Welding vertically?

  1. Nial Member

    Messages:
    45
    Edinburgh
    I'm practicing my mig'ing on thin sheet in advance of a fair bit of work
    on a mini. I want what I do to be neat and strong.

    My horitontal welding is getting better, the welds are neater and seem to
    have about the right amount of penetration. (I found reducing the wire
    feed and holding the nozzle nearer the weld helped a lot).

    I will have a reasonable amount of 'vertical' welding to do, running welds
    horizontally and vertically on vertical panels. To date I've only tried
    quick experimental runs vertically and they have all ended in disaster.

    When running a horizontal weld things will tend to droop so I presume the
    torch should be aimed upwards slightly.

    Should vertical runs start at the top and move down or vice versa?

    Am I going to end up doing the whole things with pulse welds?


    Does anyone have any recommendations?


    Thanks in advance,

    Nial.
     
  2. malcolm

    malcolm & Clementine the Cat

    Messages:
    9,134
    Location:
    Bedford UK
    The trick to welding vertically and even upside down is accurate wire speed and temperature settings. The wire speed needs to be increased slightly over horizontal welding to ensure a good bite.

    I tend to weld from the bottom upwards. That way gravity helps a little bit. I tend also to pulse weld a little - taking a moments break rather than the second you might take for really thin metal. That helps the weld to cool down and reduces the risk of drips.

    For the angle of the torch - I think I angle it slightly downwards to get some heat into the weld I've already applied.
     
  3. beatle_bayly Member

    Messages:
    10
    N.T Australia
    Nial,

    When I did my certificate course the official instruction was always from bottom to top on vertical welds. However, once the course was finished the instructors gave us all a few "tricks-of-the-trade" and said that welding downwards was best on thinner metals. This way you aren't chasing the heat upwards and blowing a gaping hole near the top.
     
  4. Nial Member

    Messages:
    45
    Edinburgh
    Gas flow increased?

    I was doing some experimenting last night and the results weren't
    bad. The welds didn't look as shiny and bright as a good hands down
    weld, not quite porous just a bit duller.

    Some questions....

    Do I need to increase the gas flow for vertical welds?

    Is Argon heavier the air? (if so then welding bottom-> up might
    maintain gas coverage slightly longer).

    How long does the gas need to shield the weld?


    Thanks for any answers.


    Nial.
     
  5. Hitch

    Hitch Moderator Staff Member

    Messages:
    12,343
    Somerset
    Nial, for vertical weld in anything under about 4mm start at the top and work down. Make sure the welding is reasonably slow though, or it will not penetrate fully, resulting in a weak joint.

    Over 3/4mm if it needs any strength, start at the bottom and work up.
    Use a lower setting than you would normally, and move your torch in a slow zig zag manner. It will almost always be difficult to make a vertical up weld look as neat as a downhill weld.
     
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