Hire the best Gas Fitter

Leaks in threaded pipework

Results 1 to 18 of 18
  1. #1
    Novice
    Join Date
    Oct 2020
    Location
    Bowen Mountain
    Posts
    34

    Default Leaks in threaded pipework

    Hello all, I am now in the final stages of my ensuite renovation and am currently installing a custom vanity cabinet. I have come across a slight problem with trying to obtain watertight threaded joints with the threaded pipes that protrude from the walls. I have tried pink teflon tape with about 6-8 wraps but although it appears OK, I notice after a while that there is a very slow drip forming. From what I read on the internet, it seems to me that it is due to the fact that these are parallel pipe threads and so do not tighten up on the teflon tape properly when screwed in. I'm also suspicious that the newer threaded pipe threads may be looser than the original pipework.

    I am now looking at using thread sealant (aka thread dope in USA) as it appears to be touted as a better and more permanent solution. I found some called "Christys Ultra Seal Thread Sealant Virgin PTFE" although it is not that commonly available (I will need to drive about 40km to get it). I found a similar product at Bunnings (Loxeal), but it doesn't sound quite like what is recommended on other sites (eg. more difficult to remove as it is not a PTFE paste).


    Does anyone have any other suggestions? Thread dope seems to be more commonly used in the US; surely others have run into this issue?

    Thanks

  2. #2
    Seasoned DIY droog's Avatar
    Join Date
    Sep 2005
    Location
    Bendigo
    Age
    57
    Posts
    2,576

    Default

    More teflon tape.
    And make sure you get one of the better quality ones which are thicker.

  3. #3
    1K Club Member
    Join Date
    Dec 2012
    Location
    Country NSW
    Posts
    1,386

    Default

    Loctite 567
    Never argue with idiots, they will drag you down to their level and beat you with experience.


  4. #4
    Community Moderator phild01's Avatar
    Join Date
    Aug 2009
    Location
    Sydney, north
    Posts
    16,126

    Default

    Quote Originally Posted by droog View Post
    More teflon tape.
    And make sure you get one of the better quality ones which are thicker.
    Yes but you need to go to a plumbing supplier for proper pink, not the thin bunnings pink crap.

  5. #5
    Novice
    Join Date
    Oct 2020
    Location
    Bowen Mountain
    Posts
    34

    Default

    Well, the pink tape I have is labelled Boston High Density and "complies to BS 4375". I did try more wraps as well ... just not convinced that the tape will give a guaranteed seal with parallel threads, and I don't want even an occasional drip under the back of the vanity after installation. I also looked at Loctite 567, it may be a good alternative but from the TDS it sounds that it can be harder to disassemble if necessary.

  6. #6
    1K Club Member
    Join Date
    Dec 2012
    Location
    Country NSW
    Posts
    1,386

    Default

    Quote Originally Posted by ATMNut View Post
    Well, the pink tape I have is labelled Boston High Density and "complies to BS 4375". I did try more wraps as well ... just not convinced that the tape will give a guaranteed seal with parallel threads, and I don't want even an occasional drip under the back of the vanity after installation. I also looked at Loctite 567, it may be a good alternative but from the TDS it sounds that it can be harder to disassemble if necessary.
    No issues with disassembly, don't worry about the name "Loctite". While that company does make thread locking products, this is not one of them. Very easy to disassemble and you can just add a bit more when re-assembling without having to clean the old stuff off. It really is great stuff.
    Never argue with idiots, they will drag you down to their level and beat you with experience.


  7. #7
    Golden Member havabeer's Avatar
    Join Date
    Nov 2011
    Location
    nsw
    Posts
    944

    Default

    How far on does it actually screw?
    Remember if you don't sin, then Jesus died for nothing

  8. #8
    Novice
    Join Date
    Oct 2020
    Location
    Bowen Mountain
    Posts
    34

    Default

    It screws on slightly under 15mm - actually that is a brass cap I've been using to temporarily block the end but the fittings will be about the same.

  9. #9
    Novice
    Join Date
    Oct 2020
    Location
    Bowen Mountain
    Posts
    34

    Default

    Quote Originally Posted by Whitey66 View Post
    No issues with disassembly, don't worry about the name "Loctite". While that company does make thread locking products, this is not one of them. Very easy to disassemble and you can just add a bit more when re-assembling without having to clean the old stuff off. It really is great stuff.
    Actually that sounds very good, and I see that I can get it at Repco which is handier for me. I've also found an article recommending anaerobic sealants over solvent based pipe dopes (although it is 20 yrs old) ...
    I have to screw a short extension onto the threaded pipe (to penetrate into the vanity) and then screw on the mini-tap - I assume I need to do this pretty much simultaneously so I don't break the first seal - does it have much working time?

  10. #10
    Senior Member
    Join Date
    Apr 2018
    Location
    Western Australia
    Posts
    403

    Default

    Quote Originally Posted by Whitey66 View Post
    No issues with disassembly, don't worry about the name "Loctite". While that company does make thread locking products, this is not one of them. Very easy to disassemble and you can just add a bit more when re-assembling without having to clean the old stuff off. It really is great stuff.
    Agreed. I use the stuff regularly on far higher pressures found industrially and thus have always used it on any problematic threads at home.

