WELDING pg 150 ELECTRIC ARC WELDING

1. Explain what occurs during electric arc welding.

2. Sketch and label an example of arc welding. include parent metal, electrode, slag molten pool, penetration.

3. What is the purpose of slag?

4. What metals can be electric arc welded?

5. Give some examples of the type of work done.

6. Give three advantages of this process.

7. Why are face shields and protective clothing essential while welding. 8. Sketch and describe the welding circuit.

9. Give four main points to be observed for good welding technique. a. b. c. d. 10. Why are electrodes flux coated?

11. Explain the faults that may occur when the amperage is a. Too high,

b. Too low,

12. Explain how to strike an arc.

13. Give two faults that could develop if the arc length is a. Too long.

b. Too short.

14. Give two faults that could occur if the rate of travel is a. Too fast.

b. Too slow

15. Why is a weaving pattern followed when welding?

16. Explain what is meant by the following defect terms a. Undercut,

b. Incomplete penetration

c. Lack of fusion,

d. Slag inclusion.

17. What is distortion and what causes distortion?

18. Explain three ways in which distortion can be overcome. a. b. c. 19. Explain what occurs during the following methods of resistance welding, a. Spot welding,

b. Flash butt welding

c. Seam welding,

d. Projection welding. OXY ACETYLENE WELDING pg 156

1. Give some applications of oxy acetylene welding, 2. How are acetylene cylinders and fittings distinguished? 3. How are oxygen cylinders and fittings distinguished?. 4. Explain the setting for the following flames. 5. Sketch and label an oxy-acetylene Set below. Include oxygen bottle, acetylene bottle, regulators, hand piece, tip, barrel, flow valves hoses.

6. Complete the table below. Flame type Sketch Setting Neutral

Oxidizing

Carburizing

7. Give the reason for using the following flames. a. Neutral,

b. Oxidizing,

c. Carburizing 8. Explain three methods of overcoming distortion. a. b. c. 9. Give three factors to be observed when preparing edges for welding. a. b. c. 10. Give the sequence for lighting up.    11. Give the sequence for closing down.    12. What is down hand welding? 13. Explain the following terms a. Leftward welding,

b. Rightward welding,

14. Give three points to be observed when welding steel with regard to a. Flux,

b. Flame,

c. Movement

15. Explain what occurs during oxy acetylene cutting.

BRAZING AND SOLDERING pg 60

1. Explain what happens in brazing.

2. What is the purpose of flux when brazing?

3. Discuss brazing with regard to a. Joints,

b. Filler rods,

c. Temperature,

d. Flame.

4. Discuss three factors that could cause difficulty in wetting the joint.

5. Give two uses for silver solder.

6. Give the temperature range’ for silver soldering.

SAFETY PRECAUTIONS

1. Give safety precautions with regard to a. Cleanliness, b. Clothing, c. Eyes, d. Cylinders and hoses,