An Alcohol Stove made from Aluminum Bottles
There are plenty of aluminum can stove designs out there. This one is different in that it is not made from aluminum cans but rather from aluminum bottles (aluminum beer bottles to be specific) After building a few stoves myself I wanted to design one to address a few shortcomings of other can stoves:
1. Priming - A number of stoves require an external heat source to bring the alcohol to vaporization temperature. Some require heating the bottom for a few minutes or burning some alcohol in a separate "primer pan" or on the ground around the the can as a means to heat the exterior of the of the stove to achieve a self-sustaining burn.
2. Separate pot stands - A number of stoves have a low profile and are very compact however the smallest of the small require separate pot stands to cook with. Kind of defeats the purpose of a compact stove in my mind.
Sure there are side jetted designs that hold a pot however I wanted a design that would also address a third shortcoming.
3. Cold pan Flame-out - Of the can stove designs that do support a pot, I have seen them suffer from this condition. When a pan of cold water (fresh from the camp pump) is placed directly on a can stove, it acts as a large heat sink. Before the stove can warm the water, the cold pot cools the aluminum stove so much that it cannot maintain alcohol vaporization and the stove goes out
Admittedly, there are are many great can stove designs out there; many are self priming (nothing new there) and some have integral pot stands. Each has pros and cons depending on your priorities. This is another design for consideration and besides, I just wanted an excuse to work with those cool aluminum beer bottles.
If you look hard enough you will find a local retailer that usually stocks at least a small quantity of these specialty aluminum beer bottles.
I prefer the use of these aluminum bottles over the traditional aluminum cans for the following reasons:
1. Stability - The overall diameter of a can is larger than a bottle, however, the bottles have a larger diameter where it counts, at the base were it contacts the ground. The wider base is important because we are making a stove to support a pot and every bit of width helps to prevent tipping.
2. Heavier Gauge - The bottles are a thicker gauge aluminum. The thicker metal is a little more challenging to work with (you can't cut it with a utility knife) however it brings a solid, durable feel that you just don't get from a can.
This also means more thermal mass to help counter the "cold pot flame-out" syndrome.
(Sure more metal is more weight however once you step away from a propane grill; a quarter of an ounce here or there is not my biggest priority. (By the way, don't forget to add the weight of a separate pot stand to those other designs)
The last photo show some of my trials with earlier aluminum bottle designs.
This stove is built from (3) empty aluminum beer bottles (be sure to dispose of contents responsibly...)
No glue or epoxy
No flux capacitors...
The assembly is all press fit together. The cross section below shows the naming conventions for each of the four parts referenced in the following steps
1. Cut the bottoms off of the three bottles. Cut two bottoms 1.5" tall and one bottom 1" tall
I found that because to the thicker aluminum, the bottles could not be cut easily with a utility knife. A hack saw works well to make the cuts.
The fixture shown below helped to start the cuts and made sure they were straight around the can. Several turns with the blade pressed against the can started the cut; which was finished by carefully sawing around the outside of the can with a hack saw. (do not try to cut straight through the can as the blade will bend the edges of the can once it breaks through the skin.)
2. Finish the edge of the can to remove any sharp edges or nicks. Any nicks at the edge will initiate a split when the can is stretched.
Place emery cloth (sand paper for metal) on a flat surface. Place the entire edge of the bottle flat on the emery cloth and turn the bottle to evenly smooth the edge.
Cut Burn Bowl
This part is the BURN BOWL and serves two purposes. It initially is the internal primer area where alcohol burns to heat the alcohol to vaporization. It also serves as a heat sink, when heated by the jets, to keep the stove at at self-sustaining vaporization temperature.
1. Cut off the neck of one bottle. The cut should be at the tangent where the bottle neck just reaches full diameter.
2. Make a second cut at the top of the bottle opening as shown. This location is approximate. Start out with the cut a little long. it will be adjusted when fitting the burn bowl to the jet deck in step 8.
3. Smooth the edges as before.
1. Drill a large hole in the center of the bottom of one of the 1.5" bottle bottoms. This will be the JET DECK.
2. With a file enlarge the hole to about 1 5/16" diameter (or a little smaller to leave room to tune)
3. This opening will need be tuned to create a force fit to the neck of the Burn Bowl
4. Drill (8) eight 1/16" diameter holes evenly spaced along the ridge of the bottle bottom. These are the jet holes
1. Widen the opening of the shorter 1" bottle bottom. This is the BASE This opening should be widened to allow the jet deck to tightly telescope inside to the bottom.
I used a 1.5" diameter PVC pipe fitting to widen the aluminum "cup". Place the PVC pipe in the cup and by anglings the cup while pulling, the cup is "rolled" off the pipe. This is done repeatedly rotating the cup a few degrees each time to gradually increase the diameter of the cup.
Be careful not to "flare" the edge of the cup. You do not want to create a "lip" on the edge. The goal is to increase the whole diameter of the cup to slide tightly over the outside of the Jet Deck.
