Flux core vs mig

[Gear Jammin-Dog Chasin-Yota Man]

Huh, thats almost the opposite of what my welding teacher told me

[Gear Jammin-Dog Chasin-Yota Man]

I'm a welding teacher and I don't agree that innershield is better than dual shield.  Not at all.
Dual shield is far superior to innershield (unless you are welding in a wind storm)

[junya92toy]

Ya no one uses innershied unless its outside and in wind. Ive seen many ship building places use dualshield outside as well.

[Burl]

But is any one really doing spray transfer at home in the shop? I thought that was more of an industrial, and robotic use
I always thought that mig gives you better looking welds and flux core has better penetration. Although that isn't exactly all the way right. My lincoln 180 requires you to switch polarity before going from one to the other, as does most other welders I have used/seen.

I spray transfer all the time at home with my dads miller trailblazer, especially when fish plating truck frames.

[Gear Jammin-Dog Chasin-Yota Man]

But is any one really doing spray transfer at home in the shop? I thought that was more of an industrial, and robotic use
I always thought that mig gives you better looking welds and flux core has better penetration. Although that isn't exactly all the way right. My lincoln 180 requires you to switch polarity before going from one to the other, as does most other welders I have used/seen.

Spray transfer is the best way to get SMAW (stick welding) like- penetration with a Mig Welder and get good looking welds without using flux core.

Penetration comes from Amps and Volts- the higher the heat, the deper the penetration.  Hope that helps

[junya92toy]

Spray transfer is the best way to get SMAW (stick welding) like- penetration with a Mig Welder and get good looking welds without using flux core.

Penetration comes from Amps and Volts- the higher the heat, the deper the penetration.  Hope that helps

Penetration comes from metal prep, open corners and bevels.

[Gear Jammin-Dog Chasin-Yota Man]

Penetration comes from metal prep, open corners and bevels.

Ummm.....Kinda.....

Penetration will be better in certain weld positions and joint fit ups than others (i.e. vertical up welds will penetrate more than vertical down, just like open corners will aid in good penetrating welds due to the lack of material being welded there.) 

BUT you can't get good penetration if you don't have enough amps or volts to heat your electrode enough to penetrate the material being welded.  Aside from that, the thicker the steel being welded, the more heat you need to weld it and achieve good penetration REGARDLESS of "metal prep, open corners, and bevels.

Penetration and proper welds start with setting the machine up correctly for the type of material to be welded, material size being welded, and position of the weld.

Joint fit up, "metal prep, open corners, and bevels" all produce quality welds (or poor ones depending on how you prep the material for the weld),
while open corners and bevels CAN and do get you penetration, they are NOT always an option for welds, and they should not be used as a SOLE method for penetration.  

If you think "penetration comes from metal prep, open corners, and bevels" then I would suggest the question: how then can a welder get penetration on a T-fillet weld-one of the most common welds?


Fundamentally Penetration starts and ends with amperage/ voltage and electrode selection.  

I am a certified welding instructor and have been welding for years.  The penetration concept is often confusing to folks, and it is exactly why I am going into detail about it.

[junya92toy]

Ummm.....Kinda.....

Penetration will be better in certain weld positions and joint fit ups than others (i.e. vertical up welds will penetrate more than vertical down, just like open corners will aid in good penetrating welds due to the lack of material being welded there.)  

.

BUT you can't get good penetration if you don't have enough amps or volts to heat your electrode enough to penetrate the material being welded.  Aside from that, the thicker the steel being welded, the more heat you need to weld it and achieve good penetration REGARDLESS of "metal prep, open corners, and bevels.

Penetration and proper welds start with setting the machine up correctly for the type of material to be welded, material size being welded, and position of the weld.

Joint fit up, "metal prep, open corners, and bevels" all produce quality welds (or poor ones depending on how you prep the material for the weld),
while open corners and bevels CAN and do get you penetration, they are NOT always an option for welds, and they should not be used as a SOLE method for penetration.  

If you think "penetration comes from metal prep, open corners, and bevels" then I would suggest the question: how then can a welder get penetration on a T-fillet weld-one of the most common welds?


Fundamentally Penetration starts and ends with amperage/ voltage and electrode selection.  

