DCEN vs DCEP. All my sources have conflicting info.

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I've been trying to find the real difference between DCEN and DCEP stick welding.I've googled and read about 4 different sources, and half conflict with the other half.  For example, half of them had said that DCEN Puts 2/3 of the heat in the electrode, and 1/3 in the work, but the other half said the exact opposite, that its 1/3 in the work and 2/3 in the electrode.  I don't know which to believe.Same with the comparisons on which is better to not melt through thin metals, which has better penetration, which spatters less.  The sources all seem to conflict.  Can anyone help point me towards a straight answer?  Thanks.
Reply:Burn some rod both ways on different materials and see the results for yourself for a fifth "swing vote".If you happen to get one correct and one wrong answer here, you'd be in the same boat.Or you could use the Search feature above.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Electrons leave the negative side of any source (battery or welder) and return to the positive side. When electrons leave a rod tip and hit the work (dcen) they put more heat into the work than the electrode. When electrons leave the work and hit the rod tip (dcep) they put more heat into the rod than the work. All else being equal, DCEP puts less heat into the work, DCEN puts more heat into the work.City of L.A. Structural; Manual & Semi-Automatic;"Surely there is a mine for silver, and a place where gold is refined. Iron is taken from the earth, and copper is smelted from ore."Job 28:1,2Lincoln, Miller, Victor & ISV BibleDanny
Reply:Hi carl1864,I reported the same frustration in a prior thread http://weldingweb.com/vbb/showthread.php?t=44005From that post... the most authoratative source of information I found was...Here's the Lincoln Electric web linkhttp://www.lincolnelectric.ca/knowle...ntent/acdc.aspBUT THAT DOESN'T SEEM TO WORK ANYMORE.The article was titled, "AC/DC: Understanding Polarity".Source: adapted from New Lessons in Arc Welding, The Lincoln Electric Company, 1990The author (unknown 'guru' at Lincoln Electric) makes two statements:Statement #1"With few exceptions, electrode-positive (reversed polarity) results in deeper penetration. Electrode-negative (straight polarity) results in faster melt-off of the electrode and, therefore, faster deposition rate. The effect of different chemicals in the covering may change this condition."Statement #2"For proper penetration, uniform bead appearance, and good welding results, the correct polarity must be used when welding with any given metallic electrode. Incorrect polarity will cause poor penetration, irregular bead shape, excessive spatter, difficulty in controlling the arc, overheating, and rapid burning of the electrode."I tried welding with different polarities but at the time, I couldn't lay down a bead worth sh*t.Thread was getting contentious (happens here ) and was closed.Rick V 1 Airco Heliwelder 3A/DDR3 CTC 70/90 amp Stick/Tig Inverters in Parallel1 Lincoln MIG PAK 151 Oxy-Acet
Reply:make sure you are not confusing the terminology too as it always seems bass akwards.    negative is straight and positive is reverse...Tiger Sales:  AHP Distributor    www.tigersalesco.comAHP200x; AHP 160ST; MM350P,  Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma.  For Sale:  Cobra Mig 250 w/ Push-pull gun.  Lincoln Wirematic 250
Reply:Here is the welding manual used a few years ago to train Navy Steel Workers (CB Welders).  It is both downloadable and printable.  Your question is addressed in Chapter 7.  You will find clear easy to understand explanations.  Enjoy the book; keep reading, welding and asking questions.I offer three choices: Good, Fast, & Cheap. You may pick two.Hobart AC/DC StikMate LXHarbor Freight AD HoodHarbor Freight Industrial Chop SawDeVilbis 20 Gallon, 5 HP Compressor
Reply:I do not see the link to the manual. Could you please post it again?  Thanks.
Reply:Originally Posted by nadogailHere is the welding manual used a few years ago to train Navy Steel Workers (CB Welders).  It is both downloadable and printable.  Your question is addressed in Chapter 7.  You will find clear easy to understand explanations.  Enjoy the book; keep reading, welding and asking questions.
Reply:Originally Posted by carl1864For example, half of them had said that DCEN Puts 2/3 of the heat in the electrode, and 1/3 in the work, but the other half said the exact opposite, that its 1/3 in the work and 2/3 in the electrode.
Reply:Originally Posted by larry08Sounds like you repeated yourself there bud, DCEN/DCSP - 2/3 into work and 1/3 in electrode.  DCEP/DCRP - 2/3 in electrode, and 1/3 in work.  This is why tig welding uses DCEN for DC, because in DCEP it will melt/ball your tungsten pretty easily.  AC current is split 50/50
Reply:Originally Posted by larry08Sounds like you repeated yourself there bud, DCEN/DCSP - 2/3 into work and 1/3 in electrode.  DCEP/DCRP - 2/3 in electrode, and 1/3 in work.  This is why tig welding uses DCEN for DC, because in DCEP it will melt/ball your tungsten pretty easily.  AC current is split 50/50
Reply:Originally Posted by Black WolfExcellent Point!  I was coming to post the same information the GTAW (TIG)  I am aware that there are ELECTRONS moving and all that, but I have never seen the point in confusing the issue - Give a visual image that they can refer to in the future.
