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Where to 'look' while MIG welding?

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  • Where to 'look' while MIG welding?

    I've been a hobby welder on a Lincoln 220 AC stick model for 30 years, so I can hold my own when stick welding. But the very high level of visibility using rods when horizontal welding on a butt joint seems to have spoiled me somewhat. Being right handed, my preferred technique welding on a bench is to move left to right with the rod tip angled back toward my left. I can see the joint line I am following by glancing past the rod to my right. I position my head angled slightly left to watch things.

    With a fat MIG nozzle and 3/8 stickout that is not possible. The nozzle hides several inches of joint. So I'm looking for suggestions how to see where the bead is headed, yet also watch the puddle and forming of the bead. I tried moving the nozzle away from myself along the bead but then that hides the puddle on the far side of the nozzle.

    Practicing, I can lay down a relatively straight bead by watching it as it forms behind the nozzle, (rather like steering a car by only looking backwards), and when I later moved from practicing flat butt joints to a T joint I found it much easier to keep my bearings as I moved the nozzle along. So I suppose lots of practice will ultimately show the best way for me.
    Last edited by Metalmuncher; 03-20-2012, 09:16 PM.

  • #2
    I decided to look around on the non-MIG sections tonight, and I found some helpful tips for answering my question in this thread under the General Welding section:

    http://www.hobartwelders.com/weldtal...809#post417809

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    • #3
      If at all possible when I push a weld, I like to go from right to left, right handed, looking from the left side. And dragging it is ideal for me to go from left to right also looking from the left side. That being said its not always practical, or possible.

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      • #4
        Thanks for the reply!

        When trying out pushing, I also did the same as you describe, moving right to left. But so far it appears to me that pushing, while using C25 gas and solid 0.030 ER70S-6 Hobart wire , DCEP, seems to build a taller deposition of weld than when I drag the same setup, moving at the same speed along the work. Dragging seems to penetrate better. Should pushing vs. dragging be taken into consideration when adjusting the wire feed speed (amperage) for this thickness of steel?

        I ordered a 0.024 feed roll, but until it gets here I have to practice with 0.030, so I am using some scrap 1/8" mild steel plate for my practice welds. I set the HH140 welder at Tap 4 and experimented between 40 (recommended) and 50 feed setting. Dragging I am getting nice penetration. But pushing it seems to turn out colder and taller. Any suggestions?

        My sole intent in getting this HH140 is to weld the thin gauge steel that I find difficult/impossible to weld with my old trusty Lincoln AC220. So I am not intending to weld even 1/4" with the MIG. The stick welder does that and thicker just fine. I am only interested in the thinner gauge materials this welder can weld.

        The current project I am practicing up to attempt involves welding threaded inserts into the ends of an 8" length of 5/8 x 0.050" chrome moly tube. The threaded sections of the inserts are pretty thin, (about the same 0.050") so I want to eventually practice with 0.024 wire before I take on the final weld of this project. It will be a custom turnbuckle made rather like a tie rod on a vehicle, and will be used to adjust the tram angle of the column on my mini mill. I have plenty of the tube to practice on when I get brave enough to set aside the scrap metal I am using now. But I do not have extra threaded inserts. So I don't want to try welding them in place until I feel confident using the MIG.

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        • #5
          MGAW tip visibility

          Today I decided to mount a knotted wire wheel in my 4" grinder and make my scrap piece as pristine as possible before practicing more. It does make a difference, as the beads look like the penetrated better using the same settings and technique as before. But after watching some MIG videos last night I decided to try moving a little faster with the tip. Doing that, I don't get the higher deposition build as I did before while pushing the tip. Also, working with the clean steel I can maintain more stick-out and tip angle to see better, yet still get a good bead. I'm learning something new every time I practice.

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          • #6
            Solid wire / gas shield ? You should be pushing your puddle watching the wire feed into the weld joint ahead of your nozzle.

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            • #7
              Thanks for the reply!

              At this point along the learning curve I am using 75/25 CO/Argon gas shield at 20 LPH, and have been working with .023 solid core wire (70S-6 I believe). I also have the newer model of Hobart autodarkening helmet and this time I got the adjustable one. The new helmet actually seems darker to me on the 11 setting (it goes to 13) than my older helmet which is a 2/11 helmet. Does the darkening ability of these lenses degrade over time? I've had that older helmet quite a while.

              I am much better able to see what is going on with the newer helmet. The whole reason I started this question had to do with how trying to view directly into the wire/puddle junction seemed to be too bright and would 'wash out' my vision so I didn't see very much detail. Now I can really see what is going on, so I guess I have come to the answer for this question. I was indeed "looking in the right place", but I just needed a better helmet lens to see the details without being blinded by the glare (even through the #11 shading the older helmet provides). I've read a great deal about the MGAW process on several websites since starting this thread, and have been able to apply what I am reading to get better MIG welds.

