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Thread: EMI and Cast Iron Sewer

  1. #1
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    Default EMI and Cast Iron Sewer

    I recently went out to locate a residential sewer line. The sewer went out under the basement slab to the small backyard downstream. Typically, I like to knock these out using my locateable-rodder, and transmitter set 8K (b/c of small yard surrounded by chain-link fences). However, the basement had clutter and junk in the way - also, the c/o cap was rusted shut - no access for rodder. Recalling my metrotech manual, I tried to use a magnet to induce current onto the 6" iron pipe. I used 50-ft extension cable to put nice ground outside with a ground rod driven 1.5-ft deep (the ground was wet from rain). Still, no signal, and I tried 8K to 200K.

    Anyone know any tricks to working with cast?
    Any luck using a magnet - the example in metro-tech manual suggests using magnet to induce signal on street lamps...?
    Any luck using ring-clamps in this situation?

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    Default Re: EMI and Cast Iron Sewer

    Quote Originally Posted by WNC Utility Locator View Post
    I recently went out to locate a residential sewer line. The sewer went out under the basement slab to the small backyard downstream. Typically, I like to knock these out using my locateable-rodder, and transmitter set 8K (b/c of small yard surrounded by chain-link fences). However, the basement had clutter and junk in the way - also, the c/o cap was rusted shut - no access for rodder. Recalling my metrotech manual, I tried to use a magnet to induce current onto the 6" iron pipe. I used 50-ft extension cable to put nice ground outside with a ground rod driven 1.5-ft deep (the ground was wet from rain). Still, no signal, and I tried 8K to 200K.

    Anyone know any tricks to working with cast?
    Any luck using a magnet - the example in metro-tech manual suggests using magnet to induce signal on street lamps...?
    Any luck using ring-clamps in this situation?
    Cast is tough with 8k better to use 512hz with a small sonde on a duct rodder if you don't have a sewer camera to use. No Cleanout access then pull a toilet or use the roof vent or a small diamond grinder to cut the old cleanout cap off.

  3. #3
    Senior Member yahoo's Avatar
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    Default Re: EMI and Cast Iron Sewer

    cast iron is difficult for everyone . You will have to try a lot of different tricks to end up seeing what best works for you. It appears that Cuda is giving you a good idea . prolly start with that . I have used magnets thru the years with some success but sometimes NOT .
    daman1 likes this.
    wise men talk because they have something to say and fools because they have to say something....plato

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    Senior Member daman1's Avatar
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    Default Re: EMI and Cast Iron Sewer

    Sometimes a simple metal dtector works. Cast iron lights them up. Ive done it and was there for the dig to confirm. Just dont tell my supe.

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    Default Re: EMI and Cast Iron Sewer

    Quote Originally Posted by yahoo View Post
    cast iron is difficult for everyone . You will have to try a lot of different tricks to end up seeing what best works for you. It appears that Cuda is giving you a good idea . prolly start with that . I have used magnets thru the years with some success but sometimes NOT .
    I find metal pipes almost all carry 60HZ picked up thru the ground. A sweep at 60HZ, backed up by witching rods, can trace such pipe from one known point to another. After that I induce starting at some known point like a valve the indications led me to.
    clips68 likes this.

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    Default Re: EMI and Cast Iron Sewer

    None.
    Last edited by clips68; September 13th, 2018 at 10:36 PM.

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