Chapter 13 Knowledge Check

Chapter 13

Quiz yourself using the following chapter review questions to check how well you can recall the material.

Review Questions

1. True or False: The CAC-A process is similar to the Atomic Hydrogen Carbon Arc Welding (CAW) process.
2. The two primary gases produced during the carbon arc cutting process are                             and carbon monoxide.
3. What is the primary purpose of CAC?
   1. To weld metal together.
   2. To remove metal from an area.
   3. To increase the thickness of a metal.
   4. To harden the surface of metal.
4. What does the compressed air do in the CAC process?
   1. Helps cool the metal.
   2. Controls the temperature of the arc.
   3. Blows away molten metal and sparks.
   4. Increases arc voltage.
5. True or False: Most welding machines that can perform SMAW are also capable of performing CAC-A with additional equipment.
6. True or False: Oxygen is recommended to be used instead of compressed air for CAC-A.
7. True or False: Carbon arc cutting can only be done in the flat position.
8. What is the polarity used in Carbon Arc Cutting?
   1. AC only
   2. DCEP (reverse polarity) only
   3. DCEN only
   4. Both AC and DCEP
9. What is the main benefit of copper-coated electrodes?
   1. They are more flexible.
   2. They prevent overheating and improve conductivity.
   3. They are more water resistant.
   4. They are less expensive.
10. Tru or False: When using CAC-A, it’s critical to always wear ear protection due to the loud noise produced.

Answer Key

1. True. The addition of compressed air in 1948 created a new process that is popular to this day.
2. Carbon Dioxide /CO2. As the carbon rod is consumed in the arc, it combines with oxygen to produce these gases. Use proper precautions during use.
3. To remove metal from an area. CAC-A is a popular process used for rapid removal of metal.
4. Blows away molten metal and sparks. This function required a second worker to direct air to the molten puddle until a holder with built in air nozzles was invented.
5. True. CAC-C typically uses a constant current power source with DCEP, though it can also be used with AC polarity.
6. False. Oxygen is not recommended due to the reaction that can take place with the electrode.
7. False. Originally used only in the overhead and horizontal positions, modern CAC-C equipment allows use in all positions.
8. Both AC and DCEP. While usually operated with DCEP, CAC_C will also work with AC polarity.
9. They prevent overheating and improve conductivity. When using higher currents, copper coated electrodes will last longer and function better.
10. True. CAC-C process can produce noise up to 120 dB. Exposure to this level of noise will result in hearing loss over time.