use pure argon for standard aluminium and steel TIG welding applications.
For thicker materials, an argon-helium mix enhances penetration and heat control.
Maintain a stable gas flow (typically 15–25 CFH) and use a gas lens to optimise coverage.
Avoid cross-drafts or air movement that can disrupt the gas shield.

Arc Welding Problems & Solutions

Arc (stick) welding is widely used due to its simplicity and portability, but poor technique and equipment settings can still lead to quality issues.

Welders often encounter:

Electrode sticking
Rough or inconsistent weld beads
Inadequate arc control

While traditional stick welding doesn’t rely on external shielding gases, hybrid processes and some advanced applications benefit from improved shielding environments.

To improve outcomes:

Adjust amperage and voltage according to electrode type and material thickness.
Ensure a stable ground and good contact with the workpiece.
In specialised applications, CO₂ or argon mixes may be used to support more stable arcs in semi-automatic or hybrid systems.

Aluminium Welding Problems & Solutions

Aluminium’s properties—such as its rapid heat dissipation and surface oxide layer—make it particularly challenging to weld.

Common problems include:

Porosity and soot
Cracking in the weld or heat-affected zone
Incomplete fusion due to poor shielding

In laser welding, aluminium’s high reflectivity and thermal conductivity can cause:

Irregular weld penetration
Surface defects from poor energy absorption

To mitigate these:

Use high-purity argon or argon-helium mixes to ensure full shielding and adequate heat.
Clean the surface thoroughly to remove oxides and contaminants.
Adjust flow rates and use appropriate nozzles to maintain gas coverage throughout the weld.

See our argon products for shielding options tailored to aluminium.

How to Choose the Right Gas Mix for Welding

Different processes and materials call for different shielding gases. Here are a few quick guidelines:

MIG welding: Use argon-CO₂ blends for mild and stainless steels.
TIG welding: Pure argon is suitable for most applications; add helium for thicker materials.
Aluminium welding: Stick to inert gases like argon or argon-helium mixes.
Laser and hybrid welding: Use high-purity argon to prevent contamination.

Gas purity also affects weld quality. Contaminated shielding gas can introduce defects, especially in sensitive materials like aluminium and stainless steel.

For more detailed comparisons, visit our guide on choosing the right welding gas.

Choose Pacific Gas for Your Welding Gas Needs

High-quality shielding gas is required for consistent, professional, defect-free welding. At Pacific Gas, we provide a wide selection of gases—including argon, CO₂, and oxygen—as well as premium blends like PACShield® 52 and PACShield® 8020, formulated to meet a range of process requirements.

We offer:

Consistent gas quality across all cylinders
Support in selecting the best gas for your application
Reliable delivery and responsive customer service