Posts Tagged ‘Metal detector’

We often get asked, why does my stud finder have trouble with lath and plaster when it works perfectly through drywall? Or, what is the best tool or technique for finding studs in lath and plaster walls?

The front of this lath and plaster wall is smooth - no problem for your stud finder.

The front of this lath and plaster wall is smooth – no problem for your stud finder.

Your Zircon stud finder finds studs by looking for an increase in density compared to where it was first calibrated on the wall.  Drywall and other manufactured sheet materials have very consistent density, but lath and plaster walls have very inconsistent density on the backside of the wall. This is where the plaster is squeezed between the lath and ‘keys’ onto the back of the lath and holds the plaster in place.

So, even if the front of the wall has a very smooth texture, the back of the wall is what gives your stud finder trouble because there are changes in density everywhere as you scan.

Shown here is a peek behind the wall. Lath and plaster walls have an irregular surface that are a problem for stud finders.

Shown here is a peek behind the wall. Lath and plaster walls have an irregular surface that are a problem for stud finders.

As a result, your stud finder can show a false positive (a stud indication when it is actually not a stud) when it finds an increase in density, even if it is just a glob of plaster.

The best solution is to use a Zircon MultiScanner® wall scanner that has Metal Scan Mode or one of Zircon’s dedicated metal detectors, such as the MetalliScanner® m40 or MetalliScanner® MT 6, so you can find the little nails or tacks that are fastening every piece of wood lath to the studs.

Use a Zircon metal detector to locate the nails that fasten each piece of lath to the studs.

Use a Zircon metal detector to locate the nails that fasten each piece of lath to the studs.

Since you can detect the nail heads all the way up and down the entire height of the stud with the Metal Scan mode, this is a much more reliable way to find studs.

Please see the video demo of an m40 finding studs through lath and plaster on the Zircon web site.

Note:  All photos were taken in a test lab environment.

Working on hanging a flat screen television or want DIY help? Make sure to take a look at our Zircon in the Real World blog, “Think Outside Your Wall“. For more useful tips, please follow us @zircontools or like us on Facebook.

 

 

 

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Famous for beautiful views, much of California’s Highway 1 runs along cliffs on the Pacific Coast, but mudslides from the steep terrain above Highway 1 often close sections of the road for months at a time, including here at Devil’s Slide.

Famous for beautiful views, much of California’s Highway 1 runs along cliffs on the Pacific Coast, but mudslides from the steep terrain above Highway 1 often close sections of the road for months at a time, including here at Devil’s Slide.

Zircon end-users really appreciate that they can call or email us with their questions and quickly get answers from someone who really knows the products very well. One day when I was covering a shift on Zircon’s end-user help desk, I got a call from the crew who were building the Devil’s Slide tunnel.

Entrance to Tunnel – The State of California decided to build 2 tunnels; 1 for northbound traffic, and 1 for southbound traffic.

Entrance to Tunnel – The State of California decided to build 2 tunnels; 1 for northbound traffic, and 1 for southbound traffic.

Each tunnel is approx. 4,200 feet long (about 4/5ths of a mile).  It is a much more challenging application for using the MT6 compared to a concrete and steel building or slab because of the massive amount of rebar. I told Zircon’s engineers that instead of a concrete wall with steel reinforcement, Devil’s Slide Tunnel is more like a steel wall with concrete filler.

Each tunnel is approx. 4,200 feet long (about 4/5ths of a mile). It is a much more challenging application for using the MT6 compared to a concrete and steel building or slab because of the massive amount of rebar. I told Zircon’s engineers that instead of a concrete wall with steel reinforcement, Devil’s Slide Tunnel is more like a steel wall with concrete filler.

They were having trouble using the Zircon MT6 to locate rebar in the ceilings of the mechanical room. They needed to miss the rebar to install ventilation. The problem was that the tool seemed to indicate metal everywhere.

Because Devil’s Slide is such a large infrastructure project, and in earthquake country, a massive amount of steel exists compared to a typical concrete wall or floor. I decided to go to the site to see if I could help them. Please see photos and captions for the solution we found.

The 2 tunnels are connected with 10 mechanical rooms, and this is the first location where they needed to use MT6. The California State contract requires that the workers must scan the concrete with a metal scanner such as the MT6 before penetrating it with a fastener to install this ventilation system.

The 2 tunnels are connected with 10 mechanical rooms, and this is the first location where they needed to use the MT6. The California State contract requires that the workers must scan the concrete with a metal scanner such as the MT6 before penetrating it with a fastener to install this ventilation system.

Before using any scanner the workers hit rebar about 1/3 of the times they drilled, so they would have to try a new location and patch the unneeded hole, as you can see in this first of ten mechanical rooms. But for mechanical rooms 2 – 10 (using a Zircon MT6) they were about 99% successful in missing the rebar.  Rather than focusing the MT6 to finding metal, instead we looked for the weakest signals, and that system worked.

