Welding For Dummies E-Book

Steven Robert Farnsworth

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 503

Veröffentlichungsjahr: 2010

Beschreibung

Get the know-how to weld like a pro Being a skilled welder is a hot commodity in today's job market, as well as a handy talent for industrious do-it-yourself repairpersons and hobbyists. Welding For Dummies gives you all the information you need to perform this commonly used, yet complex, task. This friendly, practical guide takes you from evaluating the material to be welded all the way through the step-by-step welding process, and everything in between. Plus, you'll get easy-to-follow guidance on how to apply finishing techniques and advice on how to adhere to safety procedures. * Explains each type of welding, including stick, tig, mig, and fluxcore welding, as well as oxyfuel cutting, which receives sparse coverage in other books on welding * Tips on the best welding technique to choose for a specific project * Required training and certification information Whether you have no prior experience in welding or are looking for a thorough reference to supplement traditional welding instruction, the easy-to-understand information in Welding For Dummies is the ultimate resource for mastering this intricate skill.

Leseprobe

Welding For Dummies®

Table of Contents

Introduction

About This Book

Conventions Used in This Book

What You’re Not To Read

Foolish Assumptions

How This Book Is Organized

Part I: Understanding Welding Basics

Part II: Welding on a Budget: Stick and Tig Welding

Part III: Discovering Mig Welding

Part IV: Getting Fancy: Plasma Cutting, Oxyfuel Cutting, and Other Processes

Part V: Putting Welding into Action with Projects and Repairs

Part VI: The Part of Tens

Icons Used in This Book

Where to Go from Here

Part I: Understanding Welding Basics

Chapter 1: Diving Into the World of Welding

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

Fabricating metal products

Repairing metal pieces or products

Getting Familiar with Metals

Steel

Stainless steel

Aluminum

Taking the Time to Understand Welding Safety

Exploring Welding Methods

Stick welding

Mig welding

Tig welding

Other welding methods

Looking at the Future of Welding

Chapter 2: Considering Commonly Welded Metals

Steeling Yourself for Using Steel

Getting a handle on forms of steel

Knowing when steel is appropriate

Preparing steel for welding

Exploring steel welding methods

Going with Stainless Steel

Understanding the differences between steel and stainless steel

Deciding when to use stainless steel

Looking at stainless steel welding methods

Working with Aluminum

Perusing the properties of aluminum

Eyeing aluminum welding techniques

Considering Other Metals

Chapter 3: Setting Your Sights on Welding Safety

Gearing Up to Protect Yourself

Choosing eye protection

Keeping the right fire extinguisher on hand

Wearing protective clothing

Watching health hazards: Using a respirator and Material Safety Data Sheets

Observing Basic Safety Rules

Keeping your work space clean

Checking for leaks

Getting the ventilation right

Storing flammable liquids and gases

Knowing your surroundings

Protecting yourself from electric shock

Shielding yourself from burns

Maintaining your equipment

Being Prepared for Injuries and Accidents

Equipping your first-aid kit

Knowing how to handle injuries

Chapter 4: Setting Up Your Welding Shop

Choosing a Location

Deciding how much space you need

Contemplating indoor versus outdoor

Equipping Your Welding Shop

Making sure you have the basic hand tools

Choosing a welding table

Selecting your welding machine

Considering a few accessories for your welding shop

Part II: Welding on a Budget: Stick and Tig Welding

Chapter 5: Getting on the Stick: Understanding Stick Welding

Looking at the Pros and Cons of Stick Welding

Understanding the Factors That Influence Stick Welding

Getting Familiar with Stick Welding Equipment

Discovering the differences among stick welding machines

Setting up your stick welding machine

Nailing down the basics of stick welding’s electrodes

Choosing tools and supplies every stick welder needs

Chapter 6: Getting to Work with Stick Welding

Preparing to Stick Weld

Setting up your work area

Understanding stick welding electrodes

Setting the Machine

Choosing polarity

Setting the amperage

Preparing to weld

Striking and Maintaining an Arc

Assume the Position: Stick Welding in All Positions

Welding on a flat surface

Going vertical

Exploring horizontal welding

Reaching overhead

Chapter 7: To Tig or Not To Tig: Understanding Tig Welding

Taking a Closer Look at Tig Welding Components

Considering the Advantages and Disadvantages of Tig Welding

Brushing Up on Tig Welding Basics

Showing your metal: Looking at a few metals for tig welding

Taking steps to ensure quality welds

Stocking the Shop: Examining Tig Welding Equipment

Considering fully equipped tig machines

Thinking about tig torches

Selecting and managing shielding gas

Controlling current and amperage

Selecting filler metal

Exploring tungsten electrodes

Chapter 8: Trying Out Tig Welding

Getting Your Welding Setup Tig-ether

Taking care of tungsten electrode details

Making sure your shielding gas is set up correctly

Figuring out your tig filler rods

Matching Materials and Settings

Getting a Handle on Using Your Tig Torch

Choosing an electrical current and striking the arc

Get a grip: Holding your tig torch correctly

Giving Tig Welding a Try

Tackling the first weld

Trying a butt joint

Welding a lap joint

Making a T joint

Part III: Discovering Mig Welding

Chapter 9: Understanding the ABCs of Mig Welding

Understanding How Mig Welding Works

Considering Mig Welding’s Advantages and Limitations

Bringing out the Big Guns (And Other Mig Welding Equipment)