I am a certified welding instructor and have been welding for years.  The penetration concept is often confusing to folks, and it is exactly why I am going into detail about it.

Im a certified welder, with a college degree too, I know how it works.
The correct settings let you you fusion. You cant get 100% pen welds without a bevel.
You can get 100% with forge welding, with the pen being on the microscopic level
and the less heat you put into the metal the better.

[Burl]

Ok, coming from the man himself, Flux core and dual shield are spray transfer as well as dual shield.  You can't just trade out an electrode negative spool of mig wire or (short arc) to a spool of flux core wire.  Polarity must be changed to accommodate the two styles.  There are two types of spray transfer one can be done with solid mig wire which is known as globular, the other is open arc which is used with tubular flux core and dual shield.  With electrode negative spray transfer (globular) proper welds can be achieved with the homeowner sized machines (mine is a miller 210), you just have to get over 22 volts consistently.  This also can only be achieved indoors because is the 75/25 cover gas is removed during the globular method, your weld will have severe porosity and look like  .  That's why most spray transfer is done with flux core and dual shield because it doesn't matter if the wind blows the cover gas away.  Dad is the manufacturing department head at southwest Oregon College, he's pretty smart when it comes to this kinda stuff .

[junya92toy]

Ok, coming from the man himself, Flux core and dual shield are spray transfer as well as dual shield.  You can't just trade out an electrode negative spool of mig wire or (short arc) to a spool of flux core wire.  Polarity must be changed to accommodate the two styles.  There are two types of spray transfer one can be done with solid mig wire which is known as globular, the other is open arc which is used with tubular flux core and dual shield.  With electrode negative spray transfer (globular) proper welds can be achieved with the homeowner sized machines (mine is a miller 210), you just have to get over 22 volts consistently.  This also can only be achieved indoors because is the 75/25 cover gas is removed during the globular method, your weld will have severe porosity and look like  .  That's why most spray transfer is done with flux core and dual shield because it doesn't matter if the wind blows the cover gas away.  Dad is the manufacturing department head at southwest Oregon College, he's pretty smart when it comes to this kinda stuff .

thats not spray, thats short arc, spray is tiny droplest that melt right out of the tip
you know you are doing it right when it doesnt make any noise.
gas-98-2 argon-02

[Burl]

thats not spray, thats short arc, spray is tiny droplest that melt right out of the tip
you know you are doing it right when it doesnt make any noise.
gas-98-2 argon-02

Negative short arc literally means short arc as in short piece of wire that sticks out of the contact tip and enters the pool of molten metal in the weld area.  Globular is by no means short arc welding.

[Burl]

thats not spray, thats short arc, spray is tiny droplest that melt right out of the tip
you know you are doing it right when it doesnt make any noise.
gas-98-2 argon-02

You would go through a lot of contact tips if molten metal were dripping out of it then landing in the weld area, an extra long stick out is required when utilizing both globular and flux core.  I'm pretty sure molten weld wire would cool and clog up your contact tip if that occurs and no welding would be produced.

[junya92toy]

No you dont melt the tip, and yes it does melt across the arc,  globular is not spray, its short arc. short arc makes contact with the plate and then melts.  Trust me, Ive done it many times on stainless, steel and aluminum.

http://www.esabna.com/euweb/mig_handbook/592mig1_7.htm

Spray
Spray transfer GMAW was the first metal transfer method used in GMAW, and well-suited to welding aluminum and stainless steel while employing an inert shielding gas. In this GMAW process, the weld electrode metal is rapidly passed along the stable electric arc from the electrode to the workpiece, essentially eliminating spatter and resulting in a high-quality weld finish. As the current and voltage increases beyond the range of short circuit transfer the weld electrode metal transfer transitions from larger globules through small droplets to a vaporized stream at the highest energies.[36] Since this vaporized spray transfer variation of the GMAW weld process requires higher voltage and current than short circuit transfer, and as a result of the higher heat input and larger weld pool area (for a given weld electrode diameter), it is generally used only on workpieces of thicknesses above about 6.4 mm (0.25 in).[37] Also, because of the large weld pool, it is often limited to flat and horizontal welding positions and sometimes also used for vertical-down welds. It is generally not practical for root pass welds.[38] When a smaller electrode is used in conjunction with lower heat input, its versatility increases. The maximum deposition rate for spray arc GMAW is relatively high; about 60 mm/s (150 in/min).[16][31][39]
[edit]


