DELTA SCHOOL OF TRADES pdf

DELTA SCHOOL OF TRADES 5418 PULASKI HIGHWAY BALTIMORE, MARYLAND 21205 410-485-3449 WWW.DELTASCOOLOFTRADES.COM DELTA SCHOOL OF TRADES WELDING HANDBOOK 2 CONTENTS CHAPTER PAGES SAFETY FOR WELDERS 3 17 SMAW STICK 18 31 SMAW ESSENTIAL VARIABLES 32 42 GMAW MIG 43 58 GTAW TIG 59…71 CERTIFICATION 72…80 BASIC JOINTS 81…88 WELDING SYMBOLS ___ 89…102 PRACTICES_____________ __ ___103 140 THIS TEXT WRITTEN AND PUBLISHED BY; NORMAN J. ASHLEY DELTA SCHOOL OF TRADES First printing January 2000 Latest Printing March 2005 Revised September 1st, 2007 3 CHAPTER ONE SAFETY FOR WELDING SAFETY FIRST CLOTHING FOR WELDING WELDERS UNIFORM FOR DELTA SCHOOL OF TRADES WELDING MACHINE SAFETY SHOP AND WELDING ENVIRONMENT SAFETY HANDLEING GAS CYLINDERS GENERAL SAFETY STUDENT OBJECTIVES STUDENTS WILL BE ABLE TO: 1. List and describe the type of clothing appropriate for safely welding. 2. List and describe the 8 items that make up the welders uniform used at Delta School of Trades. 3. Describe the safety guidelines relevant to working with welding machines at Delta School of Trades. 4. Describe safety rules relevant to the welding shop and environment. 5. Discuss safety issues relevant to using gas cylinders in the welding industry. 6. List and describe 4 items related to safely picking up loads in the shop 7. List and describe safety concerns for using hand grinders at Delta School of Trades. 4 SAFETY FOR WELDERS SAFETY FIRST Safety should be the first consideration when beginning any Trade. Welding is an Industrial trade and as such has many hazards that can cause injury if the proper safety guidelines are not followed. In addition to the safety guidelines for welding training there are many safety rules that apply to the welding field in general and to the particular company you will work for. Students and employees should continue to take an active interest in safety throughout their careers. CLOTHING FOR WELDING Since welding produces intense heat and hot sparks that may cause serious burns, it is important to wear the proper work clothes. The following describes the type of clothing appropriate for welding operations. WORK SHIRTS Shirts should be made of thick heavy materials such as heavy cotton or denim that is not easily burned. The shirts must be long sleeved and should not have pockets unless they have button flaps on them. Open pockets may trap hot sparks or globules of hot metal that could burn the skin. The shirt should not have frayed edges that sparks from welding can easily ignite. The work shirt should not have any torn areas that allow hot sparks to penetrate. Matches, lighters, or paper materials should never be carried in shirt or pants pockets when welding. WORK PANTS The pants should be close fitting and made of a heavy material such as work jeans. Overalls are appropriate if other clothing is worn under them. The pants should be long enough to cover the top of the boots and have no cuffs that may trap sparks or hot slag. Like the shirts the pants should have no frayed edges or torn areas in them. It is advisable not to have metal keys or other devices dangling from the pants that could arc against the work surface. BOOTS High top leather boots are required for welding and general shop use. Canvas boots or dress shoes should not be worn. The boots should fasten all the way up to prevent sparks falling into them. Leather laces that will not easily burn or smolder should be used. Wear heavy work socks not nylon or thinner socks for added protection against sparks. Safety boots with steel toe caps are advisable for welding shops and work to protect the feet. Spats or leggings are leather pieces that fit over the top of the boot to prevent sparks falling into the boots and are available at welding supply stores. 5 CAPS A cap or some form of head covering should be used for welding, especially in other than the flat position. The cap must be compatible with the welding head gear called the welding helmet. Welder’s caps or welders beanies (cap with no peaks) are available from welding supply stores. WELDERS UNIFORM FOR DELTA SCHOOL OF TRADES Students or welders at the School need to have the proper welding protection equipment in addition to wearing the proper welding work clothes. The protection equipment is used to safely view the arc and make the practice welds at the school. It is the same type of personal equipment all welders use on the job. The Welding Uniform is the individuals’ choice of manufacturers and styles, for the following items: 1. THE WELDING HELMET (WITH SUPPLY OF LENSES) 2. LEATHER WELDING GLOVES 3. LEATHER JACKET OR CAPE SLEEVES AND BIB 4. SAFETY GLASSES 5. WELDING CAP 6. SLAG (CHIPPING) HAMMER 7. WIRE BRUSH 8. PLIERS 1. THE WELDING HELMET The welding helmet is designed to protect the welders face and head from the ultraviolet and infrared rays of the welding arc, while allowing the welder to view the molten weld pool or puddle. There are a variety of welding helmets and styles available, among them are the flip front, the wide lens, and the auto-darkening lens. The flip front allows the welder to view the weld area through a clear lens, while still wearing the helmet, to safely slag the work or use a grinder. 