Mig welding machines

Mig welding guns

Electrode wire feeders

Sifting through Shielding Gases for Mig Welding

Taking a Look at Electrode Wire

Adjusting Mig Equipment to Suit Your Mig Welding Project

Chapter 10: Practicing Mig Welding

Preparing to Mig Weld

Getting the equipment ready

Setting the wire feed speed and voltage

Trying Out Mig Welding

Making vertical mig welds

Joining pieces of sheet metal

Watching Out for Common Mig Welding Defects

Part IV: Getting Fancy: Plasma Cutting, Oxyfuel Cutting, and Other Processes

Chapter 11: Examining Plasma and Oxyfuel Cutting

Understanding Plasma Arc Cutting

Identifying some good materials for plasma cutting

Taking a look at plasma cutting’s advantages and disadvantages

Perusing and Preparing Plasma Arc Cutting Equipment

Getting a handle on plasma cutting equipment

Setting the equipment up properly

Exploring Oxyfuel Cutting Basics

Considering what you can (and can’t) cut with oxyfuel

Looking at the pros and cons of oxyfuel cutting

Checking Out and Setting Up Oxyfuel Cutting Equipment

Examining oxyfuel cutting equipment

Deciding among different gas cylinder sizes

Setting up oxyfuel cutting equipment

Chapter 12: Ready, Set, Cut! Trying Out Plasma Arc Cutting and Oxyfuel Cutting

Exploring Plasma Arc Cutting

Slicing a straight line

Cutting a circle

Creating a bevel

Practicing Oxyfuel Cutting

Lighting the torch

Making a straight cut

Cutting out a circle

Taking on a beveled edge

Chapter 13: Exploring Special Weld Processes

Working through the Basics of Welding with Gas

Taking a gander at gas cylinders

Looking at more gas welding equipment

Getting to work with gas welding

Discovering Brazing (Braze Welding)

Keeping a few brazing rules in mind

Giving brazing a try

Finding Out about Fusion Welding

Soldering On: Exploring Soldering

Following the rules of soldering

Understanding the two types of soldering

Trying the soldering process

Chapter 14: Exploring Pipe Welding

Delving into the Different Kinds of Pipe

Getting Down to Welding Steel Pipes

Getting set up and preparing the pipe

Making the tacks

Welding the pipes

Trying some other angles

Peeking at a Few More Types of Pipe Welding Joints

Keeping an Eye Out for Common Pipe Welding Defects

Chapter 15: Working with Cast Iron

Casting Light on the Three Most Common Types of Cast Iron

Gray cast iron

Malleable cast iron

Nodular cast iron

Getting the (Cast) Iron in the Fire: Welding Gray Cast Iron

Stick welding cast iron

Oxyfuel welding cast iron

Mig welding cast iron

Part V: Putting Welding into Action with Projects and Repairs

Chapter 16: Two Welding Projects to Boost Your Welding Shop

Creating a Torch Cart

Gathering the materials

Acquiring the right steel pieces

Measuring and cutting pieces

Making the welds

Adding the wheels

Checking your welds

Picking out your paint

Fabricating Your Own Portable Welding Table

Rounding up your tools

Picking out the parts

Assembling the pieces

Ensuring smooth edges

Choosing your paint

Putting on the wheels

Chapter 17: Constructing a Campfire Grill

Fabricating a Campfire Grill

Getting your tools in order

Obtaining the proper steel pieces

Cutting the steel pieces to length

Welding the grill

Picking out your paint

Seasoning the cooking surface

Chapter 18: Fixin’ to Fix Things: Analyzing and Planning

Determining Whether Something Is Fixable

Planning a Repair Strategy

Identifying the metal and what it means for the repair

Deciding which welding process to use for your repair

Making and following your plan

Getting Ready to Make Repair Welds

Preparing your repair piece and work area

Gathering your equipment and tools

Selecting filler rods and electrodes

Considering Cracks

Part VI: The Part of Tens

Chapter 19: Ten Tools Every Welder Wants

41⁄2-Inch Grinder

Hacksaw

Air Compressor

3⁄8-Inch Electric Drill

Wrench Set

Steel Sawhorses

Cutoff Saw

Bench Grinder

Bottle Jack

Toolbox

Chapter 20: (Not Quite) Ten Advantages of Being a Certified Welder

More Job Opportunities

Better Pay

More Chances for Advancement

Certification that Travels with You

Ability to Join a National Organization

Qualification in Specific Areas of Welding

Increased Confidence in Your Welding Skills

Listing in the American Welding Society Database

A Head Start on Additional Types of Welding Certification

Chapter 21: (Almost) Ten Welding Defects

Incomplete Penetration

Incomplete Fusion

Undercutting

Slag Inclusions

Flux Inclusions

Porosity

Cracks

Warpage

Spatter

Chapter 22: Ten Signs You’re Welding Correctly

The Weld Is Distributed Equally between Parts

The Slag or Shielding Material Doesn’t Stick to the Weld

No Holes or Irregularities on the Weld Surface

The Weld Is Tight

The Weld Is Leakproof

The Weld Has Full Penetration

The Weld Has No Undercutting

The Weld Has No Overlap

The Weld Meets Strength Requirements

You’re Safe and Healthy

Chapter 23: Ten Maintenance Tips for Your Welding Equipment and Shop

Checking on Your Hand Tools

Taking Care of Power Tools

Doing Basic Housekeeping in the Shop

Protecting Your Welding Helmet

Seeing to Stick Welding Machine Maintenance

Working on Maintaining Your Mig Welding Machine

Tuning Up Your Tig Welding Machine

Taking Care of Your Oxyfuel Equipment

Keeping Your Air Compressor Working

Drill Press Maintenance

Glossary

Welding For Dummies®

by Steven Robert Farnsworth

Welding For Dummies®

Published byWiley Publishing, Inc.111 River St.Hoboken, NJ 07030-5774www.wiley.com