  11. #11
    3K Club Member
    Join Date
    Jun 2012
    Location
    Sunshine Coast
    Posts
    3,695

    Default

    How to fit a cap using rocket science
    Fit tap washer inside cap and screw into place, no sealant/thread seal required
    or use a compression nut and insert a jumper valve ditto above

    Attached Thumbnails Attached Thumbnails dscn0705.jpg  

  12. #12
    Senior Member
    Join Date
    Nov 2013
    Location
    Vic
    Posts
    297

    Default

    Does anyone have any other suggestions? Thread dope seems to be more commonly used in the US; surely others have run into this issue?

    Thanks[/QUOTE]
    Loctite 55

  13. #13
    Novice
    Join Date
    Oct 2020
    Location
    Bowen Mountain
    Posts
    34

    Default

    Quote Originally Posted by cyclic View Post
    How to fit a cap using rocket science
    Fit tap washer inside cap and screw into place, no sealant/thread seal required
    or use a compression nut and insert a jumper valve ditto above
    Thanks Cyclic, but I am only using the brass cap until I install the vanity and then replace the cap with a short extension / mini-cock. I could have put a washer in it as you suggest, but after seeing that thread tape didn't seal it completely I continued testing without a washer because I wanted to make sure that (when replaced with the extension / mini-cock) there would be no leaks. Using a washer would just have temporarily avoided the problem until the cap was replaced.

  14. #14
    Novice
    Join Date
    Oct 2020
    Location
    Bowen Mountain
    Posts
    34

    Default

    Quote Originally Posted by RodEye View Post
    Loctite 55
    Thanks RodEye, but I think it may have the same problem as tape for parallel threads. If you look at the TDS, it specifically states that it is recommended for metal and plastic tapered pipe threads.

  15. #15
    Senior Member
    Join Date
    Nov 2013
    Location
    Vic
    Posts
    297

    Default

    Quote Originally Posted by ATMNut View Post
    Thanks RodEye, but I think it may have the same problem as tape for parallel threads. If you look at the TDS, it specifically states that it is recommended for metal and plastic tapered pipe threads.
    Beg to differ, I've been using for years.

  16. #16
    Novice
    Join Date
    Oct 2020
    Location
    Bowen Mountain
    Posts
    34

    Default

    Quote Originally Posted by RodEye View Post
    Beg to differ, I've been using for years.
    OK thanks for that, makes sense that it should fill up the voids in the threads regardless - actually looking at the TDS for 567 it says the same thing, so take it with a grain of salt I guess.

  17. #17
    3K Club Member
    Join Date
    Jun 2012
    Location
    Sunshine Coast
    Posts
    3,695

    Default

    Quote Originally Posted by ATMNut View Post
    Thanks Cyclic, but I am only using the brass cap until I install the vanity and then replace the cap with a short extension / mini-cock. I could have put a washer in it as you suggest, but after seeing that thread tape didn't seal it completely I continued testing without a washer because I wanted to make sure that (when replaced with the extension / mini-cock) there would be no leaks. Using a washer would just have temporarily avoided the problem until the cap was replaced.
    Ok then, use 12 wraps of white thread tape or about 8 wraps of pink and use Locktite #3 as well.
    But you will need to wire brush the old stuff off before redoing the joint for the extension and mini cock so might be best to fit the extender now with the washer in the cap because you might have trouble putting the tape on once the vanity is in place.

  18. #18
    Senior Member
    Join Date
    Nov 2013
    Location
    Vic
    Posts
    297

    Default

    Quote Originally Posted by ATMNut View Post
    OK thanks for that, makes sense that it should fill up the voids in the threads regardless - actually looking at the TDS for 567 it says the same thing, so take it with a grain of salt I guess.
    Can only really recall one incident many years ago where this stuff let me down. It was was on a 1" brass thread, tried teflon tape as a secondary measure, which failed. In the end, resorted to hemp and paste.
    Roughen up thread, wind on in clockwise direction and apply amount according to advisory note on side of canister.
    You may get a bit of shock at the price, but you are saving money aren't you? Doing the work yourself.

Similar Threads

  1. can PEX pipework come adrift?
    By Cecile in forum Plumbing
    Replies: 38
    Last Post: 1st Sep 2018, 01:03 PM
  2. Threaded Rod
    By phild01 in forum Structural Renovation
    Replies: 13
    Last Post: 23rd Sep 2017, 08:58 PM
  3. Bathroom vanity and pipework
    By LordBug in forum Plumbing
    Replies: 4
    Last Post: 9th Jul 2008, 08:00 PM
  4. sizing hot water pipework for HWS
    By emptybucketman in forum Plumbing
    Replies: 3
    Last Post: 24th Jul 2007, 10:10 PM
  5. natural gas pipework
    By scottyb in forum Plumbing
    Replies: 3
    Last Post: 15th Jun 2007, 06:03 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •