[rahtreelimbs]

Let's say you are welding 1/8" or 1/4" carbon steel, is there a time when spray may be desired over short circuit?

[Superiorwelding]

Yep!
-Jonathan

[AKweldshop]

Yep!
-Jonathan

Wow this is so uncharacteristic of you, belittling a person for asking a question.
Where is Jonathan and what have you done with him???

[weldin mike 27]

Meow. The thing is, you can spray on 1/8 but try not to short circuit (dip) on 1/4 inch.

[Superiorwelding]

Yep!
-Jonathan

Wow this is so uncharacteristic of you, belittling a person for asking a question.
Where is Jonathan and what have you done with him???

Belittling? I was being funny. Apparently it didn't work.
-Jonathan

[Otto Nobedder]

I rarely have the opportunity to spray-arc anything, as I'm in repair and very little I ever fix is in a flat position.

If you're welding 1G, and can use disposable backing (ceramic tape), or a permanent backing bar, you can make some serious tracks on 1/4", as you can do root, fill, and cap in one pass. Consider, though, in this case you are using, say, 28V and 250ipm for an .035 wire. You will almost certainly get complete fusion, but you're putting one hell of a lot of heat in a small zone, and advancing at a slower speed than you would with a short circuit pass (but you're only doing it once).

This is why processes are qualified for each circumstance. I'm no welding engineer, and I've not sensed any rhyme or reason yet as to when spray is preferred to short-circuit.

I hope some knowledge comes in to reply.

Steve S

[rake]

We sprayed a lot in the shipyard 1G, 2G, 1F & 2F with .045" and 1/16" wire but thin stuff for us was like 1/2".
On non hull with 80S wire we did a good bit of spray twin arc. 2F with a 50%-50% knife edge bevel your lead welder
puts in 2" - 3" of root pass and then your lag welder starts pouring it in behind him from the other side. No back
gouging or grinding required!

[jroark]

The only reason I could see using spray arc on 1/4" is if you get paid by the inch. In that case though I would crank up the wire speed. Right now my machine at work is set at 31.5V and 850+/- ipm. That's how my boss likes it but you'd get a better weld using slower wire speed if you can.

[Boomer63]

I have a couple of welders set up in my shop so students can practice spray, as a departure from their normal routine of short arc. If I am fabbing a project and the welder I happen to have available is set for spray, I spray. If set for short, I short. ("I" not short, arc be short!) I like spray, but would rather have the short circuit around for day to day use. Industry in this area uses anywhere from 85% to 95% with spray. From experience, the only position I have not done spray is overhead. I have used spray with all diameter of wire, up to .045. I have folks lecture me and explain that spray can only be used in 1G ... right after I just took a 3/4", closed root plate test in 2G.

I understand why industry likes spray. I also feel like it is easier to teach wire feed with short.

Take your pick!
Gary

[Superiorwelding]

All right, to put a real answer out here instead of being funny, there are major advantages in spray transfer (GMAW) over short-circuit (GMAW-S). The first, and probably most important, is better penetration or depth of fusion. While GMAW-S works well for some applications one of its down falls is lack of fusion, depth of fusion or little penetration whichever you want to call it. This is why ASME and AWS do not recognize GMAW-S as a pre-approved process (AWS D1.1 3.2.1 Prequalified Processes)and must have a PQR done to get your WPS and be approved to be used under the codes. I talked to a good friend, who I would call a expert, about this topic a while back and he challenged me to the fact that GMAW-S should not be used beyond 1/8" material thickness. Some of his reasons, besides his lab results, were GMAW-S is used it must be set correctly, which can be hard to do if inexperienced, and the gun angle must be correct so the weld hits the weld joint correctly which can be hard to do as well. I have seen many tests failed when trying to use GMAW-S and even have had a few practice pieces I was doing fail when trying to prove/disprove this. Spray transfer is more efficient in terms of travel speed but one of its best features is the penetration profile and of course the fact of you being usually above 200 amps while in spray. Lets look at a hypothetical scenario. Given a fillet weld using a 1/4" fillet weld in the 1G positon, and using both GMAW in spray transfer and GMAW-S I can achieve a better depth of fusion profile, cut the heat input in half or better and have a cleaner, more consistent weld profile (face) with little to no clean up. Besides depth of fusion heat input is one of the most important factors you need to consider. In this given hypothetical test the base material would (could) have more grain growth causing the HAZ to be more brittle with the GMAW-S than the spray transfer which is important if taking a bend test or is the weld sees torsional loads.

There is a lot more we can talk about, and probably write a book, but I will stop here for now.
-Jonathan

[Boomer63]

Jonathan - I agree with you and I really do respect your opinions! I am just trying to relate to you what companies in this area are doing. What I find confusing is the wide difference of opinion about process, structural integrity, etc. Is everyone 'right'? You are spot on when you describe how welder must be very sure of gun angle when doing spray.

I try to teach my students to be flexible and adaptable. To be able to do what ever is asked of them, even if they have not specifically seen that before. I have been on jobs where the welder is lecturing the CWI (or whomever) about how they are doing process X the 'wrong' way. I tell the crew that the way they do the weld is they way the WPS says to do it!

Anything else you could relate to me on this subject would be greatly appreciated! I will try to compose some kind of paper where I present what I know industry is doing, and what some of the contributors here know to be almost in contradiction. If it came down to it, my bet is on the guys from the forum ... but that is just me!

