Rusted threaded end of drain pipe under sink

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by TSGarp007, Dec 18, 2012.

  1. TSGarp007

    TSGarp007 New Member

    Messages:
    10
    Location:
    Virginia Beach, VA
    I just posted about a shutoff valve in my bathroom. This post is about the drain pipe for the sink in the same bathroom. It is metal, (cast iron?, rusted galvanized?). When I removed the old sink and plumbing, it revealed this pipe end (linked photo here). It is rusted on the end with the threads and part of the threads on the bottom are rusted completely off. The pipe slopes slightly downward (into the room), although I'm not sure if that was the case before I removed the plumbing, maybe it was holding it up slightly.

    You can probably guess my questions...

    1) Can I just attach this to pvc piping using a fernco adapter or something like it?
    2) Does the rusted section of the pipe need to be cut off? -if so, best way for a diyer to do so?
    3) Even worse, do I need to go into the wall for bigger repairs?

    Thanks for the help. I hate the plumbing part, I just want to start laying tile, trim, etc!
  2. MACPLUMB 777

    MACPLUMB 777 TROJAN WORLDWIDE SALES RP

    Messages:
    679
    Location:
    Houston, Texas, United States
    That is a galv. Steel nipple that can be removed and replaced !
  3. toebone51

    toebone51 New Member

    Messages:
    8
    Location:
    LA
    It's an iron pipe nipple that is screwed into an iron or cast iron fitting in the wall. If you try to unscrew it, the threads on the fitting in the wall might break off. Then you have to open the wall. If you try to cut the threads off with a saws-all it could break whatever seal is in the wall.
  4. Terry

    Terry Administrator Staff Member

    Messages:
    14,891
    Location:
    Bothell, Washington
    A sawzall or hacksaw will cut that pipe and it can be coupled too. Or you can unthread the pipe and replace the nipple.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,488
    Location:
    Cave Creek, Arizona
    I have unscrewed 'hundreds' of those nipples, at least 40 on a job a few months ago. I had to use a 5' cheater bar on an 18" wrench for some of them but NONE of them broke the fitting and all the threads in the fiittings were intact.
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,892
    Location:
    New England
    FWIW, before you take that out, put a level on it to see how it is sloped...it should slope down, into the wall slightly. If it goes the other way, you'll have water sitting at the low end and it doesn't work as well. Galvanized should all be removed when doing remodeling if at all possible, and replaced with plastic or cast iron.
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,488
    Location:
    Cave Creek, Arizona
    quote; Galvanized should all be removed when doing remodeling if at all possible, and replaced with plastic or cast iron.

    They do not make cast iron threads nipples. It is probably screwed into a drainage tee which has "automatic" pitch in the thread. This is one location where galvanized should be used. A plastic male thread could snap off.
  8. TSGarp007

    TSGarp007 New Member

    Messages:
    10
    Location:
    Virginia Beach, VA
    Thanks everybody! Between this and the toilet supply line I may just hire a professional.

    Jadnashua: The pipe is sloped the wrong way, it slopes down into the room. How will a plumber fix this?

    I wish I knew more about this stuff, but I don't want to mess it up and ruin my entire reno project.
  9. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,488
    Location:
    Cave Creek, Arizona
    quote; How will a plumber fix this?

    About the only way it could slope the wrong way is if it is screwed into an elbow, and in that case, the plumber will just rotate it upwards.
  10. TSGarp007

    TSGarp007 New Member

    Messages:
    10
    Location:
    Virginia Beach, VA
    I see, thanks. Plumber is coming tomorrow. I'll try to learn at least a little by watching. No doubt these issues will come up again somewhere else in my house!
  11. TSGarp007

    TSGarp007 New Member

    Messages:
    10
    Location:
    Virginia Beach, VA
    Thanks everyone, we ended up taking the drywall off the lower half of the wall and replacing the galvanized piping with plastic (ourselves). The galvanized pipe was corroded on the interior with significant hair/rust/etc buildup. In the process we noticed the galvanized piping was slightly sloped the wrong way (both in the wall and after the 90 into the room). We over corrected of course, so the pipe coming out of the wall is sloped upward into the room, which caused a little more work getting the sink drain hooked up, but all done now. Thanks again for the help!
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