Terminology, polarity and penetration

[Jack Ryan]

Why is it so?

I was looking for information related to welding polarity on the Internet and found quite a lot of conflicting information. Not just a bit different – the complete opposite. I was also distracted by some of the archaic terminology that some authors insist on using. DCSP (DC Straight Polarity) and DCRP (DC Reverse Polarity) for example, should, in my view, be dropped from the welding vocabulary. I realise many of you grew up with that terminology but now, it has no meaning.

DCSP used to be the conventional polarity used in SMAW (also called ARC and STICK welding). The electrode is negative, and the work is positive (DCEN) because this gave better penetration. DCRP (DCEP) was used if less penetration was needed when, for example, welding thin sheets. Those days of bare electrodes are long gone and now flux covered electrodes like the 6010 give best penetration using DCRP (DCEP).

DCSP and DCRP no longer reflect the original use and do not give any hint to the actual polarity being used. They are misleading, confusing and many don’t know what they mean. For example, the AWS defines STRAIGHT POLARITY:

Is when the flow of electrons travels from the workpiece, which is the negative pole, to the electrode, the positive pole.

https://awo.aws.org/glossary/straight-polarity/

Even the AWS can’t come to grips with it. Its definition of reverse polarity is also wrong.


Then there is polarity and penetration.


Universal Technical Institute - Without reference to a specific process:

It’s important for a welder to know the meaning of polarity and understand how it affects the welding process. Typically, electrode-positive (reversed polarity) welding results in deeper penetration.
https://www.uti.edu/blog/welding/welding-polarity

That is not the typical case at all. In TIG welding, where the electrode is not consumed, DCEN is used and about 67% of the arc heat (and consequent penetration) is delivered to the work piece via a stream of electrons. If the polarity is reversed (DCEP), the electrode gets very hot and the work is bombarded by a stream of positive Ions causing cathodic etching (cleaning).


In GMAW, where the electrode is consumed, the use of DCEP heats the electrode and the melted electrode is transferred to the weld pool via the metallic arc along with its heat. This heat transfer tends to balance heat distribution and helps ensure that there is sufficient penetration.


There are many other variables affecting penetration including joint preparation, the use of flux, flux composition, transfer mode and shielding gas.

The statement “DCEP gives better penetration” is not true unless it is fully qualified with the process, parameters, shielding etc. In a different context, even using the same process, DCEN might give better penetration.

Some sort of on-line consensus would be good.

Jack

[JDM Welder]

Just wait until you find out that "electron flow" isn't really a thing, and has nothing to do with current in the conventional sense

[Oldiron2]

Why is it so?

I was looking for information related to welding polarity on the Internet and found quite a lot of conflicting information. Not just a bit different – the complete opposite. I was also distracted by some of the archaic terminology that some authors insist on using. DCSP (DC Straight Polarity) and DCRP (DC Reverse Polarity) for example, should, in my view, be dropped from the welding vocabulary. I realise many of you grew up with that terminology but now, it has no meaning.

DCSP used to be the conventional polarity used in SMAW (also called ARC and STICK welding). The electrode is negative, and the work is positive (DCEN) because this gave better penetration. DCRP (DCEP) was used if less penetration was needed when, for example, welding thin sheets. Those days of bare electrodes are long gone and now flux covered electrodes like the 6010 give best penetration using DCRP (DCEP).

DCSP and DCRP no longer reflect the original use and do not give any hint to the actual polarity being used. They are misleading, confusing and many don’t know what they mean. For example, the AWS defines STRAIGHT POLARITY:

Is when the flow of electrons travels from the workpiece, which is the negative pole, to the electrode, the positive pole.

https://awo.aws.org/glossary/straight-polarity/

Even the AWS can’t come to grips with it. Its definition of reverse polarity is also wrong.


Then there is polarity and penetration.


