Harrison Crettol
Sheet 05 · May 2026 · Combustion / Physics / $12 Total

Don't Build a DIY
"Plasma" Cannon

(Until reading this.) I saw a video of a DIY "plasma cannon" and thought there was no way it was real. Naturally, I decided to test it for myself — total build cost: twelve dollars and one literal backfire.

I started with a small-scale prototype using two 16.9-ounce water bottles. To my surprise, it actually worked. So I scaled up to 1-gallon water jugs — and my first attempt backfired (literally) and blew apart, which was a pretty dangerous lesson in combustion dynamics.

After taking the time to fix the design flaws, I rebuilt the rig with my two remaining jugs. To my relief, the new setup worked flawlessly, producing an incredible blue plasma wave that looks amazing in slow motion.

Final hardware demo [ Active ]

The breakdown

Behind the scenes

The $1.25 upgrade

These 1-gallon bottles were about $1.25 each; the heavy-duty 5-gallon jugs in other videos were $30 each. For 15× the price, the result is definitely not 15× cooler. Cheap plastic worked perfectly fine.

Jury-rigged cinematography

The camera rig was a dining room chair, electrical tape, and my phone — propped to the perfect angle with a couple of bricks I found outside. Incredibly stable, easy to operate in the dark.

Bill of materials

Purchased

  • Clear vinyl tubing $7.00
  • 4× 1-gallon water jugs $5.00
  • Total build cost $12.00

Lying around the house

  • Propane torch $0.00
  • Drill + spade bits $0.00
  • Electrical tape $0.00
  • Camera (iPhone) $0.00
  • Camera stand (chair + bricks) $0.00
  • Editing software (Shotcut) $0.00