Gas or Flux

[slaggy]

Is there any advantage in using Gas (c25 or Co2) instead of flux cored wire in mig welding, besides maybe cleaner welds. I'm debating whether or not to move up to gas. Maybe someone could explain the difference in these two processes.

Slaggy.

[LuzRD]

less cost in the long run (solid wire costs less than fluxcore and should offest the price of gas)
and no chipping = }

of course there is the concern of less penetration using gas, so if your pushing your machine to its upper limits gas may not be a good idea. gas welding also requires alot more attention to clean surfaces

otherwise i say go for it, i also keep a small roll of fluxcore around just incase i run out of gas or need to work in windier, or dirtier conditions

[MAC702]

MAYBE cleaner welds? Actually, the cleanness of the welds with GMAW versus FCAW is PLENTY of enough reason. You can weld and paint almost. FCAW requires the same chipping and especially wire-brushing that SMAW does, although it's usually easier and faster. The productivity goes way up with the GMAW process.

Also, as mentioned, you'll save money on the long run buying solid wire and shielding gas versus buying FC wire.

Disadvantages already mentioned also: less penetration v. FCAW, cleaner material requirements to start with, and need a fairly indoor environment or very still air.

[383bigblock]

My understanding is that the flux cored is better if you are welding outdoors and have issues with wind. My neighbor uses it at his ranch because it's just easier and he gets better penetration in the field than trying to use gas.


Michael

[Island]

I had heard a rumor (no experience myself) that flux core welds tend to rust faster than GMAW even when painted. Is that true? If so, does it simply reflect poor attention to clean up of flux before painting?

[zapster]

Originally Posted by Island

I had heard a rumor (no experience myself) that flux core welds tend to rust faster than GMAW even when painted. Is that true? If so, does it simply reflect poor attention to clean up of flux before painting?

fluxcore has acids in it that no matter how good you clean it it will eventually eat paint from the inside out.
i know.

...zap!

[weldrwomn]

Gas shielded flux-core doesn't eat paint.

[gnm109]

What the above posters said about fluxcore vs.gas is correct. Additionally, I run solid wire on my Lincoln SP175 plus. I've used .023 and .030 so far and I use straight C02 gas. It has slightly more splatter than Argon/C02 mix but penetration is excellent and it's cleaner than fluxcore, whiich I have also tried.

As pointed out above, gas shielding with solid wire may even turn out to be more economical than fluxcore when you take in to account the higher cost of the consumable wire.

[Weldtek]

Flux core wires - gas shielded or self shielded are good choices for dirty work. A big plus for gasless wire is not needing to haul cylinders, hose, regulators to remote locations or up elevations to get to the work. For clean shop work nothing beats solid wire for user appeal.

[zapster]

Originally Posted by weldrwomn

Gas shielded flux-core doesn't eat paint.

gas....shielded...FLUXCORE????????
kinda defeats the purpose now dont it?

...zap!

[Weldtek]

Oh yeah, the original question. Primarily, the solid wire has nothing to help clean the puddle. All the gas does is protect the puddle from oxygen, hydrogen and nitrogen in the air; and the ionization of the gas in the arc helps to stabilize the arc because electricity does not like to travel through air. Anyone that has ever stick welded with bare rods knows what that's like.

[Rick V]

Slaggy
I would agree with LuzRD who said, "of course there is the concern of less penetration using gas, so if your pushing your machine to its upper limits gas may not be a good idea."

I recently tried to make the transition to gas - but came up short because my welder hasn't got the amps. (See - my posting of last week for details - MIG Welds don’t stick.) In short, my DC wire feed welder is rated at 70 Amps output. Running straight CO2 with 0.030 sold wire, the largest thickness I can weld reliably is about 18 gage. e.g. Today I tried welding 5/16 bolt heads to a 3/32 inch thick strap hinge (on top of a Formica covered box) - no dice... oh the welds looked pretty but I could knock them off in chunks with a chipping hammer - not enough fusion. I had to switch to flux core, then there was no lack-of-fusion problems.

MAC702 said, "MAYBE cleaner welds? Actually, the cleanness of the welds with GMAW versus FCAW is PLENTY of enough reason." I agree with that 100% PLUS!
In my bolt head/strap hinge application, the solid wire / gas made some metal splatter localized adjacent to the weld. BUT flux core... what a mess it made! With flux core the splatter (metal and brown slime) traveled a lot further - and it was hotter, burning in deep close to the weld and it made an awful mess out of my Formica top - there were many [looked like hundreds] 1/64 - 1/16 inch burn holes over an area two feet in diameter from the weld plus straight streaks of brown-liquid residue from the flux that shot out in all directions from the weld. I could clean that brown crap off with cleaner and water - but the burn holes are permanent!

