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  • sheet metal - Am I doing this right?

    New to this and I am butt welding patches in body panels. I am stitching (?) them in puttting a bead every inch or so an then repeating.

    MM175 C25 .023 ER70S-6 metal ground down and shiny

    When I think things are going well and how I think it should work, I pull the trigger the arc silently, instantly starts and makes kind of a hissing noise. I can see what is going on and move the puddle between the two pieces. The spot bead is relatively flat and blends in to the surrounding metal.

    Other times it takes an instant to start and by the time the arc is stable and I can see what is going on the pool is about to fall through. The bead has a more vertical edge with the surrounding metal. These two situations occur on the same guage metal and the same settings.

    Should I always expect it to work as it does in the first case? The second case will work but I am doing this as a hobby and want to learn all I can and do it right.

    The other question I've got is when I was looking MIGs at the gas place they all had much heavier (springier) ground clamps than what is on my smaller machine. Home Depot sells a Lincoln Clamp that seems to have a little more clamp force and contact area than the battery clamp that came on my MM175. Do you guys think ground contact is a variable in this?

  • #2
    I prefer lap welds, but it sounds like your techniqe is good. I'll bet the "clean" starts happen on a fresh-cut wire end, or on a wire end that didn't "ball" when you stopped the last bead. Check it. If there's a little ball, cut it off.

    Hank
    ...from the Gadget Garage
    Millermatic 210 w/3035, BWE
    Handler 210 w/DP3035
    TA185TSW
    Victor O/A "J" series, SuperRange

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    • #3
      Sheet metal welding

      Grounding is always a consideration..... Consider if, you tried to flow electricity thru your mig wire and you have a bad ground...only some of the electricity can cross thru the wire to your work...consequently, only some of your wire can be heated enough to melt and flow.....the balance that cannot be heated because of low electricity flow, just balls up like partially melted goo !!!

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      • #4
        how big is the gap?
        Lincoln SP170T
        ESAB 875 Plasma
        Smith oxy set
        Dynasty 200DX
        pulsed mig is next...

        Long Island Cummins Ram Owners Club

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        • #5
          Rick,
          I've done quite a few patch panels in past few years.
          The best way to do this is to invest in a panel flanging tool. I don't know if you're familiar with this tool, but, what it does is it offsets the area to be welded and your panel sits flush with patch. You then have no gap to fill. I usually cut the opening a 1/2" small all the way around, drill 3/16" holes into the patch on the ares to be welded and plug weld the patch in. Then weld the perimeter in with pulsed beads and grind it all down. Most of the time you will be able to metal finish the area or use very little filler to finish.
          In the rare instances were a butt weld is necessary, I usually put a backing strip behind the patch. I do this by putting 3/16" holes along the weld area and plug weld the strip in. Then I weld into the strip.
          The last technique to use if the backing strip will be visible, and you dont want to use one, is, tack weld the patch in, and use a copper "spoon" behind the weld and pulse weld the perimeter moving the spoon as you proceed with the weld.
          I hope this information helps you, it has worked for me the past 30 years or so.
          Millermatic 251
          Synchrowave 180
          Hobart Beta-mig 200
          Lincoln SP175
          HyperTherm 380
          Victor O/A

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          • #6
            Originally posted by df5152
            how big is the gap?
            I have a Harbor freight panel saw and I think the gap is 1/32". I use broken hacksaw blades.

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            • #7
              Where can you get a panel flanging tool at?

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              • #8
                Try... http://www.eastwood.com/

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                • #9
                  Originally posted by napier
                  Where can you get a panel flanging tool at?
                  Panel flanging tools are available at: Eastwood company. www.eastwood.com. I'm sure they are available at other metal tools sites, but I bought mine from Eastwood and it's been worth it's weight in gold for panel repairs.

                  Thanks tims37 for answering that, I missed your answer the first time through.
                  Millermatic 251
                  Synchrowave 180
                  Hobart Beta-mig 200
                  Lincoln SP175
                  HyperTherm 380
                  Victor O/A

                  Comment


                  • #10
                    Harbor Freight also has a flanging tool. I have it and can say it works well. It also has the hole punch on the other side. Personally, I like butting panels together. It is a LOT of work to get fit up correctly, but in the end looks better to me (even though you wouldn't normally see the inside anyways).
                    Joshua

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                    • #11
                      Panel Patches

                      Good advice above, here is some further reading:

                      http://www.autobodystore.com/basics.htm

                      http://www.repairnation.com/paint_n_...corner_pg1.htm

                      http://www.autobody101.com/

                      http://floorpans.pontiac455.com/


                      Hi all, new to this board.........these are some of my bookmarks.

                      Edit: Recently purchased a MM135 and also replaced that ground clamp with something more substantial.

                      Comment


                      • #12
                        Originally posted by Bowtieman31
                        Rick,
                        I've done quite a few patch panels in past few years.
                        The best way to do this is to invest in a panel flanging tool. I don't know if you're familiar with this tool, but, what it does is it offsets the area to be welded and your panel sits flush with patch. You then have no gap to fill. I usually cut the opening a 1/2" small all the way around, drill 3/16" holes into the patch on the ares to be welded and plug weld the patch in. Then weld the perimeter in with pulsed beads and grind it all down. Most of the time you will be able to metal finish the area or use very little filler to finish.
                        In the rare instances were a butt weld is necessary, I usually put a backing strip behind the patch. I do this by putting 3/16" holes along the weld area and plug weld the strip in. Then I weld into the strip.
                        The last technique to use if the backing strip will be visible, and you dont want to use one, is, tack weld the patch in, and use a copper "spoon" behind the weld and pulse weld the perimeter moving the spoon as you proceed with the weld.
                        I hope this information helps you, it has worked for me the past 30 years or so.
                        Bow: GOOD STUFF! I had not heard of the "spoon" tech. I like that.

                        Mark
                        Dynasty 200DX w/Coolmate 3
                        MM252
                        MM251
                        Hypertherm 600 Plasma
                        Ready Welder II (Trail repairs)
                        One really big hammer for the rest

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