Announcement

Collapse
No announcement yet.

MIG wire for autobody work

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • MIG wire for autobody work

    I have done very little sheetmetal work over the years, so I don't bring much in the way of personal experince to the question I'm about to pose. When I was building expansion chambers for 2-stroke racemotors a long time ago I had no TIG or MIG gear so I gas-welded those pipes. But I like to read articles on sheetmetal work by autobody men and builders of custom cars and motorcycles, in case I need to try something.

    One of the observations they make, expressed by metal-forming instructor Ron Covell for one, is that MIG-welding sheet steel puts down a fast-freezing and hard bead that makes forming the welded panel more of a chore. Since most welders today own MIG equipment, and would prefer that process for sheetmetal work, I have this question:

    Why is it, apparently, desirable that the standard wire used for autobody welding have an as-deposited UTS of 70kpsi when the basemetal is nowhere near that figure? Wouldn't it be helpful to tin-benders and panel-beaters if one of the electrode manufacturers would offer a lower-UTS, more maleable wire in .024 and .030" specifically for this kind of work?

    I would ask this question of the manufacturers directly, but figured I better put it to y'all first, in case my idea is completely ignorant and out-to-lunch (wouldn't be the first time).

  • #2
    Yes there is one for it,made by ESAB called Easygrind,Frank
    Millermatic 252
    Millermatic 180
    Dynasty 200DX
    Hobart spoolmate 3035
    Digital Elite

    Comment


    • #3
      "Easy Does It"

      Originally posted by Frank Motoweld View Post
      Yes there is one for it,made by ESAB called Easygrind,Frank
      Frenchy: Learn something new everyday. Just looked it up in my ESAB book, sure enough!

      Thanks

      Dave
      "Bonne journe'e mes amis"

      Comment


      • #4
        That stuff is much much easier to blend in so as not to ruin body panels.Us french canadians use a lot of church words when cursing.Surprised i didnt get a bolt of lightning up my rear end yet...Thanks ESAB!
        Frank
        Millermatic 252
        Millermatic 180
        Dynasty 200DX
        Hobart spoolmate 3035
        Digital Elite

        Comment


        • #5
          "Ask, and ye shall recieve." Thanks much, Frank; I'll look for it.

          Comment


          • #6
            ESAB Easy Grind

            Originally posted by seattle smitty View Post
            "Ask, and ye shall recieve." Thanks much, Frank; I'll look for it.
            Smitty: It's available in convenient 2# spools .023" & .030" dia.

            You can look for a distributor near you on the ESAB web site along with item numbers for the spools.

            Hope this helps

            Dave
            "Bonne journe'e mes amis"

            Comment


            • #7
              Originally posted by davedarragh View Post
              Smitty: It's available in convenient 2# spools .023" & .030" dia.

              You can look for a distributor near you on the ESAB web site along with item numbers for the spools.

              Hope this helps

              Dave
              I get mine at Linde gas.

              Hey Dave,when you leave for that big job remember,keep the tire side down and watch out for those Captain Coma,Frank
              Millermatic 252
              Millermatic 180
              Dynasty 200DX
              Hobart spoolmate 3035
              Digital Elite

              Comment


              • #8
                "Captain Coma?"

                Originally posted by Frank Motoweld View Post
                I get mine at Linde gas.

                Hey Dave,when you leave for that big job remember,keep the tire side down and watch out for those Captain Coma,Frank
                Maybe the "Captain and Tennille." Gotta look out for the Elk more than anything, that and Antelope.

                Quick run over to Gallup, NM. Capitol of the Navajo Nation. Interesting place, very windy, chilly (32F, 0C) tonight.

                Au revoir & bonne nuit

                Now I have to practice my Navajo, Apache and Hopi

                Dave
                "Bonne journe'e mes amis"

                Comment


                • #9
                  Originally posted by seattle smitty View Post
                  Why is it, apparently, desirable that the standard wire used for autobody welding have an as-deposited UTS of 70kpsi when the basemetal is nowhere near that figure? Wouldn't it be helpful to tin-benders and panel-beaters if one of the electrode manufacturers would offer a lower-UTS, more maleable wire in .024 and .030" specifically for this kind of work?


                  Unfortunately, everyone missed the key concept here.

                  The workability of metal is related to the modulus of elasticity and not the ultimate tensile strength.

                  With steel, you are sort of stuck with an E of 29,000 ksi.

                  It would probably surprise a lot of people to know that bronze brazing alloys can also have ultimate tensile strengths in the 50-70 ksi range because we all know they are softer than steel.

                  Being more workable, ie, having a lower E, does not necessarily mean a lower tensile strength. And being extremely stiff doesn't mean a high tensile strength. There are some very stiff materials out there with a very low tensile strength.

                  Silicon Bronze has an E of about 15,000 ksi, which is roughly half of that of steel.

                  That means it's twice as workable. Twice as bendable. But still 50ksi tensile strength for ER CuSi-A

                  It's about 15 bucks a pound.

                  And as an aside, the basemetal does indeed have an ultimate tensile strength in the 50-60ksi range.
                  Last edited by Bodybagger; 10-16-2009, 02:45 AM.

