Copper Threaded Adapter Leaking

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Mr Fixit eh, Aug 2, 2012.

  1. Mr Fixit eh

    Mr Fixit eh DIYer

    Messages:
    34
    Location:
    Ontario, Canada
    I haven't been on the forums for quite a while - no plumbing projects until now! Great site.

    I'm installing a frost-free hosebib. I used a threaded adapter with 2 wraps of teflon tape to connect to the hosebib and then soldered the 1/2 inch copper to the adapter.

    First try - small drip coming from the threads (about a gallon over 24 hours). Ok, so I was being a bit careful to avoid stripping the threads, so we'll try again using more force and an extra wrap of teflon tape.

    2nd try - a tiny drip (about a cup over 24 hours). Hmmnh. So I thought I was being pretty forceful, but we'll try again with another wrap of tape and put as much force as I can before I think threads will strip.

    3rd try - a teensy, tiny little drip (about 1 drop every 10 minutes - just enough to keep a cotton cloth damp). Growl, growl, growl:mad:

    1. Would it be a reasonable solution to cut the pipe, tighten a bit more, then use a compression union to rejoin the copper line? If my tightening doesn't eliminate the leak, I can re-tighten the threaded adapter without having to start over.

    2. Is it possible to strip the threads, or am I just being silly?

    Thanks for your help,

    Steve
  2. Hammerlane

    Hammerlane Member

    Messages:
    252
    Location:
    Ohio
    Did you solder the the stub of 1/2 onto the adaptor before you wrapped the adaptor with the tape?
  3. Terry

    Terry Administrator Staff Member

    Messages:
    15,136
    Location:
    Bothell, Washington
    You can't strip the threads on a hosebib.
    Normally what we do, is solder a length of pipe onto a male adapter, let it cool, and then either tape it or dope it. Thread the puppy on tight, and then solder a coupling to the rest of the copper.
    A compression coupling would work too,
  4. Mr Fixit eh

    Mr Fixit eh DIYer

    Messages:
    34
    Location:
    Ontario, Canada
    No, I wrapped the tape, threaded and tightened the threaded adaptor onto the hosebib, then soldered - is that a problem?
  5. Mr Fixit eh

    Mr Fixit eh DIYer

    Messages:
    34
    Location:
    Ontario, Canada
    What about stripping the threads on the threaded adaptor?

    I'm guessing from what you've posted, the heat from soldering the threaded coupling to 1/2 stub probably expanded the coupling enough to create a leak....?

    If I use a compression coupling, is there any problem using it with the thicker-walled copper pipe (M)? I read somewhere that compression fittings could be a problem on the thicker walled pipe?

    Steve
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,156
    Location:
    New England
    The tape doesn't like the heat from a torch. Plus, many of the fittings available these days are made overseas and the threads can be absolutely horrible. Your best bet may be to use both some tape and some pipe dope - sort of a belt and suspenders solution.
  7. kreemoweet

    kreemoweet Member

    Messages:
    372
    Location:
    Seattle. WA
    The different copper water tube types (M, L, K) all have the same OD so compression fittings should work the same on all. You need some
    more reliable reading material.
  8. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,843
    Location:
    Cave Creek, Arizona
    HEating the joint AFTER assembling it destroys the joint compound, whether it is tape or paste. In addition, since the two parts expand and contract at different rates heating them can loosen the thread. You cannot strip the threads by overtightening them, but you can deform/expand the female portion or crack it.
  9. Mr Fixit eh

    Mr Fixit eh DIYer

    Messages:
    34
    Location:
    Ontario, Canada
    That's why I'm here:D

    Thanks for the reply.

    Steve
  10. Mr Fixit eh

    Mr Fixit eh DIYer

    Messages:
    34
    Location:
    Ontario, Canada
    Thanks for all the replies, you've been a big help.

    Once again - this is a great web resource you have here.

    Steve
  11. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Small point: 2 types of fittings love to leak - copper male adapters because the threads are rolled, not cut. and stainless steel because its so hard that it does not "flow" - For these I use permatex teflon dope then wrap with US made teflon tape - real stuff, rated. Not that old air mattress vinyl the indonesions remake and call teflon. Better to use scotch 33 than that.
  12. Mr Fixit eh

    Mr Fixit eh DIYer

    Messages:
    34
    Location:
    Ontario, Canada
    Success - I wanted to let you know that I've had success, thanks to all your advice.

    Thanks again,

    Steve
  13. hagakure

    hagakure New Member

    Messages:
    16
    Location:
    nyc
    Heh putting it with teflon/dope before soldering. Just sitting here, remembering the barrage of insults hurled my way in Eastern European "English".
Similar Threads: Copper Threaded
Forum Title Date
Plumbing Forum, Professional & DIY Advice Can I solder a copper to brass threaded connection? Jul 28, 2011
Plumbing Forum, Professional & DIY Advice trying to remove tub spout adapter from threaded copper Dec 4, 2010
Plumbing Forum, Professional & DIY Advice Solder threaded copper? Feb 16, 2007
Plumbing Forum, Professional & DIY Advice How tight - copper to brass threaded fittings Jan 7, 2005
Plumbing Forum, Professional & DIY Advice Kink in copper service line Oct 16, 2014

Share This Page