Telescope Jet Deck to Base
1. Insert the Jet Deck into the Base.
2. Press evenly to fully set the Jet Deck to to bottom of the base. You may need to place a board over the assembly and use a hammer to finish stretching the base to fully seat the Jet Deck
Be careful to force the two pieces together evenly. They need to be aligned or the side wall of the Base could split or the side wall of the Jet Deck could crease.
Take the Burn Bowl from step 4 and remove material from the small end of the neck as necessary, until the neck is short enough to allow the tapered portion to fit tightly in the hole of the Jet Deck.
It should be a tight force fit without gaps. Also the narrow end of the Burn Bowl neck should be touching the bottom of the Base so do not remove too much material at once.
This part will be the COLONNADE. Openings are cut in the sides to allow for the jet flames to burn while the remaining series of columns support the Burn Bowl.
At this point use emery cloth and steel wool to remove the paint (if you like the bare metal look). It is easier now before all the openings are cut.
1. Widen the opening of the remaining 1.5" tall bottom.
Only widen the first 1/2" of the opening so that it just fits tightly over the Jet Deck.
2. Drill a hole in the center of the bottom and widen it as described in step 5 however this hole is wider. Make it about 1.75" in diameter ( widen the hole to remove the "dish" in the bottom - just to the ridge at the edge.)
3. Cutout (8) openings in the side walls to form the Colonnade. These openings are approximately 0.5" wide by 0.75" tall. (Make sure they line up with the jet hole in the Jet Deck)
I could not find an easy way to make these openings. I started with a few drill holes and widened with a file from there.
4. Assemble the Colonnade over the Burn Bowl and press the bottom opening of the Colonnade over the top of the jet deck.
Note: the Colonnade should press tightly down on the top of the Burn Bowl. it bottoms out on the top of the base prematurely, material may need to be removed from the bottom of the Colonnade to allow it to seat down far enough on the Jet Deck. The goal is to clamp the burn bowl into the opening in the Jet Deck.
Time to Cook
I use Ethyl rubbing alcohol as fuel. An old plastic film canister is a good dosing tool. It is the right amount for about a 10 minute burn (enough to boil a few cups of water.)
Safety note: Never use petroleum based fuels in this type stove. There explosive nature make them unsuitable for this type stove.
Pour the alcohol in the burn bowl and light.
After about 30 seconds the stove is hot enough to vaporize the alcohol and ignite the jets.
At this point the pot can be placed on top of the stove.
The jets will heat both the pot and the stove.
This continuous heating of the outside of the burn bowl is what keeps this stove lit when a cold pot is placed on it.
Make an option cap from another can bottom and then you can store a canister of fuel in the stove for transport.
The Alcohol is stored in a separate container. The cap is used to retain a small fuel container/bottle inside the stove. In this case I referenced using a plastic film canister but any small plastic bottle with a secure lid that fits in the stove could be used.
You could also store other small related items inside the stove like matches, folded aluminum foil for a wind brake, or a pocket knife, etc.
With a perfect seal at the bottom, the alcohol would never reach the jets. In other designs with similar inner walls they notch the bottom of the wall to create a "weep hole" for the alcohol to reach the pressurized outer chamber.
In Stoves designs (with a center chamber open to ambient ) the pressure stops in the outer chamber when the liquid alcohol level drops to the top of the weep holes (the inner and outer chamber pressure equalizes to ambient). In short, the weep holes typically want to be as small as possible for the longest burn time. With this design however the size of the weep hole would not be a factor because the inner chamber is also pressurized throughout the burn because it is sealed by direct contact with the cooking pan. Because all pans are not perfectly flat and may not totally seal the inner chamber, I chose to not add weep holes to maintain pressure in the outer chamber as long as possible.
Having said all that... the type of tolerances we are working with here, the seal at the bottom is not perfect and the alcohol manages to seep into the outer chamber without weep holes. The seal at the neck of the burn bowl is much better as the neck actually deforms the hole in jet deck to form a nice press fit.
Venom has crazy thick cans too, and they're real cheap and good so grab one of them for the under 21 crowd
Wal-Mart caries Pepsi in aluminum bottles.
There’s less fancy ones made of two soda can bottoms shimmied together but I like how much more sturdy this one looks, and that fact that it doesn't need a separate stand. It also looks a lot better in my opinion but that has a lot to do with how much work he put into making this, not just the design.
Denatured means ethanol mixed with methanol and some chemicals to make it taste bad, so people won't drink it.
Rubbing alcohol is simply any kind of alcohol used for disinfecting cuts. It is usually isopropyl alcohol.
Isopropyl doesn't burn as cleanly as other alcohol and can cover your stove with soot.
Ethanol is the type of alcohol that you drink, like vodka (about 40%) or Everclear (about 90%). It is also called grain alcohol.
Methanol is similar to ethanol except that it is poisonous and will not make you drunk. It is also called wood alcohol and is used as race car fuel and in fuel-line antifreeze (those yellow "Heet" bottles at the gas station). It burns with a very light blue flame that can't be seen in daylight.
If you can find pure ethanol or denatured alcohol I would go with that. It's probably cheaper than methanol anyway.
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