If you use a regular box, you will need to leave it sealed shut until after a potential EMP goes off. You can remove the lid of a shoe box to access electronics stored inside quickly.
You can measure the box using inches or centimeters, just make sure you use the same unit of measurement consistently throughout the project. As an example, a box that is 10 inches (25 cm) long and 4 inches (10 cm) high would look like this: 4 inches (10 cm) x 2 = 8 inches (20 cm). 8 inches (20 cm) + 10 inches (25 cm) = 18 inches (46 cm). Then add the extra 1 inch (2. 5 cm) for a total of 19 inches (48 cm). The extra 1 inch (2. 5 cm) of foil will allow you to fold it over the top edges of the box.
Using the previous example; you’d need to cut 3 pieces of foil that each measure 19 inches (48 cm).
The placement of the box does not need to be exact. Do not put the lid on the shoe box yet.
Fold excess foil around the exterior of the shoe box. Some of the box will still be visible, but at least the bottom and two shorter sides should be completely covered in aluminum foil.
The box itself is now completely covered in aluminum foil. Use long strips of tape to ensure all three sheets of foil are in constant and direct contact with one another. There should be no gaps in the foil.
Be careful not to tear the foil as it won’t have overlapping layers like the rest of the box.
Fold the foil under the lid so the insides of the lid’s sidewalls are covered in foil as well. You can add more layers of foil if you tear it or the box lid is too large to be covered in a single sheet.
Make sure the foil on the interior sidewalls of the lid is making contact with the exterior of the box’s walls. You can seal the box closed with aluminum tape for extra protection. Remember, if you seal the box, you’ll tear the foil when you unseal it.
The bucket must be made of galvanized metal for the Faraday cage to work. Plastic buckets will not redirect the flow of an EMP. Choose a bucket that has a metal lid. You can purchase a galvanized metal bucket at your local hardware store.
Your Faraday cage may work without lining the seam with aluminum tape. Doing so is an additional precaution to ensure there are no gaps in the protection created by the bucket. You can find aluminum tape at your local hardware store.
The holes where a handle passes through into the bucket are the most likely areas for a gap that could compromise your Faraday cage. These holes may already be covered by the aluminum tape you used on the bucket’s seam.
Cut a circle of cardboard out and place it on the bottom of the bucket. Slide cardboard into the bucket, so it is standing upright, and wrap it around the interior. When you’re done, the inside walls and the floor of the bucket should be lined with cardboard.
Test your Faraday cage using radios or your cell phone to ensure it works.
You’ll need a way to call your cell phone once it’s inside the Faraday cage.
It’s best to conduct this experiment somewhere that you have the best possible service your phone is capable of receiving.
If your phone doesn’t receive the call, there’s a problem with it and you won’t be able to use it to test the Faraday cage. If the phone rings, hang up the call.
The phone should not be coming into contact with any metal or foil inside the Faraday cage.
If your phone does ring, it means there’s a gap somewhere in the Faraday cage that is allowing the signal to pass through. Test your cage more than once to ensure it works.
This test does not guarantee that your Faraday cage will work, but it offers the easiest way to assess any potential signal leaks. Repeat the test and keep covering gaps until the signal no longer passes through the Faraday cage.
