Build a Faraday + Surge Locker

🧰 What You’re Building

A sealed, grounded **Faraday cage** with built-in **surge absorption and anti-static lining**. Designed to protect:

• External SSDs, USB drives, NVMe backups
• Radios, walkie-talkies, Baofeng HTs, CB rigs
• Routers, RasPi, microcontrollers
• Encrypted drives & backup wallets

Think of it as your **vault of continuity** — when the grid hiccups or your surge protector decides to take a nap.

🛠️ Materials List

• 1× Steel Ammo Can (caliber doesn’t matter, **all-metal body**) or small steel toolbox
• Aluminum HVAC tape (NOT duct tape)
• EMI gasket foam strip (optional: conductive adhesive backing)
• Anti-static foam sheet or ESD bags
• Desiccant packs (keep it dry, reduce corrosion risk)
• 1× MOV/TVS surge board (e.g. USB-to-ground or RJ45 inline suppressor)
• Ground wire + ring terminal (optional: case-to-Earth lug)
• Rubber shelf liner (optional: base padding)

🧪 Assembly Steps

1. Clean and inspect the can — remove rust, old paint at lid edge, wipe interior.
2. Apply aluminum tape along the lid edge (overlap lip and body) for better contact.
3. Add EMI gasket foam along lid rim to ensure metal-to-metal contact with pressure.
4. Cut anti-static foam or liner to fit the base + side walls.
5. Insert your items into ESD bags or wrap in anti-static foam.
6. Place items inside can. Add desiccant pack to control moisture.
7. Optional: Install a ground wire to a bolt inside, connected to case wall (ONLY if grounding to Earth).
8. Optional: Attach MOV board or USB surge suppressor to inside lid with removable mount (Velcro or magnet).
9. Seal & label. Test lid closure — resistance should drop near zero (use multimeter continuity mode).

🔍 How It Works

• Faraday shell: solid metal body + tight lid = EMF blocker
• Aluminum tape: improves surface contact; no gaps for RF to sneak through
• Gasket foam: keeps compression pressure on contact edges
• Anti-static foam: reduces charge buildup inside
• Desiccant: blocks rust, mold, data rot
• Surge board: MOV/TVS components clamp any charge spike before it arcs into your gear

✅ Test It

Use a multimeter in continuity mode:

• Touch probe 1: inside lid
• Touch probe 2: inside wall or base
• Result? Beep or low-ohm reading = continuous metal = Faraday win

Now test shielding: place phone inside, call it, try Bluetooth/wi-fi. It should drop.

⚠️ Final Notes

• This is passive protection — it won’t stop water, fire, or memory loss. 😅
• Don’t ground unless you understand the loop risks — sometimes better ungrounded for portable setups
• Update backups every 1–3 months; dry-pack and verify reads before storing
• If you live in a lightning-prone zone, consider keeping this in a basement or steel rack