Copyright © 2010 by Wiley Publishing, Inc., Indianapolis, Indiana

Published simultaneously in Canada

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Library of Congress Control Number: 2010933466

ISBN: 978-0-470-45596-8

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About the Author

Steven Robert Farnsworth hails from Iowa, close to the age of dirt being born in 1955. He attended Archer School until they closed it and went on to Sanborn Community High School, where he graduated in 1973. He was one of the lucky ones. While attending high school, he also attended a vocational school, graduating with a welding diploma.

Steve enlisted in the U.S. Navy in July of 1973. After boot camp, he attended HTA (Hull Maintenance Technician) in San Diego, California, and transferred to the USS ARD 30 (the floating dry dock for fast attack submarines), where he worked in the repair division. Steve was then sent to C1 Welding School in San Diego, where he qualified as a high pressure plate and high pressure pipe welder. After attending C1 Welding School, he was transferred to the USS Basilone DD824 until his honorable discharge in July of 1977. Steve began his civilian career at a construction company in Spencer, Iowa, working as the welder, semi driver, and heavy equipment operator. In August 1979, he acquired the position of Welding Instructor at Iowa Lakes Community College, teaching the following classes:

Oxyacetylene Theory and Lab

Electric Arc Theory and Lab

Structural Welding

Brazing and Soldering

Mig and Tig Theory

Mig and Tig Lab

Pipe Welding

Production Welding

Special Processes

In 1984 Steve left teaching and went back into the Navy, receiving orders to the USS White Plains AFS-4 (the Orient Express), home ported in Guam. After 36 months, he received orders to the USS Hunley AS-31, home ported out of Norfolk, Virginia. After four years in that naval tour, he returned to instructing at Iowa Lakes Community College and has been there ever since. Steve is a Certified Welding Educator and Certified Welding Inspector through the American Welding Society.

Dedication

I dedicate this book to all the welders and welding students who put everything together that makes this world go around. I cannot imagine a world without welded products. So thank you, welders who have breathed a little smoke and saw the flash of products being welded together. I would also like to thank Iowa Lakes Community College for allowing me to write this book and putting up with me for all these years.

Author’s Acknowledgments

When I was young, my first job was moving chicken manure for 90 cents an hour. (Believe me, you never had a cold after you scooped that stuff.) Welding at the local factory paid 35 cents more an hour. (Wouldn’t you change jobs?) At that time, who would have ever thought I would author a book on something that I enjoy doing? I would like to thank all the people who have helped me teach welding students how to weld over the last 25+ years. I hope this welding book helps you become the welder that you want to be.

Publisher’s Acknowledgments

We’re proud of this book; please send us your comments at http://dummies.custhelp.com. For other comments, please contact our Customer Care Department within the U.S. at 877-762-2974, outside the U.S. at 317-572-3993, or fax [phone].

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Introduction

Welding has become one of the most important trades in the world, and that isn’t likely to change anytime in the near future. So many of the objects people have and need are created either directly or indirectly by welding. If everyone woke up one morning and no one could remember how to join metals, the world would be a very different place by the afternoon.

But welding isn’t just important — it’s also fun. The idea of welding as a hobby is catching on more and more. It’s an extremely versatile skill that can be quite rewarding after you get the hang of it. Something is very empowering about knowing that you can harness some pretty powerful forces — electricity and intense heat — to melt metals and join them together. Even experienced welders get a kick out of the fact that they can take a machine and a few pieces of metal and create something new, functional, and even beautiful. That’s an extremely fulfilling feeling, and I think it’s a product of welding that people don’t always mention when they talk about the trade.

One quality of welding that people do talk about a lot is its usefulness. You can use welding skills to accomplish a lot, whether you want to eventually make a career out of welding or just have the ability to make and fix metal objects for your personal pursuits. Over the years I’ve taught and worked with both kinds of welders, and I know that after they really figured out the ins and outs of welding, they were able to do things that made their personal and professional lives a lot easier.

About This Book

Welding For Dummies helps you understand the basics of how welding works and lets you begin practicing several of the most prominent and useful welding techniques. I walk you through the fundamentals that hold true for all types of welding, and I dig into the details of specific welding processes — stick, mig, tig, and more — to show you how to practice those skills in a safe, productive way. Don’t worry; I don’t have you welding the Statue of Liberty’s torch back onto her hand or anything, but I do hope this book puts you well on your way to achieving the welding goals you’ve set for yourself.