Universal Technical Institute - Without reference to a specific process:

It’s important for a welder to know the meaning of polarity and understand how it affects the welding process. Typically, electrode-positive (reversed polarity) welding results in deeper penetration.
https://www.uti.edu/blog/welding/welding-polarity

That is not the typical case at all. In TIG welding, where the electrode is not consumed, DCEN is used and about 67% of the arc heat (and consequent penetration) is delivered to the work piece via a stream of electrons. If the polarity is reversed (DCEP), the electrode gets very hot and the work is bombarded by a stream of positive Ions causing cathodic etching (cleaning).


In GMAW, where the electrode is consumed, the use of DCEP heats the electrode and the melted electrode is transferred to the weld pool via the metallic arc along with its heat. This heat transfer tends to balance heat distribution and helps ensure that there is sufficient penetration.


There are many other variables affecting penetration including joint preparation, the use of flux, flux composition, transfer mode and shielding gas.

The statement “DCEP gives better penetration” is not true unless it is fully qualified with the process, parameters, shielding etc. In a different context, even using the same process, DCEN might give better penetration.

Some sort of on-line consensus would be good.

Jack

Those terms have meaning to many people, whether or not you like them or choose to use them yourself. I could even argue that when trying to teach younger, less disciplined or perhaps retarded people, "Straight Polarity" can be explained as meaning the gun, torch or holder goes to the straight (-) side of the power supply, and as such, is more likely to be remembered. All words are arbitrary in the sense that language is a human invention; you weren't born with the label Jack stenciled on your chest, any more than the word "welding" existed anywhere in 200BC.

As for penetration, in books some generalities do exist but few are expressed without already having the discussion narrowed to specific processes. What applies to MIG or TIG obviously (to anyone with basic knowledge in the field) doesn't necessarily apply to stick welding, where the coating has a profound effect on the arc and the deposition of metal and these differences are explained in well-written books.

Just about everything people say needs some qualification, whether stated or not; what often is not said is still often understood, or at least accepted by general consensus.
When somebody asks "how are you" when you walk into a business, rarely is that person interested in hearing about whether you 'got out of the bed on the wrong side' today, have had too little sleep lately, or even are fighting cancer. That's just the way the world works, whether we're standing right side up as we do here, or are upside down, as Australians and New Zealanders do.

[Jack Ryan]

To clarify my view..

Those terms have meaning to many people, whether or not you like them or choose to use them yourself. I could even argue that when trying to teach younger, less disciplined or perhaps retarded people, "Straight Polarity" can be explained as meaning the gun, torch or holder goes to the straight (-) side of the power supply, and as such, is more likely to be remembered.

You could argue that but it is only true some of the time - those terms used to have a specific meaning but now they are arbitrary as the original meaning no longer applies. My point is, that in new books, it would be better to use (say) DCEN and put DCSP is brackets if it was thought necessary.

All words are arbitrary in the sense that language is a human invention; you weren't born with the label Jack stenciled on your chest, any more than the word "welding" existed anywhere in 200BC.

Not all words are arbitrary. My name and yours are proper nouns and those are often arbitrary. DCEN is not arbitrary, it describes a specific configuration in current English.

As for penetration, in books some generalities do exist but few are expressed without already having the discussion narrowed to specific processes. What applies to MIG or TIG obviously (to anyone with basic knowledge in the field) doesn't necessarily apply to stick welding, where the coating has a profound effect on the arc and the deposition of metal and these differences are explained in well-written books.

The reason I brought this up is that there are quite a few welding texts and many WEB sites that do not define a context. If they did, there would be no issue.

Just about everything people say needs some qualification, whether stated or not; what often is not said is still often understood, or at least accepted by general consensus.
When somebody asks "how are you" when you walk into a business, rarely is that person interested in hearing about whether you 'got out of the bed on the wrong side' today, have had too little sleep lately, or even are fighting cancer. That's just the way the world works, whether we're standing right side up as we do here, or are upside down, as Australians and New Zealanders do.

There is a difference between a perfunctory greeting and a reference book.

Anyway, my point is, if someone is going to write a book or WEB article, be precise and get it right.

Thanks for your comments.

