Questions on spray mode

[jzr75601]

Hello all just had some questions on spray mode and I was wondering if you can get into spray mode using 7525 shielding gas and also not really sure when the machine gets into spray mode I've heard that spray mode is very quiet as opposed to Short circuit transfer

[jzr75601]

I wanted to provide a little more details on the equipment that I'm using I have a millermatic 200 and I'm running it at full output voltage setting is a six and I have the wire speed about halfways up

[Oscar]

True spray transfer requires minimum 80% Argon gas, and works best with 90%+ argon.

What you've heard about the sound is correct; spray transfer has a "silent" hiss that is 99% crackle-free when dialed-in correctly. Your machine is likely too under-powered. There are both amperage and voltage thresholds that need to be attained for spray transfer.

[Louie1961]

The generally accepted wisdom is that you need at least 80% argon to go into true spray mode. There are people who dispute that however. But in general, I am going to say no, no spray with 75/25. You might get close or into globular transfer mode. And yes, spray mode is a quiet "whooshing" sound with the occasional snap, crackle or pop.

[scsmith42]

What about 100% co2

I’m using some Lincoln Ultracore 71c dual shield .045 wire in my Suitcase MIG and it requires 100% CO2. It sure acts like spray transfer..

[Oscar]

What about 100% co2

I’m using some Lincoln Ultracore 71c dual shield .045 wire in my Suitcase MIG and it requires 100% CO2. It sure acts like spray transfer..

cored-wire is a different animal altogether.

[Jack Ryan]

cored-wire is a different animal altogether.

Or at least a variation on a theme.

It is not so much the current that (helps) promote the transition to spray transfer, but the current density. Flux core wire has a smaller cross sectional area than the same diameter solid wire so it gets keen to transfer to spray earlier - so to speak. High argon shielding gases reduce the current density at the transition to spray transfer.

In addition, the filler often contains materials that will promote spray transfer. I think a large proportion of flux cored wires is designed for spray transfer.

I have no practical experience welding with straight CO2.

Jack

[smithdoor]

I agree 👍

Dave

cored-wire is a different animal altogether.

[Munkul]

I was taught that you shouldn't use pure whooshing spray for steel, it's too wasteful with the long arc length, and penetration suffers.

You want a good bit of crackling, but not so much that you get spatter.

It's LOUD when set right. Not like short-arc bacon frying, it's much more intense.

We tend not to think about it too much, we just go by amps required for the job, and voltage trimmed to suit. If it's putting the right amps into the job, the arc length is short and there's no spatter, then you're probably bang on the money

[scsmith42]

Oscar, Munkul, Dave, Jack, thanks for the quick response and education.

Scott

[Louie1961]

Not the question the OP asked, but this is a great spray training video

[smithdoor]

It is interesting just changing gas will how you welded.

When I was in someone else shop I use spay mode (they paid for the gas).
In my shop I used flex core with CO2 (E71T-1 0.052") .
In retirement I use no gas flux core [E71T-11 0.030"].

It get down to type work you doing.

Most here would not know to build up a shafts and machine it is best to spay.
Oriental Iron to cost down the use short circuit transfer with CO2.
The work I did on metal builds so use Flux core with gas.
If working outside a no gas flex core is best to use..

Dave

Oscar, Munkul, Dave, Jack, thanks for the quick response and education.

Scott

[Jack Ryan]

Not the question the OP asked, but this is a great spray training video

As a matter of interest, I used the table presented in the video and added the current densities. It's pretty clear that it is the current density rather than the current that defines the spray transfer threshold - all else being equal.

Inches	mm	Gas	Current	Current Density
0.035	0.9	98% Ar, 2% O2	165	59.1
0.045	1.1	98% Ar, 2% O2	220	61.3
0.035	0.9	95% Ar, 5% O2	155	55.5
0.045	1.1	95% Ar, 5% O2	200	55.7
0.035	0.9	92% Ar, 8% O2	175	62.7
0.045	1.1	92% Ar, 8% O2	225	62.7

Jack

[N2 Welding]

Or at least a variation on a theme.

It is not so much the current that (helps) promote the transition to spray transfer, but the current density. Flux core wire has a smaller cross sectional area than the same diameter solid wire so it gets keen to transfer to spray earlier - so to speak. High argon shielding gases reduce the current density at the transition to spray transfer.

