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The best pipe dope.

REX Member Posts: 29
Potable water:Teflon tape,Megaloc.

Non potable water supplys:Blue Block

Natural Gas: 1/2 - 2" Blue Block,2 1/2 - 4" X-PANDO.

Steam: 1 - 2" Blue Block,2 1/2 - 6" X-PANDO.

Hot water heating:Blue Block.

PVC: NPS adaptors Blue Block, C.O. Teflon tape and dab Megaloc.

Other than pvc c.o. I do not use teflon on anyother joint.

So then,all i have on my truck : megaloc,blue block,xpando. What do you use?


  • Interesting summation,,,,

    Do I have to ask??, but I will,, which company do you represent?  ;-)
  • Ross_7
    Ross_7 Member Posts: 577

    I can't stand Megaloc. I don't think it performs as well as other pipe dopes. It's all about preference
  • Jim Bennett
    Jim Bennett Member Posts: 607
    Rectorseal 5....

    been using it for 30 years.
    Jim Bennett
  • MikeyB
    MikeyB Member Posts: 696
    Pipe Dope

    I like Real-Tuff by Hercules, easy to use, & clean
  • digger_2
    digger_2 Member Posts: 39
    Rectorseal 5

    I'm with Jim Bennett, Rectorseal 5 for steam and hot water since it bailed me out of a tough situation 20 yrs ago. The contractor I have been working for the last 5 yrs rolls his eyes when I ask for it. He's a Slik Tite guy. He thinks leaks are normal though. Teflon on steam is not allowed in the pharma and nutritional facility we work in. Engineering firm says offgassing at initial start up is toxic.
  • Ross_7
    Ross_7 Member Posts: 577
    Rectorseal #5

    Yes,  I agree I also like Rectorseal #5.

    I have been also using Tru-Blu by Rectorseal.
  • clammy
    clammy Member Posts: 3,111
    whitlams blue magic

    i have used most of the pipe dopes that are listed and about 7 years ago i had some black pipe delivered to a job it looked as though it had been pulled out of the hudson river very dirty ,well we leaned and flushed it all and did use it ,when i went to the supply house i busted there balls about the pipe to shut me up they gave me the whole display of whitlam products ,there where telpon based stuff and then there was this dope alled blue magic ,it 's rated for oil ,natural gas ,refregerants and steam ,it seems i use it for just about every thing and don't have leaks easy cleaning also now it's the only dope besides myself in the truck peae and good luck clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
  • REX
    REX Member Posts: 29
    pipe dope

    Cool,seams everyone has a fav.I used all of the dopes mentioned,its just that after 18 years of mechanical work I have gone full circle. I started being taught pride in workmanship...where nps joints should be as clean as solder joints. As time went by i realised being self employed  its all about speed  performance rather than perfect joints. Nontheless I believe I have found two sealents that make perfact IPS joints,both visually and in performance with little effort. Blue Block along with xpando go on verry smooth and get hard,i really like xpando,though i must say the fact the the joint cant or is verry difficult to remove is a issue. Funny its a bit of a connundrum,to leave a joint where the next guy will be up shitz creak,though you will deff not have leaks. I had a run in with a 1" nps nip on natural gas pipe with xpando on it,i had to use a 3' wrench with a 3' perswader on it to brake it...bent the nip to "SNAP" it loose.Spent an extra hour that I had not figured in the job,could have been worse and cost me more.With this fact in mind I reserve the xpando for joints above 2".My logic is larger pipe i not usually relocated as much,as far a steam goes,my experence with old  headers 2 1/2 and beond do not unscrew...regardless of the dope involved,i usually have to salzal the pipe and make reliefe cut and pean out the piece.  I like the fact you can apply it to the first 5-6 threads and as you tighten it pushes the extra dope foward creating a tuff leak proof and visually pleasing bead on the face of the fitting. The remaning 2-3 threads are clean and un touched. I believe there are other dopes that have the consistancy and setting  I like I havent tried yet,im sure thay work well. My bigest issue with teflon dopes and others that have that thick consisentency is that you cant get the finished joint im lookinf for,thay just dont flow.
  • REX
    REX Member Posts: 29
    edited January 2010

    Im sure all of you have tryed it...atleast once. I always thought it was a relic for back in the ol days that just stuck around for old farts...i was wrong. The consistancy of pro dope is what im lookin for,it just dosent set like i want. I always had leaks when i used it alone. Well all i can say is,if you have factory pipe/joints  or know how to adjust your dies..and use american pipe and fittings,you wont have a leak...no wick or teflon needed. Unfortunately in the real world pipe and fittings along with threading knolledge is lacking,ergo you have the need for teflon and pipe dope or these dopes that make caveman joints so you can pack the shitz out of it in hopes it wont leak. 
  • REX
    REX Member Posts: 29
    edited January 2010
    pipe dope

    A bit of knowledge,a lot of guys fight about dope....does it lube....or does it seal! The answer is first seal,and yes it does make it easier to make-up. The confusion started because some threaded joints seal them self,the joints we are all used to using dont.

    NPS: needs dope to seal creast and root of thread.

