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  • Push or Drag

    NOTE:... IT SEEMS I HAVE MY PUSH AND DRAG CONFUSES (REVERSED) IN STATEMENT BELOW!...

    Ok... Was at car show recently and I was watching a demo by 'self taught' welder using FCAW machine running on 120v.... The statement was made that you had to push the weld and I noted (to myself) his gun movement was questionable (from all I have been exposed to) as recommended using movement like curls found on Hostess Cupcake (which is ok I guess) ..... I spoke up that one can also "drag" the bead (weld) and another person spoke rather adamantly one can not drag a bead as it induces a lot of carbon into weld puddle, like I said he was rather adamant about it and claimed to be a "welding inspector"... Remember this was using FCAW (or inner shield,what ever term you prefer)...

    Ok.... Who is right and have I learned it all wrong.... The funny part is some of my best welds are out of position (vertical) dragging bead (puddle) down as Jody from Welding Tips and Tricks recommends....

    Another note is I am primarily in love with solid core and shield gas (GMAW) and most of my welds seem to be about same quality rather I push or drag weld.... IS there difference in way carbon is inserted in weld by wire types... Yes I am aware FCAW seems to have some superior penetration to what GMAW has...

    Some what stumped to how demo was done and "inspectors" comments...

    Dale
    Last edited by Dale M.; 10-22-2018, 10:01 PM.
    Lives his life vicariously through his own self.

  • #2
    Originally posted by Dale M. View Post
    Ok... Was at car show recently and I was watching a demo by 'self taught' welder using FCAW machine running on 120v.... The statement was made that you had to push the weld and I noted (to myself) his gun movement was questionable (from all I have been exposed to) as recommended using movement like curls found on Hostess Cupcake (which is ok I guess) ..... I spoke up that one can also "drag" the bead (weld) and another person spoke rather adamantly one can not drag a bead as it induces a lot of carbon into weld puddle, like I said he was rather adamant about it and claimed to be a "welding inspector"... Remember this was using FCAW (or inner shield,what ever term you prefer)...

    Ok.... Who is right and have I learned it all wrong.... The funny part is some of my best welds are out of position (vertical) dragging bead (puddle) down as Jody from Welding Tips and Tricks recommends....

    Another note is I am primarily in love with solid core and shield gas (GMAW) and most of my welds seem to be about same quality rather I push or drag weld.... IS there difference in way carbon is inserted in weld by wire types... Yes I am aware FCAW seems to have some superior penetration to what GMAW has...

    Some what stumped to how demo was done and "inspectors" comments...

    Dale
    The old rule is ,with FCAW-S. "if there's slag, you drag", and your pretend CWI and DemoMan have it backwards. However, the angle should be slight, and many X-ray quality weldors prefer to go straight in.

    Here's a Lincoln article, but it won't stop debate among the Car Show Self Taught!

    https://www.lincolnelectric.com/en-c...ws-basics.aspx

    The demo could easily be done because most slag inclusions and discontinuities would be hidden beneath the surface.
    Correction:
    I'm not sure what you are asking in the second-last paragraph, since the shielding in FCAW-S usually does not add carbon.

    After reading the following confusing post, I decided to check further to clarify and discovered that much has been done with FCAW-SS since my initial exposure many years ago, and carbon, as well as a great many other alloying elements are commonly introduced in the flux core flux, along with all the common shielding elements, such as anti-oxidant, -nitrides, and -sulphides, etc. Previously, most alloying was done in the electrode wire metal.
    Last edited by Northweldor; 10-22-2018, 08:46 PM.

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    • #3
      Ok... Was at car show recently and I was watching a demo by 'self taught' welder using FCAW machine running on 120v....

      * Good on you for getting out and about. While I like to call myself a professional, that's questionable at times?


      The statement was made that you had to push the weld and I noted (to myself) his gun movement was questionable (from all I have been exposed to) as recommended using movement like curls found on Hostess Cupcake (which is ok I guess) .....

      * The curls, swirls, circles, zigs, zags, whips of manipulation. I have a feeling I have something to say about it?


