Friday, April 10, 2009

How to Weld Metal

The average person's impression of how metal is welded is that you simply fire-up a blow torch and run it along the edge of a metal seam to weld it together. Or they probably think you can just run that same torch across any kind of metal and cut through it, like in the safe-cracker movies. But the reality is that professional welding actually involves some fairly extensive knowledge, and is somewhat of an art form that takes many years of experience to master. Even so, if you are wanting to learn, you can start with a few simple techniques. Once you've mastered the basics and have a beginner's idea, you can then move on to the more complicated skills that take longer to master.

Safety Precautions

Before you ever start any project, always think about safety precautions first. Equipment and supplies can be replaced; you cannot be replaced. You may think that getting burned is the worst thing that can happen in a welding accident. However, damage to your eyes can occur from the intense light that comes from the process. Some metal welding techniques make use of high voltage electricity to create a weld, which always raises the possibility of electrocution or death if the you are careless. As you start any welding project, be sure to wear a proper helmet to protect your eyes, head and hair. And don't forget protective gloves and clothing. Lastly, be sure to read and follow all safety precautions written by the manufacturer of the particular metal welding equipment you are using.

Oxy-Acetylene Welding (also known as Oxyfuel Welding)

This is the type of welding that the average person is most familiar with, and which is often casually described as a "blow torch". However, even though oxy-acetylene welding is the most commonly-known type, it is actually the least used technique among professionals. On the upside, it is less complicated and less expensive than other types of welding. However, oxy-acetylene is less common nowadays because it is less accurate, doesn't produce a weld bead as cleanly as other methods and can result in weaker weld joints due to the slower cooling time it involves compared to other welding techniques. Even so, if you are interested in learning how to weld metal, you may want to practice oxy-acetylene welding in addition to other types of welding. It will be a handy skill to have because it's the best type to use on certain common welding projects, such as pipes or tubes, and when you have to use welding equipment to do repairing, bending and cutting.

Arc Welding

The most common technique used these days is "Arc Welding". If you're learning how to weld metal, you will definitely need to practice arc welding. Rather than using a gas torch, arc welding involves using high voltage electricity passing into the piece of metal. In Arc Welding, a spark (or "arc") jumping across from one piece of metal to the other causes enough heat to melt metal and form a weld. This process is more desirable in most cases because it is more accurate and produces a cleaner, stronger weld. Within the category of "Arc Welding" there are actually several different methods to choose from, depending on the type of metal welding work you need to do.

Shielded Metal Arc Welding (SMAW) may be best when you have large welds or metal welding in unusual positions, where a rough weld is acceptable. With this method, the electricity runs through an electrode rod (or "stick") which actually melts, producing the welded joint. On the other hand, MIG Welding, also know as Metal Inert Gas Welding, or Gas Metal Arc Welding (GMAW), may be better if you are involved in a metal welding project that requires more speed. With this welding technique you don't use rods that you have to keep replacing as they melt. Instead, you use equipment that sends the electricity through a metal tip that doesn't melt, and a separate piece of continuous wire is fed to the tip which melts and forms the weld. TIG (Tungsten Inert Gas) Welding is somewhat similar to MIG welding, but is better when working with thin materials where you need a high-quality weld and speed is not important. As you learn you will also hear of other methods, such as Flux-Cored Arc Welding (FCAW), Submerged Arc Welding (SAW), Plasma Welding, etc. But don't worry too much about remembering all of the various techniques. Just focus on one method at a time and get to the point where you are comfortable that you know how to weld with that method before you learn something new.

Other Welding Methods

Although you will primarily be concerned with Arc Welding and Oxy-Acetylene Welding as you learn how to weld, you might hear about other types and wonder what they are, such as Resistance Welding, Energy Beam Welding and Solid-State Welding. Don't let that overwhelm you right now. Many of those welding methods are primarily useful in large, specialized industrial applications and don't really affect you as you learn how to weld.

Conclusion

Hopefully you now know a little more about the basic concepts that will be important to you as you learn how to weld. As you can see, although there are numerous methods, each with it's own unique set of equipment, procedures and purposes, there are actually only a couple of basic methods you need to remember and practice. To get started learning, start practicing with an inexpensive arc welding setup. Get yourself a machine and just start experimenting with it on some scrap pieces of metal (after reading all instructions and taking all safety precautions, or course). Figure out what works, and what doesn't. You will soon begin to develop a style that is most comfortable for you. Also, get yourself some oxy-acetylene equipment and try that type, too. With a lot of practice, you will become a good novice fairly quickly and will be able to master just about any common project you may encounter.

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