Changed my tune on pre-heating thick plate after a bad weld in Duluth

I was working on a boiler replacement up in Duluth last winter, fitting a new section of 1-inch thick plate. It was about 10 degrees outside in the shop, and I figured I could just run a hotter bead to get good penetration, skipping the pre-heat to save an hour. Big mistake. About three inches into the root pass, I heard that awful 'ping' sound and saw a crack spiderweb out from the weld toe. My foreman, Jim, just shook his head and said, 'Told you so. That steel's colder than my ex-wife's heart.' We had to grind it all out, which took most of the afternoon. Now I always break out the rosebud torch, even when I'm in a rush, because that extra 30 minutes of pre-heat beats six hours of rework. Anyone else have a time where skipping a basic step cost them a whole day?

2 comments

2 Comments

the_miles6d ago

that extra 30 minutes" still sounds like a waste of time to me.

gavincampbell5d ago

I mean, @the_miles, it's not just time but the cost of the whole plate you risk losing.