    NPSF: root and thread cut at exact tollerence and mesh deforming them selfs together to make a mechanicaly sealed joint.
  • malp
    malp Member Posts: 27
    high temp rtv

    I couldn't get a radiator air vent to screw in. The threads were stripped. I put a glob of RTV on the vent threads and stuck the vent straight into the stripped hole. No leaks.
  • Supply House Rick
    Supply House Rick Member Posts: 1,404
    This guy must have

    Invented Blue Block or works for Blue Block or is married to someone who works for Blue Block... hahaha
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,322
    I use Pro dope

    It works and I like it. Teflon for brass or copper threads. Some time the "old farts" actually know what they are doing. K.I.S.S.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • KBP&H_3
    KBP&H_3 Member Posts: 67
    These young kids.

    Not even one vote for old dope and wicking ( string like substance) us old timers started with,,, and I'm only fifty.    Worked for years and never leaked,, Of course, we didn't have all of the inferior fittings and pipe taper we have today,,, How many different nipple threads have you seen in the past 6-7 years, and the european straight thread?....
  • Ron Jr._3
    Ron Jr._3 Member Posts: 603

    In conjuction with Teflon is what I've used for the longest time . Just a few wraps on the first threads , then paint the good ol' yellow over the Teflon , and you have a nice clean joint that can be taken apart with relative ease ........ even after decades . Anything over 1 1/4 inch we paint the sealant on the inner threads too . Out of the 4 or 5 different brands we use , Recorseal spreads the easiest when cold also .  

    Our supplier doesn't stock Rectorseal anymore so we switched to Pro Dope . I like it , but it's harder to spread when cold , and when it sets it's a **** to loosen or tighten more . Haven't had a leak using Pro Dope for the year or so we switched . Largest fittings are 2 inch steam .  
  • malp
    malp Member Posts: 27

    Will reactor seal #5 cause surging in a steam boiler? Oil based pipe dopes are discouraged for closed-loop steam, but since reactor seal is semi-hardening, I wasn't sure if that applied. Thanks
  • Timco
    Timco Member Posts: 3,040
    the straight dope

    I use 'Slick Tite' dope, a white thick paste that works well I find. As for tape, I like the new 'Blue Monster'. comes up to 1.5" wide and 3/4" wide...

    Just a guy running some pipes.
  • Ron Jr._3
    Ron Jr._3 Member Posts: 603
    A good skim and purge

    will get rid of all the excess Rectorseal easily . More easily than the harder setting sealants , imho . That stuff just oozes off the outer joints when the steam first hits it . On the inside I'll bet it doesn't have a chance to adhere to anything and is easily dumped out of the boiler while cleaning . And regardless of what brand sealant you use , every steam boiler will need a thorough cleaning when it's put on line or if there's repairs done to the piping . I'll have to say we had leaks using Rectorseal on steam joints above 2 1/2 inches though  . It might just be too soft a setting sealant for the larger sizes ........... 
  • Big Ed_4
    Big Ed_4 Member Posts: 2,785
    Pass the Dope my Friend

    I use Pro dope and lamp wick (quick wick ) and only apply on the male threads . Teflon tape I only use now a days for packing (since I cant find the wax graphite any more ) ...Old fashion I know but I just hate leaks ...
    I have enough experience to know , that I dont know it all
  • Kal Row
    Kal Row Member Posts: 1,520
    love blueBlock but..

    better have acetone and paper towles handy

    - every time i use it i get it all over the place - i think i got some on the moon ;)

    - even though i try to just put a bead on the male fitting only 2 threads away from the end - which always gives me a good seal

    - it's just hard to judge if it will or wont drip and if it drips...LOL... and the soap and water they recomend simply doesnt work
  • heatguy
    heatguy Member Posts: 102
    best dope

    rectorseal  # 5  with teflon - leak lock on anything that maybe trouble .its the original blue ,blu block came out when leak-loc plant burned, if you can afford it its the best
  • Whitlam blu magic

    is my favorite flavor of dope right now. We used to use No 5 and teflon tape when we did a lot of propane work and a factory guy from algas turned me on to PLS-2 it was lead based and didnt dry in the threads-amazing stuff-then they reformulated it and took the lead out BOO. I also like gasoila.
  • chazbo
    chazbo Member Posts: 1
    boiler tech.

    How many of you guys are having problems with black pipes leaking ?  What do you use for pipe dope? Years ago the company I worked for used Blue Block and had good results. Is there any thing else that works as well that isn't as messy?
  • jonny88
    jonny88 Member Posts: 1,139
    pro dope

    teflon and pro dope.on gas only pro dope=no problems.me and bluebloc dont get on to well,i get more on myself than the pipe...good thread
  • Rich_49
    Rich_49 Member Posts: 2,766

    Dope isn't messy my friend , installers are .  Some very interesting comments from years past on this thread . I do not work for any supplier or manufacturer and am an installer like all here.  If leaks and neatness are what count and money is not an issue or your main concern you should be using an anaroebic sealant like  Permabond LH050 . In the hands of a mechanic it is a fine tool. Hey , even the gas company guys who only know meter sets and hookups don't get leaks with it , there's a reason the gas companies use it .  It is also easier to remove later if necessary
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
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