333 6. List two actions to take to produce a smaller weld pool when overhead welding. 7. List two actions to take if you get porosity when overhead welding. 8. List two metals other than carbon steel that are frequently welded with GTAW. Use the information (charts, fi gures, and text) provided in this chapter and in Chapter 20 to answer Questions 9 and 10. 9. Determine the variables for welding a fi llet on 1/8″ (3 mm) stainless steel: Type of current: _____ Amount of current: _____ Electrode extension (beyond the nozzle): _____ Type of electrode: _____ Time of postfl ow: _____ 10. Determine the variables for welding a butt joint in 3/32″ (2.4 mm) magnesium without backing: Type of current: _____ Amount of current: _____ High-frequency voltage (Start or Continuous): _____ Argon fl ow rate: _____ Type of fi ller metal: _____ STEM Connections 1. Science. Precautions must generally be taken to prevent a weld from sagging when welding out of position. Do all metals tend to sag at the same rate or by the same amount? Conduct research to fi nd the answer to this question. Then write a paragraph explaining your fi ndings. 2. Technology. In overhead welding, higher shielding gas fl ow rates are needed for thicker metals than for thinner metals of the same type. Conduct research to fi nd out why this is so. Write a paragraph explaining your fi ndings. Curricular Connections 1. Social Science. Suppose a welder who is welding carbon steel in the overhead position becomes careless and allows molten metal to fall on his unprotected arm. Conduct research to fi nd out what the potential injury would be and what bystanders can do to treat the immediate effects of the injury. Write an essay describing the injury caused by molten metal and the steps to care for a person who has suffered this injury. 2. Critical Thinking. Welder qualifi cation tests often require welders to perform out-of- position welds because it is thought that if a welder can make good out-of-position welds, he or she can also weld properly in the fl at position. Write a short essay explaining why this assumption may or may not be correct. 3. Language Arts. Prepare a multimedia presentation demonstrating the process for making a horizontal fi llet weld on a lap joint. Use several different types of media in your presentation, such as text (written words), sound, photos, and art. Organize the presentation logically. Make sure spoken words are pronounced correctly, and your grammar and usage are correct in all media types. Double-check your facts to be sure the presentation correctly teaches the procedure. Communicating about Welding 1. Writing and Speaking. Choose one of the welding positions discussed in this chapter. Create a beginner’s instruction manual on how to perform a GTAW in that position. Include drawings and pictures that demonstrate the instructions. Test your instruction manual by sharing it with someone who knows nothing about GTAW welding. 2. Listening. In small groups, discuss with your classmates about what you know about GTAW. Conduct this discussion as though you had never read this chapter. Take notes on what you knew already, what you learned from previous chapters, and anything you were surprised to learn. Then review the points discussed, factoring in your new knowledge of horizontal, vertical, and overhead GTAW welding. Develop a summary of what new information you have learned about GTAW welding through studying the positions discussed in this chapter and present it to the class. Copyright Goodheart-Willcox Co., Inc.