Herbie's Penny Stove Construction Tips
Penny Stove Construction Tips
These are Herbie Pearthree's Tips based on Bill Waite's excellent instructions. I've simply noted the things that worked best for me along the way. Heineken can burner seems to have a better seal and burn, but a regular soda or beer can works as well. Wear gloves and protective eye wear - really. Read Bill Waite's instructions first, then watch my video for construction tips.
These instructions assume you have a cook stand and wind screen - if you don't, check out the Zen Stoves site for low-cost ideas.
I use the Swedish Mess Kit camp stove and am simply replacing the trianga alcohol stove with the penny stove to reduce pack weight and save fuel.
|Penny Stove Construction||Firing Up the Penny Stove|
|Step 1: Use can opener to remove the top lid from all of the cans. Mark one Heine can at the bottom with "Fuel Cup", the other Heine can with "Burner". Mark one of the other cans with "Base", the other with "Cap". This way you can keep track of the cans for measuring and marking where the cuts will go. Mark the Fuel Cup 28mm from the bottom of the can - the line should be just below where the narrow center of the can starts to bevel out. You can place the marker atop two gatorade lids, or in a book at the proper height.|
|Step 2: Mark burner 14mm from bottom of other Heine can (sharpie on one Gatorade cap) just below the lower wide ring where it starts to bezel out.|
|Step 3: Flip all the cans over so their top is now down on your work surface. Mark each can's simmer ring 14mm from what used to be the top of the can (sharpie on one Gatorade cap). Do the same with the base and cap using the two soda cans. You may wonder why 4 simmer rings are needed - they aren't, you really only need one simmer ring. But, if like me you appreciate baked goods when in the field, you'll find that the extra simmer rings are really good at elevating the baking tin above your cook pot to avoid burning your cake, brownies, bread, or whatever else you might want to bake.|
|Step 4: At this point, for safety's sake you SHOULD put on safety glasses and gloves. With the serrated knife, cut rough cuts on each can. Rough cut at least 3 mm away from where you marked your lines to minimize indenting the can along the lines.|
|Step 5: Once your rough cuts are complete, take the scissors and cut more accurately along the lines you marked. You should now have a Fuel Cup, Burner, 4 simmer rings, a base and a cap. If you wish (this part is optional) you may now sand the edges of the fuel cup, the simmer rings and the base and cap. I found it easiest to place a sheet of 220 grit sandpaper on the work surface and simply rub the items on if for a few. Luckily, when aluminum is trimmed with scissors, it doesn't splinter and shard like steel does. Use your judgement on whether you want to sand or not.|
|Step 6: Now grab the burner piece and flip it upside down on your work surface. Place the sharpie flat on the work surface and mark a line around it that's about 4mm from the work surface - this will mark the maximum height of the crimps you'll be adding in a couple steps.|
|Step 7:Now mark the burner for the placement of the fuel holes (4 green circles in center), jets (6 black circles on outside), and radiant holes (12 green circles on outside). You'll need 6 jets, 60 degrees apart in the middle of the outside rim of what used to be the bottom of the can (see the burner template below). If you don't want to use the template, think of an analog clock and mark holes at 12:00, 2:00, 4:00, 6:00, 8:00 and 10 o'clock. Now mark 4 holes in the center of the bottom close together so they fit under a penny - I prefer a center hole and then 3 holes that are triangulated around the center, others simply mark the four corners of a square. Next, mark the 12 burner radiant holes (these will be "on the hour" if you're thinking analog clock). The radiant holes are on the side of the burner below the line we marked and should be at least 7mm away from the burner top.|
|Step 8: Now grab your pliers and the burner, and make 12 crimps on the bottom of the burner crimping towards the center. Make sure you stay below the line we marked earlier so there's a good seal. I've found that a 30 degree angle in works very well. I read that this step helps fit the burner into the fuel cup and helps warm the fuel.|
|Step 9: Grab the rotary tool and drill out the 4 fuel filler holes, the 6 jets, and the 12 radiant holes on the burner. When you're done drilling them, take some sandpaper to the inside of the burner and remove any remaining metal hanging from the holes - proper gap size is fairly important. The fuel filler holes not only allow you to fill the stove, they also provide pressure relief (in combination with the wieght of the penny) in case the stove gets too hot and the fuel vaporizes too quickly - avoiding an outburst of flaming alcohol on you and your friends.|
