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How far does heat travel on Soldered joint.

Discussion in 'Plumbing and Central Heating' started by renishawphil, 10 Apr 2019.

  1. renishawphil

    renishawphil

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    Hi

    I am looking at using some fittings on central heating but will need some Soldered joints above the floor boards, can anyone advise me how far down the pipe it will get hot (i am not doing the soldering) before it could be a risk to a speedfit fitting,

    I have 3.5 inches between where the joint is going to be done and the speed fit fitting, thinking can put old very cold wet rags below where the joint is being done and the speedfit elbow to keep the pipe for getting to hot
     
  2. pete50

    pete50

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    Surely the pipe that you are soldering will not have any water in it because pipes with water in them are virtually impossible to solder properly. Asssuming the pipe is empty can you remove the speedfit fitting? Heat does travel quite a way in a copper pipe so I would think the sealing O rings in the speedfit would be at risk at least.
     
  3. Gasguru

    Gasguru

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    Wrap a wet dishcloth around the pipe...you can then solder with a very short distance.
     
  4. renishawphil

    renishawphil

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    Would 3 inches be ok . I was think cold very wet clothes around pipe would work maybe even some ice cubes for good measure.

    How long does it normally take to solder a joint?
     
  5. ianmcd

    ianmcd

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    Another thing to consider , make sure that the flux while soldering does not run into the speedfit fitting, it will rot the grab ring and the fitting will fail
     
  6. renishawphil

    renishawphil

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    Thanks. What would be the best thing to stop this for happening ? Wrap something round the pipe to stop the downward flow of the flux?
     
  7. JohnD

    JohnD

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    if you have a speedfit, why not take the pipe out of it and do the soldering separately?
     
  8. renishawphil

    renishawphil

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    I guess because of the access as having bathroom done, with a new radiator being hung and floor done. I guess could if really had to but not sure how feasible. If cant solder it safely then could possibly change to compression fitting ,

    If 3 inches is to close then I'll do it but if on other hand can be kept cool then I wont
     
  9. Gasguru

    Gasguru

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    Yes 3 inches distance should be fine...assuming you solder fast with a decent blowlamp.
     
  10. renishawphil

    renishawphil

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    I've read the John guest tech spec n it says 450 mm distance between plastic fittings and soldering so I am just going to take boards up and do in compression. Should have done that in first place. Better safe then sorry
     
  11. ianmcd

    ianmcd

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    yes and make sure all the flux is wiped off after the soldering is finished
     
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