No announcement yet.

welding thin tubing to thick plate

  • Filter
  • Time
  • Show
Clear All
new posts

  • welding thin tubing to thick plate

    i wanted to tig short pieces of 6x8 mm steel tubing (1 mm wall) to a 6 mm plate, with the tubes lying flat. two larger tacks on each side would have been enough. the first tack went well, but i cant recall how i did it. the second burned through the tube and the subsequent practice attempts the same.

    i would start a puddle on the plate, dip the rod into it and try to pull it up the tube. tried 120-160 amps. i then switched to 5x10 mm tube (2.5 mm wall) and managed to do it but had to be really careful. are there any tricks you can share?

    i never use a pedal, never saw a need for it, but maybe this is where it would have been appropriate? although i probably would have been too slow , the "pull up" movement was a fraction of a second only. i could have cut small pieces of rod and put them into the gaps, but thats a complication i would like to avoid. or get off the trigger earlier? or ...?
    Last edited by dian; 06-02-2020, 12:43 AM.

  • #2
    Originally posted by dian View Post
    ...i never use a pedal, never saw a need for it, but maybe this is where it would have been appropriate?
    Yup, there's a reason why pro's all use pedals...because they work. Now you know...

    Just one project too many--that's what finally got him...


    • #3
      Your thought about starting the puddle in the thicker plate for me is right. The pedal allows you to apply more heat to the plate then back off some as you try to drag the rod in the plastic state ideally onto the tube where you cn give it more heat. I have to admit, over my career I didnt ever use a tig machine without a pedal as they all had them. If you have one practice with it. I think you will like the results.


      • #4
        I'm thinking by the time you were doing the 2nd tack there was too much heat in the tube.
        Lay wire technique should help once the tube is cool enough and I wouldn't try to weld it all in one pass.
        SOMEBODY may be able to...maybe even you...but not me!


        • #5
          my problem with the pedal is that im often standing when welding and balancing on one leg is not my thing. also i weld in different areas (like in the big vise), so moving the pedal i another complication. i have been thinking to get a torch with current control, but have been putting it off, as i have four torches already. besides, the pedal is "wired wrong". it would suit me better if i could reduce the current by pressing it. can i just switch the wires?


          • #6
            Yeah, not so fun using the pedal while standing. That's why I got a torch-mounted control for my Miller. Attaches to the torch with velcro straps.

            There are no stupid questions. But there are lots of stupid answers. This is the internet.

            Location: SF Bay Area


            • #7
              Preheat the plate.


              • #8
                Use a chill plate and keep the arc more on the thick material and using the "Lay wire" technique is supposed to be cooler. A foot pedal should be on your wish list. I have used the pedal between my knees when I have to lay down or stand.


                • #9
                  Here is trick I have used... take a regular stick 6011/10 rod knock off all the flux and lay it in the fillet. Then direct the TIG heat to it and the plate, sneak up on the thin tube quickly and then back to the plate and fill rod. One of my TIG setups had the knob on the handle, I could never get completely comfortable with it.
                  Retired - Journeyman Refrigeration Pipefitter - Master Electrician - Fine Line Automation CNC 4x4 Router


                  • #10
                    why the stick rod? i dont have any.