Cutting copper pipe in confined space

Discussion in 'Plumbers' Talk' started by Carl70, Dec 4, 2019 at 9:58 PM.

  1. Carl70

    Carl70 New Member

    Good evening all! I am hoping you can help me.
    I am renovating my bathroom and fitting a new suite. I have removed the old fittings and noticed a slow leak at a compression joint to the sink cold water pipe below the floor. This is an old fitting and I believe is over tightened as there is absolutely no give. I have disassembled and reassembled but no improvement so I assume the olive has failed. The application of leak seal on the male thread doesn’t help.
    So I think I need to fit a new elbow but - as you can see from the photo - the pipe sits on top of a waste stack with a hot water pipe above it so I can’t really get a pipe cutter in and - even if I could - there is probably only a few centimetres of copper pipe left to actually cut between the failed joint and the soldered t joint that comes off the fixed main pipe.
    I am an experienced DIYer and normally ok with the pipe work basics but this is nothing I have ever tackled before.
    Any ideas as to how I fix this?
    All advice will be greatly appreciated! ;)
     

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  2. cleggie

    cleggie New Member

    i would de solder the joint that comes off the fixed main pipe.then put all new pipe and fittings in place and just new solder them all.thus no cutting and its easy as long as everything is cleaned well.use either solder and flux or pr solder fittings
     
  3. Carl70

    Carl70 New Member

    Cheers Cleggie
    Do you mean the whole T joint?
    The only problem is that to the left Marley stack the pipes veer off to the void between joist and wall and then disappear downstairs. To the right hand side, the pipes go underfloor and out of the bathroom to the boiler. So I am not sure there will be any movement in the main pipe to remove the desoldered fitting.
     
  4. Heat

    Heat Well-Known Member

    Not really ideal to have compression joints hidden and not accessible.
    To remove and replace that brass elbow should be easy though.
    A junior hacksaw would cut the olive carefully if cut on the angle to the pipe.
    A olive splitter would probably work but not worth a diy person buying one just for occasional job.
    Paste on olive is the only way to help seal the olive on new joints. No point in using paste on threads of compression joints as those threads are not a seal.
    On bathrooms and a lot of other plumbing I would replace all old plumbing if anything wrong with it, with new copper all soldered work.
     
    Joe the Plumber likes this.
  5. cleggie

    cleggie New Member

    re do the lot from the solder joint as per my new pics 4FB869E8-68C9-45F2-A768-29813A27EB90 2.jpg 4FB869E8-68C9-45F2-A768-29813A27EB90 3.jpg
     
  6. Carl70

    Carl70 New Member

    Cheers.
    I could probably desolder that joint and protect the other joints with wet rag etc. But - once I have the new section prepared, how do I resolder to the existing joint noting that it is a Yorkshire solder ring joint and most of the solder will come away when the old pipe is removed?
     
  7. Heat

    Heat Well-Known Member

    Risky and difficult to unsolder and remove a piece of copper from one side of an old soldered fitting, - especially close to plastic pipes etc and for a diyer.
    Often soldered fittings are half soldered.
     
  8. Heat

    Heat Well-Known Member

    That is the least of your problems!
    Adding solder (end feeding it) will work perfectly on part of a fitting that is horizontal (or top vertical joints).
    Getting it all removed and cleaned up and soldered again properly is difficult. I should know as it is my job. :)
     
  9. Tricky Dicky

    Tricky Dicky Active Member

  10. Carl70

    Carl70 New Member

    Thanks Heat.
    If I leave the t joint alone and cut off the olive on the failed joint I think I will still have the problem of a damaged joint (olive will have “cut” into the copper pipe) so how would I rectify that if I can’t cut off the section with the olive groove?
    Also - the flomasta paste says to only apply to the male thread of the compression fitting. Are you saying this is wrong and it should be applied to the olive?
     
  11. Carl70

    Carl70 New Member

    cheers Tricky.
    I had some Fernox in my cupboard but sent it back to Amazon when I realised it was non potable. I got the flomasta thread seal instead (as an alternative to ptfe).
     
  12. Heat

    Heat Well-Known Member

    The old olive will hopefully not have squeezed into the pipe and created much of a groove.
    But you won’t know until you remove the fitting.
    You could use a Conex brass compression elbow. Very good quality and olive is large meaty soft brass.
    The paste must be only for the sealing parts of a joint - which are on a compression joint the olive and where it tightens against.
    The instructions for using only on male threads is for male joints - like a fitting screwed into a cylinder or a radiator valve tail into a radiator using ptfe tape etc.
    Compression joints for pipes are not male joints.
    The threads on compression joints are for the nuts to pull the fitting and olive together on pipes.
     
  13. Carl70

    Carl70 New Member

    Cheers Heat. That makes sense. I will cut off the olive first (or at least try) but have a conex ready. I suspect the thread on the inside of the old joint might have old thread seal inside so that won’t help so I really need an entire new fitting methinks.
    Out of interest is there any tool that would enable a straight cut on that shirt section of pipe..... or is t just too short? I am just thinking ahead if plan A fails.
     

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