Reply:Hey Black Wolf... for a few moments there, I could of sworn you couldn't tell your "electrodes" from your "electrons"! But hey, maybe you guys are moving a lot of electrodes in Alberta!Rick V 1 Airco Heliwelder 3A/DDR3 CTC 70/90 amp Stick/Tig Inverters in Parallel1 Lincoln MIG PAK 151 Oxy-Acet
Reply:Yeah, I know... I'm a DUMBAZZ! Go ahead - Climb on - It doesn't happen often. Later,Jason
Reply:That`s OK.. likely nobody else spotted that minor error.Yep, that`s Canadian 'cultural diversity' in action... Grand Prairie has 'electrodes', Ottawa has 'elections'!Silly, when what we all just want is 'erections'... you know... of buildings... to get the economy going... and all! (I'm probably going to get 'zapped' for that...)Rick V 1 Airco Heliwelder 3A/DDR3 CTC 70/90 amp Stick/Tig Inverters in Parallel1 Lincoln MIG PAK 151 Oxy-Acet
Reply:In respect of stick welding, I think the 1990 Lincoln Electric statement in "AC/DC: Understanding Polarity" is correct."With few exceptions, electrode-positive (reversed polarity) results in deeper penetration. Electrode-negative (straight polarity) results in faster melt-off of the electrode and, therefore, faster deposition rate. The effect of different chemicals in the covering may change this condition."Examples:-  Most DC electrodes are run electrode positive (deeper penetration)- To avoid burning through sheet metal, it is recommended to run 6013 electrode negative (less penetration)- The pipeline guy on here welds big pipes with 6013 electrode negative (faster deposition)That of course is contrary to the US Navy article - that was written published sometime after 1990 - latest date in their list of references.The most important statement in the Lincoln Electric article is, "The effect of different chemicals in the covering may change this condition." In other words, different coating = different behaviour.e.g. Similar electrode metal, different coating, run on AC  => 6011 deep penetration, 6013 little penetrationObviously the flux coating can make a large difference.In my experience, the US Navy arcticle is correct when it states, "You can recognize the proper polarity for a given electrode by the sharp, crackling sound of the arc. The wrong polarity causes the arc to emit a hissing sound, and the welding bead is difficult to control."e.g.  I experienced that "hissing sound" when trying to run DC+ only aluminum electrodes on straight polarity (DC-).I think that this whole business of 30% heat in the negative and 70% in the positive does not apply well to either stick welding (SMAW) or to MIG (GMAW) because of the transfer of consumable electrode metal to the parent metal being welded. On the other hand, I think the 30- / 70+ heat rule applies very well to TIG; only in TIG is there no metal transfer from the non-consumable tungsten electrode to the parent metal being welded.  Thus the heating effects are separated and can be clearly observed.e.g. DC+ burns up a tunsten electrode quickly while DC- does not.Something to think about...Last edited by Rick V; 07-03-2011 at 01:15 AM.Reason: spelling erros and repeated wordsRick V 1 Airco Heliwelder 3A/DDR3 CTC 70/90 amp Stick/Tig Inverters in Parallel1 Lincoln MIG PAK 151 Oxy-Acet
Reply:I'm not trying to confuse things, but a question that seems to go unanswered ( or maybe just unasked ) is; if DCEP puts less heat into the work, how does it achieve greater penetration?   And if DCEN puts less heat into the electrode, why does the electrode melt faster ( higher disposition rate )?   Those seem to be backwards.__David Hillman
Reply:Originally Posted by David HillmanI'm not trying to confuse things, but a question that seems to go unanswered ( or maybe just unasked ) is; if DCEP puts less heat into the work, how does it achieve greater penetration?   And if DCEN puts less heat into the electrode, why does the electrode melt faster ( higher disposition rate )?   Those seem to be backwards.
Reply:"The most important statement in the Lincoln Electric article is, "The effect of different chemicals in the covering may change this condition." In other words, different coating = different behaviour.e.g. Similar electrode metal, different coating, run on AC => 6011 deep penetration, 6013 little penetrationObviously the flux coating can make a large difference."This answers question #1.To answer #2 , I think its backwards. If dcen caused hire deposition everybody would be using it to increase production. Aleast I always see DCEP being used in what I do.
