10. (a) What would be the trouble, in shutting off a welding plant, if there were a reading on the high-pressure gauge and none on the low-pressure gauge, after permitting gas to escape from the hose?
(b) How could the reading on this gauge be brought back to zero?
LECTURE NUMBER NINE
Subject—Steel Welding
(Part One)
1. (a) Is the welding of steel more or less difficult than cast iron?
(b) Explain why.
2. (a) Why is the choice of the welding tip so important when working on steel?
(b) What will result if the tip is too large?
(c) If too small?
3. (a) Why is the choice of a “filler-rod” of a correct size so important for steel welding?
(b) What will happen if the “filler-rod” is too large?