Drilling with scanner

[tinpanalley]

I've got a Bosch PDO6 wall scanner, stud finder. I thought until recently that it was accurate but I recently did a test just layering several pieces of 1" thick wood in front of each other with a cable on the back that was running current. Then I used the scanner to see if I could find it. The accuracy was all over the place... it's there but it's not close...no wait, it IS close...but not there, up here...nope, nope, I was wrong it's down there but it's not close, it's closer to you on the left... actually, there's nothing on the left nevermind...

And I'm thinking with that degree of accuracy, I'm going to drill right through a main feed in this apartment. What can I do to be accurate without taking a panel out of the wall, drilling a hole to use a camera, etc. Is there a device that will be more accurate? I feel at this point like I'm guessing with this Bosch one. When there's nothing there it does it right but the electric reading seems VERY spotty.

Thanks!!

 

[NutBucket]

1" wood is pretty dense. Consider most stud finders are designed to work with drywall/plaster. I think your test was a bit too extreme.

 

[tinpanalley]

1" wood is pretty dense. Consider most stud finders are designed to work with drywall/plaster. I think your test was a bit too extreme.

Well the walls in my apartment, over 100 years old, are all plaster and drywall. So would you say the scanner in the place I'm looking to drill into is likely to be more accurate than with my solid wood test?

 

[NutBucket]

Probably since lath isn't 1" thick and is in bands across the wall. Now if it's metal lath I'd say you're screwed.

Take your time and don't hold any metal parts of your drill...just in case

 

[tinpanalley]

Probably since lath isn't 1" thick and is in bands across the wall. Now if it's metal lath I'd say you're screwed.

Take your time and don't hold any metal parts of your drill...just in case

You don't happen to know anything about this scanner though right? Can you recommend one that is considered really reliable or a brand?

 

[Humpy]

Is there a device that will be more accurate?

Thanks!!

Amprobe CT-326, Ideal 61-958, etc. There are several under $1,000 that are pretty accurate and can trace/locate live circuits.

You still need to use your brain though. What's around the area you want to drill holes and stuff? See anything that looks like a circuit breaker or electric meter or gas line or a kitten? Don't drill there.

 

[tinpanalley]

Amprobe CT-326, Ideal 61-958, etc. There are several under $1,000 that are pretty accurate and can trace/locate live circuits.

Goodness...there's no way I can afford anything like that. I know, I know you get what you pay for. But still.

You still need to use your brain though. What's around the area you want to drill holes and stuff? See anything that looks like a circuit breaker or electric meter or gas line or a kitten? Don't drill there.

Nothing blatantly important like that but I'm in an old mansion turned into an apartment building, I have no idea where mains feeds are that go up to an office on the second floor. The wall I'm talking about is the has a staircase on the opposite side and I've seen cables run up the ceilings of stairwells before.

 

[Humpy]

It's especially true in older buildings where you can't rely on building code, either pay for the more reliable tools or pay double to hire someone or pay triple that to repair the damage from screwing it up.

In the end you still need to get in there with your eyes to be sure. Might as well go straight to using your best judgement to cut a hole to have a look. If you are mounting something it might cover up the patch. If you are running new wires you might surface mount or find a long way around.