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Large adjustble Monkey or Spanner wrench for boiler and pipe fittings?

BinnacleBinnacle Member Posts: 126
Planning to remove the two-inch boiler port plug and install a skimmer valve at the end of this season and I'm not fond of adding teeth marks to the plug or to any more of the radiator valve nuts.

So the thought is to add a large adjustable wrench to  use as an alternative to the 18-inch Stillson wherever possible.  Have a four-foot cheater pipe that works well.

Which is better, a 24-inch spanner wrench or a 14-inch-plus monkey wrench?  Or would it make sense to purchase a vintage monkey wrench on eBay?  Brand recommendations welcome.

Or is it possible and better to obtain a few huge fixed size wrenches at reasonable cost?

Searched HH but didn't seen any threads on this.

Also, if there is any reason why Hercules Blue Block is the wrong type of dope to use for a nipple-to-boiler attachment please advise.


  • SWEISWEI Member Posts: 7,356
    Big hex

    wrenches can get expensive fast. are tough to beat for large diameter lower torque stuff.  Really useful, always keep it handy.

    I'm not generally a fan of the tools Harbor Freight sells, but I've had a set of these for about ten years now and they're still in one piece for higher torque stuff.
  • Steamfitter66Steamfitter66 Member Posts: 117
    ditto on the Ridgid

    Everybody should have a 110.
  • BinnacleBinnacle Member Posts: 126

    Thank You!
  • ChrisJChrisJ Member Posts: 8,601
    edited December 2013

    Just offering yet another option.  I went with a Ridgid 31400 spud wrench.  I use this along with a 3lb deadblow hammer to remove radiators.  I can see both this and the 110 being handy depending on where you're trying to squeeze in.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment

    Steam system pictures
    Central air project pictures
  • BinnacleBinnacle Member Posts: 126

    Looks good!  Seems to match the design of a Monkey wrentch, though the Wikipedia article makes no mention of "Spud" as an alternate designation.

    Tough to decide, I may end up with one of everything :-)
  • Harbor freight

    I would measure the flats on the plug and get a big socket set, with one which fits. Apply kroil liberally, and use a hammer to tap the breaker bar as you exert force with the cheater pipe. They will also have open end wrenches for a low price. These tools are of a quality and a price for limited use in these extreme situations, such as yours.

    There was also a candle/paraffin wax method detailed somewhere here which is said to lubricate the threads before the big twist.--NBC
  • BinnacleBinnacle Member Posts: 126

    I can see how, especially for a large boiler plug that's been there for 50 years (installed in early 1960s), an exact size wrench is the lowest-risk approach.  The prices on  Harbor freight are so good I now see myself purchasing big fixed-size wrenches along with the Ridgid hex and square adjustables.

    Also will take the advice to use penetrating oil or paraffin on the target.  For sure don't want to end up replacing the boiler over a plug-removal disaster.

    Many Thanks!
  • M LaneM Lane Member Posts: 123
    Old Trick

    Kind of related to this subject: always wrench an old jammed fitting towards the tighten direction first. It makes breaking the joint apart much easier. Just enough to get movement and break the thread deposits.
  • ChrisJChrisJ Member Posts: 8,601
    Ridgid vs Pittsburge

    I have one or two Ridgid wrenches and then quite a few Pittsburgh ones from harbor freight. My two 4 foot wrenches are Pittsburgh.

    The reason is I'm a homeowner who needs to do some work occasionally and if treated properly and used once in a while the Pittsburgh ones work great. However my non-professional opinion is the Pittsburgh ones will not take abuse like the Ridgid ones. I would never consider putting a pipe on a Pittsburgh wrench for more leverage where I feel a Ridgid would have no problem with a pipe on the handle. I also believe the Ridgid have better jaws.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment

    Steam system pictures
    Central air project pictures
  • nicholas bonham-carternicholas bonham-carter Member Posts: 6,535
    edited December 2013
    Clearance problems

    I think you will be better served by the socket set, as the sheet metal of the boiler jacket may not give you any room to use the standard Ridgid pipe wrench. The socket will be able to reach through the jacket and get a grip. The secret is constant torque with the cheater on the socket breaker bar at first, with constant tapping to give peaks to the torque.

    The tightening up first is a very good idea, as I have found, so thanks for that reminder.

    Off the topic slightly, but in this vein would be the necessity of turning backwards any screw you are trying to install-especially wood screws. Stripping the threads in a door jamb could be a real downer, but with a little dish washing liquid, and a turn in reverse to feel the seating of the threads makes it follow the old threads, rather than distorting the old ones.--NBC
  • BinnacleBinnacle Member Posts: 126

    Thank you everyone for the excellent advice!