Keep up the good work!
Gary

[Superiorwelding]

Gary,
Know that that post was not directed toward you in any way. It just amazes me that there are so many out there who either stick to GMAW-S religiously for whatever reasons and those who either have never heard or are not familiar with spray transfer. Case in point, and I have used this example here before I think, there is a local company who has no WPS, that I nor the employees are aware of, and they use either GMAW-S or pulse spray and both are lower amperage. Several people have tried to talk them into bigger wire and spray transfer to increase productivity and reduce cost but they will have none of it. Mainly because the older welders don't want to change their habits (and I say that with respect). I can go on and on on this subject as it interests me greatly.
-Jonathan

[hacadacalopolis]

Maybe u guys can help me out. Off topic
I came here for a tip considering the discussion of spray arc.

I am using 80series wire .045 with 26.3V, and 307 ipm. Was told to keep it around there.
Also, I am making a 1/2" fillet on 8" 1/2"wall tubing to 1" thick plate.

I get good welds but sometimes I get burn back and wire just wants to melt before deposit.
Am I too high with the heat?

[Otto Nobedder]

I am using 80series wire .045 with 26.3V, and 307 ipm. Was told to keep it around there.
Also, I am making a 1/2" fillet on 8" 1/2"wall tubing to 1" thick plate.

I get good welds but sometimes I get burn back and wire just wants to melt before deposit.
Am I too high with the heat?

Unless you are using a cored wire in dual-shield, you won't get spray arc at those settings.
Burn-back is the point, so the metal literally sprays as molten particles into the puddle.

On .035 solid wire, I'll use 27V and 250 IPM and get consistent results. I'm typically using a 90% helium blend, but 90% argon blends will work at this range, also. On .045 solid wire, I'd expect to set about 170-180 IPM.

Please give more details of your setup.

Steve S

[Boomer63]

Maybe u guys can help me out. Off topic
I came here for a tip considering the discussion of spray arc.

I am using 80series wire .045 with 26.3V, and 307 ipm. Was told to keep it around there.
Also, I am making a 1/2" fillet on 8" 1/2"wall tubing to 1" thick plate.

I get good welds but sometimes I get burn back and wire just wants to melt before deposit.
Am I too high with the heat?

Steve pretty much said it all. What is your gas mix? Manufacturers in my area who do structural level welding are going with that .045 hard wire, machine settings you describe with a 90% - 95% gas mix; they are getting the spray. I do set it up here in my shop and it is more difficult to get a hold of then you might think.
Gary

[hacadacalopolis]

I'll get back with you guys on gas. There is a chart in the parts house, I just could not match it up.
If I remember correctly I thought it was like Blue(something) #211.
Which was I think 75-argon 15co2 10helium.

I am def getting a lot of burn back at times. And at other times beautiful welds.
Sometimes pinholes and porosity at worse times.

Gas at 40-60 cfh

I would upload photos but it says board attachment quota has been reached.

[Otto Nobedder]

That "quota" thing has come up on several people recently.

I've sent the webmaster an e-mail on the subject.

There is an alternative; If you use a photo-host like photobucket, snapfish, or tinypic, you can share the [Img] code for the picture by pasting it into your post. This gives you the ability to post higher resolutions than our BBC will allow, as well.

Steve S

[hacadacalopolis]

Ok Steve,
Since I have a photobucket I will just embed the IMG tag.

I have come to realize that I am probably getting more of consumable problem then most times. I believe that I am getting the nozzle and tip too close to the weld causing all the heat build up and burn back to destroy the contact tips. I have gone through several, but each time at least better work flow for these support legs. I still do not entirely know if that is the major cause. However, I entered the machine setup did reset, But before I did I noticed my BUR setting was at .20 instead of the factory .07 it set it back to. This was for the Millermatic 225 I think. And using AirLiquide out of Houston. #21 gas composition.

Not very good photos but here they are.
Bad deposition here, restart with pinholes and porosity on left side. Root Pass


As compared to here with a consistent puddle.


The easier the job will be if I can wrap the corners with barely any undercut, valleys, and proper tie-ins. Its very frustrating to do so with the issue I am having though. Hopefully tomorrow will be a better day. Id rather just fit this all day than weld it. Jeez

[Otto Nobedder]

The "burnback" can be set to zero. This is desirable for spray-transfer.

You've told me nothing with that "air liquide composition #21". I suppose I can dig it up and figure it out, but as the wire-burner, you really should know what you're welding with.

Sorry for a less than positive post.

I'll see what I can find. Air LIquide owes me a favor.

Steve S

[Boomer63]

From everything I have heard, you need at least an 85% mix for the spray to happen. However ...
Gary

[Otto Nobedder]

A.L. says in their MSDS for "ARCAL 21" that the formulation can be anywhere from 70/30 to 90/10 (Ar/CO2).

You need an exact analysis of that gas before you discuss spray transfer issues. Ideally, you should be at 90/10 to be able to consistently get spray transfer. If you're on 85/15 or 80/20, your results will be unpredictable.

I've only once (accidentally) achieved spray with 75/25 (the most common mix of Ar/CO2), and that was when my Lincoln CV305 was accidentally turned to 32V, while my wire was set low for 18V.

Steve S

[hacadacalopolis]

Ok, thx for the help.
The chart taped to the wall was for blue shield.

I will have to get the ID sticker from the bottle because it does not list the mixture on it.
Just arcal #21