Spray Arc Transfer
(generally used for thicker metals in the flat or slightly horizontal position)

Wire Size & Wire Feed Speed:
.035" (0.9 mm) at 400-420 ipm
.045" (1.1 mm) at 210-220 ipm

Shielding Gas & Voltage Range:
98% Argon/2% O2: 24-25 Volts

Amperage Range:
200-210

[Burl]

No you dont melt the tip, and yes it does melt across the arc,  globular is not spray, its short arc. short arc makes contact with the plate and then melts.  Trust me, Ive done it many times on stainless, steel and aluminum.

http://www.esabna.com/euweb/mig_handbook/592mig1_7.htm

Spray
Spray transfer GMAW was the first metal transfer method used in GMAW, and well-suited to welding aluminum and stainless steel while employing an inert shielding gas. In this GMAW process, the weld electrode metal is rapidly passed along the stable electric arc from the electrode to the workpiece, essentially eliminating spatter and resulting in a high-quality weld finish. As the current and voltage increases beyond the range of short circuit transfer the weld electrode metal transfer transitions from larger globules through small droplets to a vaporized stream at the highest energies.[36] Since this vaporized spray transfer variation of the GMAW weld process requires higher voltage and current than short circuit transfer, and as a result of the higher heat input and larger weld pool area (for a given weld electrode diameter), it is generally used only on workpieces of thicknesses above about 6.4 mm (0.25 in).[37] Also, because of the large weld pool, it is often limited to flat and horizontal welding positions and sometimes also used for vertical-down welds. It is generally not practical for root pass welds.[38] When a smaller electrode is used in conjunction with lower heat input, its versatility increases. The maximum deposition rate for spray arc GMAW is relatively high; about 60 mm/s (150 in/min).[16][31][39]
[edit]


Spray Arc Transfer
(generally used for thicker metals in the flat or slightly horizontal position)

Wire Size & Wire Feed Speed:
.035" (0.9 mm) at 400-420 ipm
.045" (1.1 mm) at 210-220 ipm

Shielding Gas & Voltage Range:
98% Argon/2% O2: 24-25 Volts

Amperage Range:
200-210

OK, you've just agreed to what I said already about short arc no need to repeat that.  And globular is not short arc it globular there is a long stick out in the globular method and at the end of the stick out globules form and drop into the weld area which is exactly not short arc welding.  Yes you would melt the tip if molten wire were trying to come out of the contact tip, long stick out must be maintained during spray transfer and the the process that you improperly cited which is a nice word for plagiarism takes place but off the end of the wire stick out not the contact tip itself.  You have claims about degrees you should follow through and debate properly and not commit fallacies.  And we already established that spay transfer is for thicker material.

[Burl]

Just for grins I followed your link to the site and it's description of globular transfer directly contradicts your version of this method, check the facts before posting now everyone can see that your info doesn't line up.

[Gear Jammin-Dog Chasin-Yota Man]

 Oh boy-here we go

[Gear Jammin-Dog Chasin-Yota Man]

Im a certified welder, with a college degree too, I know how it works.
The correct settings let you you fusion. You cant get 100% pen welds without a bevel.
You can get 100% with forge welding, with the pen being on the microscopic level
and the less heat you put into the metal the better.

Yes, all true, But back to your original comment about penetration.  You stated that penetration does not come from aperage and volts but rather from open corners, etc.  You are simply ignoring and stating that heat has NOTHING to do with penetration, which simply IS FALSE.  you are dismissing the fundamentals of how to set up a welder and achieve proper results.

"and the less heat you put into the metal the better"  yes, less heat on the metal is better for keeping the heat affected area of the weld/metal fusion minimal for strength and breakage problems,
I am not saying that you should crank every welder to the max and burn them in there,
What I am saying is that penetration comes from amperae, volts, electrode selection, and the type of weld position/joint. ALL OF THESE ARE CRITICAL TO PENETRATION AND PROPER WELDS.  You can't hrow one out and keep another, you have to consider all those things, determine what you need to achieve the best results for the weld and material you are doing at the time-there are many variables in welding-all of which must be considered when welding-and you can't simply ignore the fact that amperage/volts aren needed for penetaration.

