Welding is a core process in metal fabrication that can quite literally make or break a metal product. It is the best way to join two metal pieces together with our current technology, and likely will be so for many more decades to come. It is not just important for structural engineering. Metal products at home and urban structures rely on welding, making it a crucial factor in evaluating the quality of metal fabrication. But how exactly does one tell if a weld is done well or not? That’s what we at Topweld, Griffith’s top aluminum and stainless steel fabricator, are here to share with you.
How Does Welding Work?
The main idea of welding is very simple. We use heat to melt the surface of two or more metal pieces and then join them together in the form we want before they cool and harden once more. This began in the middle ages with blacksmiths hammering hot metal pieces together and in the present, we have various welding techniques available to fit different kinds of works, the most widely-used being arc welding in industrial work. Under this category is Metal Inert Gas (MIG) welding, Shielded Metal Arc Welding (S.M.A.W. or Stick) welding, Tungsten Inert Gas (TIG) welding, and Flux Core welding. These techniques may vary in terms of the tools they use or the specific manner in which they move along the workpiece, but the fundamental steps in welding remain the same. As such, they may share similar signs of a bad weld.
Uneven Size and Shape
A uniform and robust weld is ideal, while a weld bead that looks like spray-painted string on the corner means the welder went too fast or had a low wire feeder speed.The implications of welds like these are less overall durability and incomplete penetration. It is a huge red flag to structural inspectors who find these in critical load-bearing components.
Bubbles and/or Small Holes
Small holes on the surface of the weld indicate porosity which is when inert gas like hydrogen, nitrogen, and oxygen get trapped within the weld and form tiny air pockets. Aside from the trypophobia-inducing spongy look, porosity also makes the joint more prone to cracking and breaking altogether. There can be many causes of porosity, but it is often because of poor shielded gas handling or foreign material present in the workpiece before the weld. If having difficulty, it’s best to let the professionals that offers welding and fabrication services in Young, NSW handle it or you can ask for advice.
Groves or Protrusions in the Weld Root
These small gaps are called undercuts and are caused by a myriad of reasons such as lack of penetration, improper weld technique, or mishandling of the workpiece. These grooves, much like other entries in this list, present a clear and dangerous area of vulnerability for the joint. Usually, a gap may form in a single side of the weld, but there are instances of both sides having roots, which indicate very poor penetration and fusion of the metals. On the opposite end of the spectrum, a small hill protruding from the other side of a weld is a sign of excessive penetration which is also bad because it may erode over time.
This is far more common in Stick welding than in other techniques. Splatter from the weld pool can displace and scatter molten metal around the bead, making the joint weaker and less appealing.. It is mostly a danger to the welder, as these droplets of molten metal can burn their clothes or skin.
So ends this short list of the common signs of poor weld work. If you notice any of these in your own work, be sure to fix them immediately. Welding is not exactly the easiest type of work, but it’s nothing a little practice can’t help. If things just aren’t working out, you can always seek assistance from the best welding services in New South Wales. Good luck, and happy welding!