In addition, the filler often contains materials that will promote spray transfer. I think a large proportion of flux cored wires is designed for spray transfer.

I have no practical experience welding with straight CO2.

Jack

I find this very interesting. I don’t run much if at all flux core wire. I got the ESAB migmaster 250 to try solid wire spray one of these days. This has me wondering, is it possible to use spray with flux core wire to reduce or eliminate spatter? I think the closest I came to spray was using ESAB Rebel 215ic .035 dual shield flux core with 75/25. Very hot process and the sound it made, well the only thing I can think of to describe it is the sound a fire extenguisher makes when it is spraying powder out of the nozzle. Loud Shhhhhh kind of noise.

I am interested in this flux core spray theory because from what I have read here on the forum is flux core runs hotter. This has me questioning if non dual shielded flux core is part of this discussion or are you only talking about dual shield here?

[Louie1961]

I am interested in this flux core spray theory because from what I have read here on the forum is flux core runs hotter. This has me questioning if non dual shielded flux core is part of this discussion or are you only talking about dual shield here?

It really depends on the wire. Lincoln 71-M gas shielded flux core runs in a volt range of 23-35 volts (essentially spray arc voltages) https://www.google.com/url?sa=t&rct=...QvCET21U1QbxAH

Lincoln NR 212 self shielded flux core runs in a range of 14-20 volts. (well below spray arc voltages) https://www.google.com/url?sa=t&rct=...nOyDBUg5f9QneO

I have to imagine if you try to increase the voltage on the NR-212 outside of the recommended range, it is going to run very poorly. So I would say that the idea of flux core running in a near spray or actual spray state is really wire dependent, based on the design of the wire.

[smithdoor]

It depends on adjustment and gas if run hot.
They all will run hot depends adjustments.
I have weld 24 gauge with flux core but adjusted to a lower setting

Dave

I find this very interesting. I don’t run much if at all flux core wire. I got the ESAB migmaster 250 to try solid wire spray one of these days. This has me wondering, is it possible to use spray with flux core wire to reduce or eliminate spatter? I think the closest I came to spray was using ESAB Rebel 215ic .035 dual shield flux core with 75/25. Very hot process and the sound it made, well the only thing I can think of to describe it is the sound a fire extenguisher makes when it is spraying powder out of the nozzle. Loud Shhhhhh kind of noise.

I am interested in this flux core spray theory because from what I have read here on the forum is flux core runs hotter. This has me questioning if non dual shielded flux core is part of this discussion or are you only talking about dual shield here?

[propanehotrod]

I used to have a powermig 200 and it loved running 95%argon 5% co2. With .035 wire and the voltage maxed it did a beautiful spray. Pay attention to your gas flow. too much or too little can affect performance.

[N2 Welding]

I just watched that video and am watching it again so all this can sink in and I get a better understanding of how all the different parameters affect the type of machine settings required for desired arc characteristics with each wire diameter and gas % being used. From what I gather from looking at the other chart previously posted I see that it looks like 95%/5% is the sweet spot for using less volts and keeping the machine running cooler with better duty cycle.

According to this chart below from the video the larger the wire diameter the less wire feed speed required to get more amps. Interesting. I understand the faster the wire spits out the higher the amps but now I also understand that the diameter of the wire will also effect the amps as less speed is required to optain higher amps when thicker wire is being used.

I was looking at the chart in the vid to try and determine the size of wire he was using hoping to get a better understanding of the voltage to wire feed speed translation of 27.7v/600ipm. Chart says 90%Arg/10%CO2 but none of the chart setting resemble his settings being used. Scratching head. Must be one of those start with the chart and adjust settings up or down for optimum sweet spot type of deals.

[Oscar]

As a matter of interest, I used the table presented in the video and added the current densities. It's pretty clear that it is the current density rather than the current that defines the spray transfer threshold - all else being equal.

Inches	mm	Gas	Current	Current Density
0.035	0.9	98% Ar, 2% O2	165	59.1
0.045	1.1	98% Ar, 2% O2	220	61.3
0.035	0.9	95% Ar, 5% O2	155	55.5
0.045	1.1	95% Ar, 5% O2	200	55.7
0.035	0.9	92% Ar, 8% O2	175	62.7
0.045	1.1	92% Ar, 8% O2	225	62.7

Jack

What are the units you are using for current density? The traditional unit is A/m², but that would not check out numerically to the values you posted.

