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AlanB · 10-22-2008, 01:58 PM

I thought some here may find this interesting.

I am getting a large tank made for here at my day job.

The body is 8' tall and 5' diameter, made from 3/16 hotrolled.

So I was at the fabricators yesterday to work out some questions / problems and got to hang around to watch the body get formed.

3 guys, working real well together rolling a BIG (at least in my scale of things) sheet through a big roller.

So they get the primary rolling done, and get too the point where they are going to tack the thing together, and the guy goes out and gets an old lincoln Buzz box. There is a new Millermatic 350 digital Mig sitting beside the roller, plugged in. My point I am trying to stress is he went out of his way, to go get this thing and do the welding with 7018 stick. (DC+ by the way, Murex (by Lincoln) rods)

I could not stand it, so I asked the lead guy why, my teaching has always been that mig yeilds about 70,000 lb strength (same as 7018) and his answer was that the 7018 would be a more ductile weld and would respond better to running through the roller and getting the "roll" in the area as opposed to the straight edges you get on the leads of a sheet.

Anyway, in the 3+ days I have been welding I had never heard that one, and it was coming from someone that has been doing it at least 5 days in a row

so I will assume there is something too it.

Just thought I would share, I have to ask the Lincoln guys now what the science is behind it, or is it just a shop belief.

10-22-2008, 01:58 PM	#1 (permalink)
AlanB Veteran Member Join Date: Jan 2004 Location: Clarksville, TN, USA Posts: 2,267	Interesting Welding Statement. I thought some here may find this interesting. I am getting a large tank made for here at my day job. The body is 8' tall and 5' diameter, made from 3/16 hotrolled. So I was at the fabricators yesterday to work out some questions / problems and got to hang around to watch the body get formed. 3 guys, working real well together rolling a BIG (at least in my scale of things) sheet through a big roller. So they get the primary rolling done, and get too the point where they are going to tack the thing together, and the guy goes out and gets an old lincoln Buzz box. There is a new Millermatic 350 digital Mig sitting beside the roller, plugged in. My point I am trying to stress is he went out of his way, to go get this thing and do the welding with 7018 stick. (DC+ by the way, Murex (by Lincoln) rods) I could not stand it, so I asked the lead guy why, my teaching has always been that mig yeilds about 70,000 lb strength (same as 7018) and his answer was that the 7018 would be a more ductile weld and would respond better to running through the roller and getting the "roll" in the area as opposed to the straight edges you get on the leads of a sheet. Anyway, in the 3+ days I have been welding I had never heard that one, and it was coming from someone that has been doing it at least 5 days in a row so I will assume there is something too it. Just thought I would share, I have to ask the Lincoln guys now what the science is behind it, or is it just a shop belief.