Aluminum Mig Overhead
RSS | Subscribe | Contact Us | Advertise | About Us
Results 1 to 8 of 8
  1. #1
    Join Date
    Sep 2004
    Posts
    86

    Aluminum Mig Overhead

    Looking for some opinions here. I have a lot of experience welding aluminum and do it frequently. Recently, I was doing some welding on an aluminum trailer. I was welding 1/4" aluminum tube to 1/4" aluminum angle. My problem was in the overhead position the results were disastrous. Welding flat, as usual, was not a problem and produced great results.

    My question is, is there an operator error here that I am not getting in doing overhead aluminum MIG?

    I have a Lincoln 350MP and Prince XL spool gun with 3/64" 5356. I don't recall the settings I used but I used the same settings I welded in the flat position.

    Any comments or suggestions would be appreciated.

  2. #2
    Join Date
    Nov 2005
    Location
    Wayne County, OH
    Posts
    397

    Re: Aluminum Mig Overhead

    Based on my own experience with a Lincoln Pro-MIG 175 (no spool gun) on aluminum. For the brief overhead welding, I turned up the heat higher than necessary, but kept the wire speed consistant with what I would have used for a vertical down. The trick was to limit the bead length to basically tack welds. The end result resembled TIG welds more so than MIG. I can't attest for the quality of the welds, but for that application, those welds were not that critical. I also had to weld from underneath a welding blanket to keep from getting peppered with molten aluminum. Since then, I've avoided any overhead welding.

    Where I work, all the aluminum welding, robot or manual, is structural. The welders invert whatever they're working on (regardless of size) to have either flat or vert down welds.
    There are no small projects

  3. #3
    Join Date
    Jan 2005
    Location
    Baton Rouge, LA
    Posts
    26

    Re: Aluminum Mig Overhead

    Where you using stright MIG or pulse?

  4. #4
    Join Date
    Sep 2004
    Posts
    86

    Re: Aluminum Mig Overhead

    Straight Mig - 100% Argon

  5. #5
    Join Date
    Feb 2006
    Location
    Alberta Canada
    Posts
    82

    Re: Aluminum Mig Overhead

    Quote Originally Posted by imagineer
    Based on my own experience with a Lincoln Pro-MIG 175 (no spool gun) on aluminum. For the brief overhead welding, I turned up the heat higher than necessary, but kept the wire speed consistant with what I would have used for a vertical down. The trick was to limit the bead length to basically tack welds. The end result resembled TIG welds more so than MIG. I can't attest for the quality of the welds, but for that application, those welds were not that critical. I also had to weld from underneath a welding blanket to keep from getting peppered with molten aluminum. Since then, I've avoided any overhead welding.

    Where I work, all the aluminum welding, robot or manual, is structural. The welders invert whatever they're working on (regardless of size) to have either flat or vert down welds.
    Hmm I've actually done the opposite with decent results.
    For me it would always seem like the wire would melt back on me when doing overhead, so now i just give it an extra bit of wirespeed to keep the wire in the arc, but again, like you say, I can only weld for a short bit before it becomes to tall of a bead.
    Freelance Fabber
    91 GMC 3500 Portable welding truck
    Lincoln Weldanpower 8000 gas welder
    Miller CST 250 Smaw/Gtaw inverter
    Millermatic 210 gmaw line welder
    Hyperterm plasma

  6. #6
    Join Date
    Sep 2004
    Posts
    86

    Re: Aluminum Mig Overhead

    I pulled this off the Lincoln website and found it interesting and somewhat applicable to my situation.


    What's the deal with Pulsed MIG Power Supplies? What is the advantage over traditional CV Machines?

    For aluminum, the goal of pulsing is to have the ability to use spray transfer while minimizing heat input. This makes pulsing especially suitable for thin aluminum – say ¼” or below. While it is not wrong to use pulse welding for much thicker aluminum, pulsing begins to lose its advantage.

    Pulse welding out-of-position is also much easier than spray transfer out-of-position welding. And it is much easier to learn to weld aluminum using pulsed transfer because the arc is more controllable.

    In pulsed spray transfer, we pulse the current between a “Peak Current” that is above the transition current and a much lower “Background Current”. We have spray transfer when the arc is above the transition current. When the arc is at the Background Current, no droplets are transferred.

    Pulsing occurs several hundred times per second. Therefore, we get spray transfer at a much lower average welding current so that we can easily weld thin aluminum.

  7. #7
    Join Date
    Jan 2005
    Location
    Baton Rouge, LA
    Posts
    26

    Re: Aluminum Mig Overhead

    When I am welding aluminum overhead (pulse) I also turn my wire speed up a little and depending on the situation I might turn my heat down some too. I usually move a lot faster also.

  8. #8
    Join Date
    Sep 2006
    Posts
    1,052

    Re: Aluminum Mig Overhead

    Could gas flow be the issue? argon is heavier than air and all. noob question.
    Various Grinders
    Victor Journeyman torch
    200cf Acet. 250cf oxygen
    Lincoln 175 plus/alpha2 gun
    Lincoln v205t tig
    Lincoln 350mp
    Esab 650 plasma
    When you can get up in the morning, Its a good day.
    Live each day like its your last.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
RSS | Home | Penton Media | Contact Us | Subscribe | For Advertisers | Terms of Use | Privacy Statement