Why does flux core wire weld thicker metal than MIG?

[sixdogs]

Why does the same machine setup with flux core wire weld thicker metal than the same machine set up as MIG? My Lincoln SP170T owner's manual gives a chart that shows flux wire welding a noticeably thicker steel than just MIG wire with shielding gas. I don't understand this.

 

[Shield Arc]

I don't really know the technical answer. I would assume because flux core has a hotter puddle. Now dual shield with gas coverage, has the best of both worlds. Slag and gas coverage.

I have welded up to 4-inch thick material with 1/16-inch Mig wire. Worked in a fab shop in the 1970s, we had to test every 3-months with Mig on 1-inch thick V-butt plates.

 

[sixdogs]

Flux core with gas. Very interesting.

 

[Shield Arc]

You'll see dual shield used more often than Mig in structural fab shops. And boy is it fast! :cool2:

 

[CNC Dan]

Why does the same machine setup with flux core wire weld thicker metal than the same machine set up as MIG? My Lincoln SP170T owner's manual gives a chart that shows flux wire welding a noticeably thicker steel than just MIG wire with shielding gas. I don't understand this.

I think it has to do with the vapor that the flux core wire makes.

Kind of like using helium, instead of argon, will produced a hotter weld (same current) with TIG welding.

 

[sixdogs]

You'll see dual shield used more often than Mig in structural fab shops. And boy is it fast! :cool2:

What does the weld look like? Quality?

 

[Shield Arc]

Here are some dual shield welds I made a few years ago.
First pictures shows the slag coverage.
Third picture is a vertical up hill weld.

 

[sixdogs]

wow is that impressive.

 

[Shield Arc]

I didn't do any of the welding, I was the project superintendent. This was for an outfall just down river of the Bonneville dam, on the Columbia river. We drove 10-feet diameter pipe, drilled them out, and welded another section to the driven section, and drove it. The outboard piles went over 200-feet into the rock. All welded with dual shield, 100% x-ray.

 

[CNC Dan]

I didn't do any of the welding, I was the project superintendent. This was for an outfall just down river of the Bonneville dam, on the Columbia river. We drove 10-feet diameter pipe, drilled them out, and welded another section to the driven section, and drove it. The outboard piles went over 200-feet into the rock. All welded with dual shield, 100% x-ray.

Would love to be able to have a close up look at that kind of operation. how long does it take to drive a pile that deep, and how far does it go with each blow of the pile driver.

 

[Shield Arc]

These were very slow going piles. We used a hydraulic vibrating hammer to drive them. No impact hammer at all. In the second picture I posted above the crane to the left of the derrick, the red one with a blue boom. Was gearing up to drill out the inside of the pipe. Here are the augers we used. The large hole saw looking auger really got a workout drilling through the rock. It was amazing how many carbide teeth we went through!:shocked: The Kelly bar was powered with a 750-HP diesel engine.

 

[Mark @ Everlast]

One reason is that most flux core is straight polarity.

 

[Oldpath05]

Why does the same machine setup with flux core wire weld thicker metal than the same machine set up as MIG? My Lincoln SP170T owner's manual gives a chart that shows flux wire welding a noticeably thicker steel than just MIG wire with shielding gas. I don't understand this.

(Why does flux core wire weld thicker metal than MIG?)> False ?, On some welding equipment, the heat input doesn't go high enough for the same size wire, .045 70s3 requires more heat vs. .045 71T Duel shield flux core wire when using the same shielding gas 75/25, there for both wire's can weld the same size plate.
Side note, 101 TM Duel shield flux core wire is not allowed on some steel stricture on some US Navy ships. Lincoln La 100, or Esab 100s, solid wire with 95/5 shielding gas must be used.

 

[yomax4]

It takes fewer volts to liquidate cored wire as opposed to solid. You just have the thin metal sheath outer with powder core.. The smaller machines like the 115v can only get away with 035 wire if its cored. 20 years ago the 71T1 dual shielded wires were supposed to be a direct replacement for 7018 stick. In most cases now days that's true. Most heavy plate ag and military have evolved over to either dual shield, metal core or hard wire pulse. You can use 3/32 cored wire to do heavy plate or hard surfacing but it would be difficult to run a 3/32 solid wire.

 

[Oldpath05]

I went through another 10lb.roll of .045, 71t duel shield today at work, mostly on vertical up and some flat, it sure welds better then that 71t self shielding wire flux core wire, I tried that stuff several times and could never get it to run smooth, awful spattery, I'd give it one star and wouldn't recommend it to a friend. But I would give 71t duel shield 5 stars, and recommend it to a friend if the friend could afford it, pricy. That's why for home use I mostly use 70s, .030.