WTF Went Wrong Here!?!?

[FreedMan]

I got my ass handed to me this afternoon on a simple residential private locate. My customer needed a copper gas line from his yard lamp run back to it's source to do some plumbing repairs. I hooked up to both ends with multiple instruments (810, rd400, ph, and even the old surelock) and NOTHING would touch that mother######!

It was a short run, under forty feet, and the copper line had been in direct contact with the ground for at least 10 years. I tried everything I could imagine including grounding the far end of the run from my connection. The only thing that finally found it was a shovel, but that's not what people call a private locator to see! It was embarrassing. What am I missing here?

I felt so bad about it I didn't even charge him (lucky it was on my way home from two cell towers I marked out earlier, so all I lost was my pride and a little time.

[RD_Wrangler]

My guess would be 1 of 2:

1. Because the copper line was in direct contact with the soil, with no sheathing or shielding (even steel water and gas lines have either a coating of grease or wrapping), you had a direct circuit loop basically straight from your point of contact to your ground rod. The capacitance of your signal was so quick, it couldn't travel the distance.

2. The copper tubing had degraded to the point that there were points where it was mostly verdigris (the green stuff) and the signal didn't have a route to travel even though you grounded the far end (Verdigris is a VERY poor conductor). If this is the case it should probably be replaced as it's a hazard.

[FreedMan]

That's along the lines I was thinking, glad to see I'm not losing my mind. Thanks for the feedback Wrangler

[locator00566]

Try a pipe horn next time

[Wingfoot]

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[FreedMan]

That's what "ph" in the list of instruments I tried stands for, the run was less than forty feet and I didn't trust the signals I got from it. And I was right, that close was airlocked.

[FreedMan]

Ahhh, witchcraft, I suppose I could have tried that Wingfoot, but I really don't like pulling out the wires with a customer watching.

[Mke]

I don't know about NC, but out here most private (home owner type) gas lines are copper or metalic going into the ground, then transitions to polly. I'm not saying their can't be weird forces of nature masking the line, but 10yrs ago is well within the time period of having a transition of materials in the line.

Mke

[RD_Wrangler]

I don't know about NC, but out here most private (home owner type) gas lines are copper or metalic going into the ground, then transitions to polly. I'm not saying their can't be weird forces of nature masking the line, but 10yrs ago is well within the time period of having a transition of materials in the line.

Mke

Good point Mke, I didn't even think of transition of materials.

[Paint'n & Flag'n]

could you have turned the gas off and pushed a tracer wire through the hose like you would do for di-electric cable?

[FreedMan]

That was an option P&F, but would have involved taking apart the lamp on the post to do it and the homeowner didn't want to do that and I wasn't about to disconnect it from the other end. Too much liability for no more than I was going to make on the job. Mke, we actually discussed that possibility while I was there. I'm thinking that it was either the direct contact with the ground, age of the pipe, or the material. I checked all my locators this afternoon and everything works as it should. Thinking this was a fluke unlocatable line where I didn't expect one.

Funny how the jobs we expect trouble on always go easy and the one's we think will be cake end up being nightmares.

[Goldenboy]

Funny how the jobs we expect trouble on always go easy and the one's we think will be cake end up being nightmares.

Isn't that the truth.

[Danger]

what model pipehorn did you use?

[FreedMan]

100

[Danger]

did you try laying the transmitter on it's side to flood the area and then sweeping?