Soldering copper pipe with heat gun? What about brass?

Discussion in 'Plumbing Tools and Equipment' started by kotterr, Feb 24, 2017.

  1. Feb 24, 2017 #1

    kotterr

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    Is it possible to connect copper pipe by solder using a heat gun instead of a torch? I know a heat gun can quite easily melt a bar of tin down to a puddle and it would have likely done the same with the lead bar I had in there had I not dropped the entire piece in there (solder is used in MUCH smaller quantities). But can it work to solder copper pipe together? What about brass to copper?

    https://www.amazon.com/Astro-9425-Dual-Temperature-Heat/dp/B00MAB80EU/
     
  2. Feb 24, 2017 #2

    Nehmo

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  3. Feb 24, 2017 #3

    WorkingStiff

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    I would have thought no, given that copper is such an effective heat sink. It must be incredibly slow though right? Still work with larger sections of pipe? (that is a pretty short section there).
     
    Last edited: Feb 24, 2017
  4. Feb 24, 2017 #4

    SHR

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    No. And the fitting in the pic is a type known for failure. For safe and reliable connections, no heat gun for soldering and no pre-soldered fittings. I realize some will argue but I have seen them fail regularly. Heat gun soldering and pre-soldered fittings ARE good for increasing my bank account due to frantic calls from homeowners to fix their leaking joints. They always say they "saw it on the internet, so why didn't it work?"...
     
    Last edited: Feb 24, 2017
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  5. Feb 24, 2017 #5

    frodo

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    agreeing with SHR
     
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  6. Feb 24, 2017 #6

    Matt30

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    Why would you want to do this? Its 10x easier and safer to use a propane torch and proper fittings
     
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  7. Feb 24, 2017 #7

    Matt30

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    Also, who solders a coupling onto a pipe in a vice???
     
  8. Feb 25, 2017 #8

    kotterr

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    I saw that video, too. No, I wasn't about to use presoldered fittings. Sounds expensive and you don't get to apply the solder to your satisfaction. I was just wondering if it were doable in a situation where I did not want to have an open flame. Does anyone have any personal experience with doing it with a heat gun?

    Also, what about soldering copper to brass or to stainless steel? Is it possible? Would I need something hotter, like MAPP gas?
     
  9. Feb 25, 2017 #9

    Matt30

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    You can solder copper to brass without issues. You cannot solder stainless steel. If you are worried about open flame, get yourself a heat shield of some sort. Ditch the heat gun idea, trust me. Its going to be way harder.
     
  10. Feb 25, 2017 #10

    Nehmo

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    Pre-Soldered Fittings use an alloy of solder that melts at a lower temperature than standard solder. Since a typical electric heat gun supplies much less heat than a torch, to get the job done in a reasonable time, the heat gun demonstrator chose to use a Pre-Soldered Fitting.

    The merits of such fittings are debatable, (and that discussion deserves a thread of its own), but I wonder if those who had trouble with Pre-Soldered Fittings hadn't yet gotten the hang of them. With a Pre-Soldered Fitting, you heat the pipe more than the fitting. That's the opposite of the usual technique.

    The other issue is the brass you asked about. While brass’s affinity to copper (actually brass is an alloy of copper and zinc) presents no problem, the thickness of the brass fitting may. Often a brass fitting is much thicker than the copper pipe it joins to. The thicker a fitting, the more heat it requires during the soldering process, and the weak electric heat gun may tax your patience.

    You might consider practicing a little on some scrap pipe and a few extra fittings. Before you do your actual project, you should be confident in your own ability to succeed.

    I don't know what of your situation makes you want to avoid the flame, but I assume it's a legitimate concern. If there's flammable material in range, get it wet first, and protectively cover it with something. A precautionary water hose wouldn’t be a bad idea too.

    If you really want to be cool, get a 5 kilowatt power supply, and learn [ame="https://www.youtube.com/watch?v=FMVqsSNO07g"]inductive soldering[/ame].
     
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  11. Mar 10, 2017 #11

    frodo

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    yes, you can solder stainless steel and copper all you need is the correct flux

    I have soldered SS to SS and copper to SS




    yes,
     
    Last edited: Mar 10, 2017
  12. Mar 10, 2017 #12

    plumb_bob_square_pants

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    I was hoping you wod chime in on this one. Can you list the right Flux or where to get the stuff. I saved a pic you had posted one time. I'm just wondering it is the same stuff.
     
  13. Mar 10, 2017 #13

    frodo

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    sta clean liquid flux by harris

    I get it at a welding supply house where i get my b tank refilled

    https://www.amazon.com/Harris-SCLF4-Stay-Clean-Soldering/dp/B0015DWPV8/ref=sr_1_fkmr0_1?ie=UTF8&qid=1489164700&sr=8-1-fkmr0&keywords=star+clean+liquid+flux+by+harris


    you just have to remember the 2 metals heat sync at different temps

    get your flame off the ss and on the copper after you preheat.

    and i have found that if you pre-tin your work, it works out a lot better
    the stainless does not seem to ''wick'' the solder like copper
     
    Last edited: Mar 10, 2017
  14. Mar 10, 2017 #14

    frodo

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    And there is the problem, we as licensed plumbers are required by code

    solder or fluxes with a lead content which exceeds 2/10 [0.20] of 1 percent shall be prohibited in piping systems used to convey potable water

    if it is a lower melting point then the lead percentage is going to be to high

    Oatey Silver Lead Free and Safe-Flo® Solder

    melting point 415 degrees f - 455 f
    tin 60-100 %
    bismuth 1-5 %
    copper 1-5 %
    silver 1-5 %

    Oatey 95-5 lead free
    450 degrees f- 465 f
    tin 60-100 %
    antimony 3-7 %


    in my opinion, all these neat tricks work great in a vice, in a closed environment
    now, jump down in this ditch with the wind blowing
    or maybe a sprinkle or 2

    we work in the weather, very very very rarely do we ever get a chance to solder a pipe in pristine conditions as a lab setting
    hell man, most of the buildings do not have windows yet !!!!!!!!!!!
     
    Last edited: Mar 10, 2017
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  15. Mar 17, 2017 #15

    WyrTwister

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    How about in the crawl space under a house , where there is barely enough space to get my old , fat behind / gut ?

    As an aside question , is tin / lead solder legal on things like automotive radiators ? Hot water heating systems ?

    God bless
    Wyr
     
  16. Oct 16, 2017 #16

    manju123

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    you can solder brass to copper no problem.stainless steel you cannot solder
     
  17. Oct 17, 2017 #17

    frodo

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    oh contraire mon frère

    yes you can, been there done that

    DSCN5476.JPG
     
    Last edited: Oct 20, 2017
  18. Feb 23, 2018 #18

    PlumberMike

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    How does a heat gun heat the copper fitting that hot to sweat it up.
     

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