So gnm109 said it all, "I run solid wire on my Lincoln SP175 plus. I've used .023 and .030 so far and I use straight C02 gas. It has slightly more splatter than Argon/C02 mix but penetration is excellent and it's cleaner than fluxcore, which I have also tried."

I envy gnm109's because his Lincoln SP175 is rated at 130 amps - that has the amps to make solid wire with gas work well for a wider range of metal thickness and would have easy handled my bold head/hinge welds.

What about a Lincoln SP-135 at a rated 90 amps - is that is sufficient? Maybe somone can comment.

The Bottom Line - Have you got the Power??? If so - GO GAS!

Rick V

[MAC702]

Originally Posted by Rick V

I envy gnm109's because his Lincoln SP175 is rated at 130 amps ...

What about a Lincoln SP-135 at a rated 90 amps - is that is sufficient?...

Just to clarify, rated amperage is not the maximum output. It just the standard point they use for computing duty cycles and input amperages. I agree, it's misleading and confusing at times.

The SP-135 will output 135A when it needs to, likewise the SP-175 will top out at 175A, but the duty cycle will be significantly lower than at the rated amperage. It's still usually plenty for non-production work.

Also, MIG amperages to steel thicknesses will be different than Stick amperages to steel thicknesses. Don't try to compare them directly.

[MAC702]

Originally Posted by zapster

gas....shielded...FLUXCORE????????
kinda defeats the purpose now dont it?

...zap!

Check out Lincoln's Outershield line. FCAW-G is a great process for penetration and speed. Best of all worlds if your machine has the guts to run it and you still have a decently calm environment.

[TEK]

Originally Posted by zapster

gas....shielded...FLUXCORE????????
kinda defeats the purpose now dont it?

...zap!

Nope. It's called dual-shield. But you knew that already

[Sandy]

I see it as more of a gas and flux core issue if the budget allows at all. Each has its place where the other just won't do. It is very handy to have the choices and options right there at hand. Use gas and solid when it best suits the needs and switch to flux when it seems the best.

[Island]

Does anyone else agree with Zapster about rusting through paint after FCAW or do they agree with Weldrwomn with the statement that use of gas with FCAW is not associated with rusting through? Seems to me these two statements are incompatable if one assumes Zapster's statement that acids left in the weld are responsible for the rust through?

[JKC9392]

Wind tunnels for Roush racing and Chrysler proving grounds welded with fluxcore. Both projects have been done for years and show no signs of rusting. I personally believe if properly cleaned [ bead blasted] fluxcore holds paint as well as gas shielded welds. I almost always use gas at home unless it is something like gravity wagon that won't fit in garage ,and wind is a issue.

[99blackzr2]

Originally Posted by MAC702

Check out Lincoln's Outershield line. FCAW-G is a great process for penetration and speed. Best of all worlds if your machine has the guts to run it and you still have a decently calm environment.

here is a gas shielded fluxcore weld i just did at school.how does it look? 3 passes 3/4 inch plate.

[emerickwelding]

I run solid wire with 95% argon and 5% oxygen. You will get VERY deep penetration with this combo and virtually no spatter at all. It does run VERY hot and alot brighter. Some disaggree about using this but I love it

I have never been a fan of gas sheilded FC. I always seem to get worm holes no matter how hard I try. I gave up on it.

[chopper5]

emerickwelding that the way i like it too good old spray transfer now thats mig welding

[elderthewelder]

Originally Posted by emerickwelding

I have never been a fan of gas sheilded FC. I always seem to get worm holes no matter how hard I try. I gave up on it.

I ran some dual shied the other day, 1st time in ages, and kept getting those worm holes in it, what is the cause of that?? It was driving me and my co worker nuts, we thought it may have been the gas, we were using c25

[MAC702]

Originally Posted by elderthewelder

I ran some dual shied the other day, 1st time in ages, and kept getting those worm holes in it, what is the cause of that?? It was driving me and my co worker nuts, we thought it may have been the gas, we were using c25

We can't answer that question unless you tell us what wire you were running. Some wires use C-25, others use CO2, others use other mixes.

[TEK]

Originally Posted by elderthewelder

I ran some dual shied the other day, 1st time in ages, and kept getting those worm holes in it, what is the cause of that?? It was driving me and my co worker nuts, we thought it may have been the gas, we were using c25

Depending on the wire, could have been voltage. Some are a little sensitive.

[Weldtek]

I agree with TEK. Voltage problem, maybe stickout too long, which makes volts rise. But as an inspector, I can tell you as long as there are no holes in the worm tracks, they're not a defect by most codes or specs. But they sure look like hell when painted.