flux core weldin with co2 or other gas?

[Gold Boy]

what happens?

[hydrogeo]

For one thing you waste gas. That's what the flux is for.

[Wile E Coyote]

Double shielding, it's supposed to aid penetration. Think 110v welder trying to weld like the bigger boys. Sometimes used in large production jobs, but I can't remember any further details just off the cuff.

[Mace]

Takes a LOT of power to run dual shield.
A 110V welder is not up to the task..

[Wile E Coyote]

I've never used dual shielding, but this is what I've learned about it.
Dual shielding uses mixed or straight CO2 shielding gas along with a specific flux-cored wire. The particular wire (ESAB makes one popular one) does not have all the proper shielding properties as regular ole flux-core (Think Lincoln's Innershield), thus requiring addtl shielding gas. It's used in shipyards, railyards, and general fab applications. It's not specific to large machines, just that's the most common useage. As I said, 110v users have tried it to eek out just a little more penetration from a small machine. Something users of industrial spec'd machines should have no concerns over.
The process is more forgiving than straight solid or flux-cored apps, and allow for faster transfer rates (welding speed) as well. It comes in several varieties, like single pass vs multi pass, and etc.

[Mace]

Originally Posted by Wile E Coyote

As I said, 110v users have tried it to eek out just a little more penetration from a small machine.

It will do the exact opposite.
If you want penetration use straight flux core. Dual shield is not for a tiny welder..

With a properly sized machine the welds look/are nice and have awesome penetration.

[hydrogeo]

If thickness is an issue why not just do multiple passes with the wire and gas you have. Flux core has its place but I usually use it only when I'm welding outside or run out of gas. When thickness is an issue I just plug in the trusty AC stick welder...

[Gold Boy]

thanks for the replies.

i think the fluxcore wire they use for this technique is different from the regular......

meanwhile i will stick with the regular fluxcore, i do all my welding outside.

[brian]

they'res two different wires being talked about here.

dual shield(outter shield), often called flux-core, is not a self shielded filler. try running it with no gas, and you'll end up very unhappy. and as mace said it's a man's filler...i really doubt any of the 110V toys have the balls to run it.

flux cored(inner shield) wire is a self shielding filler. the best i come up with is it's basicly sticking welding with a roll instead of a stick.

it's been a while since i actually looked. but.
a machine set up for flux core will need to have the polarity switched...iirc to dc reverse(electrode postive)..i'm pretty sure mig machines run on dc straight(electrode negative).

co2 as a shielding gas increases the arc temp(it's a greenhouse gas), so while a selfshield filler would not need gas, i could see how using straight co2 might help weld thicker stuff than the machine is rated for.

any other gas or a c02 mix would just be a waste of money.

[Wile E Coyote]

Update: Looks like the smallest sized dual shielded wire (0.045" ) is rated by ESAB at needing a minimum amp and volt just at the max #'s of the average 110v welder. Not to mention problems fitting 0.045" wire through a gun sized for usual 110v use. While technically still feasible for my source to have used dual shielding with a 110v welder, it's not something reasonable I shoulda even mentioned as I did above. It is , however, true that dual shielding penetrates better than a similarly-sized self-shielding setup.
So, I was only mostly wrong, hehe. Sorry for the bad info.

[MTJohn]

Dual shield is available in .035 also - I'm using it in my Miller 212. I have been playing with 3/16 steel to practice and tweak the settings to make sure I can get good penetration when I finally start my trailer build. With a little bevel and a weave pattern, I get full penetration on a butt joint with wire speed at 4 and the volts at 7. No idea what the 7 means in actual volts. This is one notch above what the manual recommends for the solid wire.

I spent hours doing vertical up weaves with this stuff in my welding class. Wish it didn't smoke so much and there was no slag to clean, but I guess I can't have anything.

[Gold Boy]

Originally Posted by MTJohn

Dual shield is available in .035 also - I'm using it in my Miller 212. I have been playing with 3/16 steel to practice and tweak the settings to make sure I can get good penetration when I finally start my trailer build. With a little bevel and a weave pattern, I get full penetration on a butt joint with wire speed at 4 and the volts at 7. No idea what the 7 means in actual volts. This is one notch above what the manual recommends for the solid wire.

I spent hours doing vertical up weaves with this stuff in my welding class. Wish it didn't smoke so much and there was no slag to clean, but I guess I can't have anything.

thanks for that detailed info...

encouraging.....