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Technical Metal Temperature - Welding?

Discussion in 'The Hokey Ass Message Board' started by midnightrider78, Oct 10, 2019.

  1. midnightrider78
    Joined: Oct 24, 2006
    Posts: 897


    I feel kind of stupid asking this question, but here goes.

    I am not a newbie welder by any stretch, but it just occurred to me that I have never welded sheet metal in a building that was less than 65-70 degrees. Since the parts I am about to weld are structural sheet metal, I thought I would throw this out there. First, this is just plain old sheet metal(floor/trunk pans, quarters, frame rails, etc on a '70s GM). None of the newer high strength low alloy or anything like that. It will be MIG welded. Since fall seems to have just assaulted us in my area and there is no heat in the building I am working in, I am guessing the air temperature in the building when I weld will be in the upper 40s.

    So, will this colder temperature impact the strength/quality of my welds or am I concerned about nothing?

    Thanks in advance.
  2. Budget36
    Joined: Nov 29, 2014
    Posts: 3,030


    Hmnn, I've never given it a concern, I'll be interested in the replies.
    klleetrucking likes this.
  3. G-son
    Joined: Dec 19, 2012
    Posts: 611

    from Sweden

    Not much difference if you start out with 40 or 80 degrees when you are going well above the 2500°F that steel melts at. That's what I'm guessing anyway.
    clem and Boneyard51 like this.
  4. Gearhead Graphics
    Joined: Oct 4, 2008
    Posts: 3,277

    Gearhead Graphics
    from Denver Co

    Ambient temperature has nothing tons with it. Think of when they made the transalaska pipeline.
    Boneyard51 likes this.
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  5. oldiron 440
    Joined: Dec 12, 2018
    Posts: 1,372

    oldiron 440

    I've welded for well over 40 years and never gave it a thought, but then the shop was 60 to 80 degrees all year round. o_O
    Boneyard51 likes this.
  6. pitman
    Joined: May 14, 2006
    Posts: 4,773

    from Hampsha

    If you were welding @ 0°F, the difference would be ~ 50-60° colder. Simplest of % change using the 2500° mentioned would be 2%. Think except for slight increase in distortion, you're ok.
  7. 19Fordy
    Joined: May 17, 2003
    Posts: 6,602


    Short answer is "No". No need to worry about ambient temperature.
    clem, j-jock and Boneyard51 like this.
  8. mlagusis
    Joined: Oct 11, 2009
    Posts: 955


    You only need to be concerned about thermal controls when welding thick members. With sheet metal, you are fine.
  9. midnightrider78
    Joined: Oct 24, 2006
    Posts: 897


    Thanks guys. I was hoping I was just being paranoid.
    Boneyard51 likes this.
  10. error404
    Joined: Dec 11, 2012
    Posts: 229

    from CA

    For significantly thicker steel, I've found that pre-heating the metal helps out with welding. But that may also be due to the fact that my MIG machine only goes to 180 amps. Seems to help create a flatter weld if the metal is already hot.
  11. Petejoe
    Joined: Nov 27, 2002
    Posts: 10,346

    from Zoar, Ohio

    It all comes down to base material temperature.
    The voltage and amperage welding adjustments are based on material temps.
    You normally never think about it during welding, but an experienced welder will automatically adjust his machine on this factor.
    If you are welding a thick piece of material with a 110 volt mig and find it’s not blending into the base material you will automatically turn up the voltage and amperage.
    Now here’s something many may not have thought about....
    If you are welding and find your cheap flux core mig isn’t hot enough. And turning it up doesn’t help.
    You simply heat the base material and the weld will blend right into the base material.
    Bottom line.
    Doesn’t matter how cold the ambient temp is as long as you have enough experience to see your getting penetration and make changes to accomplish it.
  12. Petejoe
    Joined: Nov 27, 2002
    Posts: 10,346

    from Zoar, Ohio

    Now here’s another idea many haven’t thought of.
    Your welding sheet metal, maybe a small piece that will burn up at the touch of the arc. Some piece very near and dear to you.
    Beside backing it with copper as a heat sink, you can stick the piece into a bucket of water.
    Now don’t jump to conclusions. We aren’t welding underwater.
    You simply hold the un-welded part of it in the water. Giant heat sink at your disposal.
    joel likes this.
  13. Rickybop
    Joined: May 23, 2008
    Posts: 6,051

    from Michigan

    I'm glad you asked this.
    I was wondering about this very thing recently... because I am a fairly inexperienced welder... but I'm going to be doing quite a bit in the near future. I doubt that I'll be welding in freezing temperatures, but maybe.
    My specific concern was if welding cold sheet metal, will the metal outboard of the heat affected area draw heat away from the weld quicker and require more hammering to control shrinkage.
    I like PJs answer. Whatever you're doing, in whatever conditions, you watch your results and adjust as needed.