One of my favorite aspects of Welding For Dummies is that you can move around within it however you want and still end up with a huge amount of welding knowledge. You may initially be interested in one welding process but quickly discover you should be reading about a totally different process, and that’s okay — you can jump to that other discussion without worrying that you’ve missed something important. Just beware of paper cuts from flipping back and forth between chapters.

Conventions Used in This Book

Here are a few conventions I use to make reading this book even easier:

The world of welding is full of jargon, so I present new terminology in italics and make sure to give a definition nearby.

Bold text highlights the action parts of numbered steps and also designates keywords in bulleted lists.

I’ve tried to stick to welding standards supported by the American Welding Society (AWS), which is the largest and most prominent welding organization in the United States.

All Web addresses appear in monofont. When this book was printed, some Web addresses may have needed to break across two lines of text. If that happened, rest assured that the address doesn’t contain any extra characters (such as hyphens) to indicate the break. So when using one of these Web addresses, just type in exactly what you see in this book, pretending as though the line break doesn’t exist.

What You’re Not To Read

Far be it from me to tell you what you should read, but allow me to make one quick point. In several spots throughout this book, I include sidebars (gray shaded boxes) that contain interesting (and possibly entertaining, depending on what kind of mood you’re in) information that you don’t absolutely have to read in order to understand and practice welding. If the how-to, functional information in the book is the entrée, the sidebars are like garnish. Not parsley, though — I like to think that the sidebars are at least a little more interesting and useful than an herb that tastes funny and doesn’t do much more than crowd a plate. You can also skip anything with a Technical Stuff icon; this information is more technically involved than the basics you need to weld.

Foolish Assumptions

I’m not really crazy about guesswork, but I did make a few assumptions about you as I wrote this book. (They’re all nice, I promise.) If any of the following statements applies to you, this book is for you.

You’ve never welded but want to know more about metals and how to join them by using welding.

You’ve welded a little but really want to figure out how to improve and start taking advantage of all welding has to offer.

You’ve done a fair amount of one type of welding but want to expand your skill set so you can weld with a variety of different processes and techniques.

You understand a few basic tools (such as hammers and screwdrivers) and what they do.

You know how important taking necessary safety precautions is to keep yourself (and others) out of harm’s way.

How This Book Is Organized

This book is divided into six parts. Each part offers something different, but all of them are geared toward helping you figure out welding processes and put them to good use. Here’s a quick look at what you can find in each part.

Part I: Understanding Welding Basics

This part provides the kind of welding information that crosses all types of welding. If you’re really just starting out in welding, this part is a good first stop for you because it gives you the lowdown on metals (especially the ones that are commonly used in welding), the tools and equipment you use for welding, and the kind of environment you need in order to weld successfully. It also includes the chapter that’s without a doubt the most important one in the book. That’s Chapter 3, and it’s all about welding safety.

If you read only one chapter in the book, let it be Chapter 3. Welding is a fantastic skill, but it’s not worth getting hurt over.

Part II: Welding on a Budget: Stick and Tig Welding

Part II focuses on stick welding (the most commonly used welding process) and tig welding (also a great, useful technique). You can read all about the advantages and disadvantages of both stick and tig and understand how they work and what makes them unique. I explain the different equipment you need if you want to get into stick or tig welding, and I also give you plenty of information on how you can try out the techniques.

Part III: Discovering Mig Welding

Mig welding is a fast, efficient welding process, and it’s great for new welders because it’s relatively easy to pick up and get started with. I devote Part III to the basics of understanding and executing mig welding.

Part IV: Getting Fancy: Plasma Cutting, Oxyfuel Cutting, and Other Processes

Arc welding isn’t the only way you can weld — welding includes lots of other processes, such as soldering, brazing, and gas welding, that are all useful in their own distinct ways. I cover those processes in Part IV.

I also cover a few cutting processes in this part, because cutting is an important task in any welding shop, and you’ll probably need to do some (or a lot) of it if you stick with welding for any extended period of time.

Part V: Putting Welding into Action with Projects and Repairs

This part is probably the most fun because it gives you a chance to try out your welding skills and build some great, useful items. The chapters contain a welding project or two that is designed with the beginning welder in mind. You can read about how to build a portable welding table, a torch cart, a campfire grill, and more! This part also includes a chapter that helps you to figure out whether fixing something or buying (or building) it new makes more sense.

Part VI: The Part of Tens

If you’ve read a For Dummies book before, you already know all about this part. The Part of Tens is always a favorite; it features lists full of useful information in an extremely easy-to-read format. You can read about the advantages to becoming a certified welder, the tools that every welder wants, and more. There’s also a glossary to help you with basic welding terminology.

Icons Used in This Book

Throughout the book, you’ll occasionally notice little pictures in the margins. These icons help flag specific information I want to highlight; check out the following list for details on what those icons indicate.

When you see this icon, expect to find a helpful bit of information that will help save you time and money and keep you from making mistakes when you’re welding.

If I really want you to slow down and commit something to memory, I use this icon. It’s important stuff, so take the time to read it!

The last thing I want is for you to get hurt, or for you to hurt others or damage property. With that in mind, please pay attention to these icons so you can keep from hurting someone (yourself included) or damaging your equipment or surroundings.

This icon denotes technical or historical information that’s more involved than what you need for your basic welding practice.

