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"New Galvanized Pipe" leaks - Right Way?

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  • "New Galvanized Pipe" leaks - Right Way?

    I've been doing plumbing a little here and there for many years. But I have never asked how to do things "right".

    Since I have a lot of work to do with new galvanized pipe soon, I suppose it is time I learned...

    Every time I assemble a series of galvanized pipes with many joints, there is always one joint which will leak a little (say 1 joint out of 10). Tightening stops it. I mostly use Teflon tape.

    And I many times have leak problems with things like valves or "T's" where they need to be oriented a certain direction.

    Also I have a fear of tightening things too tight and breaking them (from experience, but never had this happen with galvanized pipe).

    So what is the correct way to do this. Do I need to clean the threads first (I have not been doing this). Maybe a bit of dirt is in a thread or something?

    Proper way to apply Teflon tape?

    And how tight is tight enough?

  • #2
    Re: "New Galvanized Pipe" leaks - Right Way?

    Are you going to be making your own cut and thread ends.


    • #3
      Re: "New Galvanized Pipe" leaks - Right Way?

      No. I have my pipes cut and threaded at the hardware store. BTW I will be working with mostly 1/2 and 3/4 galvanized.


      • #4
        Re: "New Galvanized Pipe" leaks - Right Way?

        If the machine they are using has an adjustable threading head they may not set it correctly.They need the taper on the pipe to match the fitting.Three loose,three tight,three left is a saying an old timer told me when I was starting out.This was with domestic fittings back in the day though.The imported pipe now is much softer and easy to tighten past the designed taper of the fitting.

        Three to four rotations of teflon tape in the same direction of the threads with pipe dope on the first few threads.

        Once a joint is complete don't let it move around ruining it's seat,use a backup wrench to keep it immobile.


        • #5
          Re: "New Galvanized Pipe" leaks - Right Way?

          Too tight is an individual term.

          I've had young strong kids grunting to tighten the larger sizes when I can get at least one more rotation.

          It is easy to over tighten.

          I can run 1/2-3/4 with channel locks and get the system to hold test pressure.I do not like to do this.A 10" wrench is a good size for 1/2,14"for 3/4.

          Feel the taper,if you go slow you can tell when you have gone past it.


          • #6
            Re: "New Galvanized Pipe" leaks - Right Way?

            10 wraps of teflon and than some good pipe dope on top that always does the trick
            Clark County Plumbing And Drain


            • #7
              Re: "New Galvanized Pipe" leaks - Right Way?

              problem with teflon is that you can't back it off, or it will leak.

              also the hardware store is not the best place to have your threads done.

              it would be better to buy a good set of hand dies, and do it yourself. the larger 12-r will do 1/8-2'' or the smaller oo-r will do 1/8-1''

              or you can really splurge and get a 600 electric hand threader for up to 1.25'' pipe.

              problem with a hardware store is that you typically don't get a professional doing the threading. too many variables with a threading machine.

              even cutting a key is sometimes hit or miss

              my very first part time job at 13 was working at a hardware store. my buddie still owns it and some of the guys know what they are doing and some don't.

              and yes, i have my own key machine, so i'm to blame if the key doesn't fit

              plus i needed to make a key for joey almost 4 years ago

              phoebe it is


              • #8
                Re: "New Galvanized Pipe" leaks - Right Way?

                The only time lately I have had to use excessive teflon is on a wannabe euro faucet that did not have a manufactured taper on the 1/2" female threads.


                • #9
                  Re: "New Galvanized Pipe" leaks - Right Way?

                  I would guess that you are having a deficiency in thread sealant. I was taught 6 to 8 wraps of teflon for metal threads. Never had a problem using that much teflon. Also I would use teflon and Keytite for threads near soldering joints. Never had a problem there either.
                  I think we are all wondering why you must use galvanized pipe though.


                  • #10
                    Re: "New Galvanized Pipe" leaks - Right Way?

                    I had a problem with proflo teflon tape, I found out I had to wrap it double the amount I would wrap with other tape.

                    you might be wrapping it the wrong way? maybe someone else pointed this out already.

                    I always use dope and teflon, unless I am instructed by manufacturer to only use teflon tape due to filters, etc. Nothing gets past keytite



                    • #11
                      Re: "New Galvanized Pipe" leaks - Right Way?

                      When using imported teflon tape, I always apply more wraps because it's a lot thinner than domestic tape.

                      When ever I re-stock, I usually specify domestic tape, not only because it's thicker, but also because the plastic reel is of better quality.

                      The import reel has a little barbed tail from the casting flash which tends to hook the tape and shred it while trying to wrap pipe.



                      • #12
                        Re: "New Galvanized Pipe" leaks - Right Way?

