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Plumbing copper pipe

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  • Plumbing copper pipe


    I have three questions.

    1. How pure is copper pipes that are used for household plumbing?

    2. can they be annealed to that it can easily be bent?

    3. I purchased 1/4" flexible plumbing copper tube thinking that I could use it as goose neck (flexible link), but to my surprise, after bending it few times it got very stiff. Would this be similar to work hardening?



    P.S. Just got back from my vacation and the whole time I was thinking about all the projects that I had lined up and added few's a sweet feeling being back in the workshop.

  • #2
    I do not know the actual purity of copper pipe, except that it is probably "commercially" pure whatever that means.
    It can be annealed by heating to red heat and allowing to cool.
    Yes that is exactly what work hardening is. If you want a gooseneck, and it must be copper, take a long piece of annealed tubing, and wrap it around a mandrel two or three times. It will take some flexing this way.
    Jim H.


    • #3

      The attached website may provide some interesting info and might answer some of your questions about copper.

      It's been a long time since I studied metalurgy, but except for possible trace elements that might be included to impart certain mechanical qualities, I believe that you can consider copper plumbing pipe to be "pure copper". It comes in a variety of forms. Annealed (soft) and hard are two of them. I think "half hard" is also available, but not being a plumber, I couldn't tell you what each is most commonly used for.

      I see that you discovered one of copper's interesting abilities. It "work hardens" if you bend it. You can get away with "minor" mistakes, but if you bend it wrong......better plan on scrapping that piece and try another.

      I think that most long runs are made with the hard types. Someone will have to check me on that. As far as bending, the soft "flexible" tubing that you used is usually the "soft" variety.

      Hope this helps some. I'm sure there will be other help soon.



      • #4
        The table of copper alloys in Machinery's Handbook shows three alloys used for plumbing pipe and tubing. C10800 is described as low phosphorus, oxygen free. 99.95% Cu, 0.009% P. C12200 and C12210 are phophorus deoxidized, high residual phosphorus. 99.90% Cu, 0.02% P. There may be others, but I quit after I found the first three.

        [This message has been edited by Uncle Dunc (edited 05-08-2002).]

        [This message has been edited by Uncle Dunc (edited 05-09-2002).]


        • #5
          soft copper work hardens from the first time its bent. Copper wire (and Al also) are susceptable to work hardening- doesnt have to be tubing. Try to avoid letting someone unwrap your tube to measure it and then re wrap it. That next bend will be stiff.

          I think most know ferrous metals tend to work harden too. A rail (from the rail road) is hard to grind after its been in service a few years.


          • #6
            albert/jc....something sticks in my mind that work hardened brass is annealed by heating & PLUNGING in h2o ( reverse of steel ) ,repaired musical instruments for a year or so ,back in 1950's....could easily have forgotten ...long time ago ,but taking dents out of brass instruments & burnishing DID work harden the metal...... & copper/brass spinners had same problems......periodically annealed while work in progress.....probably need to check the handbook!!.....hope i havent thrown out some bad info!!!!
            best wishes


            • #7
              Doc, you are correct as usual. Heat, then cool in cold water. Temperature 1100-1200* F, either immerse immediately, or wait a few seconds, then cool.
              My mind was somewhere else.
              Jim H.


              • #8
                Copper work hardens quite rapidly. Probably a poor choice for an adjustable device. The water after heating is not necessary to anneal, but it is more fun.


                • #9
                  Yep, copper work hardens. It's also easy to anneal, as already pointed out. Heat it dull red, let it cool. Stepside's right -- the quench afterwards is irrelevant. It cools it off faster, but has no actual bearing on the annealing.

                  A friend of mine is building Kozo Hiroka's (sp?) switcher engine that was serialized in Live Steam. When he formed the boiler, he had to anneal the copper sheets numerous times during the process. Bend it a little, stop and anneal, bend some more.....
                  Try to make a living, not a killing. -- Utah Phillips
                  Don't believe everything you know. -- Bumper sticker
                  Everybody is ignorant, only on different subjects. -- Will Rogers
                  There are lots of people who mistake their imagination for their memory. - Josh Billings
                  Law of Logical Argument - Anything is possible if you don't know what you are talking about.
                  Don't own anything you have to feed or paint. - Hood River Blackie


                  • #10
                    I be DERNED!!!!!!
                    All these years I have quenched in water cause it "had to be done"

                    "Its the things I "know" that ain't so that get me in trouble"
                    Thanks Steve