    Sent from my VS835 using The H.A.M.B. mobile app
    midnightrider78 and Petejoe like this.
  14. 66gmc
    Joined: Dec 4, 2005
    Posts: 475


    I once welded a model A box together in an unheated garage when it was minus 59 outside. The welds held up after several years of abuse so I think you shouldn't have any issues. There was a local old school bodyman that used to gas weld everything, he would wait until the coldest winter day and then push the car outside and do all his welding to avoid warpage.
    williebill and scrap metal 48 like this.
  15. treb11
    Joined: Jan 21, 2006
    Posts: 3,341


    I would be more concerned with condensation in the metal. But that's quickly driven out as you weld. Really more of an issue with heavy sections and alloyed steels.

    Sent from my SM-G965U using The H.A.M.B. mobile app
  16. goldmountain
    Joined: Jun 12, 2016
    Posts: 1,462


    If it's that cold, wear gloves.
    pitman likes this.
  17. 1ton
    Joined: Dec 3, 2010
    Posts: 357


    Definatly helps to preheat aluminum.
  18. TagMan
    Joined: Dec 12, 2002
    Posts: 5,966


    What is important is how fast it cools. I recall a "TTT" curve (Time, Temperature Transformation) that changes the molecular structure of steel, as well as warpage, if it cools too fast or too slow. Each composition of steel has a different curve. That was for heat treating / quenching, but I'd guess it would be the same for werlding.
    Learned that 50+ years ago, so maybe things have changed - either that or I know just enough to be dangerous.
  19. Deuce Daddy Don
    Joined: Apr 27, 2008
    Posts: 4,886

    Deuce Daddy Don

    WOW!!-----Just turn up the power a bit!!!----Welding since 1951
  20. deathrowdave
    Joined: May 27, 2014
    Posts: 2,072

    from NKy

    Are you pro welder and can pass X-ray tests ? If you are you might be able to determine outside air temp effects your welds. If your not weld any temp until your finished with your project. Just be sure the PPE is in place. I found this out years and years ago, those little foam ear plugs are your real friend when cutting or welding over head. Man does it suck to hear it burning through the the ear drum and you can’t do Schmidt about it . All the time knowing you could have prevented it from happening .
    midnightrider78 likes this.
  21. Mr48chev
    Joined: Dec 28, 2007
    Posts: 26,239


    Those ear plugs aren't a bad idea any time you are welding.
    The main thing on sheet metal is don't get in a hurry and run long beads. That is what does more damage than anything. I've seen a lot of panels that guys warped the tar out of because they tried to run a continuous bead because the welder was working so great they just kept burning wire.
  22. You’ll not have a problem other than condensation. I generally like to warm the sweat out before welding if I can. A halogen light does that well enough
    Rickybop likes this.
  23. Rickybop
    Joined: May 23, 2008
    Posts: 6,051

    from Michigan

    I enjoy reading all the responses.
    But it's nice when someone just answers the freaking question, too.
    Thanks, 31 V.

    Sent from my VS835 using The H.A.M.B. mobile app
  24. Rickybop
    Joined: May 23, 2008
    Posts: 6,051

    from Michigan

  25. Blue One
    Joined: Feb 6, 2010
    Posts: 10,159

    Blue One
    from Alberta

    I love it :D Another welding question that I ignored and let the resident “experts “ try to answer.

    Life has been great since I learned not to respond to welding questions on the HAMB. :D:D
  26. kjmmm
    Joined: Dec 7, 2011
    Posts: 8


    Watch the regulator for frost/icing up. Under some conditions the gas flow is messed up and the welds go from OK to not so good.
    Rickybop likes this.

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