Reply:Yes, it's confusing for sure! To make this easier to follow and maybe to add to the confusion, here's the text of the Navy Article - that is a Great Resource - Thanks nadogail !Note: Blue is the text of the article.  Black is my comments.  Underlining is mine.Electrode negative (DC-) is called DCEN or straight polarity.In straight polarity, the electrode is negative and the workpiece positive; the electrons flow from the electrode to the workpiece.Electrode positive (DC+) ) is called DCEP or reverse polarity.In reverse polarity, the electrode is positive and the workpiecenegative; the electrons flow from the workpiece to the electrode.Polarity affects the amount of heat going into the base metal. By changing polarity, you can direct the amount of heat to where it is needed.When you use straight polarity, the majority of the heat is directed toward the workpiece. When you use reverse polarity, the heat is concentrated on the electrode.In some welding situations, it is desirable to have more heat on the workpiece because of its size and the need for more heat to melt the base metal than the electrode; therefore, when making large heavy deposits, you should use STRAIGHT POLARITY.On the other hand, in overhead welding it is necessary to rapidly freeze the filler metal so the force of gravity will not cause it to fall. When you use REVERSE POLARITY, less heat is concentrated at the workpiece.  This allows the filler metal to cool faster, giving it greater holding power. Cast-iron arc welding is another good example of the need to keep the workpiece cool; reverse polarity permits the deposits from the electrode to be applied rapidly while preventing overheating in the base metal.In general, straight polarity is used for all mild steel, bare, or lightly coated electrodes. With these types of electrodes, the majority of heat is developed at the positive side of the current, the workpiece.  e.g. 6010, 6011, 7010, 7011However, when heavy-coated electrodes are used, the gases given off in the arc may alter the heat conditions so the opposite is true and the greatest heat is produced on the negative side. e.g. 7014, 7024, ... 6013? or 7018?Electrode coatings affect the heat conditions differently. One type of heavy coating may provide the most desirable heat balance with straight polarity, while another type of coating on the same electrode may provide a more desirable heat balance with reverse polarity.Reverse polarity is used in the welding of nonferrous metals, such as aluminum, bronze, Monel, and nickel. Reverse polarity is also used with some types of electrodes for making vertical and overhead welds.You can recognize the proper polarity for a given electrode by the sharp, crackling sound of the arc. The wrong polarity causes the arc to emit a hissing sound, and the welding bead is difficult to control.So there it is... sounds definitive... until you read it's all in the coating folks! Rick V 1 Airco Heliwelder 3A/DDR3 CTC 70/90 amp Stick/Tig Inverters in Parallel1 Lincoln MIG PAK 151 Oxy-Acet
Reply:Originally Posted by David HillmanI'm not trying to confuse things, but a question that seems to go unanswered ( or maybe just unasked ) is; if DCEP puts less heat into the work, how does it achieve greater penetration?   And if DCEN puts less heat into the electrode, why does the electrode melt faster ( higher disposition rate )?   Those seem to be backwards.
Reply:Originally Posted by Oldiron2Penetration is as much a function of the nature of the electrode, specifically the flux coating, as it is the heat input to the work vs electrode. When 6010/11 electrodes are run, they produce jets of gas (which is probably ionized and may be a plasma) which 'dig' into the molten base metal. Since these jets depend on energy to be produced, they're stronger on Reverse  Polarity then with Straight P.
Reply:I  hope this helps. When burning 6010 the cellulose coating burns off creating CO2. When migging CO2 creates a more agressive arc then a Ar/CO2 mix because the CO2 allows more ionization and the same applies to arc/stick.
Reply:Originally Posted by David HillmanThanks for the thought-provoking reply ( and to others as well ).  I was with you here until you got to the part about energy produced.  As far as I know, the same energy is produced on DCEP versus DCEN ( bad terminology, I know, since we're never 'producing' energy when we weld, or for that matter, ever ).  If the amps don't change, and the resistance is the same...
