# How (theoretically) can metal detectors be defeated? **URL:** \ **Category:** Factual Questions\ **Created:** [April 24, 2014, 1:48am UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830 "2014-04-24T01:48:50Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Flyer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/flyer/32/7298_2.png) [@Flyer](https://boards.straightdope.com/u/Flyer)\ **Post date:** [July 4, 2016, 8:00pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/22 "2016-07-04T20:00:34Z")
Some years back, when I worked in construction, I had to wear steel-toed boots. I’ve kept up the habit for various reasons. As you might guess, I have issues when going through metal detectors. But so far, I’ve never had serious trouble. I just tell the people about my boots, they manually wand me, and that’s that. I’ve sometimes thought about the possibility of hiding a small weapon in the toe of my boots. However, I’ve never cared to actually try the experiment. ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [July 5, 2016, 11:44pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/23 "2016-07-05T23:44:29Z")
I’ve had large [Nimh accessory batteries](https://www.amazon.com/Anker-High-Capacity-16750mAh-Portable-External/dp/B00N2T7U90/ref=sr_1_1?ie=UTF8&qid=1467762052&sr=8-1&keywords=anker+e5+16000mah) like this go through without the carry on case being opened for inspection. I assumed they recognized the item but maybe I was wrong. Not sure how the battery components would react magnetically or look to the scanner viewer. A magnet does stick securely to the battery. Anker Size (LWH): 5.91 inches, 2.44 inches, 0.91 inches Weight: 10.88 ounces ---
**Author:** ![Metal\_detector](https://avatars.discourse-cdn.com/v4/letter/m/5e9695/32.png) [@Metal\_detector](https://boards.straightdope.com/u/Metal_detector)\ **Post date:** [October 18, 2018, 4:21pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/24 "2018-10-18T16:21:56Z")
Similar to the CCA comment, we had a guard who would help visitors get through the metal detector- He would have them hold their hand over the piece of metal- For instance, wires in bras, or a belt buckle. He would also have them go through sideways, extremely slowly. You can keep your feet low to the ground- Concrete floors are constructed with re-bar, so the detector can’t be accurate near the floor. That’s why you’ll see blocks placed in the detector to ensure feet are raised into the detection zone. These are experiences of 10 years ago, so i’d assume the latest tech has changed. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [October 18, 2018, 5:09pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/25 "2018-10-18T17:09:21Z")
Nice to see the actual device chime in on this. ---
**Author:** ![Penalimplant](https://avatars.discourse-cdn.com/v4/letter/p/9d8465/32.png) [@Penalimplant](https://boards.straightdope.com/u/Penalimplant)\ **Post date:** [June 9, 2022, 8:00am UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/26 "2022-06-09T08:00:49Z")
I think that the question is too broad. I think that it depends on what type of metal and how much of you areattempting to shield. I can tell you for an absolute fact that a corrupt prison guard brings a cell phone onto a facility they do so by wrapping it in a specific type of tape. Obviously the metallic content of a cell phone is different than a gun but this tape completely Shields the cell phone detection ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 9, 2022, 4:09pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/27 "2022-06-09T16:09:03Z")
If a corrupt guard wants to bring in contraband, they do it by just not bringing it through the detector at all, or by turning off the detector, or by being the one who’s running the detector and ignoring the beep. They wouldn’t need any sort of special tape or other high-tech solution, because, being the guards, they have much easier solutions. Which is good for them, because that tape doesn’t exist. ---
**Author:** ![Just\_Asking\_Questions](https://avatars.discourse-cdn.com/v4/letter/j/ba9def/32.png) [@Just\_Asking\_Questions](https://boards.straightdope.com/u/Just_Asking_Questions)\ **Post date:** [June 9, 2022, 4:19pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/28 "2022-06-09T16:19:30Z")
> [@Penalimplant](#): > > I can tell you for an absolute fact Yea, sure. ---
**Author:** ![Crane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crane/32/3495_2.png) [@Crane](https://boards.straightdope.com/u/Crane)\ **Post date:** [June 9, 2022, 6:15pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/29 "2022-06-09T18:15:26Z")
> [@Chronos](#): > > You could in principle do it with an active device that produced an opposing magnetic field. Once when testing coils with a digital ‘Q’ meter I observed that some objects could be oriented in the field so that they appeared lossless. I toyed with this for a while and assumed that the permeable alloys in the material were balancing out the eddy currents generated in the non-magnetic materials. Don’t really know , but it seemed to explain what I was observing and it opened the possibility of a device that would be invisible to a metal detector. Sounds good enough for a Bond movie script: “The weapon, James, is made from alloys that balance magnetic permeability with eddy current losses. It is blind to metal detectors” I believe a passive or active device would be defeated by the diversity of TSA inspection. Induction, X-ray and whatever that full body thing is, are all different technologies in different orientations. And then there’s the hand held wand. Those things are cheap and unpredictable. So, theoretically possible, but practically improbable. ---
**Author:** ![Dissonance](https://avatars.discourse-cdn.com/v4/letter/d/85f322/32.png) [@Dissonance](https://boards.straightdope.com/u/Dissonance)\ **Post date:** [June 9, 2022, 6:31pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/30 "2022-06-09T18:31:39Z")
You’re questioning the authority on this topic of someone who chose the username named Penal Implant? 😉 ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [June 9, 2022, 6:41pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/31 "2022-06-09T18:41:41Z")
