Welding For Dummies. Steven Robert Farnsworth

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      ❯❯ Paying special attention to welding safety

      ❯❯ Taking a look at welding methods

      ❯❯ Thinking about what’s in store for welding in the future

      Ever since our early ancestors starting making ornaments out of gold thousands of years ago, metal has played an important role in the lives of all people. Just take a second to look around and think about all the various kinds of metal that are nearby. Dozens (if not hundreds) of metal items are probably all around you, and the items that aren’t made out of metal were likely manufactured by using metal equipment.

      By and large, metal is tough stuff. (That’s one of the reasons why it’s so useful, of course.) Throughout history, humans have needed to come up with more and better ways to defy the strength of metals, bending, cutting, and joining it so they can take advantage of its many useful properties. One of the biggest and most important advancements on that front has been the advent and development of welding. Welding allows humans to connect pieces of metal in remarkably strong, sturdy ways, and it has opened up seemingly endless possibilities for what people can do with metallic materials.

      This chapter introduces you to all things welding, including its importance, the materials, equipment, and methods you use to accomplish it, and the need for safety precautions while doing it. In addition, the chapter gives you a glimpse into welding’s crystal ball.

If You Can’t Beat ’Em, Join ’Em: Understanding Why Welding Matters

      Welding is the process of using heat to join metals. When you’re looking to join metals, you can find no easier or more cost effective way to get the job done than welding – it allows you to join metals in a way that’s faster, more versatile, and more dependable than any other process (by a long shot). (And no, using duct tape doesn’t count because that’s not really fixing anything.) The availability and cost of so many of the items you depend on every day are kept within your reach because of the widespread use of welding processes. Just how prominent is welding? Well, it’s estimated that half of the U.S. gross national product is affected by welding. That’s about $7 or 8 trillion. How many other skills or trades can claim that much of an impact? Not many.

      The uses of welding break down into two very broad categories: fabricating and repairing. The following sections offer a little more detail on both of those divisions.

      In welding, fabricating simply means that you’re taking pieces of metal and welding them together to create something new. That can be as simple as welding a few pieces of metal together at a 90-degree angle to make a pair of bookends in the welding shop you set up in your backyard, or as complex as using underwater arc welding to help build a section of submerged pipeline off the coast of Angola. (Don’t worry – you can expect a lot more of the former than the latter in this book!)

      Most metals can be joined by one welding process or another, so in theory you don’t have many limits when it comes to fabricating. However, for a new welder the amount of fabricating you do with your newfound welding skills is often limited to some degree by cost (some metals can be pretty expensive), time (if you’re welding as a hobby, chances are your fabricating time takes a backseat to other obligations like your job and your family), and degree of difficulty. Because developing your welding skills takes time, some fabrication projects may be out of your reach in the short term.

      The difference between fabricating and repairing is simple. When you weld to fabricate, you’re making something new. When you weld to repair, you’re welding on something that already exists but needs fixing or modifying. Repairing can be as simple as welding to fix a tine on your favorite old rake, or welding to fix a crack in a helicopter fitting assembly. (Of course, I lean a lot more toward rake repair than helicopter maintenance in this book!) Although metals are durable and tough, they do break down because of damage or repetitive use, and when that happens, welding is the best way to fix them.

      

The big question with repair work is whether it makes more sense (especially with regard to time and money) to make a repair or simply replace the broken part or product. That’s not always an easy call to make, and I address the various facets of that question in Chapter 18.

      

When you’re welding to repair something, your goal should always be to produce a weld that’s stronger than the original piece or product. If you’re going to be working on something, why not improve it?

      Getting Familiar with Metals

      Any welding endeavor is much easier if you have a solid working knowledge of metals. The more you know about the metals you’re using and how they’re likely to respond to the intense heat involved in welding, the more likely you’ll be able to manipulate and join them in the way you have in mind for a specific project.

      You probably remember from your high-school science class that, like other materials, metals expand when you heat them and contract as they cool off. If you heat them enough, they start to get soft, and eventually (with more heat), they melt. I know that sounds simple, but it’s awfully important for welding. Some metals melt at relatively low temperatures, and others have extremely high melting temperatures. A metal’s melting point is just one of several important properties for welding.

      Here are just a few others to consider: