Test Your Knowledge
  1. Name three benefits of using GMAW.
  2. The polarity used for almost all GMAW and FCAW is DCE _____ or DC _____ _____.
  3. Name three metal transfer methods.
  4. _____ is the property in an electric circuit that slows down the rate of current change.
  5. Spray transfer only occurs when the current is set above the _____ current.
  6. Spray transfer only occurs when at least _____ % argon is used.
  7. Which gun angle gives the deepest penetration—forehand, perpendicular, or backhand?
       forehand perpendicular backhand    
  8. How many pounds and kilograms of filler metal can be deposited per hour with the spray transfer method?
  9. Other than setting switches, what are the two main variables made on the welding machine or wire feeder prior to welding?
  10. A GMAW power source used for pulsed spray transfer must have what additional controls?
  11. Using spray arc transfer, _____ volts and _____ amperes are used with a 0.045″ (1.1mm) electrode to weld stainless steel.
  12. _____ volts and _____ amps are used to weld mild steel using short-circuiting transfer and 0.035″ (0.9mm) diameter wire.
  13. On the wire drive unit shown in Figure 9-23, wire guides and drive rolls are aligned by loosening the _____ _____ securing bolts and moving the _____ _____ up or down.
  14. To feed the welding wire through the electrode cable to the arc welding gun, the _____ switch is operated.
  15. What factors must be considered when choosing a shielding gas?
  16. Argon has a(n) _____ thermal conductivity than helium, so _____ is used to weld thick aluminum or copper sections.
  17. Why is good ventilation important when using CO2 gas?
  18. What effect does oxygen (O2) have on the arc when mixed with argon?
  19. Which gases are suggested for use with pulsed spray transfer?
  20. What argon flow rate in ft3/hr. and L/min should be used to weld 0.125″ (3.2mm) thick magnesium?
  21. What part of the gas metal arc welding gun contacts the welding wire and passes electricity to the electrode?
  22. How can metal spatter be kept from sticking to the nozzle?
  23. Electrode extension is the distance from the end of the _____ _____ to the end of the _____.
  24. The suggested travel angle to obtain the best weld pool control with backhand welding is _____ ° to _____ °.
  25. List three possible causes for an undercut weld bead.