6 The wide lens helmet offers a wider view of the weld area. (Approximately 4 X 5 instead of 2 X 4) A flip front model of the wide lens helmet is also available. The Auto darkening helmets have a lens that is clear to allow the welder to see the joint before striking the arc. As soon as the welder strikes the arc, the lens darkens to the normal view of the welding puddle. The auto darkening lenses are very useful for; production welding where small welds can be made without constantly lifting the hood; for precise restarting of the weld; for striking the arc without hitting the surrounding area or other parts; for grinding and oxy-fuel cutting. Auto darkening lenses may also be purchased to fit into a standard helmet. The auto darkening style of helmet is a lot more expensive than the standard welding helmet and is not essential for use at the school. The welding helmet usually comes with a filter plate (dark plate) and a clear lens on the outer side. The filter lens should be shade number 10 for most welding. Check the documentation that comes with the helmet for information about the other lens shades that are available. 7 If you use a second clear lens on the inside of the helmet it protects the filter plate when the helmet is laid down. It is critical to clean welding lenses daily and change the outer lens when it gets pitted or scratched, about weekly at the school. If the inner clear lens is in good condition simply swap it for the front clear lens and place a new lens on the inside. The dark filter plate, if protected by the cheaper clear lenses should not need to be changed. Filter lenses and clear lenses are available as plastic or glass. I prefer a Glass filter lens for better viewing and plastic clear lens. Make sure you have an ample supply of clear lenses. 2. LEATHER WELDING GLOVES The welding gloves required for welding are the gauntlet type gloves that cover the forearms. Work gloves are not appropriate for arc welding. Lightweight gloves designed for TIG (Healy Arc) give the welder a better feel for manipulating the TIG torch and adding filler wire. The TIG gloves are not designed for STICK or MIG. Gloves that are used to handle hot metal may become hard and brittle and crack. Use only pliers to handle hot weld coupons. Wet or damp gloves should never be used for electric arc welding. Gloves that develop even small holes should be discarded and replaced before continuing to weld. The less expensive work gloves may be used for general shop work, but should not be used for welding. 3. LEATHER JACKET, OR CAPE SLEEVES AND BIB The leather jacket, worn like a coat, offers the best upper body and neck protection from sparks and hot metal globules typical of welding positions other than flat. Most jackets have an inside pocket and snap all the way up to the collar. 8 A lighter jacket made of fire retardant material may also be used in welding shops. Some of these jackets have leather sleeves. These jackets are good for light welding, but will wear and develop holes when doing a lot of vertical and overhead position welding. The Cape Sleeves and Bib outfit may be made of all leather or the fire retardant material shown above. You can select either just the sleeves or the cape and sleeves or the cape and sleeves with a front bib. Although open in the back, the all leather cape sleeves and bib are a good less expensive substitute for the full leather jacket, and is practical for all welding positions. Note: the bib may be sold separately 4. SAFETY GLASSES Safety glasses are mandatory for all industrial applications, and recommended eye protection for many hobby or home projects. In the welding environment Safety glasses further protect the eyes from the intense ultraviolet and infrared rays of the welding arc. Welders may get a condition known as an eye flash, either from striking an arc without the helmet in place, or more likely, from other welders working in the area. People that work around welders, are also vulnerable to eye flash without the proper protection. The safety glasses must have side shields to protect the corner of the eye when welders are working close by. 9 An eye flash occurs when the unprotected eye is burned in a similar manner to a sun burn on skin. Painful problems from the flash usually start several hours after exposure (At Night) and may last all night into the next day. The symptoms include: A feeling of sand or grit in the eye, an inability to keep the eye open and focus, intense pain, redness swelling and watering, burning, and headache. It is my experience that the flash will clear up without long term problems if you avoid further eye exposures. Consult a doctor if problems persist more than 48 hours. IT IS CRUCIAL TO WEAR SAFETY GLASSES WHEN WELDING If you wear prescription glasses, you should use side shields that slip on to the frames of glasses, to protect the sides of the eyes from exposure. Many flashes come from other welders and can burn the eye from the side. Goggles that fit over glasses may also be used 5. WELDING CAP A welding cap protects the head from sparks flying over the welding helmet and from falling sparks while welding overhead. A cap with no peak called a beanie is a popular choice for welders. A cap with a peak worn backward may also be used. 6. SLAG HAMMER (CHIPPING HAMMER) A slag hammer or sometimes called a chipping hammer is used to remove the slag from the completed stick weld. The slag hammer may have one pointed and be shaped like a chisel on the other end or have two chisel shaped ends. The two most common types are the wire frame and the wood handle. 