Before using any scanner, the workers hit rebar about 1/3 of the times they drilled, so they would have to try a new location and patch the unneeded hole, as you can see in this first of ten mechanical rooms. But for mechanical rooms 2 – 10 (using a Zircon MT6) they were about 99% successful in missing the rebar. Rather than focusing the MT6 to finding metal, instead we looked for the weakest signals, and that system worked.

The next job for the MT6 was in the main tunnels.  Again the workers needed to scan before installing fasteners for Jet Fans, but now they would be high up in a bucket.  The light weight of the MT6 was perfect for performing multiple overhead scans, and they appreciated that it was very quick to scan and determine the weakest magnetic field where they could install a 4 ½ fastener and miss the rebar.

The next job for the MT6 was in the main tunnels. Again, the workers needed to scan before installing fasteners for Jet Fans, but now they would be high up in a bucket. The lightweight nature  of the MT6 was perfect for performing multiple overhead scans, and the workers appreciated that it was very quick to scan and determine the weakest magnetic field where they could install a 4 ½ inch fastener and miss the rebar.

When Zircon was doing research and development on the new x8 metal scanner we took a prototype unit to the crew at Devil’s Slide.  Although the MT6 had been an extremely useful tool that saved them a lot of time and money, they really liked the x8, and they completed the job of installing fasteners to support the jet fans in the tunnel using the x8.  Two features they especially liked on the x8 are 1) the lighted screen, and 2) the ability to select three sensitivity settings.  They suggested it needed a loop for a wrist strap to prevent dropping the x8, and we incorporated it into the final design.

When Zircon was doing research and development on the new MetalliScanner x8 metal scanner we took a prototype unit to the crew at Devil’s Slide. Although the MT6 had been an extremely useful tool that saved them a lot of time and money, they really liked the x8, and they completed the job of installing fasteners to support the jet fans in the tunnel using the x8. Two features they especially liked on the x8 are 1) the backlit screen, and 2) the ability to select three sensitivity settings. The workers suggested it needed a loop for a wrist strap to prevent dropping the x8, and we incorporated it into the final design.

The Devil’s Slide project is a great example of showcasing the ease of use, functionality, and performance of Zircon’s tools. Whether you’re a do-it-yourselfer or a professional tool user, we’re happy to answer your Zircon tool questions. Our Zircon in the Real World blog, “We Just Want it to Work” addresses this subject in more detail and I invite you to take a look. Please also follow us @zircontools, like us on Facebook, or visit http://www.zircon.com.

Kurt Stauss at Honeywell

Classroom training started with a video, followed by questions and answers, hands-on training on demonstration walls, and a written applications test.

Zircon has received requests for training at large industrial complexes around the country because the safety departments now require workers to fill out a form certifying that they have scanned the wall, floor or ceiling before workers penetrate these materials, whether they are concrete or drywall.

As these photos show, I conducted classroom and hands-on training for subcontractors who work at a Department of Energy (DOE) site managed by Honeywell, near Kansas City.  Each attendee was trained in the usage of the Zircon MetalliScanner MT6 and the Zircon MultiScanner i500. At the end of the training session, the attendees received a certificate after demonstrating basic proficiency in operating the MT6 and the MultiScanner i500.

The head of the safety department personally researched and tested various brands of metal detectors for concrete and multi-function wall scanners (stud finders) for drywall.  He could have selected different vendors for each category, but Zircon was selected to fulfill both goals based on the performance of the tools, and especially because of their ease of use.

Kurt Stauss at Honeywell near wall

First step in the training was to demonstrate that the MT6 worked in the environment, by locating high voltage lines in conduit in the wall behind me here

Before starting the classroom training, I was asked to demonstrate the MT6 onsite, as this would get the men excited about the capabilities of the MT6. At the onsite location, inside the wall behind me, there were high voltage electrical lines, but they didn’t tell me that.

I was easily able to locate and trace the power lines inside the steel conduit by using the MT6.  Of course, conduit offers some protection in many cases, but if a worker core drills through the wall in that location, it would cut through the conduit (and high voltage lines) like a hot knife through butter! The workers were thoroughly impressed with the performance of the MT6. (They want to get home safe every night)!

Kurt Stauss at Honeywell 3

The class laughed when one guy commented on how surprised he was that the MT6 works so well, considering how inexpensive it is.

I recently did a similar training at an Intel Chip Fab facility in Arizona and they selected the Zircon MetalliScanner MT6 and the MultiScanner i500.  One comment I hear repeatedly is that they knew about Zircon stud finders, but they had no idea Zircon also made such awesome concrete scanners!

(Note: Cameras are not allowed inside the high security DOE facility, but the photos were sent to me by a DOE staff photographer).

Zircon’s in the Real Blogs also provide a service and training perspective on popular subjects, such as the blog, “Does it Have X-Ray Vision?” For additional insights, please also visit us @zircontools, like us on Facebook or ivsit http://www.zircon.com.