By 8:00 AM on Tuesday, the coffee was cold and the nerves were hot. They practiced on weld coupons—thick plates of carbon steel with intentional flaws: porosity (tiny gas bubbles), slag inclusions (trapped non-metallic residue), incomplete fusion (where the weld didn't stick to the base metal), and the granddaddy of them all: cracking.
“I’ve been welding since I was a kid,” Ray said, his voice low.
“Correct. Next: You’re inspecting a moment connection in a seismic zone 4 building in downtown LA. The preheat temperature drops 50 degrees during a lunch break. Do you keep welding?”
Ray went next. He moved fast, confident. He called out “No defects” on a weld that had a blatant lack of fusion at the root. Mack stopped him.
He looked at each of them.
“That’s not undercut, that’s just a grind mark,” Ray said, crossing his arms.
“What is the maximum allowable root opening for a CJP groove weld on 1-inch plate, process SMAW, with a backing bar?”
On the last day of the retake, Mack handed him the V-WAC gauge.