Signs of a Bad Welding Job: The Importance of Choosing the Right Welding Professionals

02 July 2019

Facts are absolutes. There’s no room for shades of grey when talking about facts. Here’s one such self-evident truth: work on structural steel projects can be undermined by a bad weld. No ifs-and-buts about it, every frame joint must be performed flawlessly. That dictum can be applied to some degree or another on just about any welding job. For structural steel, though, it’s an absolutely vital rule.

Substandard Welds Compromise Construction Projects

If the welder is a hobbyist or a craftsperson who creates welded works of art, they can play fast and loose with the rules. That’s not an option that can be entertained when structural steel elements are being welded. For one thing, the scale is different. Unlike a garage-based hobbyist, the beams and sheet metal sections that have been machined to suit this work are large and heavy. Cranes lift and manipulate them into place, then a welder finishes anchoring the parts in place. Secondly, because of their size and mass, gravity weighs heavily here, and the weather billowing around a structure just worsens matters. Strong winds, seismic events, rust and chemical attacks, there’s no limit to the number of challenges.

Identifying Signs of Bad Welds

What’s the biggest take away from the last passage of text? Clearly, welding professionals need to do their job or get out of the way so that another certified pro can take over. Assuming a welding inspector has done his rounds, what kind of problems has he found? Well, a skinny weld line isn’t going to support a load-bearing structure. Porosity problems are listed, too. Cracks and fusion discontinuities are spotted on another weld. If the building frame gets hit by a heavy wind, those cracks will propagate. The weld could even be discoloured, with signs of oxidization covering several centimetres of the joint. Worse still, some of the weld is missing or it’s not penetrating to the root of the joint, probably because the welder didn’t use enough filler rod.

In pressure vessels, weld professionals create deep-rooted seams that are designed to contain high-pressure fluid loads. A bad weld here could end up causing a nasty leak, and, worst-case scenario, that leak could combust. On a structural steel project, it’s much the same situation. Without the right welding professional, someone who can stick weld or operate a TIG or MIG rig, load-bearing elements could fail. Frankly speaking, weld inspectors provide a structural performance safety net, but that doesn’t mean a poor welder should be allowed to keep right on working. Short and to the point, accredited welding professionals are favoured by weld inspectors and structure designers alike.