10 7. WIRE BRUSH A wire brush is used to clean the weld layers between passes and to clean the completed weld. 8. PLIERS A pair of pliers is used to handle the hot weld coupons, or other hot metal. Using only gloved hands can result in a burn or at least shorten the life of the gloves. A simple pair of slip joint pliers, or a pair of locking pliers, may be used. WELDER AND EQUIPMENT SAFETY IN THE WELDING FIELD In addition to wearing the proper welding uniform there are a number of safety issues that welders must be aware of, make sure you understand the safety guidelines in effect at your company. The American Welding Society (AWS) has available several documents concerning safety for further review. Of special interest is their safety Standard Safety in welding, Cutting and Allied Processes ANSI/AWS Z49.1. The following is a brief review of some of the guidelines for welding safety: [...]... that produce either DC current or offer a choice of AC or DC current Models available provide either constant current used for STICK and TIG or Constant voltage used for MIG or may combine both The great benefits of this technology include the production of a line of machines that offer smaller more portable multiple process machines that are capable of providing a range of amperages and are less costly... used at the Delta School Of Trades LICOLN INVERTEC 250 AMPS 25 WELDING MACHINE CONTROLS There are a variety of welding machines produced by manufactures for stick welding, each with their particular arrangement of controls for selecting the variables for welding Although controls may differ with machine type and style, they serve the same basic functions Two of the welding machines used at the school are... sequence of welding Try some of the following: Weld the outsides of angles, channels or beams first where arc blow may not be as severe 29 Place a weld at the opposite ends of long sections first Instead of welding from one end to the other, use a series of shorter welds in staggered locations to completely weld the joint Weld towards a heavy tack weld or prior weld Stop and change the direction of travel... adjustment 6 Learn about the type of machine you are using on the job and how to set the controls for the specific job conditions 7 Recognize and reduce the effects of Arc blow when using DC machines or use Ac machine 31 CHAPTER THREE THE FIVE ESSENTIAL VARIABLES OF SMAW (STICK) INTRODUCTION 1 Current Setting 2 Length of Arc 3 Angle of Electrode 4 Speed of Travel 5 Selection of Electrode WELDING DISCONTINUITIES... forceful or digging at the higher settings Adjustments are made based on the type of electrode and the application (7) GTAW SMAW SETTING This control offers a choice of GTAW SMAW SOFT OR SMAW CRISP The GTAW setting is used when the TIG (GTAW) equipment is attached and aids in touch starting the arc The SMAW SOFT setting is used to soften the arc for Electrodes like the E-7018 and E-7028 The SMAW CRISP setting... means the welder can run at capacity for 6 minutes out of ten Since with stick welding the welder must stop to change electrodes the duty cycle may not be as critical as with Mig welding The size of the electrodes to be used determines the amount of amperage the machine will need to produce TYPES OF WELDING MACHINES There are four basic types of welding machines that produce the required low voltage... or more of the following tips to reduce the effects of Arc Blow WORKING WITH THE GROUND CLAMP Arc Blow usually occurs either forward or backward along the joint being welded If forward Blow occurs, place the ground connection at the edge of the joint to be welded If backward Blow occurs, place the ground connection at the start of the joint and weld towards a heavy tack, prior weld bead or run off tab... on opposite ends of the section to be welded Some welders wrap a short section of the ground cable around the workpiece to set up a magnetic field to counteract the effects of the magnetic field causing the Arc Blow effect Caution must be used to prevent burning the ground cable Try uncoiling the ground cable and electrode cable and stretching them out SEQUENCE OF WELDING The effect of Arc Blow may... types of metals also require the use of a respirator Keep the welding area clean and free of clutter, metal, excess welding cables and anything that could fall or cause tripping accidents Know where the first aid station is located and report all accidents regardless how small Burns require immediate treatment to prevent infection 12 HANDLEING GAS CYLINDERS Because of the shape, contents and weight of. .. metal for welding with this process The Shielded metal Arc Welding process is one of the oldest and most widely used methods of joining metals by welding The process is popular because of the simplicity of equipment involved, its portability, reliability and adaptability to outdoor use The process may be used to weld a variety of metal types and shapes in any position DESCRIPTION In the SMAW process, welding . DELTA SCHOOL OF TRADES 5418 PULASKI HIGHWAY BALTIMORE, MARYLAND 21205 410-485-3449 WWW.DELTASCOOLOFTRADES.COM DELTA SCHOOL OF TRADES WELDING HANDBOOK . List and describe the type of clothing appropriate for safely welding. 2. List and describe the 8 items that make up the welders uniform used at Delta School of Trades. 3. Describe the safety. available from welding supply stores. WELDERS UNIFORM FOR DELTA SCHOOL OF TRADES Students or welders at the School need to have the proper welding protection equipment in addition