Exploring the Different Types of CWB-Certified Welding Processes

In structural steel fabrication, there is no “one-size-fits-all” welding method. The choice of process affects everything from the speed of construction to the structural integrity of the joint in extreme weather. At Weld Rich & Steel, our CWB-certified technicians are experts in several key welding processes, each selected based on the project’s specific engineering requirements.

Understanding these processes helps project managers and homeowners understand why a certain technique is chosen for their site or shop-fabricated components.

1. GMAW (Gas Metal Arc Welding) – Commonly Known as MIG

GMAW is the standard for high-speed, high-quality fabrication in a controlled shop environment. It uses a continuous solid wire electrode and a shielding gas (usually a mix of Argon and CO2) to protect the weld pool.

• Best for: Indoor shop fabrication of beams, custom staircases, and stainless steel components.

• Advantages: Extremely clean welds with very little slag. It allows for high productivity and deep penetration in thick structural steel.

• Limitation: Cannot be used outdoors in windy conditions, as the wind will blow away the shielding gas, leading to porosity (weakness) in the weld.

2. FCAW (Flux-Cored Arc Welding)

FCAW uses a tubular flux-cored electrode. Self-shielded and gas-shielded variants have different equipment and environmental requirements; select the process and consumable through the qualified welding procedure.

• Best for: Heavy structural steel erection and on-site welding.

• Advantages: Highly portable and much more tolerant of wind than MIG. It is excellent for thick plates used in industrial frames and heavy-duty lintels.

• Why we use it: It provides high deposition rates, meaning we can complete large structural joints faster without sacrificing strength.

3. SMAW (Shielded Metal Arc Welding) – Commonly Known as Stick

This is the most traditional and versatile form of welding. It uses a consumable electrode (stick) coated in flux.

• Best for: Outdoor repairs, mobile welding in Toronto’s winter, and hard-to-reach structural joints.

• Advantages: It is the most “rugged” process. It doesn’t require gas tanks and can weld through minor surface rust or paint (though we always clean surfaces for CWB-level quality). It is the go-to for on-site emergency repairs.

• Site suitability: SMAW can be useful for field work, but moisture, wind, access, temperature and the qualified procedure still determine whether welding may proceed.

4. MCAW (Metal-Cored Arc Welding)

A high-efficiency variation that combines the benefits of MIG and Flux-Core. It uses a metal-filled tubular wire.

• Best for: Large-scale commercial projects requiring high-volume fabrication.

• Benefits: It produces almost no slag and very little spatter, reducing the time needed for “finishing” and cleaning before painting or galvanizing.

5. How We Choose the Right Process

At Weld Rich & Steel, the selection process is governed by the Welding Procedure Specification (WPS) approved by the CWB. We consider:

1. Environment: Is the work in our shop or on a windy construction site?

2. Material Thickness: Thin-gauge architectural metal vs. 1-inch thick structural beams.

3. Position: Is the weld being done on a table (flat) or overhead on a bridge support?

4. Aesthetics: Does the weld need to be perfectly smooth for a visible staircase, or is it a hidden structural joint?

Expertise You Can Trust

Welding process selection must match the material, joint, position, site conditions and applicable qualified procedure. Confirm the processes required for your project when discussing the scope.

Reference: CWB company certification. Confirm applicable standards, editions and project requirements with the responsible professionals.