Why? Flux vs Gas MIG welding

[I_Love_Plasma]

I know using gas vs flux core produces way different results but why?

1> Why does gas provide a clean uniform weld?

2> Why does flux core splatter so violently compared to gas?

There's a large amount of energy released from both types of welding.

[dgarnier]

how come flux core wire is so much more brittle then regular wire

[dynasim]

Flux core wire protects the weld from oxidation by covering(and reacting) the impurities(oxygen) with the flux. The result is slag, which coats the weld(on purpose). The sparking is an intersting question which I could guess about, but don't know for sure.

Gas prevents oxidation by covering the weld with an inert gas(which doens't oxidize the metal). The coating is done with gas itself. Because the inert gas doesn't create slag, the weld is clean. CO2 plays a part in the weld metallurgy that I don't understand, but I don't think it affects the "cleanliness" of the weld. There isn't any flux reactions going on with when using gas, so there won't be the sparking associated with flux utilizing welds.

Chris

[DaveO]

Adding to Dynasim's response only to say that flux core welding is basically stick electrode welding in a more convenient form. The shielding is provided by the flux which is inside the wire instead of outside the rod. That also answer's DGarnier's question: flux core wire breaks easily because the metal sheath (filler metal) around the flux is comparatively thin. A little low-cycle stress breaks it easily.

[Ram48]

Dave
A good and free resource for a lot of the questions you have can be found at the ESAB site they have a literature and poster area that lets you pick booklets and cds on Mig arc and tig welding.
check it out They sent what I asked for to my door for free and it arrived in less then a week.

[performance]

DaveO,

I would conceed that there are some similarities between stick and flux core...But I believe the differences are stark...Flux is much different. Weld appearance is much different(not as pleasant to the eye). More spatter. Faster. More efficient. Also more difficult to do correctly. IMHO.

[DaveO]

Yes, you're right- the thread drifted from the OP's original question, and I got caught up in the inert gas vs. flux shielding discussion.

[Wookie]

Flux core only splatters violently when the arc length is too long close up the arc length and the spatter will be minimized
Fluxcore has better penetration

[I_Love_Plasma]

Well I know that you break / chip the slag off the flux core welds and the look nice. But the gas welds are beautiful and uniform. Is it just because not all of the slag can be removed?

[everlastsupport]

When welding outside in the open air, you will normally be stick with stick or flux-core MIG. I do a bit of it and find my FC MIG welds look "almost" as good as using ER70 and mix gas. That is they look just fine and very small amount of spatter.

But as Wookie mentioned, I use a very tight arc length. If you pull back, you will have all the spatter you want. You should be able to get nice welds with flux core. You will have to clean it up, but hey, you can weld in the wind and do not have to lug around a gas bottle. It has it's place for me.

[I_Love_Plasma]

Thanks,

I'm hoping I can shoot some video of myself welding and post them via youtube link.

I have another question:,

What would you use to weld skid loader quick attach plates .25" thick with? Wire with upto approximately 120 amps or stick weld with a 3/32", 1/8", or 3/16"? I'm quite good with the MIG, but I really bomb out with a stick :/

[zoama]

All I use is .035 flux core with an .045 tip to keep it feeding smoothly. I've found that some brands of flux core wire aren't as clean and uniform as others, causing poor welds due to the wire dragging and sticking in the tip.
A tight arc and a truncated flux core shield on the torch help in making nice welds. I like having a fan on as well to keep me cool and blow the fumes away.

[I_Love_Plasma]

I like the fan idea. We have a 5 foot ventilation fan in our shop. It really blows!

Back to welding,

I forgot to mention that the plate ( 48"W X 18"H X .25"T ) has the bottom brackets that are 3/8" - 1/2" thick (where the skid loader attachment locks swing down and hook). That's where I am wondering if 120 amps worth of MIG will cut the mustard?

