One pulse can end the electronic age. Your gear doesn't have to go with it.
A Faraday cage is a conductive enclosure that blocks electromagnetic fields, protecting the electronics inside from an EMP. This guide explains building one from common items like a galvanized steel trash can, lining it so devices never touch bare metal, sealing seams for a continuous conductive shell, and testing it. GridDownData stores it on an air-gapped USB drive so the reference survives the very event it prepares you for.
An electromagnetic pulse can destroy unprotected electronics in an instant, and by definition you cannot look up how to protect them afterward. GridDownData carries an offline guide to building and testing Faraday enclosures from common materials, deciding what gear to shield, and why grounding rules differ for EMP versus lightning — stored on an air-gapped USB drive that itself can live inside your Faraday cage.
Frequently asked questions
How do I build a Faraday cage at home?
A common approach uses a galvanized steel trash can with a tight-fitting metal lid as the conductive shell. The interior is lined with cardboard or cloth so devices never touch bare metal, and the lid-to-can seam is sealed for continuous contact. The guide details materials, layering, and assembly step by step.
Should a Faraday cage be grounded for EMP?
For EMP protection the guide follows the common practice of not grounding the enclosure; an ungrounded cage redistributes and dissipates pulse energy around its exterior. Grounding is relevant to lightning, not EMP, and can even create a conduction path. The reference explains the distinction so you do not defeat your own protection.
How can I test whether my Faraday cage works?
A simple field test is to seal a powered-on cell phone inside and call it from another phone. If it goes straight to voicemail with no ring, the enclosure is blocking those frequencies; if it rings, the seal has gaps. The guide covers this test and how to improve a leaky seal.
What electronics are worth protecting from an EMP?
The guide suggests prioritizing hard-to-replace, high-value gear: two-way radios, spare solar charge controllers, LED lighting, medical devices, and a backup drive holding your offline references. It helps you build a small, sealed kit so that even after a pulse you retain communications, power control, and your knowledge library.