      I spoke up that one can also "drag" the bead (weld) and another person spoke rather adamantly one can not drag a bead as it induces a lot of carbon into weld puddle,

      * Induces carbon? Hmm... No.

      like I said he was rather adamant about it and claimed to be a "welding inspector"... Remember this was using FCAW (or inner shield,what ever term you prefer)…

      * "Welding Inspector"...Now I'm not going to say bad things about those guys. But if I was, I would temper it by saying, some pass with a 70% after a half dozen tries and some know more. As for your FCAW terminology, it falls under the heading, then down to specifics. I know what you meant, it was a steel bound core of flux filled wire. I'm guessing since you mentioned inner shield, It was a Self shielded type, created it's own shielding gas? No matter, some will still use an external shielding gas. Where I'm going with this is the old adage, with slag you drag. That's just any easy way of getting out of a lengthy explanation?


      Ok.... Who is right and have I learned it all wrong....

      * Well Dale...I'm going to give you my solid on this. Take it for what it's worth. You have learned it wrong. But Buddy learned it wrong'er.
      *Take a flash light and hold it to a wall. Vary the distance in or out. Tilt it for ward and back.
      * Now do that with a can of spray paint. A burst to close and you get a blob and runs, too far and you get dots dust and blank spaces.
      *Take a garden hose and spray it in the ground. Watch what the dirt does as it piles from the force. Vary the height, spray pattern? Where does the dirt go?
      * Take a magnet and hold it close to a surface with out touching to feel a pull. Brush it to collect metal particles and see the shape?
      * To answer your question...How you learned will decide how you see things work, and better able you to understand how to manipulate the metal being deposited and why? If you read a book and can remember things well, great, you still have to apply the knowledge or you end up an inspector not a doer. Your dragging the puddle down the plate, nothing wrong there. But it still involves a gun angle to the plate. Is it a negative or a positive? What is the result of that change?

      The funny part is some of my best welds are out of position (vertical) dragging bead (puddle) down as Jody from Welding Tips and Tricks recommends....

      * Jody, who I've never met has a wonderful site. He offers up some solid stuff. To give him credit, he's a solid welder, has really developed a internet presence, and helped many a fella out with advice. Mine however is free, comes with no paid ad revenue and is being typed painfully slow on a sticky key board. Who knows? You could still get a pearl.
      * Now...my two cents. Push or pull? If my previous ramblings progressed the conversation into this at all, it would be to get you thinking why do one or the other. Well, it's usually arc force or voltage that keep the slag at bey and electrode inclination forward or back helps or hinders that effect. In the same breath, it also spreads the metal being deposited, and affects penetration depths as well heat input which in turn effects expansion and contraction forces. While you didn't hear it from me, wire feed processes are by inherent nature, forward progression with the bead being deposited controlled by factors such as wire size, Voltage, and WFS. After that the arc length, travel speed, inclination effect the size and shape of deposit, as well puddle viscosity. In all of that, the material properties, thickness play a role in conduction or build up of heat energy. This stuff about doing
      curls, swirls, circles, zigs, zags, whips of manipulation...what's it doing? Ask your self that? Building and spreading a shape to the molten puddle.
      * In a nut shell, while most books will suggest slight angles of inclination, it's because it all started with SMAW and slag covered electrodes, keeping slag at bey. FCAW is a continuation of that purpose so it would stand up to why a slightly dragging puddle is preferred over a push, but if the slag is at bey, it doesn't matter aside from the problem of pushing a puddle forward with out adequate heat to fuse, or a lack of heat input leading to rapid quenching, or a lack of build up if required in the weld profile.


      Another note is I am primarily in love with solid core and shield gas (GMAW) and most of my welds seem to be about same quality rather I push or drag weld....

      * Well, if I had to guess I'd say you're consistently staying 90 degree to the plate and traveling progressively. Slight push or pull won't be noticed. Again, welding parameter come into play, but when it comes to the wire feed processes, most don't judge gun inclination
      degrees very well. As well, shielding gas plays a role in droplet formation and heat input.

      IS there difference in way carbon is inserted in weld by wire types...

      * Well, if you buy a wire with higher carbon, yes. Depending on weld parameters you get dilution, although some carbon present is possibly depleted, most is dispersed or collecting in grain boundaries. Something about atomic structures and such thing.

      Yes I am aware FCAW seems to have some superior penetration to what GMAW has...

      * No, what it has is a hotter arc. Smaller droplet crossing the arc. As a result, they strike with greater force. As well, GMAW solid wire cools quicker so if you think about it, it's freezing and moving you forward faster.

      Some what stumped to how demo was done and "inspectors" comments...

