Making a “penny stove” out of cola cans is a classic DIY project for ultralight backpackers. It is incredibly lightweight, surprisingly efficient, and runs on denatured alcohol (methylated spirits).
Here is a step-by-step guide to building a standard, pressurized penny stove.
🛠️ Tools and Materials Needed
Materials:
- 2 Aluminum cans (standard 330ml or 500ml cans, undamaged)
- 1 Copper coin ( UK 1p/2p coin)
- High-temperature aluminum foil tape (optional, but great for a tight seal)
- Denatured alcohol / Methylated spirits (for fuel)
Tools:
- A sharp utility knife or box cutter
- A thumbtack, pushpin, or a drill with a tiny bit (approx. 1mm)
- A thick book or wooden block (to use as a height gauge for cutting)
- Scissors
- Fine-grit sandpaper
📐 Step-by-Step Instructions
Step 1: Prep the Cans
Thoroughly wash and dry both cans. Use your sandpaper to sand off the paint around the bottom 2 inches (5 cm) of both cans. Removing the paint prevents toxic fumes when the stove burns.
Step 2: Make the Burner Holes (Top Half)
Take Can A (this will be the top of your stove).
- Turn it upside down so the concave bottom faces up.
- Using your thumbtack or pushpin, poke 4 fuel-drainage holes inside the central, indented ring of the can bottom.
- Next, poke 16 to 24 evenly spaced jet holes around the outer rim of the can. These are the jets where the flame will shoot out.
Step 3: Cut the Can Bottoms
You need to cut the bottom off both cans to create two shallow cups. To get a perfectly straight line:
- Place your utility knife blade between the pages of a thick book so it stays flat and level at about 1 inch (2.5 cm) from the table.
- Hold the knife steady and rotate Can A against the blade until it scores and cleanly cuts the bottom off.
- Repeat this process for Can B (the bottom half), but make it just a fraction taller—about 1.25 inches (3 cm).
Step 4: Create the Inner Wall (The Cup)
You need an inner wall inside the stove to create a fuel chamber.
- Take the remaining middle cylinder scrap of aluminum from one of the cut cans.
- Cut a strip that is about 1.3 inches (3.3 cm) wide.
- Roll this strip into a circle that fits tightly around the inner raised ring of the bottom can (Can B).
- Cut three small V-shaped notches into the bottom edge of this ring. This allows fuel to flow from the center to the outer jets.
Step 5: Assemble the Stove
This is the trickiest part, as the two can bottoms are the exact same diameter.
- Take Can A (with the holes) and slightly crimp or pleat the edges inward using your fingers or pliers so it can slide inside Can B.
- Place your inner wall ring inside Can B (notches facing down).
- Carefully press Can A down into Can B. It should be a very tight, snug fit. Press them together until the inner wall is firmly sandwiched between the top and bottom.
- (Optional) Wrap a single layer of high-temperature aluminum tape around the seam to ensure it is airtight.
🔥 How to Operate It Safely
⚠️ Safety First: Alcohol burns with an almost invisible blue flame in daylight. Always operate outdoors on a fireproof surface (like the brick in the photo).
- Fill: Pour about 30ml of alcohol directly onto the top of the stove. It will drain through the center holes past the penny.
- Cap: Place your penny directly over the center holes. This seals the chamber so it can pressurize.
- Prime: Pour a tiny splash of alcohol into the indented rim around the penny, or into a shallow tray beneath the stove, and light it.
- The Bloom: The burning priming fuel will heat up the stove. Within 30 to 60 seconds, the alcohol inside will boil, turn to vapor, and shoot out of the outer jets, lighting into a beautiful ring of flame. Once it “blooms,” you can place your pot on top.