DCEN vs. DCEP depending on weld method - recent realization

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More experienced welders must already understand this, but it just occured to me. I had to write it down so if you already knew this, cut a guy some slack.  So, in recent experiences I have found that with MIG welding:EP is best for solid wireEN is best for flux core wireHowever, for GTAW or TIG, I read that:DCEP makes for a hot electrode (use up more tungsten) and shallow weld (better for thin metals?)DCEN increases heat transfer to the material and is better for deeper weldsIt seemed to me that there was a mix up. EP for solid MIG wire but EP for shallow welds? What?Then it occurred to me that the "electrode" in MIG welding is actually your wire.  If you have electrode positive, you are transferring the electron plasma to the electrode, i.e., you are pre-melting the MIG wire. This also makes sense why it might be helpful to pre-heat the work piece, as you are now reducing heat transfer to the piece itself if you switch polarity from EN to EP.Holy cow. That's why my stainless welds looked like sh*t before I figured out that I still had EN. My stainless wire was still cold by the time it hit the work piece, and I got a sh*tty melt pool and sloppy weld bead. When I switched to EP, I had some fancy welds. Ohhhh. And now the whole AC thing makes a lot more sense now, too. You can tune the square wave to bias heat toward work piece or electrode. For instance, aluminum has a low melting point, so you want to be careful about heat transfer to the aluminum work piece to avoid blow through. So you set a square wave with more EP than EN to control heat transfer to the aluminum. For thicker aluminum, you have more dwell time on the EN side. That's pretty frickin' genius... I wish I would have invented that.So, this is new to me (not everybody), but might be helpful to someone else who is a blooming welder. Thanks for the opportunity to publish my discovery. [FYI for those that don't knowDCEP = direct current electrode positiveDCEN = direct current electrode negative]Hobart Handler 140 MIGHypertherm Max 43 Plasma CutterA Bernzomatic Torch, and some solder.
Reply:Good call DCEP with TIG you need to be using either very low amperages, or a massive tungsten, because it'll melt that sucker in a heartbeat.  Often enough, when welding with a pure tungsten on a transformer machine, I'll flip it over to straight, and strike an arc on some scrap to make a perfect ball on the tip for welding aluminum.
Reply:Different strokes for different folks. I ball my tungstens very quickly with DCEP.Seems easier ,for me .BUT, then , i switch back to dcen, or A C  for the tig WELDING. Only ball the tip for aluminum .[SIZE="5"Yardbird"
Reply:Doh!  Ignore my previous post.  Said straight to ball the tungsten, meant to say reverse.
Reply:Originally Posted by DHillSo, in recent experiences I have found that with MIG welding:EP is best for solid wireEN is best for flux core wire]
Reply:I find that tungsten will make a nice little ball on AC if you start with a sharp tip. On my transformer machine I'm 50% EN and 50% EP on AC. Good old sine waves! It only takes about a minute to ball up. Mr. Zap suggests that we use red tungsten on most everything. I've found that it makes a nicer ball than the green pure tungsten. Keep the heat down also and it won't tend to split. I seldom use DCEP for anything on the TIG side of my welder. If I were welding with Heklum on some gigantic part with a big tungsten, then OK. I use all three, DCEP, DCEN and AC, on stick depending upon which rod I have. On MIG, EP is used for solid wire, EN is used for flux core wire. It's not only best but your welds will not be very nice if you use the wrong polarity.Miller Millermatic 252Miller Syncrowave 200Liincoln AC-DC 225Victor O-A Set
Reply:This is something I've been wondering about. Suppose you had a welding rig on an assembly line with AC biased toward something like 60% DCEP - assume shallow welds or thin metal.  How often would you be replacing electrode? What if it is actively cooled? Or to rephrase the question, what ratio of DCEP/DCEN would be best in order to minimize down time to replace electrodes?Hobart Handler 140 MIGHypertherm Max 43 Plasma CutterA Bernzomatic Torch, and some solder.
Reply:I set wave balance for best weld, as in what I need for cleaning, then set amps for the best heat.  DavidReal world weldin.  When I grow up I want to be a tig weldor.