If you don't agree with that then answer me this: how do up expect to get a penetrating weld with a t-bevel fillet or even just running beads on 1/2" plate in the flat position without adjusting your volts/ amperage??

Don't tell me you leave your welder on the same setting for every kind of weld and metal out there....that would be ridiculous-only a complete greenhorn would try that-and fail.  So amperage/volts DO contrubute to penetration-unlike you argued with me originally.  You have to adjust your amperage properly for the electrode used, thickness of the metal, and penetration needed-This is a fundamental FACT in welding basics.

This really is getting into more of a "who's right ad prove the other one wrong" session- Which it shouldn't be.  We are all simply trying to share our knowldege with each other here.  That being said- I can't let someone de-bunk what I know to be true and let it slide-especially when you haven't answered my original questions about how to get penetration with a t-fillet and not touching the amps/volts dial?

What are you certified in-what positions and what processes?

[junya92toy]

I have certs for all positions in d1.1, d.15 with stick, dualshield gmaw, d1.5 submerged arc.
Again, like on flat plate, its fusion. Ever done forge welding? you get fusion, dont a microscopic level
And burl I didnt plagerise anything, I was trying to bring up sites that state what spray really is. It clearly states what spray is, re read it.

Key sentence, As the current and voltage increases beyond the range of short circuit transfer the weld electrode metal transfer transitions from larger globules through small droplets to a vaporized stream at the highest energies.

My whole point is this, penetration will be very little with anything, even big welders. I ran a submerged arc welder, 5/8s plate, with a bevel down to a 3/16ths land. Put one pass in, turn the plate over, back gouge and then weld it up, with 4 passes, turn the plate back over and finish. 34 volts, 600 amps, 1/8 wire. Thats what it takes to get penetration. Power alone from the welder is not enough sometimes. Yes welds are done with a t joint, no bevels, there is really no penetration at the root, the strength comes from the weld re enforcement its self. Ive done plenty of t joints with bevels too, for 100 % penetration welds.

[Gear Jammin-Dog Chasin-Yota Man]

Nice Cert's.

So what are you getting with about forge welding and fusion on flat plate?  No, I haven't forge welded more than once or twice. 

What does that have to do with anything in regards to getting penetration and good results with a MIG welder?

You are gonna have to explain yourself further if you are wanting to make a point about fusion-
And how does that answer my question to you about how you get penetration with a t-fillet weld and not touching the amps/volts on the machine? 
I must be missing something here I guess

[Burl]

My bad I was getting caught up on side topics as well,  good way to bring about point of order.

[junya92toy]

Nice Cert's.

So what are you getting with about forge welding and fusion on flat plate?  No, I haven't forge welded more than once or twice. 

What does that have to do with anything in regards to getting penetration and good results with a MIG welder?

You are gonna have to explain yourself further if you are wanting to make a point about fusion-
And how does that answer my question to you about how you get penetration with a t-fillet weld and not touching the amps/volts on the machine? 
I must be missing something here I guess

I was trying to point out that forge welding is "little" penetration, just like mig welding, its fusion thats key
How do you get penetation in a T joint without "turning up" the welder, you bevel the edge of the plate

[Burl]

Proper metal prep in conjunction with higher amps/volts with the appropriate welding procedure in the correct position can yield greater penetration.  Versatility and experience also is a factor when performing certain in and out of position welds to achieve proper penentration.

[Gear Jammin-Dog Chasin-Yota Man]

I agree and don't question your comments, they are true.  I think it is all a mis understanding of each other.
I just don't understand why you originally did not agree with me that penetration does come from amps/volts/electrode selection.

Just run a basic bead on a flat plate, you aren't going to get penetration if your machine isn't adjusted properly with the right volts/amps.

