A Specialist Rank Project Written by: CFC Luke Wills Texas 6th Charlie May 2012 Table of Contents Introduction 3 Welding Equipment 5 Additional Accessories 7 Hazards 8 Safety Equipment 9 Preparation 12 Welding 15 Reorganization 18 Conclusion 19 Acknowledgments 20 Introduction What is Shielded Metal Arc Welding? Welding in its most simplified form is the fusion of metal pieces. The temperature of the metal is heated to such a high degree that the metal being welded melts into liquid in order to fuse together. There are many different types of the same action of welding; forge welding, oxyacetylene welding (more commonly known as gas welding), laser welding, electron beam welding, explosive welding, ultra sonic welding, friction welding, and arc welding to name a few. Arc welding is defined as welding that uses a power supply to direct an electric arc in order to form a molten pool of metal at the welding point. There are many different types of arc welding such as gas tungsten (more commonly known as TIG), gas metal (more commonly known as MIG), flux-cored, submerged, plasma, and shielded metal. Shielded metal arc welding is the technical name that the American Welding Society gave what is more commonly known as stick welding. This is one of the oldest, simplest, and most multipurpose welding methods. It uses a consumable electrode that is coated with a dry chemical called flux. While welding, the flux is burnt off the electrode at the welding point and shields the metal from atmospheric contaminates. The flux then cools and hardens to form slag. Slag is a layer of porous, brittle metal formed from the residue of flux that coats the top of the weld. What is the purpose of welding? Welding is used for three main purposes; to fix broken gear, to construct both useful equipment and metal art, and to strengthen weak areas or areas that are subject to constant friction. Why should I learn about welding? Luke 16:10-11 “He that is faithful in that which is least is faithful also in much: and he that is unjust in the least is unjust also in much. If therefore ye have not been faithful in the unrighteous mammon, who will commit to your trust the true riches?” Welding is a good way to practice being faithful with what we have been given. Instead of throwing a broken tool or piece of equipment away and buying a new one, you could fix it by welding and still continue using it long after its life expectancy. In Matthew 25 Jesus tells a parable about three servants who were put in charge of different amounts of the master’s money. The two that doubled the amount they were given, were praise by their master in verses 21 & 23 “…Well done, good and faithful (servants); thou hast been faithful over a few things, I will make thee ruler over many things: enter thou into the joy of thy lord.” The servant who just hid the money was called “wicked and slothful” (verse 26) and his portion was given to one of the other faithful servants. One definition of the character quality of resourcefulness is: Making wise use of that which others would overlook or discard. Welding is an excellent way to practically demonstrate Resourcefulness while being faithful with what you are given as well. 3 What will I learn about welding in this document? You will learn about the different parts to a stick welder and how it works, the equipment you will need to safely operate a stick welder, the hazards, safety precautions, and a process of how to weld from start to finish. 4 Welding Equipment Parts of a welding machine The welding machine has five parts: the power supply, the ground clamp, the electrode holder, the electrode, and the leads. The power supply is the box shape part of the machine that regulates the electrical power from either an electrical outlet or a gas generator. The ground clamp is a clamp that is clamped to either the metal you are welding on, or the metal that the metal you are welding on is clamped to. The electrode holder has a simple definition; it is a clamp that holds the electrode. The electrode is a rod coated with a dry chemical called flux. The leads are the wires connecting the ground clamp and the electrode holder to the power supply. The path of electricity through a welding machine Electricity flows into the power supply from either an electrical outlet or a gas generator. It then goes out through the electrode lead and electrode holder to the electrode itself. The small space that is between the tip of the electrode and the piece of metal that is being welded is traversed by electricity forming an arc. It continues its path through the ground lead and the power supply where it finishes by going into the ground. 5 Other welding tools Though the welding machine is a must have, these other items are crucial for good welds. Chipping Hammer A chipping hammer is used to break off the large pieces of slag that normally form on the top of each weld from the melting flux. Wire Brush A wire brush is used to clean the weld from small pieces of slag that the hammer can’t get to. It can also be used to clean off dirt and rust on the metal to be welded in order to obtain a better weld. Clamps In order to keep the metal you are welding stationary, clamps are employed. There are many different types of clamps are used such as; c-clamps, locking pliers, and table-mounted vises. 6 Additional Accessories Wire Wheel An electric powered wire wheel is very useful for cleaning off multiple welds or preparing a large surface for welding. It can also shine the finished weld and give the metal a cleaner look. Grinding Wheel An electric powered grinding wheel is useful for grinding down welds in order to reweld or in order to add another weld on top of it. It can also polish the finished weld and give the metal a metallic look. 7 Hazards Clutter Clutter is defined as anything that hinders your speed, productivity, or compromises your safety while welding. Flammables such as paint & gas cans, an oxyacetylene torch, paper, and leaves should all be swept or moved away. Sharp edges, tangled leads, and unnecessary tools, etc… should all be moved, or picked up and stored in their proper place. Temperature The tip of the electrode can get 4 to 20 times hotter than the maximum temperature of a common household oven. The temperature of the arc can be anywhere between 2,500 ° F and 10,000° F. Skin, clothing, plastic, leather, wood, and other materials will burn if in contact with that amount of heat for most any period of time more than a brief brush. Light The light that is emitted by the arc contains harmful Ultra-violet (UV) rays which can burn the corneas of your eyes. Looking directly at a welding arc with little or no protection can cause what is commonly called arc eye or corneal flash burn. The medical term is photokeratitis and its symptoms are a feeling of small glass pieces or sand in your eyes. If prolonged eye exposure to the arc occurs without adequate protection, permanent blindness or black spots in your vision may result due to the burning of the retina. Fumes While the flux on the electrode provides a shield of gas around the arc to keep it from atmospheric contaminates, it also emits a chemical that is poisonous at higher concentrations and after being constantly inhaled over a longer period of time. Sparks & Flying Pieces of Metal Sparks and flying pieces of metal are hazards for more than one reason. The sparks may splatter in or near flammables such as aerosol cans, grass, paint cans, leaves, and gas cans. They also will sting and can severely burn any exposed skin. The most sensitive part of your body to sparks and flying pieces of metal (such as slag and rust from prepping for or cleaning a weld) are your eyes. Slag is lightweight with a potential of flying a long distance. 8 Safety Equipment Welding Personal Protection Equipment (PPE) Welding Shield A welding shield (more commonly known as a helmet) is the most crucial part in a welder’s PPE. It protects the face and eyes from sparks and can reduce the amount of fumes that is inhaled by a welder. The average entry-level helmet is made out of nylon has a filter lens that is interchangeable. Some other helmets are made out of NORYL, leather, and fiberglass and many have special features such as an auto-darkening lens or a flip front. Welding Gauntlets Since your hands are the closest to the arc welding gauntlets (more commonly known as gloves) are necessary to keep your hands protected. Most are made from leather and will absorb some of the heat from the arc and metal that you are working with. Always retire or patch gloves that have holes in them. Also make sure that the gloves are not wet or sweaty since they can then become a conductor of electricity. Safety Glasses or Face Shield It is very important that you protect your eyes even after you have finish welding. The slag that builds up on a weld has a tendency to ping off as the metal contracts and cools. Some welders will wear safety glasses under their welding helmet in case a stray spark ends up on the inside.