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Stubborn Plug at End of Main

I'm trying to remove the plug at the end of one of my mains to install a main vent. I could use some pointers!

I have a weenie 12" pipe wrench and I can't budge it. I'm afraid to go too nuts with a cheater bar because I'm afraid I might crack the Tee that it screws into. Being heating season, I'd rather not screw this up!

I've been putting drops of Kroil on the threads every day but still no luck. Any thoughts?


  • Gary SmithGary Smith Member Posts: 336
    Try tightening it just a little first, then loosen. Sometimes that breaks it free.
  • AdmiralYodaAdmiralYoda Member Posts: 109

    Try tightening it just a little first, then loosen. Sometimes that breaks it free.

    That's a good one, I'll have to try that. I was also thinking of busting out a Butane Torch and heating the heck out of it if all else fails.

    I'll probably wait for a warm spell to try this in the event I break the Tee.
  • ethicalpaulethicalpaul Member Posts: 2,061
    edited November 17
    How big is the pipe? A 12" wrench wouldn't stand a chance of busting loose any of my pipes bigger than 3/4".

    I used an 18" or 24" wrench with a 3-4 foot cheater pipe on it to break loose my 2" main pipes.

    I've done a lot of them including a whole bunch of fittings that I reused when I installed my boiler and I never had a fitting break.

    I have had nipples (pipes) get ovalized, but that's it. I was replacing them anyway. The fittings were bulletproof.

    Just be sure you support your main pipe. In my case, I cut a 2x6 to fit between the floor and the fitting, then use my cheater to rotate toward the floor so the 2x6 takes the load instead of the main pipes.

    If geometry mandates you are lifting instead of pulling (or in your case, pushing sideways), you can put a similar brace against the ceiling joists probably.
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
  • AdmiralYodaAdmiralYoda Member Posts: 109
    Yeah.....its a 2" (or maybe 2.5") main, I forget. So my 5" Vice Grips won't work either??? lol.

    Its pretty close to the ceiling and I'll be pushing sideways, I'll have to figure out someway to brace it. With my 12" pipewrench I got more movement in the pipe than I would have liked.

    I'll try and take a picture for the fun of it this evening.
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 7,538
    Your going to need 2 2' wrenches and a couple of cheaters. Kroil oil and heat are good the other trick is to take a hammer and wack the plug a few times.....more like a heavy tap.

    Plugs are cast iron so they can't be cut with a cutting torch. They can be cut out with a sawzall and a cold chisel but that is time consuming and a bit of work
  • motoguy128motoguy128 Member Posts: 227
    I’d tighten first as mentioned. 24” wrench is a given. When that fails, then you drill out the venter big enough to get a sawzall blade into it and cut maybe 4 slots just short of the threads. They put the wrench back on it and tighten then loosen. the gaps created in the plug should snap and collapse and the now smaller diameter will spin right out. Got a 1-1/2” bushing out of a 115yo radiator that way recently. Took maybe 15 minutes. Was a waste of effort using a 3’ wrench
  • kcoppkcopp Member Posts: 3,551
    If it were me I wouldnt even try the wrench on an old steam fitting. They have been on there years and are all but welded into the fitting.
    A good sawzall, a Diablo cast iron blade and a cold chisel is what I would use. Cut off the square plug and slice carefully into the plug . whack out the sections.
  • AdmiralYodaAdmiralYoda Member Posts: 109
    I'm getting less and less motivated to tackle this lol.  Anyone want to make a couple bucks?
  • STEAM DOCTORSTEAM DOCTOR Member Posts: 1,249
    Try hitting plug with a hammer. Or better yet, put wrench on plug and hit end of wrench with 5 pound sledge hammer ( or whatever size you have handy and is manageable). The impact can sometimes break the tension. Try both clockwise and counterclockwise. 
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 7,538
    where are you located. Try "find a contractor" on this site
  • AdmiralYodaAdmiralYoda Member Posts: 109
    @AdmiralYoda where are you located. Try "find a contractor" on this site

    I'm in central MA.  New England Steam Works does my maintenance and they are an awesome company.

    They are an hour plus away and I think this may be too small a job for them.

    What makes this tough is the plug is in a corner right next to some plumbing, so a saw won't have enough room to get in there.

    It's basically a pipe wrench and some Kroil type of job.

  • AdmiralYodaAdmiralYoda Member Posts: 109

    So here is the enemy.  As you can see, it's too close to a wastewater pipe to get a saw on it.  I've been soaking it with Kroil twice a day and plan to try and loosen it this weekend.

    I'm going to buy a big 1.25" wrench for the square end and try whacking the wrench with a hammer to see if some impact will help loosen it.

    I definitely don't think the plug is original to the house (1900) as there was some dried white junk on the threads next to the Tee.  Probably old pipe dope.  Someone probably removed a main and plugged it up.
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 7,538
    You could drill and tap a few hole to put vents on instead of struggling with that plug.
  • AdmiralYodaAdmiralYoda Member Posts: 109
    You could drill and tap a few hole to put vents on instead of struggling with that plug.
    That's the back up option.  If I feel like I'm going to break the Tee, I'll stop and give that a shot.  Is it hard to tap a 1/2" hole in a 2" pipe?  Never tapped a pipe before.
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 7,538
    I wouldn't tap a hole that big. Tap at least (2) 1/4"npt holes and if you vents have 1/2" connections put short 1/4 " nipples in and then put an increaser on to get you up to 1/2".

    It wont be perfect but you will have more venting than you have now. You can deal with the tee next summer
  • Larry WeingartenLarry Weingarten Member Posts: 1,951
    Hi, If you can get two 24" pipe wrenches, I'd put one on the plug and one on the pipe. Then use a lever between the ends of the two wrenches. Things will want to slip out doing this, but done carefully, it's a good way to get it to begin moving. Also, a mapp torch on the fitting couldn't hurt, unless you catch the insulation or other things on fire! o:)

    Yours, Larry
  • AdmiralYodaAdmiralYoda Member Posts: 109
    Thanks guys!  I've been soaking it in Kroil 1 or 2 times a day and just ordered a 1-5/16" wrench off of Amazon.

    I'm gonna put the wrench on and give it a couple good whacks with a small sledge.

    If that don't work I'll break out the blue wrench and try again.
  • dabrakemandabrakeman Member Posts: 154
    Might want to reference my post from last year when I moved my mains. Nearly identical situation with the stubborn plug. 18" wrench with 4' cheater and penetrating fluid for days no go. Hammering on 12" wrench to shock, no go. Tightening, no go. Torch, no go. Ended up plug was cut off and hole drilled through to get sawzall blade in. Made 6 radial cuts short of threads knocked out some sections and then it busted loose.
    Must say I deferred to a plumber to do the cutting though, although I would have attempted with better access. The 3ft crawl area wasn't agreeing with my back. Worked out nice in the end though.
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 7,538
    Sometimes a drill and a sawzall are what is needed. Big wrenches and cheater pipes are fine too.

    Both methods have there own risks, depends on access and a a few other things

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