Copper pipe that wont solder.

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by syncman, Mar 2, 2013.

  1. syncman

    syncman New Member

    Messages:
    7
    Location:
    Marietta GA
    Hot water heater replacement. The old copper pipe seems thicker and darker than the new, and wont solder for anything. The new pipe and connectors melt the solder and flux, coating the entire joint in seconds. The old pipe will not cover "tin" or solder. No matter how long I heat it with the butane torch, the solder melts but will not stay on the pipe. Just beads and rolls off. Any help? I did clean with wire brush and then coat the pipe with flux.
  2. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,260
    Location:
    Land of Cheese
    Butane? Really?

    I would first try cleaning the pipe with emery cloth. If it's not shiny, it's not clean, and if it's not clean it won't hold solder.

    I think most of us use MAPP gas or Propane. Butane might work for thin-wall copper, but I have never tried it.
  3. takatsu

    takatsu New Member

    Messages:
    6
    Location:
    Georgia
    Hi!

    I'm not a pro, but use sandpaper or emery cloth and polish around the end, well past where the fitting will be. The copper must be bright and shiny. Old pipes oxidize on the surface and turn dark- they won't take solder even with flux. Also be careful heating the pipe too long with a torch. It will change the pipe and soften the copper. If you've produced a pinkish/orange colored copper, you may want to consider cutting that section out a few inches back. I take it you need to solder a fitting onto an old section. The fitting should be brushed on the inside with a fitting brush- a couple of turns is not enough. A new fitting is shiny most times, but it still needs to be cleaned with many turns from a brush. A picture would help.
  4. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,266
    Location:
    New England
    Truly clean is a requirement! Some of the fluxes are not very DIY'er friendly. The one I prefer is one that has powdered solder in it. You still need to add solder, but it helps to pre-tin the connection.
  5. syncman

    syncman New Member

    Messages:
    7
    Location:
    Marietta GA
    Sorry, make that Propane. The blue tank? Really scrubbed those joints in and out with the wire brush cleaner thing. Just wont catch on the old pipe. Have used a Shark bite on one, but the other has no play in the pipe, or space to allow for the shark bite.
  6. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,047
    Location:
    Cave Creek, Arizona
    If you did everything properly and the solder will not bond, there is nothing we can do to help you, because we think WE could do it.
  7. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,266
    Location:
    New England
    Depending on what you use, it could itself be contaminated with oil or some similar material, contaminating the pipe or fitting. If the copper is really clean, solder will flow and bond.
  8. Terry

    Terry Administrator Staff Member

    Messages:
    15,298
    Location:
    Bothell, Washington
    If you have sanded and fluxed well, it should work.
    I like to make sure there is no water, and an open faucet somewhere.

    Propane or Mapp will work on that.
  9. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,047
    Location:
    Cave Creek, Arizona
    Are you sure it is copper tubing? Does it clean to a bright "golden" color?
  10. CanOfWorms

    CanOfWorms Member

    Messages:
    179
    Location:
    New Jersey
    I always use the yellow can MAP gas. It gets hotter.

    But if it wont work why not try a shark bite connection.

    They are costly ($5-$10 a connection), but if you are only doing one joint it's not the end of the world and it is done.
    The directions are usually on the packaging and you must buy the disconnect tool for a dollar or two in case you need to correct it.
    A slip fitting coupler is nice if it is your first time.
    They make ones that connect to just about anything on either end (pvc to copper to pex)
    A piece of advice that I think might get a few gripes from the pros, (sorry pros) .
    The last one I installed on a hot pipe got a drip that formed a drop every two minutes. I just wrapped a rag around it and within a day it was less, within a week it was gone.
  11. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,047
    Location:
    Cave Creek, Arizona
    quote; the last one I installed on a hot pipe got a drip that formed a drop every two minutes. I just wrapped a rag around it and within a day it was less, within a week it was gone.

    You must have been a fire sprinkler pipe installer, because that is what they do, but they put salt around the joint under the rag to speed up the "rusting" process. Sharkbites seal using an "O" ring so any corroding that occurred would not have repaired the damage to the ring, but must have caused corrosion at the ring.
    Last edited: Mar 11, 2013
  12. CanOfWorms

    CanOfWorms Member

    Messages:
    179
    Location:
    New Jersey
    I'll keep that in mind the next time I run out of pipe dope. LOL.
    I assumed the combination of hard water deposits plus corrosion caused it to stop. I usually only use the sharkbites when I am either flush with cash or when I am only doing one or when there is water in the pipe and I don't want to light the joists on fire trying to boil it out.
    Although, I just got a box full of them from sears on clearance sale for $1.50 a piece. Couldn't resist it.
  13. mikeplummer

    mikeplummer Plumber

    Messages:
    190
    Location:
    Ontario, Canada
    my thoughts as well....
  14. CanOfWorms

    CanOfWorms Member

    Messages:
    179
    Location:
    New Jersey
    Edge you serious about the salty rag? I have a galvinized pipe with a slow drip . It's in the middle of a section just did and would rather not disconnect t the whole thing.
  15. Dustinmorris8

    Dustinmorris8 Newmax Plumbing

    Messages:
    2
    Location:
    Cincinnati
    I had a similar problem this very day changing a tankless water heater. I switched to MAP gas and cleaned the pipe as much as possible with emery cloth, then It worked just fine.
  16. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,266
    Location:
    New England
    The key word is 'clean'. Unless all surfaces to be soldered are clean, and then there's flux, heat is not as critical (but it is still important) as you need it to get hot enough before you've boiled or burned out all of the flux for the solder to flow...heat with no flux allows corrosion which means a lousy connection. Heat the fitting (primarily), not the pipe.
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