Tin, Tupperware, or Ammo Box? We Stress-Tested 7 Household Enclosures So You Don't Melt One
Photo: Bendix Corporation, No restrictions, via Wikimedia Commons
The Enclosure Tax Is Real
Every maker knows the pain: the PCB is done, the firmware is tuned, and now the project needs a $22 Hammond box plus $9 of standoffs. Meanwhile, your recycling bin contains at least seven candidates. We grabbed the most common ones, wired in some test loads, and ran them through four criteria: heat tolerance, sealing, EMI shielding, and mountability.
How We Tested
Each container hosted a small load board pulling about 8W, with thermocouples on the internal air and the enclosure wall. Sealing got a splash test and an overnight humidity check with silica gel as an indicator. EMI shielding was measured crudely with a nearby FM receiver and a 2.4GHz RSSI readout. Not lab-grade, but consistent — and brutally honest.
The Rankings
1. Aluminum ammo can — The Genius Pick. Military-surplus cans have gasketed lids, real RF shielding (we measured a 15–20dB drop in 2.4GHz leakage), and you can drill and tap them like butter. Punch out the paint under your standoffs for grounding. Verdict: buy a $15 can before you buy a $25 project box.
2. Metal mint tin — The Classic, Earned. TheAltoids tin has carried a thousand badge projects for a reason: it shields RF, survives soldering-iron contact, and looks intentional. Weaknesses: no sealing whatsoever, sharp edges, and the moment you need real connector cutouts, the thin walls get wobbly. Great for pocket electronics, wrong for anything outdoors.
3. ABS junction box (hardware store, ~$6) — The Boring Winner. Technically you're buying this, not reusing it, but it belongs on the list because it beats everything in the drawer. UV-stabilized, screw-lid gaskets, molded standoffs. If your project lives outside or runs hot, skip the improvisation.
4. HDPE food containers (yogurt tubs, deli cups) — The Fine-for-Now. HDPE handles 100°C+ briefly, doesn't shatter, and is free. But it's terrible to drill cleanly (it grabs and tears), impossible to glue with most common adhesives, and offers zero EMI shielding. Fine for a bench prototype that never leaves the desk.
5. Plastic VHS or project cases from old gear — The Underrated Sleeper. Old consumer electronics shells are pre-molded, pre-vented, and often come with screw bosses. Heat performance is fine at low power. Just check for yellowed, brittle ABS — if it snaps when flexed, retire it.
6. Glass mason jars — The Pretty Problem. Excellent sealing with a lid, totally transparent, terrible in every other way. No shielding, no easy feedthroughs, and one bench mishap away from shattered glass near your electronics. We'll allow it for a desiccator or a decorative Nixie clock. Nothing else.
7. PVC pipe fittings — The Fire Hazard Flag. Yes, the internet loves PVC project tubes. But standard Schedule 40 PVC softens around 60°C — below the internal temperature of many projects we've built — and burns into hydrochloric-acid-laden smoke. If your enclosure gets warm to the touch, you're past its limit. Use ABS pipe instead, or just don't.
Your Junk-Drawer Checklist
Before committing a container to a build, run through this:
- Wall temp test: Run the project 30 minutes sealed. If the wall exceeds ~55°C, upgrade.
- Does it need sealing? Outdoor or humid = gasket or die, silica gel at minimum.
- RF sensitive? Plastic does nothing; metal or lined metal only.
- Can you make openings without cracking it? Test on the lid first.
- Fire spread: Anything that melts-and-drips (PVC, cheap polystyrene) is disqualified near lithium cells.
Bottom Line
The ammo can wins on pure merit, the mint tin wins on charm, and the junction box wins because sometimes the boring answer is correct. The mason jar and PVC pipe can stay in the garage — one for pickles, one for plumbing.