Paging Dr. **Qadgop**! ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [June 9, 2022, 6:42pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/32 "2022-06-09T18:42:08Z")
Once upon a time, I heard a guy lecture on [metamaterial](https://en.wikipedia.org/wiki/Metamaterial_cloaking)-based “cloaking”, which is basically a variant of the kind of stealth technology mentioned which still has the problem of not being tuned against more than one of a possible battery of different types and frequencies of detectors, but for a James Bond movie, why not? ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [June 9, 2022, 6:44pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/33 "2022-06-09T18:44:23Z")
You can use electrolysis to deposit metal around an object. If the object is non-metallic then you can coat the object first with graphite and then coat metal layers by electrolysis. I have worked in the Chemical Industry where it is routine to fabricate piping and pressure vessels and inspect the welds using X-ray. The problem is that above a certain metal thickness, x-ray cannot penetrate properly. At these thicknesses, we usually use gamma-rays for inspection. I doubt airports have gamma ray machines, but I maybe wrong. So say you have a roll of 100 dollar bills rolled into a cylinder. Put the roll in a ziplock, coat it with graphite and coat a few inches of metal on it. Next shape the metal object into a statue of Jesus or Buddha or Ganesha or an abstract sculpture. When you get to your destination, you can dissolve the metal out using electrolysis or acids. ---
**Author:** ![jnglmassiv](https://avatars.discourse-cdn.com/v4/letter/j/f07891/32.png) [@jnglmassiv](https://boards.straightdope.com/u/jnglmassiv)\ **Post date:** [June 9, 2022, 7:55pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/34 "2022-06-09T19:55:41Z")
Slight of hand tricks? [![](https://img.youtube.com/vi/6fFzu8i7e8w/hqdefault.jpg "A Fish Called Wanda - Get a Gun Through Airport Security") ](https://www.youtube.com/watch?v=6fFzu8i7e8w) ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 9, 2022, 10:42pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/35 "2022-06-09T22:42:01Z")
> [@am77494](#): > > You can use electrolysis to deposit metal around an object. If the object is non-metallic then you can coat the object first with graphite and then coat metal layers by electrolysis. Sure, but if that’s your goal, you could also just put the object in a metal box (and maybe make the box in the shape of a statue or whatever). I’m not sure what that’s supposed to accomplish. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [June 9, 2022, 10:48pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/36 "2022-06-09T22:48:17Z")
The box may raise suspicion and people may want to open and inspect it. Nobody will ask to break a statue (especially a religious statue) For example - you may electroplate a huge religious statue around a handgun. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [June 9, 2022, 10:55pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/37 "2022-06-09T22:55:35Z")
I read an article in a survivalist magazine that suggested that in addition to burying a stash of guns on your property, you should bury random bits and chunks of metal in various places too, the theory being that government stooges or Russkies with metal detectors would give up after a bunch of false alarms. I suppose that might work if you have a lot of obvious junk on your property, but it can’t enhance property values, to say nothing of interfering with gardening. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [June 9, 2022, 10:57pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/38 "2022-06-09T22:57:51Z")
Also the main idea of electroplating is to avoid high temperatures that may come with melting metal and pouring it around an object. ---
**Author:** ![Just\_Asking\_Questions](https://avatars.discourse-cdn.com/v4/letter/j/ba9def/32.png) [@Just\_Asking\_Questions](https://boards.straightdope.com/u/Just_Asking_Questions)\ **Post date:** [June 9, 2022, 11:12pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/39 "2022-06-09T23:12:37Z")
> [@Jackmannii](#): > > the theory being that government stooges or Russkies with metal detectors would give up after a bunch of false alarms. The reality would be, the Russkies or government stooges would just shoot you, and then no one would know where the guns were buried, forever. ---
**Author:** ![Asuka](https://avatars.discourse-cdn.com/v4/letter/a/dec6dc/32.png) [@Asuka](https://boards.straightdope.com/u/Asuka)\ **Post date:** [June 9, 2022, 11:26pm UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/40 "2022-06-09T23:26:07Z")
If we can now bring up fictional examples, there was a bad 90s action movie I saw once where hijackers were able to bring small pistols onto a plane by hiring a patsy to walk through a metal detector first with a lighter in the shape of a gun. When the security guards immediately told him to stop he put up a struggle and as the security guards were busy with that guy the man holding the pistols walked right through as the alarm blared but the security guards were too distracted by the first guy. ---
**Author:** ![Marvin\_the\_Martian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/marvin_the_martian/32/2898_2.png) [@Marvin\_the\_Martian](https://boards.straightdope.com/u/Marvin_the_Martian)\ **Post date:** [June 10, 2022, 12:36am UTC](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830/41 "2022-06-10T00:36:47Z")
Only works if you have Jamie Lee Curtis to provide a distraction. [Previous page](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830.md?page=1) [Next page](https://boards.straightdope.com/t/how-theoretically-can-metal-detectors-be-defeated/686830.md?page=3)