Thanks

[bobwills]

I dont know a whole lot about mig but I know enough to say i dont think 120 amps whould quite be enough. We get a 250 amp miller in our shop and I think its only rated for 1/2 but thats in a single pass. If your welding to 1/2 inch you will prolly want to use stick and if your not to great then make a few passes cause that will make it stronger yet. Cause there is a lot of stress on that peice the lock goes in when your backdragging. What you might could do is use a 6011 to make a good root pass then go over that with your little mig. Does that sound about right to everyone?

[I_Love_Plasma]

Yeah tomorrow I will post a couple pictures of just practice welds. They are just me practicing getting good penetration, I wasn't even attempting to get uniform with the puddles. I do like that idea I'm wondering if I could possibly reverse your plan use the MIG to get the root pass since the main fill work will be on top. Then fill and cap with a 7018? I want the plates to be as durable or more than the loader we're mounting to. "Cause 'nothin runs like a Deere" they build skidloaders like tanks around here.

Thanks!

[bobwills]

Actually maybe what would be the best is run a root with a 6011 cause its gonna penitrate more than anything then fill with the mig cause i looked up a 120 hobart mig in my northern and it says it welds 3/16 with flux core and 1/8 with solid plus sheilding gas so i would only use that for fill and up. And you can use a 7018 for the cap and that would work real good. I personally would arc the whole thing but I just love to arc weld a lot. lol.
O another tip if you use the mig maybe use .023" wire cause you can use that on its highest setting and go real slow with a slow wire speed and it will have a lot longer time melting it all then more penitration. One of my friends told me thats what they do for welding 1/2" hardened steel for his dads snow plows so it might work good for you. Just would have to go really slow and watch that puddle.

[I_Love_Plasma]

I've found that some brands of flux core wire aren't as clean and uniform as others, causing poor welds due to the wire dragging and sticking in the tip.

You hit it on the head! Some brands even corrode, we bought some wire about 8 months ago...it's so fouled up it hates feeding.. :/ I'm pretty certain it was even Hobart brand!

[I_Love_Plasma]

Thanks for the info Gabe. Now would it be okay to tack it just enough to hold it there with the MIG, then 6011 stick on the root? I have lot of problems with my starting technique, almost every time I put the rod to the metal it sticks. I think I would end up pulling my piece, to be welded, down or off. Would the stick just pass right over the MIG tack, as long as I don't put a big blob of there? I want to cap with 7018 low hydrogen rod. I'm uploading pictures now. "What am I doing wrong with the stick?"

[I_Love_Plasma]

Look at the shiny welds...rusty welds are someone else's farmer weld.

MIG(flux-core)


MIG(flux-core)


MIG(flux-core)


My best weld with the stick


Kind of thick....I think....Your thoughts?


Another shot of the best welds I could get with stick..


Top weld is my instructor's weld.....Bottom weld is mine....and so are the butt welds in the center. If I was going to buy a skidloader plate I wouldn't buy one with welds that looked like that center weld! Lame, Lame, and even more lamer. haha


Yep, kinda messy!

[Steve]

When welding outside in the open air, you will normally be stick with stick or flux-core MIG. I do a bit of it and find my FC MIG welds look "almost" as good as using ER70 and mix gas. That is they look just fine and very small amount of spatter.

But as Wookie mentioned, I use a very tight arc length. If you pull back, you will have all the spatter you want. You should be able to get nice welds with flux core. You will have to clean it up, but hey, you can weld in the wind and do not have to lug around a gas bottle. It has it's place for me.

I agree totally. Flux core is very useful outdoors in the wind and when the metal is dirty. Flux core seems to weld rusty metal really well....just like some sticks. I have welded together some really crappy rusted metal without having to clean it up.

My flux core welds are very splatter free and I believe it is because I use it enough to know how to keep the splatter down. It is my opinion that flux core welding is even more responsive to correct amp and speed settings than mig welding. My flux core use is about 55% of the time.