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Sealing damaged threads

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ChrisJ
ChrisJ Member Posts: 15,919
If I want to seal a very questionable NPT connection with damaged threads, what would you use?

I was thinking RTV but maybe there's a better product out there?
Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment

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  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
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    Water? I like what I call lamp wick.

    There was an error rendering this rich post.

    ChrisJmattmia2mvickersBill_Kitsch69
  • dko
    dko Member Posts: 644
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    anaerobic thread sealants like Permabond
    ChrisJHomerJSmithAlan (California Radiant) Forbes
  • ChrisJ
    ChrisJ Member Posts: 15,919
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    Water? I like what I call lamp wick.


    Low pressure air, a few pounds or so.
    If it seeps it's not the end of the world but I'd rather it didn't.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • HomerJSmith
    HomerJSmith Member Posts: 2,511
    edited April 2023
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    The only thing that has ever worked for me with great success is Lock-n- Seal or Locktite. Clean all the threads well and rinse with lacquer thinner.
    ChrisJ
  • mattmia2
    mattmia2 Member Posts: 9,959
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    Lampwick and dope will work the same as lampwick with water. I think there is a very fine teflon cord out there that you can lay in the threads like lampwick too.
    ChrisJmvickersBill_Kitsch69
  • Alan (California Radiant) Forbes
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    Hernon Dripstop 923 or Superdope, both anaerobic. Usually hand tight will do it. 
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
    ChrisJ
  • pecmsg
    pecmsg Member Posts: 4,961
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    M or F thread?

  • Mad Dog_2
    Mad Dog_2 Member Posts: 7,245
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    For that application Permtex and blue monster  Teflon tape  md
    ChrisJrick in Alaska
  • pecmsg
    pecmsg Member Posts: 4,961
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    I’ve used Stainless Steel fittings to clean up rough copper and brass threads. 
    ChrisJmvickersMikeAmann
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,839
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    If you dont think you will have to ever take it apart use X-Pando as @Karl Reynolds mentioned
    ChrisJttekushan_3rick in Alaskakcopp
  • ChrisJ
    ChrisJ Member Posts: 15,919
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    pecmsg said:
    M or F thread?

    Kinda both...

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    MaxMercy
  • mattmia2
    mattmia2 Member Posts: 9,959
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    what is this part?
  • Big Ed_4
    Big Ed_4 Member Posts: 2,831
    edited April 2023
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    Run a tap or die to recut the threads if you can . The threads are more important ..

    There was an error rendering this rich post.

    mvickers
  • gerry gill
    gerry gill Member Posts: 3,078
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    We use high temp permatex gasket maker for that.
    gwgillplumbingandheating.com
    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

    ChrisJ
  • SSmith
    SSmith Member Posts: 11
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    I have used X-Pando in the past, it certainly works, but seems brittle as it sets, now I use wire brushes to clean the male threads, then a light layer of teflon dope. Then wrap with four to five winds of 'flax' aka hemp, then another light layer of dope to hold the stuff in place. The hemp fibers are not woven as dense as rope; it actually looks like a disassembled hemp rope. Not to be confused with Oakum as it is dried not oiled or waxed. I used it working in Ireland and it is popular all over the EU (and England) to deal with their BSP threads. The hemp expands when exposed to moisture and seals up nice!
    ChrisJttekushan_3
  • Steve_Wheels
    Steve_Wheels Member Posts: 28
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    XPando! Works great to 600F! Works on HP Steam! Great stuff!! If you ever want to take the fittings apart, put your pipe wrenches on the pipe and fitting, have someone tap the fitting three or four times with a hammer and presto, comes right off.
    ChrisJ
  • MrStu02
    MrStu02 Member Posts: 7
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    If possible, chase the threads first. Tap and die. Then, as I do for all threaded connections in hwh, apply a leak lock sandwich. We use a hardening type of pipe dope called “Leak Lock” on the male threads, followed by a layer of the pink Teflon, and covered with another layer of Leak Lock. Best used during installation as some time is required for the leak lock to harden.
    ChrisJ
  • eclecticmn
    eclecticmn Member Posts: 121
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    Homeowner here. I bought some used cast iron hot water radiators. I could not get the replacement 1/8(?) inch bleeder valves to seal. Did not trust my skills so hired a mechanic off craigslist to drill and tap next size up 1/4(?) inch for bushing. That leaked around the bushing with tape and blue monster dope. I used two part JB Weld epoxy around the bushing and it worked. Any thoughts on that? Should I have used red Loctite?

    Also, I know what the word anearobic means but why is it used here?
    Home owner near Minneapolis with cast iron radiators, one non working slant fin now ripped out, and hot water heat.
    ChrisJ
  • mattmia2
    mattmia2 Member Posts: 9,959
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    Also, I know what the word anearobic means but why is it used here?

    There is no air in the parts of the threads you want to seal. It is basically super glue.
    ChrisJ
  • CLamb
    CLamb Member Posts: 299
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    ron said:

    pecmsg said:

    M or F thread?

    quite insensitive of you to assume his fittings are only one of two possible genders. That's probably his problem - not recognizing the correct gender of the fittings is why they are leaking.



    That's what came to my mind when @ChrisJ said they were "Kinda both...".
  • Jackmartin
    Jackmartin Member Posts: 196
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    The best sealant for damaged threads is expanding. We use to buy the stuff in 50 pound caskets in the ammonia trade put it on leave it for 24 hours no leak. Expanding is a type of cement it hardens like concrete and you cannot get it loose without hearing checkpoint to 300 degrees if it will seal ammonia at 400 psi it shpuld work for you
    ChrisJ
  • ChrisJ
    ChrisJ Member Posts: 15,919
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    Does X-Pando have a long shelf life?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,839
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    @ChrisJ It's a dry powder that mixes with and absorbs water. I think it will last as long as it is kept dry.
    ChrisJ
  • jumper
    jumper Member Posts: 2,331
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    US and other governments have gone rogue. What's wrong with six hours? What will be different between six hours and six minutes.

    It often takes weeks to reach a bureaucrat. Phone mailbox is full when its system even works. Best way is ordinary mail –forget registered– and then somebody will call weeks later.