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Professional needs professional advice. . .

BigRed Member Posts: 104


  • Keith_13
    Keith_13 Member Posts: 21
    Having real trouble with drilling out a stuck pipe plug. . .

    Alright this is with a somewhat sheepish tone that I ask, but. . . I stopped into a million dollar apartment in Manhattan this morning to do a 1-2-3 job of popping some pipe plugs out of some old steam ells in the floor, and install a new free standing radiator. I overprepared, bringing 12 point sockets, pipe wrenches, vise grips, penetrating oil - the works. I was able to get the half inch return plug out in about 4 seconds, but as soon as I put anything on the 3/4 supply plug, it started to strip and crumble on me. I worked at it for almost an hour, until the top of the plug looked about as perfectly round as 1/2 inch bar stock. Talk about frustrating. . . anyway, the building staff in this very exclusive co-op needed to turn the boilers back on, so I re-plugged the return side and left the supply plug in, with no progress made except the bad kind.
    I'm now left with a situation where I've got almost 600 dollars of material on the job with no payments because I couldn't make the steam connection, and I've got to formulate a way to get that plug out in less than an hour without damaging the ell underneath the floor - you can all imagine the headache that would cause in the middle of heating season. This is what I'm thinking:
    - Put a 3/4" hole saw bit on the plug head, drill a core out of it.
    - Take a fine jabsaw and try to cafer the thread.
    - Clean the threads with a 3/4 pipe tap.

    I mean, in favorable circumstances that should be okay, but I've really got to hustle with no chance of serious failure. And anything I do HAS to work once I've committed to it, because the steam eventually has to come back on within a reasonable amount of time. Anyway, if any of you have had to drill out a plug (which really isn't that common once you think about it) please give a little observation; otherwise I'm just going to have to do this blind.

    Thanks a bunch,

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  • John S.
    John S. Member Posts: 260
    sounds like a plan...

    Howvere, a hole saw would be to unpredictable for me, though. I'd make sure you're as dead center as possible and start with regular twist drills. Start small (1/8") and work your way up. Then make a cut perpendicular to the threads trying not to get into them. Finally, take a small chisel to start the piece towards the center. Once you get the thread seal 'cracked' along the cut line the rest should twist right out.

    I've been in a few harry situations like that as well and fortunately my experience and thorough thinking has done me well. I'm sure yours will too!

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  • Keith_13
    Keith_13 Member Posts: 21

    You're right about the twist bits. . . I just thought I'd cut some time out by going straight to the large size. . . it might be me acting silly again, but it just seemed to me like the plug was cast iron, just by the way it crumbled, and not malleable steel. What material bit should I use to attack CI?

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  • John S.
    John S. Member Posts: 260

    Cobalt HSS or Titanium Nitride bits. Make sure to bring lots of rags and to cool the bit with some cutting oil or water. (Don't let it get too hot.) Also, make sure not to drill at an extremely high RPM. Just take it slow as CI tends to grab bits quite violently. You'll get a feel for it once you start drilling.

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  • Mark_60
    Mark_60 Member Posts: 13

    Pour some iodine on the plug, yes iodine. Let that sit for a while. If you can score the head of the plug with a hacksaw and use the largest srewdriver you can find to pry the plug loose.
  • Mark Hunt
    Mark Hunt Member Posts: 4,909
    Iodine eh?

    Never heard that one.

    Curious as to what it does.

    Another trick to keep in the hat!

    Mark H

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  • m dewolfe
    m dewolfe Member Posts: 92

    Ok....Try this....file the plug as square as you can and then drill a 18..14....then a 38...Bring with you a selection of large torq bits. they use these in cars to hold down the seatbelt screws..bang this baby in until it is nice and tight and put you ratchet handel on. grab the plug and the ratchet and give er all you got. If this fails I would then use a unibit and drill the sucker out then clean up the threads......good luck...we have all been there
  • jim lockard
    jim lockard Member Posts: 1,059
    I was

    Thinking of a heat gun and a 3/8 rigid pipe extracter. My plan B Mark would be to have a round brass dowel rod and a file should you run out of time you can make a plug and pound it into the hole, so the boiler can run. Best Wishes J.Lockard
  • Anthony Menafro
    Anthony Menafro Member Posts: 197
    Oil on cast iron

    I think that you would be better off changing out bits and allowing them to cool rather than trying to oil to keep cool. I was always told(by machine shop techs) to never use oil on cast iron while drilling it.