Jack

[Jack Ryan]

Just wait until you find out that "electron flow" isn't really a thing, and has nothing to do with current in the conventional sense

Tell that to the electrons in a plasma busily transferring heat from the arc to the anode.

Jack

[tapwelder]

How would manufactures tell users how to connect the leads for specific rods? I have not seen red and black terminals in years.

What convention do you suggest for describing connections to a weldor?

[Oldiron2]

Anyway, my point is, if someone is going to write a book or WEB article, be precise and get it right.

Thanks for your comments.

Jack

I took your first post to mean that all the "archaic terminology" shouldn't be used anywhere, including here. I still disagree about it being archaic, even if not as formal as the newer terms (that are more unwieldy for common use).

Regarding the passage:

For example, the AWS defines STRAIGHT POLARITY:
Is when the flow of electrons travels from the workpiece, which is the negative pole, to the electrode, the positive pole.
https://awo.aws.org/glossary/straight-polarity/


Even the AWS can’t come to grips with it. Its definition of reverse polarity is also wrong.

can you find anywhere the AWS has that backward definition in printed documentation? I've seen a few other situations where information being transcribed to the internet has been mistyped, or rewritten by some low-level employee who is unqualified or thinks he knows better; I'd guess that might have happened here. As for the rest of the internet [Web Articles], I don't give much credence to information there unless I have some knowledge of the author or about the site, and even there mistakes can happen. I haven't seen such errors in any of the older books I own.

FWIW, a few weeks or so ago on this site, I pointed out some misleading passages from welding information cited by the thread's OP. I've also pointed out that I don't go along with the new grammatically incorrect usage of pronouns...but I doubt many care or understand my reasoning, even among readers here.


.

[Jack Ryan]

How would manufactures tell users how to connect the leads for specific rods? I have not seen red and black terminals in years.

What convention do you suggest for describing connections to a weldor?

The terminals are marked in various ways - often with a '+' and a '-'.

If you look at the spec sheet for the electrode/rod you are using, it will tell you. This from an E6010 spec.

Recommended Parameters

SMAW (DCEP – Electrode+)

Wire Diameter Voltage Amperage
0.10” 60-80
0.13” 80-130
0.16” 110-170
0.19” 140-200

Jack

[Jack Ryan]

I took your first post to mean that all the "archaic terminology" shouldn't be used anywhere, including here. I still disagree about it being archaic, even if not as formal as the newer terms (that are more unwieldy for common use).

Oh no, I'm not the gramma police.

I think documentation should use the newer term (say) DCEN and put DCSP in brackets if needed. What I don't like is an entire document using only old terminology. Personally, I don't mind of the old terminology goes away altogether but I recognise that won't be happening any time soon.

Regarding the passage:

can you find anywhere the AWS has that backward definition in printed documentation? I've seen a few other situations where information being transcribed to the internet has been mistyped, or rewritten by some low-level employee who is unqualified or thinks he knows better; I'd guess that might have happened here. As for the rest of the internet [Web Articles], I don't give much credence to information there unless I have some knowledge of the author or about the site, and even there mistakes can happen. I haven't seen such errors in any of the older books I own.

I think that increasingly the standard is online or "soft" documentation. I no longer purchase hard copies and haven't for more than a decade.

One instance might be a typo but both straight and reverse polarity are wrong. I checked A3.0 and all I find is:

direct current straight polarity. A nonstandard term for direct current electrode negative.

straight polarity. A nonstandard term for direct current electrode negative.

The definitions themselves no longer appear.

FWIW, a few weeks or so ago on this site, I pointed out some misleading passages from welding information cited by the thread's OP. I've also pointed out that I don't go along with the new grammatically incorrect usage of pronouns...but I doubt many care or understand my reasoning, even among readers here.

You are right, most people don't care and seriously don't care is you or I do care. I guess that's fine but a reference needs to be correct and unambiguous.

Jack

[StandarDyne]

I guess the thing to remember is: DCEP usually gives deeper penetration on stick, and DCEN usually gives deeper penetration on TIG. I don't understand why -- I've tried to figure it out, but never came up with an understandable explanation -- so now I just remember it by rote. And dispense with the "straight polarity" and "reverse polarity" terms. As for which direction the electrons and current travel -- I'll leave that to Ben Franklin and the rest of them to thrash it out. I just generally remember / arbitrarily define current and electrons as traveling from negative to positive, or from anode to cathode. "Cathode" has more letters than "anode" so I use that to remember cathode = + and anode = -.

[Eelspike]

Terms don't just fall out of the welding vernacular overnight but common usage has changed. I don't tell the apprentice when setting that i need straight or reverse polarity i say i need my lead for the stinger or wire feeder to be positive on negative. I try to explain at the appropriate time that electrode positive is also known as reverse polarity and electrode negative is called straight polarity.

[rexcormack]

That's why I like AC!

[MISSING LINK]

I guess the thing to remember is: DCEP usually gives deeper penetration on stick, and DCEN usually gives deeper penetration on TIG. I don't understand why -- I've tried to figure it out, but never came up with an understandable explanation -- so now I just remember it by rote. And dispense with the "straight polarity" and "reverse polarity" terms. As for which direction the electrons and current travel -- I'll leave that to Ben Franklin and the rest of them to thrash it out. I just generally remember / arbitrarily define current and electrons as traveling from negative to positive, or from anode to cathode. "Cathode" has more letters than "anode" so I use that to remember cathode = + and anode = -.

With Tig it isn't about penetration. You have AC or DCEN. If you go DCEP and give it the gusto your tungsten goes bye bye. As far as the statements of "DCEP gives better penetration" being wrong and needs to be clarified more is a moot point. The process being used will define your polarity. Stick, MIG or Dual Shield a welder knows it is DCEP for the most part. Self shield the specific wire will tell you which polarity as there is both out there.
As to the terms Reverse or Straight polarity, the are not just welding terms, but mech/electrical terms. So they should be taught and learned not discarded just because we don't care for them.
Not sure why anyone would want that. We just learned them and moved on with it. No fuss, no muss.... It is similar to the MIG vs. MAG welding argument, pointless to me. Just my two peso's...

[MISSING LINK]

That's why I like AC!

I agree. Learned to weld 6010 and 7018 on my old 1930's AC machine. Much easier for me than DC. But i'm weird I guess.

[123weld]

en and ep, would be simple/easy. i got a cv/cc machine that refers to cc as "variable voltage". it goes on in other trades as well, when u really look at it, the ones that bother me is , the dr. that came up w/ "near sighted and far sighted", along w/ the lawyer who came up w/ "dismissed w/ prejudice and w/o prejudice", as for as i'm concerned, they got those *** backwards. at the rate were going w/ our sick societies - get used to iit, pretty soon mother, father, sister etc. will be replaced w/ "birther people" etc., or man and woman will be replaced. i already saw a diff in "mothers day" this yr.. so itll be like welding, several names to the point some what know what the heck the other is talking about

[StandarDyne]

With Tig it isn't about penetration. You have AC or DCEN.

Indeed. And AC is half EP and half EN. (Assuming no balance control. ) But even if the AC balance is set to 99.999% EN, it's still going to give less penetration than DCEN. But I said that already.

The process being used will define your polarity..

Sometimes, but not always. There are a lot of rods that you can stick weld with using either DCEP, AC, or DCEN. If you want less penetration, you can use AC, or -- for even less -- DCEN.

As to the terms Reverse or Straight polarity, the are not just welding terms, but mech/electrical terms.

Can you give an example? I've never heard those terms used with anything except welders. I've heard of "polarized" plugs, but those are for AC, not DC.

[farmersammm]

Bottom line..................terms change with the times(shrug)

[Jack Ryan]

I guess the thing to remember is: DCEP usually gives deeper penetration on stick, and DCEN usually gives deeper penetration on TIG. I don't understand why -- I've tried to figure it out, but never came up with an understandable explanation -- so now I just remember it by rote. And dispense with the "straight polarity" and "reverse polarity" terms. As for which direction the electrons and current travel -- I'll leave that to Ben Franklin and the rest of them to thrash it out. I just generally remember / arbitrarily define current and electrons as traveling from negative to positive, or from anode to cathode. "Cathode" has more letters than "anode" so I use that to remember cathode = + and anode = -.

