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Extraordinarily Tight Skim Port Cap

Rob_40 Member Posts: 55
I tried to remove the cap sealing the nipple to the skim port.  I don't think it has been removed for twenty or more years.   I tried double pipe wrenches on it and became afraid that I was going to deform the nipple.   Any reliable tricks for removing this cap.

 This is an old coal steam boiler.   And it wont be here this time next year.  But I want to get through one more season and replace it when the weather turns warm.

Failing to open the skim port,  I had tried to skim the water through the  the lower feed to the inspection glass, a pretty narrow pipe.  Water looked clean until the very end trickle of the skimming and I saw some orange discoloration in the water.

 I could heat it up the skim port cap with my torch, but would like to hear from others before I start.



  • Rod
    Rod Posts: 2,067
    Let it Be....

    Since you're going to replace the boiler in the near future and as long as the boiler is working reasonably well, I would just leave it.  If you break something trying to remove it you'll be in hot water. (No pun intended! :)

    - Rod
  • Rob_40
    Rob_40 Member Posts: 55
    Now I've Screwed It

    While tidying up the area around the boiler, boiler being off and cold, I noticed the tiniest drop of water clinging to the underside of the skim port nipple.  Closer inspection with magnifying glass reveals a tiny crack in the crevice of one of the nipple threads, weeping water.  So, this is a leak even without the boiler on and no pressure.  I dare not start this boiler up.   I must have cracked the nipple yesterday trying to loosen the cap.

    I would like to find a solution short of calling the boiler installers.

    Would JB Weld be sufficient to patch this for at least one New Jersey winter?

    Should have left well enough alone!   CHEESE AND CRACKERS!

    Any advice is most welcome.

  • Rod
    Rod Posts: 2,067
    Temporary Leak Fix

    Hi- Iis the crack on the boiler end of the nipple or on the cap end.?   If on the cap end you might rough up the thread an cap area and run a bead of JB Weld between the cap and the nipple. as a stop gap measure. Depending where the crack is located you might even be able to use some sheet rubber with a hose clamp

    If the crack/leak is on the boiler end of the nipple you will probably need to remove the nipple. Noit seeing the nipple i can only suggest a possible scenario. Carefully think this over first for feasibility before proceeding..You didn't mention the size of the nipple but I'm considering it big enough to get a saw blade inside to cut the pipe length wise.

    1. Leaving enough. length of nipple to get get a wrench on, saw off the nipple.

    2. Make 3 strategic cuts on the inside of the nipple. When you cut through the pipe be careful not to cut the threads. (In actual fact if you do hit slightly cut the threads it should still be okay, Just try and stay clear of them)  With the three cuts done you should then be able to take a hammer and cold chisel and slightly collapse the pipe.inward. Gberally at this time you can easily turn out the cut/collapsed nipple with a wrench.

    Having a sawsall really makes the job easier

    - Rod
  • Rob_40
    Rob_40 Member Posts: 55
    I'll Patch It

    First of all, thanks to everyone for giving your time and advice. 

    The crack is in the threads near the cap.  So I think I will try to patch it.   JB Weld seems to be the miracle epoxy putty according to their website.  The regular version allegedly withstands heat up to 500 F.   So, this may the stuff.  I was thinking also about a rubber sheet and hose clamp too, but I am not sure the it would seal the crack that lies at the bottom of a thread crevice.

    Thanks again.

  • BobC
    BobC Member Posts: 5,473
    Might help

    One cosideration is a piece of soft rubber (red silicone rubber if you can find some) and a hose clamp might force the JB Weld into the crack rather than have it just laying on top. In anycase clean that area as well as you can.

    good luck,

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Rod
    Rod Posts: 2,067
    Prep Work

    Hi- When using epoxy, the success of patch depends on how well the prep work was done.

    I would use a rotary wire brush (on a drill or die grinder)  to thoroughly clean/rough up  the area where you will be applying the JB Weld.  (Be sure to use safety glasses as rotary wire brushes tend to throw bits of wire)

    - Rod
  • Long Beach Ed
    Long Beach Ed Member Posts: 1,188
    Learn Anything?

    You have learned the less that every professional has learned.

    And every one of us remembers the day he learned the same lesson!
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