    Anthony Menafro
  • Keith_11
    Keith_11 Member Posts: 25

    Ok, hold on just a second. . . you're telling me that you've poured iodine onto the plug threads and been able to simply pry the head off? Do you mean "pop the top" or loosen it up enough to turn it out? My final question is, and really what I've been meaning all along, is at what rate do twist bits cut into cast iron? Is it an impossibly long, tedious experience or does it proceed quickly (or at least noticibly)? Think of the depth of a plug with a solid bottom - it's at least an inch thick, not such a simple task with a power drill. I'm soaking it all in, though, guys, thanks for the advice. I'll attack this next week when the weather warms up just a tad.


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  • John S.
    John S. Member Posts: 260

    cuts pretty easy with a sharp bit. The first hole will be the worst. Make it easier after that by slowly stepping up drill sizes. Maybe by the 1/8"s.

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  • leo g_13
    leo g_13 Member Posts: 435
    Here's another ridiculous

    sounding idea. When I run into a stuck piece of pipe, etc. I try tightening the piece first. 9 out of ten times, this "breaks" the seal and away I go.

    Leo G

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  • Christian Egli_2
    Christian Egli_2 Member Posts: 812

    Can you simply (and I say "simply" with a big grin) remove the ell and change the whole thing? Could you even hack-saw into the pipe itself, rethread it and move on?

    What is the ell made of? Will it crack if you hammer on it? If you can hammer on it, you could expand it. Then the plug would get loose much easier.

    I am surprised the pipe wrench is not biting anymore. Maybe a brand new one with sharp jaws would work better. Maybe just a bigger one. Try, after all, your penetrating oil has been working overnight now, that will help a lot. If the stub is all tapered, you could file it back parallel for the jaws to bite fully.

    For the drilling idea

    Why not stop at drilling a small hole first and then use an extractor in that hole and "simply" unscrew with a big wrench.

    I'd stay away from the hole saw, they're only kind of good on sheet metal and extra large holes, but they don't drill to size. Take several ordinary drill (none carbon steel) When drilling cast iron, only the external crust that was in contact with the sand mold is destructive to drills, once you brake the skin, stop, resharpen the drill and go on, it will drill like a charm. Carbide tipped drills are perfect for this. Oiling while drilling sometimes can make the first bite difficult, there is nothing particularly wrong drilling cast iron dry. For tapping use lots of tallow, more is always better than a broken tap or a stripped thread, cleaning up afterwards is no big deal.

    For insurance, plan on taking whatever you might need to temporarily plug the hole, even just a sheet of rubber, some bailing wire and a weight might come in handy in a panic. Ooh, that really sounds like a professional repair!

    Good luck. You'll get it out.
  • Christian Egli_2
    Christian Egli_2 Member Posts: 812
    Sucked into a black hole

    Drill directly 1/4 or 3/8. Don't rev the drill full blast. The risk (not big) is if you get the HSS drill to turn gray-blue, just on the cutting edge, then it's too late, you lost the temper on the drill. You'll need to resharpen it until you remove all the turned-blue area. With tungsten carbide tip drill, there is no such risk.

    Hole saws, in particular, are very prone to this turning blue risk, that's why you can't get anything done with them unless you turn real real slow - like old vinyl record player slow.

    On starting the hole, because of the outer layer cast iron carbide skin crust that is very hard, push hard into the metal, with no hesitation. Letting the drill just turn without biting wears it out a lot.

    Then, as soon as the hole is started, stop pushing so hard, if fact it will go like butter. To drill through 1 inch, it should take what? a minute, two tops. If it takes longer, you need a sharpened drill. Thus, bring several drills of the same size.

    Back off from pushing on the drill when your drill is coming out the other side. The slower you exit, the nicer the hole will look.

    Practice first on an old fitting that you tighten in a wise, so you'll gain confidence. And remember, your plug seems to be very soft, it should be easy.
  • ChrisL
    ChrisL Member Posts: 121
    Make sure you don't break the drill bit

    One last thing....be extra careful not to break the drill bit while drilling. Nothing like a stuck hardened steel bit to contend with.