      * Well Dale...smoke and mirrors. Weld hot, find the stick out, move like a son of a gun. As long as your on the leading edge, puddle isn't rolling forward, stuff is filling behind you, push or pull isn't a big issue, again assuming it's a slight push or a slight pull. Welding parameters, shielding gas does play a roll and without specifics, it's a game where the rules can change.

      * I'm sure other valued comments will find there way along soon enough. I surely didn't address it all, and again, not saying I'm a professional, take it for what it's worth. The comment's of the inspector as if it was gospel...like I said before with the addition of you don't even have to know how to weld to be one, disappointing.


      Dale

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      • #4
        Well I generally try to stay away from telling folks that you have to always do this or that, never do this or that, because there is usually some situation where you need to vary from the preferred technique. Vertical up/down are just a quick mention of a couple.

        Having said that, the 1st thing I try to do is get my info from the industry experts then add to that from the wanna be experts. Throw out anything I hear that doesn't coincide with the industry recs.

        Lincolns says------------------

        SPECIAL CONSIDERATIONS
        Travel Angle
        Always use a drag travel angle with flux-cored electrodes, trailing the slag behind the puddle. Do not use a push travel angle, as this greatly increases the chance of trapping slag and/or decreasing penetration.

        Travel angle is the angle between the electrode and a line perpendicular to the surface of work piece, as measured from the weld side view. Depending on the welding process, use either a “drag” travel angle or a “push” travel angle. The general rule is “drag slag and push gas”. Therefore, always use a drag travel angle of typically 20º to 30º with flux cored electrodes. Do not use a push travel angle, as this greatly increases the chance of rolling slag ahead of the puddle and trapping it underneath. Pushing can also cause the arc to ride on top of puddle instead of in front of it, resulting in less penetration.

        FCAW-S WELDING GUIDE
        https://www.lincolnelectric.com/asse...-MP/c32400.pdf

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        • #5
          Well crap, guess I was wrong all the way around about FCAW ....Oh well, we try to learn.... Maybe I had my push and drag backward or wrong... Maybe I should stay with trapping gophers....

          OK... Now a question.... Is it ok to push the puddle with solid wire/shield gas?.... My best welds are with solid wire an pushing the puddle!...



          This is two pieces of 2x2x1/4 back to back. and "V grooved...I know its got a coat of paint on it so it looks better... But this was with .030 solid wire with C25 at about 140 amps (hh 140 on step 4)... And pushing the puddle...

          Dale
          Last edited by Dale M.; 10-22-2018, 10:02 PM.
          Lives his life vicariously through his own self.

          Comment


          • #6
            Pushing with solid wire and gas is fine and probably the more preferred method. I do both depending on where and what I want. I can see where I'm going a bit better with a push for sure. A lot of time I find myself almost perpendicular with gas too. Sometimes I start with a drag angle and just roll to a push. More of a roll of the wrist. Really depends.

            Comment


            • #7
              Adds carbon? Hmm?

              "
              After reading the following confusing post, I decided to check further to clarify and discovered that much has been done with FCAW-SS since my initial exposure many years ago, and carbon, as well as a great many other alloying elements are commonly introduced in the flux core flux, along with all the common shielding elements, such as anti-oxidant, -nitrides, and -sulphides, etc. Previously, most alloying was done in the electrode wire metal."

              While this may be almost to simple to comprehend, the big difference between the flux coating on a electrode and what's missing inside the steel bound flux in a cored wire is a binder for gluing it to the rod. Your still left with acidic or basic type flux. Simple speaking, rutile, lime/basic, or like a cellulose in the form of self shielding wires.

              The carbon you speak of is a component of Ferroalloys. So yes, additions of iron particles will add carbon, but again as a component of increasing deposition rates with iron powder additions. Iron and carbon go together.
              Similar to a high iron powder coating as found in a E7028 Electrode. They don't just add carbon. They add additional iron particles and those come naturally with carbon.

              In the case of minor additions of trace elements, depending on quantity and finished weld metal compositions, expense to manufacture, could go either way, as they do with SMAW electrodes.

              As far as additional elements, most are deoxidizers.

              "Technical Brief: Insight on Slag Chemistries
              The slag systems in self-shielded flux cored arc welding are unique. They predominantly use an aluminum-magnesium deoxidizing and de-nitriding system. These elements enter the weld pool and form aluminum oxide and magnesium oxide, two compounds with high melting temperatures. Combine these with low-melting-temperature elements in the flux, and you get an effective slag system. The slag elements
              aluminum oxide and magnesium oxide
              melt first and float to the top of the molten weld pool, protecting the process from atmospheric contamination."