That's fine. It is not necessary to fully understand physics and metallurgy to weld and the people who do often can't weld.

Jack

[Jack Ryan]

Terms don't just fall out of the welding vernacular overnight but common usage has changed. I don't tell the apprentice when setting that i need straight or reverse polarity i say i need my lead for the stinger or wire feeder to be positive on negative. I try to explain at the appropriate time that electrode positive is also known as reverse polarity and electrode negative is called straight polarity.

You probably don't even need to mention the older terminology - deal with it if asked.

You are right, old terms don't disappear overnight. DCSP and DCRP have been obsolete for decades - but they remain.

Jack

[Jack Ryan]

That's why I like AC!

Even with AC, you still connect using DCEN or on most inverter type TIG welding machines, the tungsten will likely explode.

Jack

[Willie B]

Indeed. And AC is half EP and half EN. (Assuming no balance control. ) But even if the AC balance is set to 99.999% EN, it's still going to give less penetration than DCEN. But I said that already. Sometimes, but not always. There are a lot of rods that you can stick weld with using either DCEP, AC, or DCEN. If you want less penetration, you can use AC, or -- for even less -- DCEN. Can you give an example? I've never heard those terms used with anything except welders. I've heard of "polarized" plugs, but those are for AC, not DC.

Ben Franklyn guessed at the direction electricity flows. At the time he considered electricity to be an invisible fluid flowing from a place of surplus (+) to a place of deficit(-). He later learned he was mistaken about the direction of flow. He had drawn too many diagrams, stated too many experiments. By that time his negative items were found to be the critters that flow. I'm not going to now address the NEW theory that nothing flows at all.

Electrons have long been believed to move. Direct polarity in welding is considered to be electrons flowing from the electrode to the workpiece. In DC TIG we use direct polarity. With the flow of electrons goes the direction of heat transfer.

Stick welding is different because we depend on the majority of the heat moved to cause a jetting action in the end of the filler rod. Most DC stick welding is done in the reverse polarity. Electrons move from the work to the rod, causing rapid boiling of molten filler metal, blowing it into the joint.
Very thin delicate metals benefit from DC direct polarity. less violent, less likely to blow a hole in the thin metal.

AC TIG welding involves cathodic etching to clean oxides off the surface of aluminum & magnesium. There you want enough RP to blow off the oxide layer, but not so much you deform the tungsten. You want as much as possible EN (straight polarity) as possible to heat the base metal. Older AC TIG machines operated at 60 or 50 HZ & 50% balance.
Inverter & earlier square wave welders make the transition from en to ep sudden enough to be more effective. The same cathodic etching job can now be done at 80% EN with square wave technology.

AC stick is used mostly to avoid magnetic arc blow.

MIG welders switch polarity for hard wire or flux core.

[Jack Ryan]

With Tig it isn't about penetration.

I think pretty much all welding is about penetration (depth of fusion). More penetration isn't necessarily better but there must be penetration.

You have AC or DCEN. If you go DCEP and give it the gusto your tungsten goes bye bye.

That is normally the case but somewhere, someone will have an application for DCEP TIG welding (using large tungstens).

As far as the statements of "DCEP gives better penetration" being wrong and needs to be clarified more is a moot point. The process being used will define your polarity. Stick, MIG or Dual Shield a welder knows it is DCEP for the most part. Self shield the specific wire will tell you which polarity as there is both out there.

It is not just the process that defines the polarity. There are so many other factors that affect penetration it is more the polarity required to achieve a stable arc and proper penetration in a particular context. In some cases, it is the flux that determines the required polarity.

As to the terms Reverse or Straight polarity, the are not just welding terms, but mech/electrical terms. So they should be taught and learned not discarded just because we don't care for them.

Really? Where are they defined as electrical terms and who uses them?

