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  • Bedini coil core question

    I was never able to find the welding rods that John says to use in his coil design so I have cut up coat hangers in there and they work just fine. What I need to know is, are there any core materials that I can use that are not magnetic but will still have the same effect as a full metal core? The issue is that an air core is nowhere near as strong as a metal core, and I do not want the magnets to be attracted to my core while still retaining the power of a metal core vs an air core. Anyone know this?

  • #2
    Originally posted by Rit_Man View Post
    I was never able to find the welding rods that John says to use in his coil design so I have cut up coat hangers in there and they work just fine. What I need to know is, are there any core materials that I can use that are not magnetic but will still have the same effect as a full metal core? The issue is that an air core is nowhere near as strong as a metal core, and I do not want the magnets to be attracted to my core while still retaining the power of a metal core vs an air core. Anyone know this?
    Hi,
    If you are using a cored coil you have to have a Ferromagnetic core or iron core. the reason is but obvious. An Iron core would store more Energy per cycle than a Air/core less. Having said that, if you are using the rotored version you have to have a iron cored or else the coil wouldn't switch when the Magnet go past it.
    JB chose R60 because it is the best among the other and yes another issue is that this welding rod doesn't retain residual magnetism but the recent welding rod that I get here in India do retain quite a bit of it. The Idea is to switch the core into and off the Magnetic Field of the coil. Coat Hanger I guess is of Aluminium metal will not work its non-magnetic. makes no sense.
    you can use laminated 'I' piece that they use for Transformer core (Cold rolled Non-grain oriented sheet). the magnetic field is required to be in a OPEN CIRCUIT state.
    Rgds,
    Faraday88.
    Last edited by Faraday88; 05-10-2019, 11:40 AM.
    'Wisdom comes from living out of the knowledge.'

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    • #3
      I'll start off by saying the I am new to this project and am trying to be as exact to JB's recommendations as I possibly can.

      Since I began this SSG project, I have been reading about the Lincoln R60 dilemma and how to purchase the proper one for the Bedini core. I just finished a conversation with Lincoln directly (via their online chat) and after about 20 minutes, was told that the Lincoln R60 copper coated is no longer available. The Lincoln alternative they gave me was a mild steel copper coated 1/16" ER70S-2 but only comes in a 10lb pack (part# ED033952). Based on everything I've read on this forum, I'm hesitant to switch.

      So, if I stick with the "R60 copper coated 1/16" statement made by JB, I was able to find this product from mscdirect.com - Welding Material 36 Inch Long, 1/16 Inch Diameter, Copper Coated, Carbon Steel, TIG Welding and Brazing Rod
      1 Lb., Industry Specification R60 for $13 (part# 59802314) - link Unfortunately, they charge about the same price for shipping!!

      I also contacted a local welding supply store and asked them if they had any R60 1/16 with a copper coated rod and they had one left from Radnor for $15.

      I've also read that you can bypass the copper coating, use bare wire and spray on a lacquer. If that's the case, then purchasing it locally or from eBay should help. I found Weldcote Metals R60 1/16" x 36" Gas Welding Rod 1lb for $17 with free shipping and a local welding supply store has Harris R60 (RG-60) 1/16" x 36" Bare High Strength Mild Steel Gas Welding Rod 1lb for $13 (local pickup).

      I'm saying all this because I've spent hours and hours researching and appreciate all the advice on this forum. If I've said something incorrect in my statements above, please let me know. I just want to pass along what I've learned regarding not finding Lincoln R60 and hope that my research on this helps someone else!!!

      Thanks,
      Jos
      Last edited by Jos; 06-06-2019, 08:45 AM.

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      • #4
        If you find a equivalent to R60 rods without the copper coating, after cutting to length, soak them in water for a while, then let them rust (oxidation) for a while, and that will create the electrical insulation between the rods that the copper patina (oxidation) on the copper coated rods creates..... It is the electrical insulation between rods that reduce the Eddie currents (Heat Loss), and focuses the magnetic fields streams through the individual rods making the created magnet field stronger than what a solid core can create....
        Last edited by RS_; 06-06-2019, 01:42 PM.