              The only question in my mind seems to have no definitive answer. And I think it would likely spark a huge debate when asked, but what the heck.

              It seems to be the general opinion of most pros and forum members that butt joint welds should ideally have 100% penetration of both sides of the base metal, and it also seems generally that if it doesn't, the weld is definitely considered poor. But when you switch to lap and fillet welds, I can find "NO" definitive resource telling how much penetration is considered "adequate" or "correct".

              I did stumble across one thread which mentioned that in auto body steel panels a penetration of 20% is acceptable. (That surely isn't much when you consider auto body sheets are so thin.) However, in the dozens of sources I have browsed discussing a fillet weld, for example, they show lots of cut and etched pictures and x-rays of "good" welds, and talk about how to inspect one to determine if it is a good weld, but I never see any actual dimensional numbers anywhere saying, for example, if you are welding two pieces of 3/8 plate into a 90 degree fillet weld, you need X.X" of penetration into both pieces. And never do I see a fillet or lap weld with even what looks like 50% penetration. Mostly what I find are threads or articles saying if the weld is critical, it needs to be replicated on a test piece, and then tested after completion, before welding on the production piece. But never any guide line figures to shoot for regarding the actual depth of penetration.

              (I realize 3/8" plate is beyond my HH140's capabilities, but that was just an example. Most of these sites are showing welds done with much larger 220V welders).

              If there is some definitive resource for these specifications when welding mild steel I would love to see it.
              Last edited by Metalmuncher; 03-28-2012, 04:34 PM.

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              • #8
                MetalMuncher:

                "If there is some definitive resource for these specifications when welding mild steel I would love to see it."

                You won't see it, and there is no " definitive resource". If you want a simple definition of an FP weld, there are many parameters involved in a WPS. Go on and list them for exactly what you want to do, and perhaps, someone can provide you with an informed answer

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                • #9
                  As I suspected.

                  Well, thanks for clearing that up.

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                  • #10
                    I know the numbers on an auto dark helmet may vary by manufacturer, but 11 seems awful dark for MIG. I have a chinese autodark, but I'm running mine on 9 with my 210 as high as 5/50 and can see real well with no discomfort during or after welding. A little less dark might help too, but it's your choice.
                    Blacksmith
                    Stickmate LX AC/DC
                    Big cheap (Chinese) Anvil
                    Hand cranked coal forge
                    Freon bottle propane forge
                    HH 210 and bottle of C25

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                    • #11
                      I haven't tried any other settings on the new helmet yet, because things looked pretty good when I set it to 11. But I can certainly give it a go. One thing I have learned is that I find myself more closely peering at the weld in progress when using the MIG than I ever needed to do using a stick. Once I got used to leaning to one side and looking 'around' the end of the nozzle things were easier to watch.

                      Unless I am welding something big, which is rare, most of my small projects fit on an elevated welding pedestal I made years ago. Its work surface is chest high, so pretty comfortable for seeing the details.

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                      • #12
                        Originally posted by Blacksmith View Post
                        I know the numbers on an auto dark helmet may vary by manufacturer, but 11 seems awful dark for MIG. I have a chinese autodark, but I'm running mine on 9 with my 210 as high as 5/50 and can see real well with no discomfort during or after welding. A little less dark might help too, but it's your choice.
                        I just finished doing some more practice welds with .023 70S-6 wire and C25 gas. I tried various settings on the helmet as I was working, and going lower does look better. In the end I decided to set it on 10. When I tried 9.5, I can't say it was ever noticeably too bright, but after welding with it that way for a few minutes I noticed my eyes felt "tired". Increasing back to 10 seemed to help.

                        I was working with 16 ga. mild steel sheet, cleaned up with a knotted wire wheel on both sides. Experimenting with variations in the basic guideline settings of tap 3 and 50 on the feed on my HH140. I found that simply running a bead across the sheet at those settings, without any adjoining parts, as well as making a butt weld, seemed to indicate those settings were too high. The topside of the bead was very flattened out, and the underside penetration was maybe 3x the thickness of the sheet, even moving along at a rather fast pace. I ended up as low as tap 2 and 30 WSF before I got on both sides of the weld what looked like the pictures I have seen for good welds. But, when I added a piece of angle in a lap weld, or practiced tacking a 1/2" nut to the face of the sheet, then I had to use closer to the 3/50 setting inside the cover. I've read in several places where welders talk about how identical machines often require different settings to get the same results.

                        I've also seen in several threads mentioned the Zen aspect of welding. That certainly seems true. Hard to put into facts and figures, until you actually do it and see the results, as well as what things can change by altering a single part of the process.

                        Thanks to all you folks for the help!

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