Reply:Originally Posted by Oldiron2The energy which is in the gases, be it the high velocity, the ionization, a plasma, or whatever, comes from the electrode side of the arc. If the greater amount of heat is produced at the work (as with DCEN), then less will go into the production of the gases. The energy quantity in the arc is the same, but how it isdistributed differs with differing polarity.".... That said, your explanation above makes perfect sense, but it leaves us back where we started.  If DCEP expends more energy on the production of gases, necessarily reducing the energy ( ie heat ) applied to the work piece, how can it create deeper penetration?.............. So what is the magic by which DCEP results in deeper penetration on the same energy budget, despite using up more for these ancillary tasks?........"Sometimes we just have to reach deep within ourselves and press the "I Belive"  button.I offer three choices: Good, Fast, & Cheap. You may pick two.Hobart AC/DC StikMate LXHarbor Freight AD HoodHarbor Freight Industrial Chop SawDeVilbis 20 Gallon, 5 HP Compressor
Reply:Originally Posted by David HillmanPlease understand I'm not trying to be argumentative
Reply:I'd keep in mind that the roughly 30%/70% thing probably only holds somewhat true in the anode/cathod arrangement with a bare consumable. Once you put a flux coating on a rod those things in the flux greatly alter the arc characteristics. I suppose an electrode designed to run equally well on either polarity might give you the representative results you would look for to back up the theory but one designed and specified as a single polarity is going to give false results if the polarity were reversed. In short it would be better to just go by the performance ratings given with each electrode. They all state whether they are deep penetrating, shallow, fast fill, fast freeze and so on. Tig is out of the picture because neither electrode is consumable. Just some thoughts."The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:Originally Posted by David HillmanThanks again for the reply.  Please understand I'm not trying to be argumentative, or insinuate that I know how this process works... I'm asking questions to try and figure it out.   That said, your explanation above makes perfect sense, but it leaves us back where we started.  If DCEP expends more energy on the production of gases, necessarily reducing the energy ( ie heat ) applied to the work piece, how can it create deeper penetration?   If we assume there are only X units of energy available in a given welding scenario, and DCEP uses up more of that energy causing a state change in the coating ( sublimation is not normally cheap in energy terms ) and accelerating it into jets, when compared with DCEN, then it must be true that less of that X energy reaches the work.   So what is the magic by which DCEP results in deeper penetration on the same energy budget, despite using up more for these ancillary tasks?  At the end of the day, to achieve deeper penetration, it seems like you need more heat energy applied to the work.  That's where the rubber meets the road.  Isn't that why we all buy as many amps as we can afford?
Reply:[QUOTE=Rick V;528577So there it is... sounds definitive... until you read it's all in the coating folks! [/QUOTE]whoever said you can't judge a book by its cover ?   think of the Flux as Welding gas.  various gases alter how much heat get transferred and the characteristics of the welding arc.    flux is like shielding gas in solid form...Tiger Sales:  AHP Distributor    www.tigersalesco.comAHP200x; AHP 160ST; MM350P,  Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma.  For Sale:  Cobra Mig 250 w/ Push-pull gun.  Lincoln Wirematic 250
Reply:Originally Posted by nadogailSometimes we just have to reach deep within ourselves and press the "I Belive"  button.
Reply:I knew this was going to be fun....
Reply:Originally Posted by soutthpawHumm Kind of like Religion?   Welding facts:  Answers that may never be questioned.   Ill have to change my Sig.
Reply:Or.  Welding.   Answers to qustions that shold never be askedTiger Sales:  AHP Distributor    www.tigersalesco.comAHP200x; AHP 160ST; MM350P,  Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma.  For Sale:  Cobra Mig 250 w/ Push-pull gun.  Lincoln Wirematic 250
Reply:Originally Posted by soutthpawOr.  Welding.   Answers to qustions that shold never be asked
Reply:I always go with the manufacturers recommendations for each rod.AWS certified welding inspectorAWS certified welder
Reply:Originally Posted by Donald BranscomI always go with the manufacturers recommendations for each rod.
Reply:I have welded with dc for 5 years.I got a piece of poster stock and mark the info on it.I dont weld much these days.At 73 memory is shot.Lincoln Electric will send free iformation that is accurate.About 1/2 the info on the internet is wrong.Started welding in the mid 50s.Had a chance to try DC, liked it and built a DC converter for my Lincoln 225 welder.
Reply:Originally Posted by Oldiron2Being an inert element, I'm not sure "ionization" is really an accurate term for argon, but I'll let that slide for now.
Reply:Originally Posted by papaharley03Ionization isn't really a function of Argon being an inert gas. You zap it with enough energy and it will ionize. The bluish light given off is the ions returning to their state of equilibrium.Papa
Reply:Originally Posted by Oldiron2The gases, being high energy, transfer that energy to the base metal so even though the arc originally delivered it to the electrode, much of it ends up in the base metal. As I said, the jet 'digs' deeply into the base metal, both by delivering concentrated energy which melts the base and by a mixing process due to the momentum of the gases. Penetration isn't just how deep the metal is melted while sitting on the surface;  it depends on the molten metal being mixed, oxides and other impurities being worked out, etc. It's also probably more complicated than this simple explanation; there are convection currents, ionization of the metal within the arc, and other factors I've probably not thought of or maybe even heard about.If I were your welding instructor, I think I'd assign this as a term paper for you and require you to post it here to educate all of us a bit. There must be detailed papers about this subject beyond what I've seen in books!    .