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Boiler additive to repair wet return leak?

I have a small leak right at the joint of a 2.5" wet return pipe and a 2.5" tee on my single pipe system, and have tried a number of external strategies (silicone, putty, etc) to stop the flow of water- all of which have failed because of the constant, though tiny, flow of water.  I have not used any of the boiler additives that purport to plug leaks and would like some feedback from those who have about how well they tend to work and/or if they are problematic in any way.



Thanks so much in advance for the advice and feedback! This will echo the feedback of many others, but the folks on the wall have been so helpful in helping me get to know my system and that gratitude bears repeating.



David

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 22,916
    my inclination

    on this is...



    Don't do it!



    Most boilers don't take very kindly to additives in general, and a stop-leak additive is, in my opinion, asking for trouble (back when I was an automobile mechanic, I can't tell you how many radiators and heating cores I replaced for folks who had added stop leak...).



    It would be much better to figure out how to take the thing apart and replace the fittings...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • David_52
    David_52 Member Posts: 30
    edited October 2010
    More external remedies?

    Thanks, Jamie- I have tried silicone, putty, and even JB weld... any thoughts/ideas on other external strategies?  I can certainly take the thing apart, that's just a job I'm trying to avoid at the moment.  I had it apart this summer while replacing the boiler sections but unfortunately that joint didn't start leaking until a week ago or so... otherwise it would have been easy to replace at the time!!



    Also still definitely interested in what others have to say about those additives.
  • Dave in QCA
    Dave in QCA Member Posts: 1,785
    It won't work

    If you were to try to add a stop leak product to your boiler, it would have absolutely no effect to the leak you describe.  You state that the leak is in a  pipe where it connects into a tee in the wet return.  I assume that you are not describing the close boiler piping, but rather a tee and pipe somewhere in your wet return piping. 

    The reason that a stop leak product would have no effect is that dissolved substances, or substances in suspension in the boiler water to not leave with the steam.  When the steam leaves, it is pure water vapor, and when it condenses, it is essentially distilled water.  Treatment that you put in the boiler will stay in the boiler, with the exception of a steam line treatment, usually an amine, that is intended to keep the PH in the condensate alkaline, to reduce condensate line corrosion.

    If the leak is in the middle of the pipe, you can always try a piece of rubber and a stainless steel pipe clamp to hold it in place.  However, this is a band-aid, and I would recommend replacement of the leaking pipe ASAP.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • David_52
    David_52 Member Posts: 30
    It's near boiler

    Thanks Dave.  It's near boiler piping (that tee serves the hartford loop), and the leak isn't (unfortunately) in the middle of the pipe- it's a very tiny drip right at the joint of the pipe and the tee.  I know I need to replace it, just hoping to buy some time!  Sounds like the additives might work if it's near boiler piping, but I would still (of course) have the same concern about putting something in the boiler water.
  • Dave in QCA
    Dave in QCA Member Posts: 1,785
    metal epoxy

    There is a product that comes in a stick form.  It is a 2 part epozy type metal putty patch product.  You cut off the amount that you need, then knead it in the palm of your hand until mixed well.  You will have to follow the mfg instructions, the surface will have to be dry.  So, you will have to drain the boiler down a bit and wait for a while for the surfaces to dry up.   This might actually work since there is probably very little pressure on this leak. 

    I successfully used this on a radiator that I cracked.  I was removing a bogus air vent that had been installed on a 2-pipe radiator.  When I installed a 1/8" pipe plug, I over tightened it and cracked the radiator slightly.  It has been 2 years now, and the stuff is still holding.  However, I do have an atmospheric system that seldom has any pressure at all.  It held on a test run when I ran it up to 2 lbs.

    Hope this helps.

    D
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • David_52
    David_52 Member Posts: 30
    Thanks again Dave

    It does help and I'm always appreciative of how wonderful this resource is!
This discussion has been closed.