|Step 10: If your burner has raised numbers on it in the center where your fuel holes are, you'll want to flatten it out so the penny can make a seal when in place. With masking tape, tape a nickle in the center of the burner over the holes. Place the burner on top of a 1x1 block of wood, put a 5/16" socket on top of the nickle, and tap it firmly with a hammer. This should leave a nice flat ring in the center for the penny.|
|Step 11: Grab the fuel cup and the burner and inspect them for any dents or sharp bends from the construction process. If there are dings, smooth them out. You can roll the burner on your work surface to smooth out any protrusions that may have occured while you were making the crimps - you want the burner sides to be very smooth for a tight seal.|
|Step 12: It's best to place the burner upside down and then press the fuel cup onto it so it goes in level. I use a large gatorade top as it fits perfectly in the middle of the burner.|
|Step 13: Place the fuel cup atop the burner.|
|Step 14: Gently but firmly press it down until it touches the working surface - this should give you a perfect fit.|
|Step 15: Inspect everything, put your penny in the center and check for a good visual fit. If every thing is fine, move on.|
|Step 16: Put the simmer ring on, narrow side up, to verify your cut of the fuel cup is good. If it's tight inserting, trim another mm off the fuel cup - you want it to easily slide in and out as you'll be putting it on a burning stove and don't want to have to fiddle with it.|
Using the Penny Stove
You will need to experiment with your stove and the amount of fuel needed to cook or boil the normal amount of water you use based on your mess kit or cook pot. This type of jet stove relies on heating the fuel to cause vaporization and thus the jets do their work. In cold weather, you'll want to have a "priming pan" to place under the stove to preheat the alcohol. There are various neat ways to do this, I found that a lid from a soup can removed with one of the "safety" side-cutting can openers works great - simply spill some alcohol onto it while you're filling up the stove, and light it instead of the stove. It will flame up, heat the fuel, and light the stove all in one. In warm weather, you may use this also if for some reason you're in a rush as the stove will jet faster and boil the water sooner - i.e. sterilizing water for medical reasons.
Generally, 2oz (or 4 Tbs.) of fuel will bring two cups of water to a rolling boil in about 6 minutes, then add your simmer ring (narrow side up) and you can keep the boil going.
To fuel up the stove, remove the penny uncovering the center holes. Fill the burner center and let it drain into the fuel cup. Do this three times and you've got about 1.5 oz of fuel ready, which is plenty for heating up water to a near boil for drinking or adding to dehydrated foods. Put the penny back in place, fill the cup again and pour some over the jet holes - this will help prime the stove and get it jetting faster.
If you're sterilizing water, fill up the cup as many times as possible, allowing it to overflow and cover the jets as well - this will give you plenty of fuel to maintain a 10 minute rolling boil as long as you remember to add the simmer ring once the boil starts.
If you're baking (yes, baking) you'll want to put the simmer ring on before you fire up the stove. This will reduce the heat output so you don't scorch your cake/bread/cookies and give you the long 30 minute burn you need for baking.
DANGER WARNING SAFETY FIRST! Never add fuel to the penny stove when it's hot. If you can't hold the stove in your hand, you can't fuel it. Violating this rule may result in fire, severe burns, blindness, or other terrible things. Be patient, it cools in a few minutes, then refuel.
I've played with various alcohol fuels and my top picks in order come down to this:
1) Grain Alcohol (aka ethanol) - Everclear or similar 190 proof
a. Pros: Burns fairly clean, non-toxic, may be used for cleaning wounds
b. Cons: Expensive, other campers might drink your fuel
2) Denatured Alcohol (ethanol with methanol) - S-L-X Denatured Alcohol from Home Depot
a. Pros: Relatively Inexpensive, burns well, low soot, easy to locate
b. Cons: Poisonous chemicals, variability in mix
3) Methyl Alcohol (methanol) - HEET gas line antifreeze (yellow bottle)
a. Pros: Relatively Inexpensive, burns hotter, low soot
b. Cons: Poisonous chemicals, toxic
4) Isopropyl Alcohol (rubbing alcohol) - drug stores
a. Pros: Inexpensive and readily available
b. Cons: Sooty, 90% difficult to find, 70% barely jets
SOURCE: Zen Stoves Fuels
A penny alcohol stove is an excellent replacement stove for expensive cannister stoves. Less waste (no canisters to throw away), cheap to make, easy to find fuel, performs better in below freezing weather, and is ultralight. Pack it safely to avoid crushing it, and it'll help you enjoy the wonderful outdoors.