                  80% of failures are from 20% of causes
                  Never compromise your principles today in the name of furthering them in the future.
                  "All I ever wanted was an honest week's pay for an honest day's work." -Sgt. Bilko
                  "We are generally better persuaded by reasons we discover ourselves than by those given to us by others." -Pascal
                  "Since we cannot know all that there is to be known about anything, we ought to know a little about everything." -Pascal

                  Comment


                  • #10
                    Originally posted by Bodybagger View Post
                    Unfortunately, everyone missed the key concept here.
                    I caught it but didn't have time to post. I bought 50 lbs of .023 sil bronze for 20 bucks and its great for the bodywork with argon gas...Bob
                    Bob Wright

                    Spool Gun conversion. How To Do It. Below.
                    http://www.millerwelds.com/resources...php?albumid=48

                    Comment


                    • #11
                      Sorry about the tardy response. My laptop suffered The Blue Screen of Death, and I have to do this on the library's computers for now. Thanks for your interest!!!


                      Originally posted by Bodybagger View Post
                      Unfortunately, everyone missed the key concept here.

                      The workability of metal is related to the modulus of elasticity and not the ultimate tensile strength.

                      With steel, you are sort of stuck with an E of 29,000 ksi.

                      It would probably surprise a lot of people to know that bronze brazing alloys can also have ultimate tensile strengths in the 50-70 ksi range because we all know they are softer than steel.

                      Being more workable, ie, having a lower E, does not necessarily mean a lower tensile strength. And being extremely stiff doesn't mean a high tensile strength. There are some very stiff materials out there with a very low tensile strength.

                      Silicon Bronze has an E of about 15,000 ksi, which is roughly half of that of steel.

                      That means it's twice as workable. Twice as bendable. But still 50ksi tensile strength for ER CuSi-A

                      It's about 15 bucks a pound.

                      And as an aside, the basemetal does indeed have an ultimate tensile strength in the 50-60ksi range.

                      Bodybagger, your post really has me hacked-off Not that you're wrong . . . I am!! Oh, I know about the high-tensile bronze wires. And as for using UTS as a measure, that was sloppy shorthand I employed because the numbering of the wire uses it. No what got me bent was your statement about the UTS of mild steel. This was one of those things that I have "known" for years, decades, . . . that ain't so!!! DANG!!! I took a fast look at Machinery's Handbook, and sure enough (sigh!). I wonder where I "learned" that . . . hmmmm.

                      But still, if "they" made an E6X wire, or softer, in addition to the standard E7X, wouldn't that make for a more workable weld?

                      Also. on the sil-bronze MIG wire: Not having tried it yet, I have to wonder how this compares to ordinary brazing or bronze welding. How does it have time to tin, or to wet-out and flow? The brazing I know about requires some amount of surface area attachment, and is considered unsuited to butt-welds, esp. on thin sections like sheet steel, esp. when that metal is going to be worked, . . . . ? ? ?

                      I'm hearing from a sheetmetal man elsewhere that while an Easy Grind bead is easier to dress off, the welded area is no easier to work when planishing, etc..
                      Last edited by seattle smitty; 10-20-2009, 01:25 PM.

                      Comment


                      • #12
                        Originally posted by seattle smitty View Post
                        But still, if "they" made an E6X wire, or softer, in addition to the standard E7X, wouldn't that make for a more workable weld?
                        There you go again relating lower tensile strength to being "softer!"

                        It is a deeply ingrained concept, so I'll forgive you.

                        The answer is, not necessarily.

                        Workability is sort of a vague concept unless you are specifying the process to be done.

                        For example, a forming process that makes tight bends would require high ductility, as indicated by the material's elongation properties. But as far as how easy it is to work, the machine, say a bending roll, will have a capacity limit based on the yield strength (and section shape).

                        The yield strength is less than the ultimate tensile strength, but that's all you can infer. For example:

                        ASTM A992 has a yield strength of 50ksi and an ultimate tensile strength of 65ksi

                        ASTM A709 grade 36 has a yield strength of only 36 ksi, but an ultimate tensile strength in the range of 58-80 ksi.

                        A709gr30 would be more easily bent than A992, even though they have about the same ultimate tensile strength.

                        I should have been clear in the original post that the specific workability trait I was referring to is how well it will hold the form it has been worked into without the tendency of springing back to the previous form.

                        Using a metal brake as an example, aluminum does not have to be bent as far past 90 degrees to hold the 90 degree bend upon release as steel does.

                        80% of failures are from 20% of causes
                        Never compromise your principles today in the name of furthering them in the future.
                        "All I ever wanted was an honest week's pay for an honest day's work." -Sgt. Bilko
                        "We are generally better persuaded by reasons we discover ourselves than by those given to us by others." -Pascal
                        "Since we cannot know all that there is to be known about anything, we ought to know a little about everything." -Pascal

                        Comment


                        • #13
                          Okay, I have to dig out the old books and give myself a refresher. I supposed that a low-carbon E60XX electrode would lay down a quick-cooled deposit that could reasonably (if non-technically) be called "softer" (more malleable, more easily worked by a panel-beater) than, say, an E120XX high-carbon quick-cooled deposit. But I don't want to be sloppy and inaccurate, or lazy, or parrot popular misconceptions, so I'll go wise myself up. Thanks, Bagger.

                          Comment


                          • #14
                            From a few years ago...Bob
                            http://www.millerwelds.com/resources...ead.php?t=8153
                            Bob Wright

                            Spool Gun conversion. How To Do It. Below.
                            http://www.millerwelds.com/resources...php?albumid=48

                            Comment

                            Working...
                            X