That apprentice who thought he could skip the preheat on a 2-inch plate

Last Tuesday we had a kid fresh out of school come onto our crew in Gary. First big job was a pressure vessel repair, 2-inch carbon steel plate. Foreman told him straight up to preheat to 300 degrees before welding. Kid laughed and said he learned a new technique that made preheat obsolete. I just looked at him and said you do you. He struck an arc on cold steel and got a crack running six inches down the weld within ten seconds. Foreman made him spend the next four hours with a grinder cutting it all out. Then he had to preheat the right way and reweld it anyway. Kid learned real quick that book learning and field work are two different animals. Anyone else watch an apprentice eat crow on something basic like that?

3 comments

3 Comments

pat_coleman14d ago

Ultrasound testing before welding would have caught those cold cracks before he even laid a bead.

williams.kim14d ago

Absolutely. I saw a guy skip pre-weld UT on a critical root pass once and the whole thing had to be cut out and re-done. Wasted a full shift and about three hundred bucks in filler metal. UT takes maybe ten minutes and saves you from grinding out cold cracks for hours. That kind of shortcut just isn't worth it.

derek65614d agoMost Upvoted

Always fought that mindset til i saw this happen firsthand. @pat_coleman was totally right.