Where to Go from Here

I know what you’re thinking: With all of this terrific, useful welding information, where do I begin?

I certainly don’t want to tell you what aspect of welding you should want to read about first — that’s for you to decide — but I do make one request. If you’re new to welding, or if you aren’t completely familiar with the practices of welding safety, please go directly to Chapter 3 and read up on it. You really do need to know how to keep yourself safe as you start or continue your welding experience, and Chapter 3 goes a long way toward keeping you out of harm’s way.

After you’re done reading Chapter 3, please feel free to jump around in the book however you see fit. There’s a whole world of welding out there, and Welding For Dummies is a great way for you to start exploring it.

Part I

Understanding Welding Basics

In this part . . .

Welding isn’t the type of skill that you can jump into without any background information, or at least a basic understanding of how it all works. (That’s why mother birds push their chicks out of the nest and make them fly instead of pushing them out and making them mig weld.)

With that in mind (the part about welding, not the part about the chicks), in this part I tell you all about metals — specifically, those you’re likely to work with as a beginning welder. I also take a full chapter to clue you in on how to set up your welding shop, which may be trickier than you think. (No, you can’t just clear the junk out of one corner of your garage and start welding there.) This part also contains the most important chapter in the book: the safety chapter. You can jump around all you want in this book, and read whatever you feel like. But unless you already know all about welding safety (and even if you do), I beg you to read Chapter 3 before you try any sort of welding operation.

Chapter 1

Diving Into the World of Welding

In This Chapter

Discovering the main uses for welding

Examining common welding metals

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.

Fabricating metal products

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.

Repairing metal pieces or products

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?

Tracing the history of welding

Welding is one of the newest metal-working trades; it can be traced back to about 1000 B.C. Most historians agree that the first kind of welding done by humans was the lap welding of gold, which was used to create simple gold ornaments. But welding really started to take shape when people figured out how to hammer brass and copper together to make bronze. Bronze was a real game changer, especially when it came to making basic types of farming equipment and tools, or weapons of war.

The next big jump in technology was during the Industrial Revolution (from the mid-1700s to the mid-1800s). That’s when hammer welding (also known as forge welding) was developed. In hammer welding, metal is heated to its plastic state, and then two separate pieces are laid side by side and hammered together. (If you’ve ever seen a blacksmith at work, you’ve seen hammer welding in action.)

The next step was based on the discovery of acetylene in the middle of the 19th century. Controlled use of acetylene gas (combined with oxygen) allowed people to cut and melt metals in a way that wasn’t possible before. But welding as you know it today came about in the early 20th century, after people had learned how to harness and use electricity. Very basic electric welding equipment and techniques were already being used across the globe at that point, and World War I made it clear that welding technology was going to be critically important for cranking out massive amounts of metal materials, tools, and machinery. Many of the prominent organizations and companies that loom large in the world of welding today got their start during that period. Improvements in welding processes and equipment came in leaps and bounds, and before the first half of the 20th century was over, the world had seen the creation of the major welding techniques that I cover in this book: stick welding, mig welding, tig welding, and oxyacetylene welding, as well as oxyfuel welding and cutting.

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.

Ductility is a metal’s ability to change shape (bend, stretch, and so on) without breaking. Gold has a high level of ductility, while tungsten isn’t very ductile at all.

Electrical conductivity is a measure of how well a metal can conduct a current of electricity. Copper conducts electricity really well; by comparison, stainless steel isn’t a great conductor of electricity.

Strength is pretty self explanatory: How much external force can a metal withstand without breaking? This one is very important for welding. Steel is a strong metal, but zinc isn’t.

You can read up on many more properties of metal, and the more you know, the more easily you can make smart decisions about how to weld those metals effectively.

Not all metals are widely used for welding, of course, and you probably won’t work with a huge range of metals in your welding shop until you’ve been welding for a while. That’s completely fine, however, because plenty of exciting welding projects — both fabricating and repairing — involve only a few select metals. (See “If You Can’t Beat ’Em, Join ’Em: Understanding Why Welding Matters” earlier in the chapter for more on those divisions.) For example, most of the welding practice exercises I walk you through in this book, as well as the welding projects I detail in Part V, focus on three metals: steel, stainless steel, and aluminum. These three are the most commonly used metals for beginning welders, and you should take the time to get to know them. In the following sections, I give you a quick look at each one.

Steel

Steel is a strong, versatile metal that you’ll use all the time in your welding projects. You may not realize it, but steel is really an alloy made up of iron and less than 2 percent of another material. Carbon is often used in steel alloys, and you can find three different levels of carbon steel: low-, medium-, and high-carbon steel. The more carbon in the steel, the stronger the alloy is.

You should use steel in your welding projects when you’re looking for a strong metal that’s pretty easy to weld and doesn’t break the bank when you’re buying your materials. You can use any welding process I describe in this book on steel, so versatility is also one of its strong suits. But steel also has its downsides. For one, it’s heavy. If you want your fabricated project to be light, steel probably isn’t your best bet. Steel is also prone to rusting and scaling (flaking off due to oxidation), so you have to spend a fair amount of time cleaning it up (often with a grinder) before and sometimes during welding.

