Seam welding and stitch welding, they sound like tailoring methods, not techniques for fusing fabrication-grade metal. Both approaches heat metal parts, fuse and join them, and produce superior joints. Nevertheless, there are several key differences between the two welding systems, and we’re here to point out those discrepancies. Let’s start with stitch welding, an approach to metal jointing that has also earned another label.
Deconstructing the Intermittent Welding System
That’s correct, “Stitch Welding” is also known as an intermittent fusing process. Shying away from the tailoring connotations, the intermittent approach welds a predetermined length of the join, leaves a gap, then continues by applying an identically sized weld. Like stitches travelling down the seam of a garment, the dash-to-dash effect travels the entire length of the in-contact surfaces. But why is this intermittent welding pattern employed? Imagine a softer metal or an alloy that doesn’t distribute heat as it’s applied. That alloy would deform and even melt if a continuous welding method was used. In structural applications, stitch welding is utilized when heat extremes are an issue and the weld doesn’t act as a seal.
Building Up the Continuous Welding Process
As any reader can guess from the title we’re using here, “Seam Welding” techniques don’t use the start-and-stop method illustrated in the above passage of text. In place of that recurrent pattern, an uninterrupted weld is utilized. It covers the entire seam, including the corners and curves that shape the path of the edges. Imagine the continuous weld following the lines of two pipe edges. Above and beyond jointing functionality, the weld seals the circular junction, thus creating a leak-free joint, a conduit that can be covered by a chosen fluid medium, be it water or diesel fuel. Make no mistake, seam joints do create superior seals, plus the final welds are more robust than that produced by the stitch welding method. Given the resilience of a continuous joint, why would anyone ever want to use an intermittent seaming solution?
To cut to the chase, stitch welding is less material stressful than the alternative. It’s also a less expensive seam welding technique, one that also works on corners and flat surfaces. Sure, the continuous seam system does produce a fine seal, one that will stop all fluids and atmospheric contaminants, but that particular feature isn’t always covered by the purchase order. If there are doubts, if this isn’t a pipe or a potential material deformation scenario, a quote shouldn’t be provided until the client is aware of both weld seaming methods.