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  • #61
    Re: Pipe Dope

    from Peter Hemp, My plumbing mentor. 4 tight wraps of tape, then dope. He says He can back of 1/4 turn on gas ,and not have a leak!
    I can build anything You want , if you draw a picture of it , on the back of a big enough check .

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    • #62
      Re: Pipe Dope

      Originally posted by toolaholic View Post
      from Peter Hemp, My plumbing mentor. 4 tight wraps of tape, then dope. He says He can back of 1/4 turn on gas ,and not have a leak!
      Whats the gas pressure? I've made pipe dope before out of plumbers putty and oil........and plumbers putty and lead based house paint.Low pressure is only about 4-6 OUNCES typically. Or just paint alone......Try it. I'm not saying to put it in service but back in the day it was done alot with success.

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      • #63
        Re: Pipe Dope

        i can remember back in the late 60's the teflon tape dope came in a plastic case with a little tube of grease in the case that was used to lubricate the teflon tape when screwing the nipple into the fitting. it looked like silicone grease.

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        • #64
          Re: Pipe Dope

          Originally posted by TheMaster View Post
          What do you do that you cant use #5 on? Oxygen? ABS maybe? I call ABS trailer pipe
          Never...Ever...Use #5 on ABS

          I did 75+50 unit tracts of single family homes where Charlotte plastics was called out to identify why their cleanout tee threaded hubs were splitting away from the rest of the fitting.They knew what they were going to find before they even got onsight.
          This was production so everything was fabricated on the emtpy lots of the tract then installed ground works.Total time in the sun was 4 weeks or so.Thank goodness cause I'm still replacing tees on other tracts in my area that were built in the mid... 1980's

          Last edited by drtyhands; 12-18-2010, 08:11 AM. Reason: Hi

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          • #65
            Re: Pipe Dope

            Originally posted by drtyhands View Post
            Never...Ever...Use #5 on ABS

            I did 75+50 unit tracts of single family homes where Charlotte plastics was called out to identify why their cleanout tee threaded hubs were splitting away from the rest of the fitting.They knew what they were going to find before they even got onsight.
            This was production so everything was fabricated on the emtpy lots of the tract then installed ground works.Total time in the sun was 4 weeks or so.Thank goodness cause I'm still replacing tees on other tracts in my area that were built in the mid... 1980's
            I dont use ABS at all,I cant even buy it at a supply house unless i would have it ordered in. Its just not used here....its imported in by manufactured homes and the box stores.....

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            • #66
              Re: Pipe Dope

              I am another 3 wraps with blue monster tape and then megalocin same direction mostly for lubercation
              SMELLS LIKE $$$$$$ TO ME

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              • #67
                Re: Pipe Dope

                Truthfully, I don't think it makes much difference weather the dope goes on before, or after the tape. I always had a thought that the dope would work better on the outside, but I continue to put it on before the tape because it's less of a mess that way. Ive tested many tens of thousands of joints at 225-250 psi, and many more than that at 200 psi.

                We generally use a generic pipe dope since my company buys it in 55 gallon drums, but I much prefer an anaerobic pipe dope, such as Permalock. Unfortunately, the good stuff is pricy, so we don't get it much.

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                • #68
                  Re: Pipe Dope

                  There is only so much space between threads.......the rest is waste.

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                  • #69
                    Re: Pipe Dope

                    Originally posted by TheMaster View Post
                    There is only so much space between threads.......the rest is waste.
                    You got that right, I like to see a small ring of dope where the fitting and pipe come together once it is tightened, and I don't mean dripping off the fitting either. I have come to the conclusion that most are relying on the dope to make the seal instead of the intended mechanical binding (for lack of a better word) of the threads. The pipe dope should be basically used for lubrication purposes. I have gone behind other sprinkler fitters that the joint was so loose their unsupported arm overs would turn 1" pipe, but they did not have any leaks. Still poor quality install. With the very poor inconsistency of china made fittings it is hard to gauge a good set of threads using a fitting at the power machine.

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                    • #70
                      Re: Pipe Dope

                      Same as most of you here, tape, then dope. I can't see the tape actually staying on while tightening the pipe/fitting.
                      Ideal Plumbing

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                      • #71
                        Re: Pipe Dope

                        We install many boilers and its my helpers job to tape and dope every fitting. Only fittings that dont get tape are for oil or gas

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                        • #72
                          Re: Pipe Dope

                          Originally posted by biscuit View Post
                          Damn, I will take that as the biggest compliment this year.

                          You are right as I do care. I do not tell my Plumbing/HVAC guys how to do their jobs. Some of them have been doing this before I was born.

                          I just want to expand my knowledge to make myself a better engineer.

                          Trust me, Universities turn out many engineers who are dangerous/ very dangerous to society. I do not have the "GOD COMPLEX" that I see in some of my peers. I know many engineers who are very intelligent and go do many good things but have that complex that they know everything and just wont listen to anyone.

                          Not tooting my own horn, but as my father said and many others," THE DAY YOU THINK YOU KNOW IT ALL IS THE DAY YOU ARE OF NO USE TO ME ANYMORE". He was right about that. You never quit learning.

                          Regards and thanks for the answer to my question.
                          You asked a good question and the answer is.....You dont need both. Simple as that. Can both cover up a bad fitting/connection? Sure it can. Now is that a good thing or a bad thing?

                          How many connections are way overtightened because teflon and pipe dope was used? A crap load ...thats how many. How many of them are stressed to the point they crack later? Alot. Teflon tape and pipe dope prevents proper tightening in some cases...allowing the pipe joint to move during the assembly of other piping.....thats bad.

                          If you use pipe dope over teflon is should be very very little and dont expect the joint to get "tight". Basically you CAN end up with an over-tightened and loose at the same time connection. The female fitting will stretch in iron screw pipe.
                          Last edited by TheMaster; 12-21-2010, 03:16 PM.

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                          • #73
                            Re: Pipe Dope

                            I have always used two to three wraps of tape and a little dope. A little dope never hurt anyone, just don't use a lot of dope at work.

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                            • #74
                              Re: Pipe Dope

                              I first saw both tape and dope being used by a sprinkler fitter that was installing a fire suppression line in a building with a 15 or 20 foot ceiling. I'm sure he did not want any leaks once the system was pressurized!! ( Does any one know if unions are allowed in those installations? I do not recall ever seeing any unions up in the air.

                              Does anyone know if any pipe dope is sold in the 5lb. (or is it 7lb.?) cans like they used to years ago?? Sure was more convenient that the quarts they sell today. We never can seem to use all of the dope before the brush breaks or the dope drys out.

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                              • #75
                                Re: Pipe Dope

                                Originally posted by APHCO View Post
                                I first saw both tape and dope being used by a sprinkler fitter that was installing a fire suppression line in a building with a 15 or 20 foot ceiling. I'm sure he did not want any leaks once the system was pressurized!! ( Does any one know if unions are allowed in those installations? I do not recall ever seeing any unions up in the air.

                                Does anyone know if any pipe dope is sold in the 5lb. (or is it 7lb.?) cans like they used to years ago?? Sure was more convenient that the quarts they sell today. We never can seem to use all of the dope before the brush breaks or the dope drys out.

                                Yep, unions are allowed for sprinkler work in those situations. Sometimes we may use a grooved coupling rather than a union. As to the bigger cans, I'm not sure. I seem to remember my dad getting pipe dope in gallon size cans, but I cant be sure.

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