Stainless steel

Stainless steel is amazing stuff. It has a lot of the good qualities that regular steel has (see the preceding section), but it also offers one added bonus: It resists corrosion (rust, for instance) like a champ. You can put a piece of stainless steel out in the yard and let it get rained on for six weeks, and when you bring it back inside it probably won’t have a single spot of rust on it. Incredible!

How does stainless steel provide such remarkable resistance to corrosion? Its alloy contains 10 to 30 percent chromium (the rest is iron, although sometimes other metals, such as nickel, are also added to the alloy).

You can weld stainless steel with all three of the major types of arc welding (stick, mig, and tig). It’s a great choice if you want your project to resist rusting or to have hygienic surfaces (those that don’t harbor bacteria and other microscopic critters).

Stainless steel is pretty expensive compared to other commonly welded metals, so be prepared to open your wallet a little wider if you choose stainless steel for a welding project.

Aluminum

Like stainless steel, aluminum is great at resisting corrosion. And aluminum offers another pretty terrific characteristic: It’s lightweight. Compared to steel and stainless steel, aluminum is a real featherweight.

Pure aluminum is a popular choice for welders, but aluminum alloys are also frequently used. Copper, manganese, and zinc are just a few of the metals that are often alloyed with aluminum to produce enhanced characteristics in the finished product.

If you’re going to be welding aluminum, I recommend going with tig welding. It just makes for a cleaner, easier job. If tig isn’t an option, take mig welding; you can stick weld aluminum, but it’s not ideal — your choices for stick electrodes are going to be limited, and you’re probably going to have a difficult time maintaining the correct arc length.

Taking the Time to Understand Welding Safety

Welding utilizes some pretty extreme forces and materials. Most modern welding requires tremendous amounts of electricity, which of course can create a risk for electric shock. No matter what kind of welding you pursue, you’re always going to be working around some incredible levels of heat, too, and those kinds of temperatures can harm you, other people, and your property in myriad ways. The metals you weld are sometimes sharp and often heavy, so with them you can get that rare and unfortunate double threat for lacerations and back injuries. Finally, you can’t forget other potential hazards that welding can create, including rays that can do serious damage to your eyes and fumes that can hurt your lungs and make you very sick.

Welding is a safe endeavor if you follow all the necessary precautions and respect the equipment, materials, and process. I know as well as anyone that welding involves a lot of potentially hazardous elements, but I also know that if you make maintaining a safe welding environment your first priority, you can weld for years and years without suffering any serious injuries or loss of property. You just have to follow the safety rules and keep your head on straight.

As you work your way through this book I ask only one favor of you: Please read Chapter 3 (on welding safety) carefully and thoroughly. Even if you think you understand welding safety, taking a few minutes to review the key steps for creating a safe welding environment for yourself and others can’t hurt.

Exploring Welding Methods

You can use heat to join metals in several different ways, but by far the most common welding methods used today are the arc welding methods. Arc welding is really pretty simple in theory: A large amount of electricity creates an arc between an electrode and a base metal, and that arc generates enough heat to melt the materials in the weld area and join them together to make a weld. In practice, however, arc welding includes three different welding processes (stick, mig, and tig) and has many different variables. For example, some kinds of arc welding use a shielding gas, while others don’t. The electrodes that you use in arc welding may be consumable, meaning they get melted and incorporated into the weld, or they may be non-consumable. The electricity used in arc welding is the source of many other variables, including amperage (which can vary a lot) and current (either alternating current or one of a couple different forms of direct current).

Because the three main types of arc welding are the most commonly used throughout the world and the easiest to pick up, those are the three that I devote the most attention to in the following sections (and throughout the book). However, they aren’t the only game in town, so I also include some information on those other types in case you want to branch out a bit.

Stick welding

Stick welding (also called shielded metal arc welding or SMAW) is an arc welding technique that has the distinction of being the most commonly used welding practice in the United States today. (More than 40 percent of all welding done now in the United States is stick welding.) The prevalence of stick is even stronger in construction; more than half of all construction-related welding uses stick. And the percentage is even higher in the maintenance industry.

Stick welding enjoys such popularity for three primary reasons. First off, it’s cheap. You can get into stick welding for less money than you’d spend to get started with tig welding. Secondly, stick welding is highly portable. The equipment is lightweight, and you can easily use it outdoors if the conditions allow it. Finally, stick welding is versatile. You can use it to work on metals with a wide range of thicknesses, and you can stick weld in just about any position that fits with your skill level.

Stick welding is great, but it isn’t perfect. One main reason is that it’s messy. Welding waste products, such as slag and spatter, get thrown around during a stick weld a lot more than they do when you’re tig or mig welding. Because of that, you have to plan on spending some time cleaning up your welds and weld area after you’re done stick welding. Another of stick’s imperfections is its speed (or lack thereof). You have to be pretty good at stick welding to do it quickly (especially compared to, say, mig welding).

You can read all about the stick welding process in Chapters 5 and 6, but generally speaking, stick welding utilizes a consumable electrode with a solid metal rod in its core that melts down and forms part of the weld. Small globules of molten metal flow from the tip of the electrode through the electric arc to the molten weld pool. The electrodes have a coating of flux that protects the molten metal from impurities in the air that can contaminate the weld as it cools.