That is all I am saying.  Yes, open welds, groove welds, etc. do allow for full penetration. 
In the welding world I came from- penetration/fusion are often used interchangably.

see below (from http://www.twi.co.uk/content/jk40.html go to the page for images):
Incomplete root fusion or penetration
Identification:
Incomplete root fusion is when the weld fails to fuse one side of the joint in the root. Incomplete root penetration occurs when both sides of the joint are unfused. Typical imperfections can arise in the following situations:

an excessively thick root face in a butt weld (Fig. 1a)
too small a root gap (Fig. 1b)
misplaced welds (Fig. 1c)
failure to remove sufficient metal in cutting back to sound metal in a double sided weld (Fig. 1d)
incomplete root fusion when using too low an arc energy (heat) input (Fig. 1e)
too small a bevel angle,
too large an electrode in MMA welding (Fig 2)
Fig. 1 Causes of incomplete root fusion
a) Excessively thick root face
b) Too small a root gap
c) Misplaced welds
d) Power input too low
e) Arc (heat) input too low


Fig. 2 Effect of electrode size on root fusion 
   
a) Large diameter electrode
b) Small diameter electrode

[Burl]

I was trying to point out that forge welding is "little" penetration, just like mig welding, its fusion thats key
How do you get penetation in a T joint without "turning up" the welder, you bevel the edge of the plate

Beveling the edge would make the parent material thinner making it easier for the un-adjusted welding machine to get the penetration, however beveling is not possible in all situations and proper adjustment or alternate welding procedures must be used, but that usually includes upping the amps/volts as well.  Doing all this is necessary for proper penetration.

[junya92toy]

THe correct setting, gets you fusion.

[Gear Jammin-Dog Chasin-Yota Man]

Beveling the edge would make the parent material thinner making it easier for the un-adjusted welding machine to get the penetration, however beveling is not possible in all situations and proper adjustment or alternate welding procedures must be used, but that usually includes upping the amps/volts as well.  Doing all this is necessary for proper penetration.

I couldn't agree More Burl

[junya92toy]

Beveling the edge would make the parent material thinner making it easier for the un-adjusted welding machine to get the penetration, however beveling is not possible in all situations and proper adjustment or alternate welding procedures must be used, but that usually includes upping the amps/volts as well.  Doing all this is necessary for proper penetration.

Mummm ever had to weld 100% in t joint? It calls for a bevel with a backing strip. A welder can not get a full pen weld simply by turning it up. This is why we have multiple pass welding.

[junya92toy]

I agree and don't question your comments, they are true.  I think it is all a mis understanding of each other.
I just don't understand why you originally did not agree with me that penetration does come from amps/volts/electrode selection.

Just run a basic bead on a flat plate, you aren't going to get penetration if your machine isn't adjusted properly with the right volts/amps.

That is all I am saying.  Yes, open welds, groove welds, etc. do allow for full penetration.  
In the welding world I came from- penetration/fusion are often used interchangably.

see below (from http://www.twi.co.uk/content/jk40.html go to the page for images):
Incomplete root fusion or penetration
Identification:
Incomplete root fusion is when the weld fails to fuse one side of the joint in the root. Incomplete root penetration occurs when both sides of the joint are unfused. Typical imperfections can arise in the following situations:

an excessively thick root face in a butt weld (Fig. 1a)
too small a root gap (Fig. 1b)
misplaced welds (Fig. 1c)
failure to remove sufficient metal in cutting back to sound metal in a double sided weld (Fig. 1d)
incomplete root fusion when using too low an arc energy (heat) input (Fig. 1e)
too small a bevel angle,
too large an electrode in MMA welding (Fig 2)
Fig. 1 Causes of incomplete root fusion
a) Excessively thick root face
b) Too small a root gap
c) Misplaced welds
d) Power input too low
e) Arc (heat) input too low


Fig. 2 Effect of electrode size on root fusion  
 
a) Large diameter electrode
b) Small diameter electrode

ANd OMG whats the main word used? FUSION FUSION FUSION
DID YOU MISS THIS PART? too small a bevel angle,

[Burl]

Some tolerances don't allow for multiple passes or beveling, you can't always use the book answer for every application/situation.  

[junya92toy]

I don't, I have put down a lot of welds for bridge and structural. X ray testing too