              As far as things go, if they were adding just carbon, how could they possibly control it's amount? Really? You couldn't. If it was in with the flux it would mean it could dilute based on position and puddle viscosity? It's still controlled through the chemistry of the wire it's self.

              Discussing this push or pull...

              "Travel Angle Always use a drag travel angle with flux-cored electrodes, trailing the slag behind the puddle. Do not use a push travel angle, as this greatly increases the chance of trapping slag and/or decreasing penetration."

              Doesn't say you can't. It says why it's not recommended. This is why I suggested you learned wrong? No one questions anything anymore or thinks to ask why?

              One thing is certain, increasing or decreasing the angle of electrode or gun inclination has a effect on where the metal is deposited, spread, weld metal is building up, heat input, and penetration profiles. Not to fail in mentioning grain growth, weld contraction and internal stress from those affects.

              https://www.lincolnelectric.com/en-c...netration.aspx

              If you look and read closely this Lincoln link, notice the pictures are using a 7/32" wire. 34 volts, travel speeds of 30" a minute and some serious amps. That's also a big ol chunk of plate. I'm just saying to the reader, think about it? How do you reconcile that to a couple of 1/4' plates for achieving a strong weld? It's starts by understand how that gun angle plays a role.
              ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
              "One main welding variable that has virtually no effect on weld penetration is arc voltage. While changes in arc voltage can result in minimal changes in weld penetration, the effect is very minor compared to welding current and the other variables just listed in this article. Arc voltage affects the arc length. At the same wire feed speed, as voltage increases, the arc length gets longer and as voltage decreases, the arc length gets shorter. The length of the arc in turn determines the width and size of the arc cone. As arc length decreases, the arc cone becomes narrower and the arc is more focused (see Figure 7). The result is a weld bead that is more narrow and ropy and the level of weld penetration may decrease very slightly. Conversely, as arc length increases, the arc cone becomes wider and the arc is broader. The result is a weld bead that is wider and flatter and the level of weld penetration may increase very slightly. The effect of arc voltage on the bead shape can clearly be seen in Figure 8. Notice also that a very slight difference in weld penetration can be detected between welds made at 27 volts, 34 volts and 45 volts (all at the same amperage, travel speed and diameter electrode). Realize however that this is an extremely large variation in arc voltage, done only on this weld sample to illustrate the point. Practically, arc voltage would only be varied by a few volts when welding. Therefore, the change in penetration caused by changing voltage (only) by just a few volts would virtually be nonexistent.

              Figure 7 Figure 8


              Ironically, many welders mistakenly think that arc voltage is the main variable which affects the level of weld penetration. Voltage is often improperly referred to as “heat”, where welders turn up the voltage or "heat" for perceived more penetration and turn down the voltage or “heat” for perceived less penetration. This misconception likely occurs because they see the weld bead widen out with more voltage and become narrow and ropey with less voltage (as illustrated in Figure 8). However, as explained above, the weld bead profile becomes wider or narrower with changes in voltage because the arc cone becomes wider or narrower with changes in voltage. The resulting weld penetration level with different arc voltage levels (but at the same current level) is virtually unchanged."
              ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

              This was pulled from the same link. Now, I'm posting this specifically because it again doesn't represent the other side of the coin. The other side is you and me holding a gun pointing it and squeezing the trigger. A little in a little out, a slight lean forward or back, little faster a little slower, and maybe a slight zig and zag, pushing metal, sculpting metal into shape to form the weld?
              At the end of the day, it's melting, dilution and fusion on solidification. Since most of us will never worry about more then that if it holds, all good.

              And Dale...nice touch with the pictures, looks good.



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              • #8
                This is what I was taught in school, As a general rule, if it produces slag, you should drag. Dragging your puddle helps ensure the slag doesn't roll out on front of your weld puddle, it helps keep the liquid slag back.
                Now with solid wire and gas I'll do both, push and drag. I'll push when welding thin sheet metal. A push has less penetration in its puddle and that can be helpful when welding thin material. When welding heavier or thicker steel with solid wire and gas I'll drag it. Dragging the puddle helps increase penetration on thicker material.
                Lincoln Idealarc 250
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