    Not much sheet metal offset where the plug is, but due to the extravagant cost of failure I'll remove the sheet metal housing if it seems even slightly in the way.  Think I'll be ready with both type of wrenches and see what feels best at the time.

    This is a project for a relaxing, warm spring afternoon with the basement doors open and a calm state of mind.  No pressure and no rush.

    Seems odd that a skim port was not installed with the boiler, but whatever oil was in there appears to be long gone and so the port is just a nicety.
  • The last few days of winter

    Do this while the boiler is hot, and turned off.--NBC
  • BinnacleBinnacle Member Posts: 126


    Might still do it in spring, but I'll be sure to run the boiler up to steam temperature and let it cool 15 or 20 minutes before going at the tap plug.  Will put penetrating oil in the threads the day before.
  • JackJack Member Posts: 936
    While I haven't used them on big stuff

    as long as we are talking about cold and useful tools I have to put this up.

    I have the 6 & 9" versions and cannot believe how well they work. Good tools aren't cheap, but once you start with these you will not believe the quality & value.
  • Great quality tools

    I would not do any hammering on these, but they are the best pliers!!--NBC
  • SWEISWEI Member Posts: 7,356
    Knipex rocks

    Bought my first pair about 12 years ago and still using them almost daily.  Everything I have from them so far has become my go-to choice in its category.
  • icesailoricesailor Member Posts: 7,265
    Pipe Wrenches:

    I have both cast steel pipe wrenches and aluminum ones. All up to 40 years old. Both Rigid and what Harbor Freight sold when they were Harbor Freight in Los Angeles in the 1970's. Except for weight and cost, they are all equal. I have a set of "Super Ego" Aluminum wrenches (10", 14", 18", 24" and 36") from HF and they have never broken. I've used cheater bars on all of them and never broken any of them. I also have a mixture of Rigid Aluminums.

    You can rent wrenches from tool rental places. Get a 36" wrench. 24" wrenches work but you will need a cheater bar if it is tight. Be careful you don't flip the boiler over when you crank on it. You really need two wrenches for any application.
  • BinnacleBinnacle Member Posts: 126

    Never crossed my mind that I could budge the boiler!  Thank you for this advice.

    With the headers attached it wouldn't flip, but I suppose I could inadvertently slide it (no floor bolts) and stress various fittings despite the 800 lbs weight of the 1961 Weil McLain E-9  (150lbs heavier than a modern EG-65 equivalent).  I'll be wary of this possibility.

    I suppose this is where judicious whacking with my heavy rubber mallet come into play.  Just enough force impulse to crack the threads lose without shifting anything.
  • BinnacleBinnacle Member Posts: 126
    tools are great, but maybe the skim plug should stay

    So far I've purchased the Rigid 110 hex and spud wrenches.  These are super tools and I found them immediately useful when installing a union between the pressure relief nipple and valve.  Many thanks!

    The relief port union gives me access to the boiler for adding Rectorseal Steamaster tablets to excellent effect.  I was also considering a TSP cleaning using the relief port for adding TSP solution and lowering in a lab thermometer, but was dissuaded on another thread regarding the hazard this poses to old boilers.

    Now I'm wondering if I should just forget the idea of removing the skim port tapping plug.  The reason is that the skim tapping is in the middle of a bolted-on cover plate rather than in the cast-iron wall of the boiler itself.  It occurs to me that torquing that plug could stress the plate and break the seal between the plate and the boiler--potentially a disaster.

    Also a suggestion from the other thread is that a safe way to go is to skim through the relief valve by adding U-turn fittings.  The relief valve exits from the top rather then the side of the boiler so it's not ideal, but seems better than wrecking the boiler.

    Happy to hear everyone's thoughts on this.
  • BinnacleBinnacle Member Posts: 126
    On the other hand

    The bolts on the cover plate appear to be brand-new.  This most likely means that the plate had already leaked sometime in the recent past and so was removed and reinstalled with a new gasket or cement and bolts.  So even if the seal broke it seems the probability of a bolt breaking on a new repair would be minor.
  • ChrisJChrisJ Member Posts: 8,601
    If it were mine

    Keep in mind as you know if it does get damaged you will have a huge problem on your hands.

    But if it was mine, I'd put the spud wrench on it and try pounding on it with a 3lb dead blow hammer to see if it starts to turn. Try to hit the wrench as far out on the handle as possible with the handle horizontal. That plug looks like it's in almost the perfect position for this. The shock breaks things loose more often than not. I changed a fill valve and pressure release on my neighbors 80 year old boiler.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment

    Steam system pictures
    Central air project pictures
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