Not sure why anyone would want that. We just learned them and moved on with it. No fuss, no muss.... It is similar to the MIG vs. MAG welding argument, pointless to me. Just my two peso's...

Why learn several languages just to talk about welding? It is not necessary but you can if you want to. I have a habit of calling SMAW "arc welding" - you probably call it "stick welding" but I grew up with "arc welding". Some people are so moved by the terminology issue that they create new terms - like weldor - but I'm not sure that helps. The AWS defines "weldor" as a non-standard form of "welder". It defines "welder" as the person operating a welding machine. British, Australian, NZ and many other jurisdictions use the same or similar definitions and I don't see them changing any time soon.

Jack

[danielplace]

If you didn't know what either meant it is so easy to find out. If your learning isn't that like the very first thing you would be taught or learn.

Takes 5 seconds to look up and find the meaning. With all the abbreviations for everything today on the internet this old stuff shouldn't be that hard.

One quick search and got the answer.

http://www.minaprem.com/joining/weld...n-arc-welding/

Depending on the connection of base metals and electrode with the ports of power supply, DC polarity can be subdivided into two categories—Direct Current Straight Polarity (DCSP) and Direct Current Reverse Polarity (DCRP). It is to be noted that for AC supply, both polarities occur one after another in every cycle for a number of times (equals to frequency of supply).

DCSP or DCEN—Base plate is positive and electrode is negative.
DCRP or DCEP—Base plate is negative and electrode is positive.

[Jack Ryan]

If you didn't know what either meant it is so easy to find out. If your learning isn't that like the very first thing you would be taught or learn.

Takes 5 seconds to look up and find the meaning. With all the abbreviations for everything today on the internet this old stuff shouldn't be that hard.

One quick search and got the answer.

http://www.minaprem.com/joining/weld...n-arc-welding/

Depending on the connection of base metals and electrode with the ports of power supply, DC polarity can be subdivided into two categories—Direct Current Straight Polarity (DCSP) and Direct Current Reverse Polarity (DCRP). It is to be noted that for AC supply, both polarities occur one after another in every cycle for a number of times (equals to frequency of supply).

DCSP or DCEN—Base plate is positive and electrode is negative.
DCRP or DCEP—Base plate is negative and electrode is positive.

My original point was that not all WEB sites agree. As an obvious example, look up those same acronyms in the AWS glossary - the complete opposite.

Jack

[danielplace]

My original point was that not all WEB sites agree. As an obvious example, look up those same acronyms in the AWS glossary - the complete opposite.

Jack

They do except when someone screws up the text. There is ONLY ONE meaning that has ever been or ever will be correct for these terminologies.

Where else but there have you ever seen or heard such definitions ?

Those are mistakes by whoever wrote that. https://awo.aws.org/glossary/straight-polarity/

That is a misprint as is evidenced by the example they have shown which is DCEN which is also from their glossary but demonstrates that a error has been made in both places.

The description is of the picture. The work is clearly on the positive and the electrode on negative which is DCEN or straight polarity.

They mixed up the electrode and the work.

https://awo.aws.org/glossary/direct-...rode-negative/



https://mewelding.com/welding-with-d...erse-polarity/

Polarity In The Welding Circuit
In the earliest days of arc welding, the welding used to be done with a bare wire. The wire would be connected to the negative terminal and work to the positive terminal. Since the current flows from the negative to the positive terminal, this connection would yield 65-75% heat on the work-piece (as opposed to the electrode).

In reverse polarity, as discussed above – electrode is connected to positive, and work-piece is connected to the negative terminal. This polarity is also called DCEP, short for direct current electrode positive.

Conversely, in straight polarity – electrode is connected to negative polarity, and work-piece to positive polarity. Hence, this polarity is sometimes also referred to as DCEN, short for direct current electrode negative.

Higher amount of heat on the work-piece would mean deeper penetration of the weld.

This connection was termed as the straight polarity. In this, the electrode is connected to the negative terminal, and the work-piece is connected to the positive terminal.