                        Originally posted by mtnman1100 View Post
                        ...I think we are all wondering why you must use galvanized pipe though.
                        Actually I am doing a bit of experimenting with reducing my electric hot water heating bill. I have this wonderful woodstove which puts out tons of heat, so...

                        I got the idea I could remove the covering and all the insulation from an old electric hot water heater. Then place this un-insulated tank next to my woodstove and the heat from the stove would heat the water.

                        The area next to my woodstove is rarely below 80 degrees F. and never gets above 115 degrees F. (I've read enough about steam and accidents to want to avoid any kind of piping directly attached to my woodstove or any piping inside the stove. These temperatures can reach 300/1000 degrees F. respectively.)

                        The water entering my home from the city is 40 degrees F.

                        I placed a tank next to my stove (painted black to absorb more heat) and after about 24 hours of heating, with the last few hours having a big fire (cold day), the water in the tank reached 96 degrees F. I had this piped directly to my hot water pipes (bypassing the electric hot water heater), and took a shower with just the hot valve open. The water was fairly warm and it even steamed up the mirror!

                        This test was more successful that I had planned on. Initially I thought I would just pre-heat the water, then let the electric hot water heater take it from there.

                        But now I have the idea to use two of these tanks next to my woodstove. I think there is water circulating inside the tank, and when cold water enters at the bottom, this circulation mixes with the warm/hot at the top. A two tank system would keep the cold water in the first tank.

                        The first tank would have cold water entering at the bottom, then a pipe running from the top of that tank to the bottom of the next tank, then warm/hot out the top of the 2nd tank. Then have the option to totally bypass the electric hot water heater with valves or route the water through it (days when not using woodstove).

                        Now needless to say, I will need a lot of valves to allow air to escape while filling the tanks, to flush the tanks, to drain either or both tanks, and to switch the water to go through the electric hot water heater or bypass it.

                        My experience with valves and copper pipe is that when a stubborn valve is turned too hard, the copper pipe connection breaks and water goes shooting everywhere! I have seen this happen too many times. With galvanized, you can crank the valve and the piping stays put!

                        Also I live in mild earthquake country (about 4.0 max) and the galvanized pipes will add a bit of structural support to the tanks. (I also am going to anchor the tanks like a regular water heater would be.)

                        Then I am not married and I think the galvanized pipes with unions, etc. coming out of the two tanks in my living room looks cool! (If I was married, the placing of these tanks in the living room would not be an option.)

                        Also there is the problem of corrosion when using dissimilar metals (copper/steel) and needing to use dielectric nipples.

                        Also I think galvanized pipes will retain the heat longer. A wood stove cycles from very hot to cooler then very hot again. I plan to route the warm/hot water piping upwards in the ceiling so the heat will travel upwards and keep the house hot water piping warm for a ways.

                        Note: I do have new T&P valves installed and am going to get new anode rods for both tanks. Plus I mounted a pressure guage on one tank.

                        For the summer, my attic gets to be very hot. I'm thinking of running large diameter *plastic* pipes in the attic to heat up the water and do this with a slow running solar powered circulation pump to circulate water to the insulated electric hot water heater.

                        Plastic because I will need to drain all the pipes in the winter to prevent freezing. Don't want them to rust. Maybe a small fiberglass uninsulated tank in the attic as well?

                        I looked at solar water heating systems and they wanted $6000.00, so my plan is a whole lot cheaper. I got one used tank for $5 and the 2nd for $30. Most of the galvanized fittings I am getting at a recycling center for 10 cents to a dollar. There are plenty of fittings as no one uses galvanized anymore.
                        Last edited by Billy_Bob; 04-04-2008, 09:28 AM.


                        • #13
                          Re: "New Galvanized Pipe" leaks - Right Way?

                          Originally posted by westcoastplumber View Post
                 might be wrapping it the wrong way? maybe someone else pointed this out already...
                          Teflon tape going on the correct direction.

                          My problem as I learned above was that I was doing "Three loose,three tight,one left" instead of "Three loose,three tight,three left".

                          Two more turns should do the trick!


                          • #14
                            Re: "New Galvanized Pipe" leaks - Right Way?

                            Billy Bob, need pics, lots of pics.
                            Buy cheap, buy twice.


                            • #15
                              Re: "New Galvanized Pipe" leaks - Right Way?

                              yep need pics of your Ambient water heater exchanger in YOUR LIVING ROOM. We all want to see that. BTW this might be the reason you are not married.

                              But seriously, you should seriously examine the safeties you should install on this type of home grown water heating. For instance, you should probably install an expansion tank and and air vent.
                              pics, pics, pics.
                              ANYONE CAN TAKE THE HELM WHEN THE SEA IS CALM.