Keyless entry and remote start systems in modern cars are incredibly convenient, but they also come with a security risk. Thieves can use signal amplification devices to intercept and relay the signal from your key fob, even when it’s inside your house, allowing them to unlock and steal your car. This is where a Faraday box comes in. These boxes are designed to block electromagnetic fields, preventing your key fob from transmitting signals. You can buy commercially made Key Fob Faraday Boxes or pouches, but what about making your own? I decided to put a DIY approach to the test using materials you can find around the house.
I read online about two main methods for creating a DIY Faraday box. The first involves using specialized RFID-blocking fabric to line a box. Many commercial Faraday pouches and boxes use this type of material, sometimes boasting about having multiple layers for extra protection. The second, more intriguing method, suggested lining a box with just two layers of regular tin foil. Honestly, the tin foil idea sounded a bit too simple to actually work. Skeptical but curious, I decided to try the tin foil method.
Using a small cardboard box, I carefully lined the inside with two layers of tin foil, making sure to cover all sides. To be honest, it looked a bit ridiculous. My wife watched me, clearly doubting my “genius” plan. To test its effectiveness, we used the simplest method possible: a phone call. If the Faraday box worked, my cell phone placed inside shouldn’t ring when called. If it rang, well, then my skepticism was confirmed, and maybe I’d get those beadlock rings I’ve been wanting for my car (a long-standing marital negotiation!).
The moment of truth arrived. My wife dialed my number while my phone sat inside the tin foil box. Ring, ring! Defeated, I started to concede, but then I noticed a tiny gap in the tin foil seam, maybe about 2 centimeters long and hair-thin. Could that small opening be the culprit? I quickly sealed the gap and asked her to call again.
This time? Silence. No ring. My wife was genuinely shocked and impressed that my seemingly ridiculous idea actually worked. She admitted it was effective, but the initial failure meant I was still on the hook to save up for those beadlock rings myself. (Seriously, someone needs to address inflation so car parts become more affordable!).
While my tin foil Faraday box experiment was surprisingly successful, for everyday use, we opted for commercially made Faraday pouches. They are more practical and convenient for hanging on our key rack. However, this little DIY experiment proved that even simple materials like tin foil can offer a degree of protection against key fob signal theft. It’s definitely something to consider if you’re looking for a quick and inexpensive way to enhance your car security.
