Estimated reading time: 11 minutes
A Faraday cage is designed to protect electronics from electromagnetic waves that can destroy circuit boards and many other delicate elements that allow electronic devices to function. There are numerous threats to electronics from electromagnetic pulses from space and nuclear detonations (EMP) to something as insidious and simple as someone stealing your Wi-Fi signals or hacking your cell phone
Michael Faraday was a British Scientist who invented the first Faraday cage in 1836. It was essentially a glass box lined with metal foil. He stepped into the box and the room was blasted with electricity by an electrostatic generator.
Anyone standing in the room would have been electrocuted but Faraday reportedly survived for two days in the box. Only foil around his cage conducted electricity and it shielded him from the electromagnetic force. The concept was simple and still works.
Why Would Anyone Need a Faraday Cage?
As the world becomes more and more dependent on electronics from computers to smartphones, the natural and manmade threat to those systems becomes a looming possibility.
An EMP or electromagnetic pulse from space occurs when a significant solar flare emerges from the sun and strikes the Earth. It happens all the time but some solar flares are extremely large and a direct hit would fry electronics around the world. It’s happened numerous times in the past and a recurrence is inevitable. The most significant recent event has come to be known as the Carrington event.
The Carrington Event
In 1859 an EMP struck the Earth. It has been called the perfect solar storm. Electronic devices were few and far between but telegraph wires around the world ceased to function and many had to be replaced.
The event was named after a man named Richard Carrington who was sketching sunspots and was temporarily blinded by the burst of light from the sun. The EMP has carried his name ever since.
The geomagnetic storm that resulted lit up the night sky with Auroras and Carrington later determined his observations of the sun were related.
What if This Happened Today?
If a coronal mass ejection or solar flare on the scale of the Carrington event occurred today the Internet would disappear overnight. All mobile devices would cease to function. Anything dependent on computer technology from finance to medicine to record-keeping for just about everything would be incapacitated.
Hard drives would be wiped clean and the immediate impact on everything would be devastating including a total loss of the power grid.
A Carrington Event is Rare but…
There have been solar flares since 1859 but none on the scale of the Carrington event. Scientists warn they could occur at any time particularly at the height of the 11-year solar cycle when the sun’s flare activity is at its peak. By the way, 2024 is going to be the peak of the latest 11-year solar cycle.
What’s more alarming is the EMP that emerges from a nuclear detonation. Every nuclear detonation emits an EMP even during tests of nuclear weapons. A designed detonation of a nuclear weapon high in the atmosphere would spread an EMP across hundreds if not thousands of miles.
The primary concern for any level of nuclear detonation is the damage from the blast and radiation, but the greatest threat today may be the EMP that travels far beyond the blast and radiation zones to destroy anything depending on electronics to function.
The Everyday Threat
Solar flares are rare and thankfully, so are nuclear detonations. But an everyday threat that is emerging is the ability of individuals to hack into cell phones and even latch onto a neighbor’s Wi-Fi signals. If your bandwidth or Wi-Fi usage seems diminished or results in overcharges on your Wi-Fi bills it may be because of a neighbor borrowing your Wi-Fi signal.
Worse, everything from laptops to pad devices and especially mobile phones can be hacked, and all manner of information downloaded by anyone determined to do so. Here again, there are all manner of commercially available Faraday cages you can buy but we’re going to explore the concept of the Faraday cage and build our own.
The Faraday Cage Concept
The fundamental concept is defined as a space surrounded by metal with a non-conducting insulating layer inside to prevent anything from coming in contact with the exterior metal.
Faraday cages have been surrounded with everything from chicken wire to aluminum foil to sheet metal. There’s even a Faraday fabric you can buy on Amazon but for our effort, sheet metal presents an easy solution to constructing a Faraday cage.
What to Put Into a Faraday Bucket
Anything else with a circuit board or electronics that will fit in the bucket
If you have larger devices like desktop computers or just too much stuff, we’ll cover some links to more information about building a variety of Faraday cages in all sizes. You can even turn a metal file cabinet into a Faraday cage if the shelves are properly insulated.
Constructing a Bucket Faraday Cage
This may be the simplest way to quickly and effectively construct a Faraday cage. What’s good about a metal bucket aside from its Faraday characteristics is that it’s inexpensive, portable, and easy to put together. It’s also large enough to hold and protect many of the electronic devices that can be harmed by any electronic intrusions from EMPs to hackers. Here’s what you need to do.
A metal bucket with a tight-fitting lid
Cut a circle from the cardboard that will fit into the bottom of the bucket.
Line the sides of the bucket with more cardboard.
Cut another circle of cardboard to place on top. You don’t want anything inside to come in contact with the metal bucket or lid.
Place your electronics inside the bucket and cover it with the top circle of cardboard.
Tightly seal the lid and you’re done.
Faraday Bucket Fails
If any electronics in the bucket come in contact with the metal sides they will be damaged by any electromagnetic charge striking the bucket. Make sure your cardboard insulation has no gaps allowing anything to touch the metal sides. You could tape together the cardboard with duct tape if you want to be sure, or are transporting the bucket with any frequency that could cause the contents to shift.
Holes or gaps in the bucket could allow an electrostatic charge to enter the interior. Seal any holes with metallic tape if you have an old bucket or a bucket with holes or gaps.
A loose-fitting lid is another bad idea. Gaps in the lid are as bad as a hole in the bucket. Make sure the lid is tightly sealed to the top of the bucket.
Not switching off electronic devices before placing them in the Faraday bucket isn’t the best idea. A cell phone or computer may continue to search for a Wi-Fi signal inside the bucket, and those will be blocked. The result is the battery will quickly run down. If for any reason you place your phone in a Faraday bucket make sure you turn it off or switch it to “airplane mode” so it doesn’t use power to find a signal.
Variations on a Bucket
Here are links to a few articles and videos that demonstrate various configurations and ways to construct a Faraday cage. Some are simple and some are more complex.
You Never Know…
For some, it seems like a bit of an overreaction to construct a Faraday cage. But if you look at the amount of conversation and instruction about Faraday cages on the Internet it makes you wonder.
Massive solar flares are a fact of nature and one of these days we’ll be in line for a direct hit like the Carrington event. On the other hand, there’s no shortage of criminal hacking taking place and it shows no sign of decreasing.
And then there’s that nuclear EMP which may unfortunately become a possibility if the global situation continues to worsen. It’s at times like that when the ability to improvise a Faraday cage quickly may become welcome knowledge, and most likely the least of our problems.