But yes, for a given wire diameter and gas mixture, the "current" threshold is a current density issue.

[smithdoor]

Very good chart.
Look at the far right columm note contact tip to work. It is where welders having problems with flux core welding I bet it is same with spay.
They make a longer Nozzle Shield Cup Gas Nozzle for spay and flux core w/gas

Dave

I just watched that video and am watching it again so all this can sink in and I get a better understanding of how all the different parameters affect the type of machine settings required for desired arc characteristics with each wire diameter and gas % being used. From what I gather from looking at the other chart previously posted I see that it looks like 95%/5% is the sweet spot for using less volts and keeping the machine running cooler with better duty cycle.

According to this chart below from the video the larger the wire diameter the less wire feed speed required to get more amps. Interesting. I understand the faster the wire spits out the higher the amps but now I also understand that the diameter of the wire will also effect the amps as less speed is required to optain higher amps when thicker wire is being used.

I was looking at the chart in the vid to try and determine the size of wire he was using hoping to get a better understanding of the voltage to wire feed speed translation of 27.7v/600ipm. Chart says 90%Arg/10%CO2 but none of the chart setting resemble his settings being used. Scratching head. Must be one of those start with the chart and adjust settings up or down for optimum sweet spot type of deals.

[Jack Ryan]

What are the units you are using for current density? The traditional unit is A/m², but that would not check out numerically to the values you posted.

But yes, for a given wire diameter and gas mixture, the "current" threshold is a current density issue.

A/mm² - sorry, non standard units but the numbers were convenient. In any case, it is the fact that it is the same for each (solid) wire diameter that I was concerned with.

Jack

[Jack Ryan]

It really depends on the wire. Lincoln 71-M gas shielded flux core runs in a volt range of 23-35 volts (essentially spray arc voltages) I have to imagine if you try to increase the voltage on the NR-212 outside of the recommended range, it is going to run very poorly. So I would say that the idea of flux core running in a near spray or actual spray state is really wire dependent, based on the design of the wire.

It is wire dependent. For any particular tubular wire geometry, the mode of transfer is defined by the composition and melting point(s) of the flux and, for FCAW-G, the gas composition and coverage.

If the welding parameters are outside of the specifications, the flux doesn't do its work properly. Often if you ignore that and just do it, you will get a "satisfactory" result anyway. Satisfactory though is quite subjective in some environments and quite objective in others.

Jack

[N2 Welding]

Very good chart.
Look at the far right columm note contact tip to work. It is where welders having problems with flux core welding I bet it is same with spay.
They make a longer Nozzle Shield Cup Gas Nozzle for spay and flux core w/gas

Dave

Yes there is a lot of pertinant details for many different parameters in that chart. I don’t recal if my nozzle has a flush tip or recessed. I’m too tired atm just to go downstairs to look at that. If I do not have a recessed tip to nozzle I could always grind down the tip about 1/16” to 3/32” for a recessed tip. Not that much of a big deal imo to trim a tip down shorter for this purpose.

Now in the video iirc the guy said that as the CO2% goes down the voltage would need to go up or maybe I have that backwards. I have to watch it again a couple more times for it to stick “for the day”. I’ll forget most of this a week from now

[Oscar]

A/mm² - sorry, non standard units but the numbers were convenient. In any case, it is the fact that it is the same for each (solid) wire diameter that I was concerned with.

Jack

Oh ok. In that case the correct chart would be

Inches	mm	Gas	Current	Current Density
0.035	0.9	98% Ar, 2% O2	165	259 A/mm²
0.045	1.1	98% Ar, 2% O2	220	216 A/mm²
0.035	0.9	95% Ar, 5% O2	155	244 A/mm²
0.045	1.1	95% Ar, 5% O2	200	196 A/mm²
0.035	0.9	92% Ar, 8% O2	175	275 A/mm²
0.045	1.1	92% Ar, 8% O2	225	220 A/mm²

correct?

[KenO]

I'm not familiar with spray transfer, is there a reason that .030 wire isn't listed?