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Grounding small parts, TIG

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  • Grounding small parts, TIG

    after wrapping up my stone, I spent a little time yesterday making a practice headlight ear for my Guzzi project. I have a Miller 250Synchrowave and water cooled torch to replace my old/dead Miller 180SD that I rarely used. Aluminum is 5000 series .125 thick. My goal is to fabricate these and dress welds to make the part look more like a casting than basic fabricated parts. My ground clamp is the typical big clamp, so is difficult to clamp to this or any other small part and still leave room for welding. I welded this part simply resting upon steel table with clamp attached to table but it produces arcs between table and part. Not ideal, but not a huge deal at this point.

    But I plan to make clamps for this ear, jig them up on a spare fork tube (steel/chromed) and then TIG the ear to the clamps while properly aligned. I don't want arcing between the tube and clamps that may damage the clamps and would rather not have to make several to learn via trial and error. Do I need to make some manner of clamp or extensions for a clamp attached to the ear and insulate the tube from ground to eliminate arcing? If I use a smaller cable for ground between the big clamp and the part, will using a smaller gauge cable (not tiny, but not as big) create a fusible link? I'm guessing padding any clamp with aluminum so arcing potential is moved away from the good part will help. No lathe yet so I cannot turn up a suitable aluminum substitute for an actual fork tube.

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    full disclaimer- I've done a lot more gas welding than anything else and never had a problem grounding any of that work....
    Last edited by cliffrod; 16-11-19, 06:21 PM. Reason: Typo/spellcheck

  • #2
    At times when I have small parts to weld up I'll cut them out on 3-1/2 sides... leaving a tab on one side for clamping in a vise or in the ground clamp. Once welding is complete, cut off the handle..


    • cliffrod
      cliffrod commented
      Editing a comment
      Thanks, Robert. Hadn't tried that yet. It makes a lot of sense.

  • #3
    Here's a sample of where we used the "Breakaway Tab" when we radiused door openings...…

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    Test fit the radius...

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    Scoring the second cut location, and tacking in place..

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    Snapped of the excess....

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    Checking the radius, and welded in and dressed...

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    Attached Files
    Last edited by MP&C; 24-01-20, 12:57 PM.


    • #4
      That's even better than what I was thinking. It would help a lot with heat sink vs melting. The punch arrived to make my clamps, so I'll be working on a practice run soon. Thanks again, Robert.


      • #5
        I use a sheet of 1/8 aluminum to put the clamp on and just set any parts on that.