Thursday, February 26, 2026

The Importance of Welding Theory in a Practical Environment

A good foundation of theoretical knowledge makes everything about the practical job easier.

By David Chalut, CLAC Welding Examiner & Instructor

When I first started as an apprentice in the trade 20 years ago, I quite often heard the older welders say things like, “I haven’t thought about the theory since I became a Journeyperson,” or “I don’t remember what the theory said.”

The one thing I noticed early on was the welders who had this mindset struggled more with welds they didn’t do regularly. They had a hard time selecting settings or employing the correct techniques for a given weld. Apprentices learn a lot of what we know from our Journeypersons, and what I learned the most from Journeypersons with this mindset is that I really want to know my theory.

I struggled with my hand skills early on as an apprentice. I didn’t improve as quickly as I would have liked no matter how much time I spent practicing on my own. That improvement came hand-in-hand with my knowledge of the theory behind welding. Once I started to understand the concepts of the science behind what I was doing, I improved greatly and quickly. Once I understood that I cannot change the laws of nature or the science of metallurgy, I stopped fighting it and used it to my advantage.

Things like knowing that voltage is responsible for the fluidity of the weld puddle or that amperage is responsible for the amount of penetration; or that understanding the thermal conductivity of a given material will make selecting parameters for welding it correctly much easier. Knowing what the electrode angle should be can help ensure that the weld penetrates the joint correctly and the weld goes where it is supposed to. Understanding and employing the correct arc length or electrode extension helps ensure that the consumable being used is melting off correctly and makes certain that the arc is operating in a manner that reflects the settings a welder has set it to.

Another reason it was so important to me to understand the theory of welding is so that I can pass this information on to the apprentices of this and the future generations of welders. Apprentices rely on their Journeyperson for their own growth in the trade and it is important to me to be able to help them achieve their goals. My favourite moments as an instructor are the moments when I see the lightbulb go off for an apprentice: that moment where they understand the theory and see it being applied practically. I call it their “ah-ha! moment,” and it often precedes the most growth they will see during training with me. Those are the days I go home with an even bigger smile on my face.

One final thought on this as I get older and my role has shifted to other areas of the trade, like examining and procedure development: Theory knowledge has made my new roles much easier, and when I do get to go weld again, it doesn’t take nearly as long to get my hand skills back. I truly believe that a good foundation of theoretical knowledge makes everything about the practical job that much easier.

The Importance of Welding Theory in a Practical Environment

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