Mig welding

Mig welding is another arc welding technique. You may also hear mig welding referred to as gas metal arc welding (GMAW) or wire welding. Mig welding is becoming more and more popular, for several reasons. At the top of the list is the fact that most people find mig welding to be easier to pick up than stick and tig. Another big reason is the speed; done correctly, mig welding can be quite a bit faster than stick or tig welding thanks to its continuously fed wire electrode, which doesn’t require changing nearly as often as the stick electrodes used in stick welding. You can just keep right on welding without having to stop and change your electrode. Over the course of a welding project, that can definitely save you quite a lot of time.

Proponents of mig welding also cite the low amount of slag and spatter that mig produces. That makes for a more pleasant welding experience, and a muchmore pleasant cleanup experience. The low chance of distortion (unwanted changes in a piece of metal’s shape) is also trumpeted by those who love mig welding. Because the process is faster, you don’t need to apply as much heat to the weld area for as long, so the metal is less likely to bend and twist in nasty ways.

Of course, mig welding also has its downsides. For starters, mig welding equipment is more complex than stick welding equipment, so it’s quite a bit more expensive. The handheld part of the mig welding equipment (called the mig gun) is often big and bulky, so it’s usually tough to mig weld in tight spaces. Mig welding also relies on the use of a shielding gas to keep atmospheric contaminants away from the weld area, so the process doesn’t really work very well outdoors (especially with any kind of breeze).

I save the details of the mig welding process for Chapters 9 and 10, but generally speaking, here’s how it works: A wire feeder continuously feeds the wire electrode to the weld area at a speed you control. That produces a steady molten stream that you can easily direct however you want on the surface of the metal you’re welding. The weld is completely covered with a shielding gas (usually argon) to prevent impurities from fouling up the quality of the weld; you control the flow of the shielding gas to suit your project’s needs.

Tig welding

The last type of arc welding is tig welding, which is sometimes called gas tungsten arc welding or GTAW. One major advantage to tig welding is that it’s extremely clean. If you’re tig welding correctly, you may very well go through an entire project without having to spend any substantial amount of time cleaning up. Tig is also extremely versatile. You can use tig welding to work on a lot of exotic metals that just aren’t in play for, say, stick welding.

Tig welding has two big drawbacks. One is cost — you can definitely spend a pretty penny on tig welding equipment and supplies, even for start-up. The second drawback is lack of speed. You get a lot of precision out of tig welding, but you pay for it with time.

The tig welding process was originally developed in the 1940s to join aluminum and magnesium, but you can use tig welding to join all kinds of different metals. The big difference in tig welding is that it uses a non-consumable electrode that’s almost always made of tungsten. It also requires the use of a water- or air-cooled torch, which holds the tungsten electrode and is connected to the welding machine by a power cable. Like stick welding (see the earlier section), tig uses an arc of electricity to heat metal to its melting point, and you manipulate the puddle to join metals together. The major difference is that tig welding uses a tungsten electrode. You can read more about tig welding in Chapters 7 and 8.

Other welding methods

There’s more than one way to skin a cat, and there are more welding processes beyond the big three arc welding techniques (see the preceding sections). Here are a few to consider; check out Chapter 13 for more info.

Brazing is unique among the welding processes because you can use it to join different materials (two different metals, for example). It uses gas rather than electricity, and the heat used in brazing surpasses 800 degrees Fahrenheit.

Soldering is a form of welding that uses (relatively) low amounts of heat. You can solder at temperatures below 800 degrees Fahrenheit. (That’s downright chilly when it comes to welding.) You can solder with gas or electricity, but the electricity you use in soldering isn’t the same as the type of electricity you use in arc welding. Instead, soldering uses an electric soldering iron that heats up and melts the filler materials you’re adding to the project you’re working on.

Oxyfuel/oxyacetylene welding is probably the most common gas welding process. You do it with a gas-powered flame that melts the base metal and any filler materials necessary to make the weld. The equipment used for this type of welding is the most portable and low cost in the welding world.

Looking at the Future of Welding

The need for skilled welders is huge right now, and it’s only going to continue to grow. New metal alloys are being created and used for a wide range of purposes every day. The industries that rely on welding are expanding rapidly across the globe, and the need for metals to be joined in skillful ways isn’t going anywhere in the near future. Welding is a versatile field that you can study in a number of different ways, from on-the-job training to education at a vocational or technical school. If you practice and develop your welding skills and work hard, you can more than likely make a career out of welding. And after you’ve been a welder for a while, you can very easily transition into a position as a foreman, inspector, or welding supervisor, just to name a handful of the possibilities.

But don’t think that you need to make a career out of welding in order to enjoy and appreciate the process. You can weld to fix things around your house, yard, or farm. You can weld to create things that you use in your personal or professional life. You can weld to create works of art or gifts for friends and family. Or you can weld just because it’s fun and rewarding (and there are few better reasons to weld than that).

Chapter 2

Considering Commonly Welded Metals

In This Chapter

Understanding steel

Getting a grip on stainless steel

Taking a look at aluminum

Reflecting on a few other metals

Good chefs know food, good carpenters know wood, and any good welder really knows metal. I know that sounds painfully obvious, but I’m sometimes surprised to learn that many seasoned welders aren’t all that familiar with the metals they work with on a daily basis. I think having a nice, rounded understanding of the metals you weld is important, and that’s what this chapter is all about.