  • Tony_23
    Tony_23 Member Posts: 1,033
    Whatever method you try,

    RELAX. Being uptight and in a hurry ALWAYS causes trouble. Chances are, it won't take that long. How much steam pressure is present when fired up ? Maybe some of this process could be done "live" ?
  • Jim Bennett
    Jim Bennett Member Posts: 607
    stuck plug

    Unfortunately, plugs do that. You usually have about a 50/50 chance of turning them out. The longer they have been in there, the worse it is.

    But they can be drilled out!

    First thing remember, "Practice makes perfect" Take a few plugs and thread them into some old fittings and try drilling them out on a bench vice. Once you do it a few times and see what it takes, you will be more comfortable when you start on the critical one.

    I grind down the crumbled part of the plug and get a good flat surface to start with. Center punch (gently) and drill a pilot hole with a small bit. This will keep the larger bit from "wandering" off center.

    Wire brush the area around the plug to clean off and paint or old pipe dope so you get a good view of where the plugs stop and the ell begins. Have plenty off light.

    Once you have your center hole, use a hole saw slightly smaller than the plug, drill slowly, I never lubricate cast iron.

    Once it is cored, you can use a hacksaw to cut into the remains and remove with a small sharp chisel. Try not to cut into the threads, this can be a fine line and is another thing learned through practice. If you score the tops of the threads, you should be ok as long as you don't cut into the "root" of the thread.

    You should be able to accomplish this in an hour. I would also caution the customer that if this fails, the floor must be opened to complete this. Let them make the call.

    Good luck,

    Jim Bennett
  • Christian Egli_2
    Christian Egli_2 Member Posts: 812
    Nice hole saw job

    I admire your patience with the Hole Saw, Jim. Either I've never got the hang of them or I've never had a good one. We've long acquired a collection of large diameter twist drills with turned down shanks for use in hand drills.

    Good tips.
  • Ryan_10
    Ryan_10 Member Posts: 26
    I've done something...

    like this many times working with hardened steel when I was working at the family gravel operation. Everything around there got stuck, and putting a 3/4" hole through 1" thick hardened steel wasn't uncommon.

    Tap a little divor for a pilot, start with a good 1/4" bit in the center. go to 3/8" then 1/2". The smaller steps you take, the easier it is. Use a helper to spray cutting fluid. Kimball Midwest is great, but hard to find. WD40 will work. With a 1/2" hole, you should be able to get a Sawzall blade in. Get pretty close to the threads, then try to hammer away with a chisel.

    Good luck. I've got a similar 75 year old stuck plug to get out with almost no clearance to work.
  • bovide_6
    bovide_6 Member Posts: 25
    Use a shop vac

    while drilling, so you can't be blamed for metal shavings causing problems in the system. Any way you can post a picture?
  • Jim Bennett
    Jim Bennett Member Posts: 607
    Nice tip Christian,

    never tried using larger twist bits. I think I'll give it a try and see how that works.

    Jim Bennett
  • Terry_14
    Terry_14 Member Posts: 209
    expansion contraction

    What causes more thread leaks than heat to cold? I have had success with heat on plug then hit it with the stuff warts are removed with freeze the plug threads should contract rapidly then try easy out and large wrench.

    I huged my kid today Terry
  • Blackoakbob
    Blackoakbob Member Posts: 252
    I just did this a month .....

    ago, started with an 1/8, 1/4, 1/2 and then a 5/8 leaving a thin wall although abit off center. Then I used a hack saw blade and cut three notches at 1 o'clock, three and five, with a chisel and a hammer I drove the wedges up into the hole and the rest peeled out, no sweat. I ran a pipe chaser through and used some Permatex 51D thread sealer. It's great stuff for steam and oil but don't get it on anything you want to take home! Planning and patience, Keith. Best Regards.
  • bob young
    bob young Member Posts: 2,177

    51D is the bomb !!! permatex --- nothing comes even close. been using it since 1962
  • JackFre
    JackFre Member Posts: 225
    One more thing

    Take a magnet on an telescoping rod to clean out the shavings. I've had good luck with the PB Blaster on loosening stuck, rusted...stuff. Nothing seems to get it to stick like steam.
  • Keith_11
    Keith_11 Member Posts: 25

    Thanks a bunch, guys. . . Normally what I'd do is just open the floor and pull out the steam ell, but this is an exigent circumstance involving - oh horror of horrors - a CO-OP building, and I'm trying to just do what I've learned from living in the old neighborhood - just don't get involved. I'll attack this with a lot more confidence with all of your advice. Thanks again.

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