Used to crank my preheat all the way up on every rod, now I barely touch it

I used to set my preheat around 500 degrees on every job no matter what, thinking hotter was always better for the weld. Last month on a boiler repair in Gary, an older hand told me I was cooking the base metal and making more stress cracks than I was fixing. Has anyone else found a specific temp range that works best for your typical jobs?

2 comments

2 Comments

drew9063d ago

You ever have one of those moments where an old timer just casually drops a truth bomb on you and you realize you've been doing it wrong for years? That was me last fall on a pipeline job, I was running 450 preheat like clockwork until this guy with 30 years in the trade just shook his head and told me to back it down to like 250. I didn't believe him at first but I tried it on a thick piece of plate and the weld came out way cleaner, less spatter, and I didn't see any cracking after it cooled. Now I keep it around 250-300 for most stuff, just enough to burn off moisture, and I only crank it higher if the material is real thick or the weather is cold. It's wild how much you can learn by just listening to the old heads who've been burning rod since before we were born.

tyler4923d ago

Same thing happened to me but with a bandsaw blade. I used to crank the blade tension as tight as I could get it, thought it would cut straighter. Old maintenance guy at the mill just watched me for a minute, walked over and backed it off like two full turns. Said I was stretching the blade out and it would snap on the next cut through some 4 inch pipe. What do you know, next day I hear this loud ping from the other side of the shop and some kid's blade let go because he had it torqued down like I used to. Now I just go finger tight plus a quarter turn, hasn't let me down since.