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        • #5
          Originally posted by RS_ View Post
          If you find a equivalent to R60 rods without the copper coating, after cutting to length, soak them in water for a while, then let them rust (oxidation) for a while, and that will create the electrical insulation between the rods that the copper patina (oxidation) on the copper coated rods creates..... It is the electrical insulation between rods that reduce the Eddie currents (Heat Loss), and focuses the magnetic fields streams through the individual rods making the created magnet field stronger than what a solid core can create....
          Hi,

          Here in India we get this type of welding rod, which doesn't have the copper coating but instead has the welding flux coat (The grey coat over the main iron rod) that acts like an electrical insulator between the rods when you arrange/stack them in the core.
          here is the picture below:
          Click image for larger version

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          Thank you,
          Rgds,
          Faraday88.
          Last edited by Faraday88; 06-06-2019, 11:33 PM.
          'Wisdom comes from living out of the knowledge.'

          Comment


          • #6
            The problem with those welding rods is that the grey flux is too thick.... if you soak those rods in water until the flux melts, and then sand the rods a little, and soak them again and then let them rust they will work, and you can get way more rods in the core than with the flux on them

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            • #7
              I have not done any comparison to see the difference, If any, in a bedini sg specifically. But one of my favorite sources for coated iron is green floral wire. It takes a LOT to fill up a core and I highly recommend you use the thickest gauge you can find. I found a source online for some 18 ga (I think) a while back. I will try to find it again and post the link if anyone wanted to try it. But it is soft iron wire coated in some green plastic. It is electrically Insulated by the coating so when cut into "rods" I would imagine they would act exactly as the r60 rods do.

              As I said I have not used this on any SG. I have used it as a core for multiple other projects and can be used like normal wire in a coil, you can use it to make torroids of any size. It is a very handy source for insulated iron wire.
              Last edited by Bradley Malone; 06-07-2019, 03:16 PM.

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              • #8
                Bradley,
                Yes green floral wire will work and even the small gauge is useful. In my understanding the more isolated rods in the core the better, creates more magnetic field streams. I contemplated using the floral wire in a MEG magnet field switching type arrangement many years ago..... never got around to building it.....

                I have seen some ppl using it to make iron coils to test SSG's with too.....

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                • #9
                  Rs,
                  I absolutely agree with the smaller gauge statement. I just know from experience that it takes, what seems like, a hundred times more than you think it would. I cut a big pile of wires from the small gauge stuff at Walmart. When I bundled it up and put it in the core it loosly filled it about 3/4 full. So another trip to Walmart and I cut twice as many as the first time. to really pack the core took every bit of it. I was for some reason amazed by the amount of those wires I stuffed into that hole. It would seem full but you could just keep sliding more in it seemed endless lol!

                  So a better way to phrase my statement is I recommend thicker gauge for the above reason only! I completely agree with the "streams" idea and the small wire does indeed work great. At least for the things I've had the patience to use it for ��

                  I was headed the meg route at one point but ended up switching to a floral wire coil / toroid wrapped with 4 coils. I was wondering if a voltage would EVER be induced in the iron coil that was playing the part of the toroid in a transformer. It worked very well as a transformer but I havent gotten around to thouroghly testing the wave mixing and other things I wanted to try to possibly induce a voltage.

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                  • #10
                    Originally posted by RS_ View Post
                    The problem with those welding rods is that the grey flux is too thick.... if you soak those rods in water until the flux melts, and then sand the rods a little, and soak them again and then let them rust they will work, and you can get way more rods in the core than with the flux on them
                    RS ,
                    Thanks for your inputs however, I noticed that despite of such thickness of the gray flux,the core is seen getting hot due to eddy current Induction, imagine what would happen if you further reduced the insulation?
                    Rgds,
                    Faraday88.
                    'Wisdom comes from living out of the knowledge.'

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                    • #11
                      If you are having heat issues in your cores, than your rods are to big in dia, or they are the wrong material

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                      • #12
                        Originally posted by RS_ View Post
                        If you are having heat issues in your cores, than your rods are to big in dia, or they are the wrong material
                        RS,
                        You are right, I have switched to using ferrite filled cores ever since this issue, no more heat now.
                        Rgds,
                        Faraday88.
                        'Wisdom comes from living out of the knowledge.'

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