If I had to pick three metals that most new welders want to begin working on as soon as possible, I’d have to go with steel, stainless steel, and aluminum. If you can familiarize yourself with those three metals and understand their characteristics as they pertain to the various types of welding, you’re well on your way to figuring out how to work with three of the most common, versatile metals out there. With that in mind, I start this chapter by devoting individual sections to each of those three metals. After that, I close the chapter with a quick look at some of the other metals that you may want to consider welding, just to clue you in on some basics and give you a feel for what’s possible beyond the old standbys.

Steeling Yourself for Using Steel

Steel is an extremely common metal. It’s all around you — chances are, you’re probably not more than a few feet away from something made of steel. For that reason alone, it’s a very important metal for welding.

Steel is an alloy that’s made up primarily of iron, along with less than 2 percent of another material. That material is usually carbon, and the amount of carbon present in the steel is an important feature. Here’s a quick look at the three different levels of carbon steel.

Low carbon or mild steel has less than .2 percent carbon. This category of steel is extremely easy to work with; you can cut and form low carbon or mild steel a lot easier than many other metals. Lots of objects, including screws, bolts, nuts, and washers, for starters, are made of low carbon steel. Sheets of low carbon or mild steel are often used to make automobile bodies and other familiar products.

Medium carbon steel has .25 percent to .55 percent carbon, and it’s more difficult to work with and form than low carbon steel. You can find medium carbon steel in some of the same products made of low carbon steel, but the medium carbon versions are stronger. Machine parts (gears, axles, levers, and so on) are also often made out of medium carbon steel because of its strength and durability.

High carbon steel is the really tough stuff. More precisely, it contains between .55 percent and 2 percent carbon. It’s the hardest and strongest type of steel, but it can be a real pain to cut and form. Manufacturers use high carbon steel to make things like cutting tools, files, and hammers because those items need to be strong enough to keep their shapes and integrity through years of heavy abuse.

Getting a handle on forms of steel

Steel is manufactured in many different forms, and each form has its own use for welding projects. Here are a few of the more common forms that you’re likely to run into as you weld.

Flat steel is exactly what it sounds like — a flat piece of steel. It’s also called sheet steel. It comes in a range of thicknesses and sizes, but when it’s larger than 12 inches wide, it’s called plate steel.

Steel bars are made in an array of shapes, but the most common are round, square, or flat. You can see some examples of steel bar shapes in Figure 2-1.

Figure 2-1: Square (a), flat (b), and round (c) steel bar shapes.

Rolled steel comes in two forms.

• Hot rolled steel is made to its finished size while the steel is still red hot. Iron oxide forms on the hot steel after it’s rolled. It’s a grayish-black coating that helps protect the steel from rusting. Hot rolled steel is used for piping, tubing, tanks, and other products.

• Cold rolled steel is made by rolling the steel to its finished size after it’s cooled to room temperature. It doesn’t get the iron oxide that hot rolled steel gets, so cold rolled steel is smooth and bright looking. It’s used for making things like nails and screws.

Like all other metals, steel goes through some changes when you apply the high levels of heat to it that are necessary for welding. The steel around the weld area is subject to distortion and cracking due to the expansion and contraction caused by all that heating and cooling. The good news is that the electrodes and filler metals you use when welding steel are designed to be just as strong (or even stronger) than the metal you’re welding, as long as you let the weld cool off on its own after you’re done welding.

Knowing when steel is appropriate

Steel is such a ubiquitous metal that it’s hard to imagine life without it. It has become an important part of everyone’s life, and the ways you live, play, and travel certainly wouldn’t be the same if steel was no longer available.

You can use steel for a wide variety of welding projects; it’s cheap, readily available, and pretty easy to weld. If you’re looking to weld objects such as farm equipment, tools, cars, automotive equipment, specialty containers (drums, pipes, and boilers), or even bridges and parts of buildings, you should strongly consider steel as your metal of choice.

The many properties of metals

It’s a little hard to believe how many different kinds of metals are out there. Metals run the gamut from tungsten, which is one of the hardest materials on Earth, to mercury, which is a liquid at room temperature. Here are a few of the physical properties of metals that combine in different ways to make metals unique.

Strength: How much external force the metal can take without breaking.

Ductility: The ability to change shape without breaking.

Magnetism: Some metals (like steel) are magnetic; others (like aluminum) aren’t.

Hardness: The resistance of a metal to being damaged when another metal is applied to it.

Resistance to oxidization: When metals combine with oxygen, they become oxidized. That’s what causes steel to rust, for example. Some metals — tungsten, for instance — are very resistant to oxidization.

Electrical conductivity: Some metals conduct electricity much more efficiently than others. For example, silver is an incredible conductor of electricity, but stainless steel doesn’t conduct well at all.

Melting point: Every metal has a melting point — the temperature at which the metal turns from a solid to a liquid. This property is critical in welding because, of course, you’re trying to melt metal. Tungsten has the highest melting point; you need temperatures of 6,170 degrees Fahrenheit to melt tungsten. That’s remarkably high compared to, say, tin, with a melting point of only 450 degrees Fahrenheit.

When is steel not appropriate for welding? Well, if you’re working on or repairing a piece of metal that’s definitely not made of steel, such as repairing an aluminum piece on a boat, using steel won’t work for that project.