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Leaky fitting on riser

I discovered this morning that I have a leak in the fitting at the base of one of my risers when the system is at full pressure. Picture is here:


It's the 90 elbow in the foreground just above the main that's leaking (you can see a streak of rust underneath it from the water). I had a GC who replaced that riser a few years ago, but it would appear he didn't put enough pipe dope on the connection.

(Also, just in case anyone asks, that Gorton's #2 is not attached to the riser. It's an optical illusion. It's attached to the end of the main just behind the riser)

Anyway, two questions:
1) Is there any short term fix that could keep the leak at bay until the end of heating season?
2) What's the best way to fix this? My instinct is to cut the middle of the pipe with a sawzall or angle grinder, replace the pipe and fitting, and then put a union in there. But maybe I can just crack the elbow open instead of cutting the pipe? It's black pipe, though, not cast iron, so I have no idea if that's doable (having never cracked a fitting before).


    EBEBRATT-Ed Member Posts: 15,517
    How bad is it leaking? I am sure it can probably wait until summer. Pictures are deceiving it looks like a tight area but maybe not. Your going to need a union somewhere. I usually cut through the elbow partially with a grinder with a cutting disk (don't hit the threads) Then drive an old screwdriver in the slot made by the cutting disk to crack the elbow
  • MilanD
    MilanD Member Posts: 1,160
    edited January 2017
    Is that 1st or 2nd floor radiator? IF it's 1st, you can detach the radiator from the valve, then back-out the vertical riser, back out the horizontal riser, and you are where you need to be. This is, if there aren't swing joints in the floor, in which case you'll have to cut.

    If it's 2nd floor, then, the saws-all it will be for sure. Looks like 1-1/4 pipe, so I'm assuming it's to the 2nd floor. I had to redo a bunch of 50 year old 1-1/4 black iron gas lines over the Thanksgiving - a bunch had to be backed-up around 3 furnaces and meters in one of my 4-plex buildings - and I also rrepiped some 3 100 year old radiators with these same fittings, so, first hand experience here: don't use a grinder. Use a good saws-all blade. Grinder will make a dusty dirty mess that will stick to everything, including your eyeballs... Just strap the pipes on both sides of the cut so they don't sag on you and pinch the blade. I would cut the horizontal long pipe.

    You can try to find a left-hand right-hand coupling and a nipple instead of using the union, for a better fit. Nipples are usually 4 inch with a coupling, and then you use a regular pipe on the long run. See this link - nipple will show-up below when you click on the coupling:

    http://www.supplyhouse.com/sh/control/search/~SEARCH_STRING=left hand right hand coupling

    Short term, you may try - try, with some 2-part plumber epoxy, that thing that comes in a long tube, like plado or clay consistency, not a squeezable one. Just make sure you get one that's rated for 212F and over. Make a nice patch, work it in the fitting well and make it 1/4 inch thick. Then, wrap it with rubber tape (something like this http://www.acehardware.com/product/index.jsp?productId=32236216), and put a few clamps along the patch.

    We had an old-timer to something like this (plus a screw into a pin-hole leak on a horizontal 2.5 inch main to plug the hole). Held for years. Actually, pipe failed on a different spot some 4-5 years later, so we finally just replaced it.

    Best of luck! (I have a main by the boiler in a corroded state, and have already bought all the patching stuff described above waiting for it to not make it through the winter. I may be doing this soon too!)

  • MilanD
    MilanD Member Posts: 1,160
    Ed must have beat me to the comment. Didn't mean to contradict his grinder use. I personally use saws-all.

    You can also try hammering and cracking the out the cast iron fitting, on the far elbow. You would still have to replace the horizontal run. All of it being old, and one being a short nipple so close to the main, I'd cut - dead smack in the center of that long run...

    Make sure you have all the fittings and pipes in extras, including the ones around the one you are planning to replace (ask me how I came to this conclusion), or easy access to them for the 'stuff happens' scenarios.

    For wrenches, make sure they are big enough for the leverage and always, always use 2 wrenches: one on pipe, one on fitting. On old pipes, both vertical and horizontal, expect a possibility of egging them out, so make sure you have 3 points of contact with the pipe wrench before you start cranking on it.

    And, do get some pb blaster or kroil (I prefer kroil as it smells much nicer), penetrating oil of some sorts (and not DW40) to get on the threads before you start backing them out.
  • Sethamin
    Sethamin Member Posts: 58
    It sprays a bunch of steam in the air when the system is at full pressure, but I guess it could probably wait; it just makes the air a little wetter in the basement.

    That riser goes to the second floor (plus it has a swing arm), so no backing it out from the radiator. Nice thought, though. Gotta cut it out. But it's not a tight space - full height basement - so it's very doable.

    Feedback taken about the grinder. I'll use a sawzall instead.

    Not sure about using the left-hand right-hand coupling. I take your point that you can get it tighter, but a union makes it obvious to a future maintainer that there's an access point here. Isn't that a good reason to prefer a union?
  • MilanD
    MilanD Member Posts: 1,160
    After I wrote about left hand right hand, I now also think the union might be better. Left hand right hand will always give you access there, but it may also hold some water in the coupling itself, so it may do some hammering at startup, it being a horizontal pipe. Union is better. The only thing with unions is that they can come apart over time (with pipe expanding/contracting over and over), or seeze. I am, however, inclined to think, once your leak is fixed, you will never have to open that pipe again. Ever.

    Try the putty/wrap/clamp thing for the time being. It may fix it for a season, or even longer, and it will save time. You would be surprised how much fresh water you may be making up with one steam leak like that, and that's bad for the boiler. Definitely do something to stop the leak.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    If you make full pressure 3 ounces, the joint may stop leaking!
    Somewhere here is the description of a temporary fix, involving painting the joint with very salty water. rust then soon forms, and seals a small leak, as long as the pressure is LOW.--NBC
  • MilanD
    MilanD Member Posts: 1,160
    > @nicholas bonham-carter said:
    > If you make full pressure 3 ounces, the joint may stop leaking!
    > Somewhere here is the description of a temporary fix, involving painting the joint with very salty water. rust then soon forms, and seals a small leak, as long as the pressure is LOW.--NBC

    @nicholas bonham-carter

    I am curious what % of people here run on 3 oz?
  • Abracadabra
    Abracadabra Member Posts: 1,948
    salt water soaked rag. wrap the leak with the salt water soaked rag and check couple times a day to make sure it stays salty and wet.
  • bob_46
    bob_46 Member Posts: 813
    I've had some luck with lead wool and caulk it with a screwdriver.
    Solder if you don't have lead wool.
  • Sethamin
    Sethamin Member Posts: 58
    I doubt my pressure gets anywhere near 3 oz. I think cut-in is at 0.5 oz and cut-out is at 2 oz.
  • Danny Scully
    Danny Scully Member Posts: 1,424
    It probably cuts out at 2 pounds @sethamin, unless you have a Vaporstat. In any event, those are cast iron fittings. You can break both elbows and repipe with union. L/r nipple and coupling isn't a bad idea either, but a union is certainly easier to work with.
  • rick in Alaska
    rick in Alaska Member Posts: 1,457
    It looks to me like it is leaking out the side of the fitting and not the joint. There could be a pin hole in the casting. If it is, you can take an ordinary pencil and push the lead in to the hole, then tamp it in a little, and it will most likely seal up. If it is the threads, then try the trick Bob said with the lead wool. I have tested joints with 200 psi that held doing this.
  • Sethamin
    Sethamin Member Posts: 58
    I have a Honeywell Pressuretrol, and you are indeed correct that it's measured in PSI, not oz. My mistake.

    The lead wool sounds pretty interesting, but where do I even get it? I don't see it listed at any big box store, or even at supplyhouse.com. Would they carry it at a local plumbing supply house?
  • BobC
    BobC Member Posts: 5,477
    It's available but you have to buy 5# -


    A plumbing supply would probably have it but you still probably have to buy 5#.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge