Welcome to the AppalachianTrailCafe.net!
Take a moment and register and then join the conversation

Alcohol Stoves

    This site uses cookies. By continuing to browse this site, you are agreeing to our Cookie Policy.

    • Alcohol Stoves

      BirdBrain wrote:

      I prefer 35mm for the stove height. I would cut one more row of squares off the hardware cloth to compensate. I like OMO's idea of trimming the hardware cloth.

      I need to find a can that has an upper rim the same diameter as the diameter of the can. If I could there would be no need for JB Weld. I wonder if Kern's cans are that way.

      Off to find some hardware cloth.


      Yes, I have 1/2" hardware cloth with every other wire cut out. It is noticeably lighter but still plenty sturdy to hold a 1 L pot full of water. I only have galvanized wire so I have to take care to burn off the zinc outside and then it starts to corrode, but for now, that seems to be only cosmetic. Haven't noticed any weakness yet. I make my pot stands as large as possible to give me a stable platform for my pot. I spilled a meal or two when using a side burning bottle stove with no pot stand, so I'm willing to carry a few extra grams for that. With the Olicamp pot, there is the heat exchanger that extends out of the bottom so you either make your stand the right diameter to be centered on the exchanger ring. Or you could make it small enough to fit inside the ring, which might be an advantage because it could not slide off, but would then need to be 1/2" taller.

    • Alcohol Stoves

      TrafficJam wrote:

      BirdBrain wrote:

      TrafficJam wrote:

      I got boiling water in 5 min but the flame was shooting up the side of the pot. Is that okay?




      gif.002 It is not desirable. This is why I use a Kmart grease pot. It suits my stoves better. Sorry. 2.gif


      Making the screen wider won't help?

      It might. Is this new with the screen? Did it do it without the screen?
      Non hikers are about a psi shy of a legal ball.

    • Alcohol Stoves

      BirdBrain wrote:

      TrafficJam wrote:

      BirdBrain wrote:

      TrafficJam wrote:

      I got boiling water in 5 min but the flame was shooting up the side of the pot. Is that okay?




      gif.002 It is not desirable. This is why I use a Kmart grease pot. It suits my stoves better. Sorry. 2.gif


      Making the screen wider won't help?

      It might. Is this new with the screen? Did it do it without the screen?


      It's new with the screen.
      Lost in the right direction.

    • Alcohol Stoves

      TrafficJam wrote:

      BirdBrain wrote:


      This is my current set up. Notice Kmart grease pot is short and wide with no handle. It is coated black too.


      I'll try to find one. I know you've talked about your wider pot before but I didn't think to measure mine to compare. Thanks for everyone's help, it's been fun learning how to use my stove.


      Stenco is same pot. Amazon and eBay sell them. Should be under $10.
      Non hikers are about a psi shy of a legal ball.

    • Alcohol Stoves

      stoviewander wrote:

      BirdBrain wrote:

      stoviewander wrote:

      I am off to Indiana to make some money. It is a long drive. I will camp for a few days and do some boil tests.


      Enjoy. I will leave you with a couple more thoughts on the CHS stoves. Everything on these things has to be so right for them to work right. Only a person with OCD would like building them for long. I love the fact the stoves keeps forcing me back to detail every time I try something new. I have changed a couple things from the original design, but not much. The designer really got this one right. The one mystery I cannot solve is why he prefers the chs-u over the chs-easy. My chs-easy stove is much more efficient than my chs-u. After I got it right, this thing became so efficient, it forced me away from my beloved side burners. There has to be a reason he prefers the chs-u. I can't find it. The chs-easy allows me to place the jets very close to the rim and to top. Efficiency drops off the further you place the jets down and away from the rim.


      I expect the jets need to be close to the rim so they can mix well with air. I do not smell anything when my nose is a safe distance above the flames.

      I punched eight holes 1/4" in diameter at the edge of the dome spaced between jets. I will see how it works when I get to a campground.

      I can get probably make the jet holes within 10 mm of the top, maybe even 8 mm if I am careful. If I use JB Weld instead of folding over the top edge, I may be able to do even better.

      The CHS-easy should weigh less and be shorter for equivalent fuel capacity. I do not drink V8. If I find some more Kern's Nectar cans, I may try a CHS-easy. If so, it will be the first time I use JB Weld. I have some already.


      I was not thinking when I wrote 10 mm for the jet holes. They are about 6 mm from the top. The 10 mm is the height of the top inner piece, which could be cut down to 8 mm and still fold over the top edge, or maybe less than 8 mm with JB Weld.

      Anyway, with the eight 1/4" holes, the time to bloom was 45 seconds. After nibbling away the dome with my 1/4" paper punch, the time to bloom was 30 seconds, with short jets just becoming visible at 20 seconds. There is still about 5 mm of the inner top piece that would need to be ground off for an apples to apples comparison with my previous version (with 10 ribs). So I guess the smaller ribs help with the bloom.



      The domed area at the bottom of the burner probably interferes with the flames and leaves little room for the flames to heat the ribbed area. I can try making a taller burner, or use the unopened top of a 7.5 ounce can as the outer piece. I will probably do a little of each. There is a raised bump that will collect fuel, preventing it from reaching the tabs. I will see if I can deform that bump to create some drainage. If so, the next version will be made from two can tops and one can bottom.

      I found a 12 ounce Red Bull can in the trash. It seems to be dimensionally similar to the 7.5 ounce soda cans, just taller.
      I am human and I need to be loved - just like everybody else does

    • Alcohol Stoves

      stoviewander wrote:

      stoviewander wrote:

      BirdBrain wrote:

      stoviewander wrote:

      I am off to Indiana to make some money. It is a long drive. I will camp for a few days and do some boil tests.


      Enjoy. I will leave you with a couple more thoughts on the CHS stoves. Everything on these things has to be so right for them to work right. Only a person with OCD would like building them for long. I love the fact the stoves keeps forcing me back to detail every time I try something new. I have changed a couple things from the original design, but not much. The designer really got this one right. The one mystery I cannot solve is why he prefers the chs-u over the chs-easy. My chs-easy stove is much more efficient than my chs-u. After I got it right, this thing became so efficient, it forced me away from my beloved side burners. There has to be a reason he prefers the chs-u. I can't find it. The chs-easy allows me to place the jets very close to the rim and to top. Efficiency drops off the further you place the jets down and away from the rim.


      I expect the jets need to be close to the rim so they can mix well with air. I do not smell anything when my nose is a safe distance above the flames.

      I punched eight holes 1/4" in diameter at the edge of the dome spaced between jets. I will see how it works when I get to a campground.

      I can get probably make the jet holes within 10 mm of the top, maybe even 8 mm if I am careful. If I use JB Weld instead of folding over the top edge, I may be able to do even better.

      The CHS-easy should weigh less and be shorter for equivalent fuel capacity. I do not drink V8. If I find some more Kern's Nectar cans, I may try a CHS-easy. If so, it will be the first time I use JB Weld. I have some already.


      I was not thinking when I wrote 10 mm for the jet holes. They are about 6 mm from the top. The 10 mm is the height of the top inner piece, which could be cut down to 8 mm and still fold over the top edge, or maybe less than 8 mm with JB Weld.

      Anyway, with the eight 1/4" holes, the time to bloom was 45 seconds. After nibbling away the dome with my 1/4" paper punch, the time to bloom was 30 seconds, with short jets just becoming visible at 20 seconds. There is still about 5 mm of the inner top piece that would need to be ground off for an apples to apples comparison with my previous version (with 10 ribs). So I guess the smaller ribs help with the bloom.



      The domed area at the bottom of the burner probably interferes with the flames and leaves little room for the flames to heat the ribbed area. I can try making a taller burner, or use the unopened top of a 7.5 ounce can as the outer piece. I will probably do a little of each. There is a raised bump that will collect fuel, preventing it from reaching the tabs. I will see if I can deform that bump to create some drainage. If so, the next version will be made from two can tops and one can bottom.

      I found a 12 ounce Red Bull can in the trash. It seems to be dimensionally similar to the 7.5 ounce soda cans, just taller.


      I have not flattened the dome on any on my chs stoves. I do not know what effect it will have. I know it was a huge issue on my original Budweiser side burners. The domed Mountain Dew bottles (what I am making my Puuuurrrrtttty Stoves out of) would not work with the BirdBrain side burner. It works fine with the Puuuurrrrtttty Stove. One thing to consider as you try to lower the prime time is that the chs stoves do not need the alcohol to heat up as much as other designs do. As a matter of design, if it is heating up as much, the stove is failing. You ought to be able to hold the stove in your hand as it is burning (swapping hands every few seconds because it is warm). The key is to provide the proper amount of fuel to the hoop in a consistent manner. Once that is accomplished jet location, diameter, number, and angle will do the rest. The height to width ration is important too. I am very happy with my 35 mm high stoves. I cannot imagine changing any of the parameters of my chs-easy. I am reading your posts with great interest just in case you make discoveries I have not. However, I suspect Tetkoba has made every discovery we will encounter.
      Non hikers are about a psi shy of a legal ball.

    • Re:Alcohol Stoves

      I know that I've asked this before, but I don't think I ever saw an answer. I've seen a bunch of stoves here, capillary hoop and otherwise, with the jets pointing inward, often with some effort devoted to vortex formation. What's the purported advantage of this design over a pressurized top burner?

      Sent from my SCH-I545 using Tapatalk
      I'm not lost. I know where I am. I'm right here.

    • Alcohol Stoves

      odd man out wrote:

      Made my first CHS- Easy today. I have to let the JB Weld set until tomorrow before I can test it.
      I am not optimistic, but who knows maybe it will work.
      I used an Ocean Spray 8.4 oz cran-lemonade can.
      It's about 32 mm tall. 8 jets drilled with 1/32" bit. 18 ribs.


      As you see I really mangled the hole cutting in the top. Not sure how critical that is. Also not sure I cut the slots between the tabs long enough. Do you cut the slots before or after making the dents for the ribs? I cut the tabs last, but then thought it may have been a good idea to do that first. Denting the ribs was hit or miss. Hole drilling went well. I am pretty confident the jets are OK.

    • Re:Alcohol Stoves

      AnotherKevin wrote:

      I know that I've asked this before, but I don't think I ever saw an answer. I've seen a bunch of stoves here, capillary hoop and otherwise, with the jets pointing inward, often with some effort devoted to vortex formation. What's the purported advantage of this design over a pressurized top burner?

      Sent from my SCH-I545 using Tapatalk


      I answered this once. There are a few advantages I can see.

      1) Open bowl allows for fuel recovery if you choose to snuff flame after boil.
      2) Focus of flame at center
      3) Flame originates at top reducing thermal feedback on stove
      4) Vortex and inward flame prohibits fuel from being burned in bowl.
      6) Very fast prime (mine start in 4 seconds with complete jets in 8 seconds)
      7) 7 - 10 gram construction

      My issue with top or center burners was the out of control fluttering of the flame. Every stove has a theoretical sweet spot for the flame. If the flame flutters and bounces, the sweet spot is constantly moving. The cat stoves are like this. The penny stoves control the flame better, but typically prime slow and don't allow for fuel recovery. Many stoves require the fuel to heat to a certain level for the stove to run. This one runs much cooler and does not require the heating of the fuel for efficiency. You can hold this stove in your hand while it is running. Ideally the stove will direct as much heat to the stove in a controlled manner. This stove does that better than any stove I have seen.

      Mind you AK, this is coming from a man that loves side burners. I stubbornly gave the center burner concept every chance to beat my side burners. I am stubborn, but not stupid. This stove kicks my side burner stove's ass.
      Non hikers are about a psi shy of a legal ball.

    • Alcohol Stoves

      odd man out wrote:

      odd man out wrote:

      Made my first CHS- Easy today. I have to let the JB Weld set until tomorrow before I can test it.
      I am not optimistic, but who knows maybe it will work.
      I used an Ocean Spray 8.4 oz cran-lemonade can.
      It's about 32 mm tall. 8 jets drilled with 1/32" bit. 18 ribs.


      As you see I really mangled the hole cutting in the top. Not sure how critical that is. Also not sure I cut the slots between the tabs long enough. Do you cut the slots before or after making the dents for the ribs? I cut the tabs last, but then thought it may have been a good idea to do that first. Denting the ribs was hit or miss. Hole drilling went well. I am pretty confident the jets are OK.


      I cut the slots 1st and use them as a guide for rib construction. I will link back to my pictures next.
      Non hikers are about a psi shy of a legal ball.

    • Alcohol Stoves

      BirdBrain wrote:

      odd man out wrote:

      What are the "dents near the top"?


      Look at the 2nd picture on my last post. They are created by pushing down on the outside of the collet with a triangle file. They make a mark to line up with the slots cut at the bottom with a piece of a hacksaw blade. These 2 reference points make it easy to see where to press down to create the ribs as shown by the bottom picture in the same post.


      Bump
      Non hikers are about a psi shy of a legal ball.

    • Alcohol Stoves

      Ya know what - BB is giving too much away for all the hard work - the one I received was very well made... I have made many stoves, none for sale its an art and a work in time. ... but well... shuffles feet... if you can get one from BB... make sure you take care of him... I love the internal stove.
      Be wise enough to walk away from the nonsense around you! :thumbup:

    • Alcohol Stoves

      WiseOldOwl wrote:

      Ya know what - BB is giving too much away for all the hard work - the one I received was very well made... I have made many stoves, none for sale its an art and a work in time. ... but well... shuffles feet... if you can get one from BB... make sure you take care of him... I love the internal stove.

      I would love to sell them for him.
      I reckon I could find a market for a few over here.
      He is way too generous to us and deserves some reward for his work.
      I have him on my list for something when I think of something suitable.
      Resident Australian, proving being a grumpy old man is not just an American trait.

    • Alcohol Stoves

      OzJacko wrote:

      WiseOldOwl wrote:

      Ya know what - BB is giving too much away for all the hard work - the one I received was very well made... I have made many stoves, none for sale its an art and a work in time. ... but well... shuffles feet... if you can get one from BB... make sure you take care of him... I love the internal stove.

      I would love to sell them for him.
      I reckon I could find a market for a few over here.
      He is way too generous to us and deserves some reward for his work.
      I have him on my list for something when I think of something suitable.



      I'm planning something for BB
      and hope to start on it soon. It's not related to hiking but it's going to be green. It's not knitted either.
      Lost in the right direction.

    • Alcohol Stoves

      TrafficJam wrote:

      OzJacko wrote:

      WiseOldOwl wrote:

      Ya know what - BB is giving too much away for all the hard work - the one I received was very well made... I have made many stoves, none for sale its an art and a work in time. ... but well... shuffles feet... if you can get one from BB... make sure you take care of him... I love the internal stove.

      I would love to sell them for him.
      I reckon I could find a market for a few over here.
      He is way too generous to us and deserves some reward for his work.
      I have him on my list for something when I think of something suitable.



      I'm planning something for BB
      and hope to start on it soon. It's not related to hiking but it's going to be green. It's not knitted either.


      I say thank you. However, you guys are nuts. I have gained far more from this community than I have provided.
      Non hikers are about a psi shy of a legal ball.

    • Alcohol Stoves

      odd man out wrote:

      I see you mark a line to control the depth of the notches between the tabs. How deep is the notch?


      About a 1/4". Don't go under that amount. If you do, the ribs can get crushed as you try to insert the collet all the way. It is okay to be a tad over that. I have noticed that Tetkoba seems to be increasing that measurement. Again, I assume there is a reason for that. I can't find it though.
      Non hikers are about a psi shy of a legal ball.

    • Alcohol Stoves

      BirdBrain wrote:

      TrafficJam wrote:

      OzJacko wrote:

      WiseOldOwl wrote:

      Ya know what - BB is giving too much away for all the hard work - the one I received was very well made... I have made many stoves, none for sale its an art and a work in time. ... but well... shuffles feet... if you can get one from BB... make sure you take care of him... I love the internal stove.

      I would love to sell them for him.
      I reckon I could find a market for a few over here.
      He is way too generous to us and deserves some reward for his work.
      I have him on my list for something when I think of something suitable.



      I'm planning something for BB
      and hope to start on it soon. It's not related to hiking but it's going to be green. It's not knitted either.


      And it will probably take a long time to complete.

      I say thank you. However, you guys are nuts. I have gained far more from this community than I have provided.
      Lost in the right direction.

    • Alcohol Stoves

      It worked. Took about 15 seconds to bloom. Burned for about 5 minutes on 15 mL of fuel. Haven't done a boil test yet. Will post that when I get to it. Here are some pics. One I photoshopped the color/contrast a bit to highlight the flames. My flame makes a left handed helix instead of a right handed helix, not that it matters. I wonder if I should angle the jets to point upward more? Could maybe to a better job cutting the hole and notches, and making the dents. I did notice hat the stove was quite hot when it flamed out. Not the cold burning effect as advertised.

      Will I like this better than my Starlyte Stove? I will see how the burn times go. I'm not such a gram weenie and I value some convenience. With the Starlyte, I can blow the flame out easily when I am done cooking and cap the stove. Plus it has that spill-preventing fuel-absorbing wick. This saves fuel since I only burn what is necessary and save the rest for next time. Also, I don't have to guess how much fuel I am going to need based on variable conditions (air temp, water temp, wind speed). With most alcohol stoves, if you guess low, you run out of fuel prematurely, If you guess high, you waste the excess fuel. A downside of the Starlyte is the stove power drops a lot (about 30%) when the fuel load get low. I did not notice this effect with the CHS-EZ. My boil test will quantify that. But because of the Starlyte's lid and absorbing wick, this isn't a huge deal since I can just load it up to the top to get maximum power and blow it out when done. One option of the CHS-EZ is to have a snuffer and a dropper to retrieve excess fuel. I saw on one pic there was a max fill line for the CHS-EZ. How do you know where that is? What happens if you over fill it?

      One other note, the lid of the Starlyte fits perfectly on the CHS-EZ. However, I don't know how tight the seal is. The Starlyte has a dimple around the top edge for the lid to snap onto whereas the side of the CHS-EZ is straight.
      Images

      • IMG_3984.jpg

        54.5 kB, 426×640, viewed 306 times

      • IMG_3985.jpg

        39.08 kB, 427×640, viewed 310 times

    • Alcohol Stoves

      So here are some test results comparing my system using my first CHS-EZ and the Starlyte. This is with an Olicamp XTS pot, aluminum flashing wind screen, hardware cloth pot stand, 24 oz of water and 15 mL XTS denatured alcohol (which is supposedly a 50/50 mix of methanol and ethanol. I intentionally use more water than will boil so I can measure both the power and efficiency of the system. Efficiency is percent of the total available energy that is delivered to the water (calculated from the change of Temp). Power is calculated from the rate of temperature rise (slope during the linear range of operation). For the Starlyte, the flame wimps out to a flicker for the last min or two. The CHS seems to go full blast right to the end. To calculate the time to boil 2 cups and mL of fuel to boil two cups, I use the heating rate and the rate of fuel consumption, and prorate that for the volume of water in the pot vs 2 cups (710 mL vs 473 mL). I think that for center burning stoves in this system, the less powerful stove will be more efficient as there is more time for the heat to be absorbed by the pot. It's the same with cars - faster cars=less MPG.



    • Alcohol Stoves

      odd man out wrote:

      So here are some test results comparing my system using my first CHS-EZ and the Starlyte. This is with an Olicamp XTS pot, aluminum flashing wind screen, hardware cloth pot stand, 24 oz of water and 15 mL XTS denatured alcohol (which is supposedly a 50/50 mix of methanol and ethanol. I intentionally use more water than will boil so I can measure both the power and efficiency of the system. Efficiency is percent of the total available energy that is delivered to the water (calculated from the change of Temp). Power is calculated from the rate of temperature rise (slop during the linear range of operation). For the Starlyte, the flame wimps out to a flicker for the last min or two. The CHS seems to go full blast right to the end. To calculate the time to boil 2 cups and mL of fuel to boil two cups, I use the heating rate and the rate of fuel consumption, and prorate that for the volume of water in the pot vs 2 cups (710 mL vs 473 mL). I think that for center burning stoves in this system, the less powerful stove will be more efficient as there is more time for the heat to be absorbed by the pot. It's the same with cars - faster cars=less MPG.





      Very nice. I would be interested in your results when you perfect a chs-easy. If you are like me, your 1st attempt will not be your best. I do expect the results to be similar. Sgt Rock's Ion Stove is even more efficient. It is to be expected that as you lower the boil time using the same fuel the efficiency will suffer. It is a matter of priority. How long to do you want to wait and at what cost, I do expect you to get better numbers with the chs-easy as you perfect it. Mine boils 2 cups starting at 70° in 3 minutes and 45 seconds on 14.5 ml of Heet.
      Non hikers are about a psi shy of a legal ball.

    • Alcohol Stoves

      BirdBrain wrote:

      Now you have me curious. Running out to test my stove on 3 cups starting at 68° with 15 ml of Heet to see what my max temp will be.


      Mine made it to 78.3 C in just under 4 minutes. I don't have your pot. I also don't have a Starlyle to compare. Oh well. I am happy where I am.

      Note: I am mixing scales. I started at 68 F (20 C) and went to 78.3 C (173 F).
      Non hikers are about a psi shy of a legal ball.

    • Alcohol Stoves



      Two 7.5 ounce soda cans were used to build my CHS-Unorthodox alcohol burner, which is based on the Capillary Hoop Stove - Universal by Tetkoba. The top 29 mm and bottom 8 mm cut from one can, and the top 41 mm cut from a second can were used. The 8 mm was measured after cutting. The 29 mm and 41 mm are estimates, based on measurements taken after assembly. The cut edges were filed gently with a flat bastard.

      There are 8 holes 1/32" in diameter in the 8 mm piece. The holes were formed by pressing a center punch at an angle into the thicker aluminum of the can bottom, as close to the side wall as practical, and then drilling the holes inward. With the burner sitting level, the holes are tilted up approximately 25 degrees away from horizontal, and approximately 40 degrees away from a line drawn tangent to the circular cross section of the can (in the horizontal plane, approximately 50 degrees away from intersecting the can's axis of symmetry). The domed portion was removed by scoring with a center punch and tearing with pliers.

      There are 20 creases / ribs in the 29 mm piece. The creases were made by pressing a 1/8" diameter shepherd's hook tent peg into the shoulder and side wall. Twenty holes were punctured with a center punch 6 mm from the cut edge and drilled with a 3/64" bit. A triangle with an approximately 2 mm base and an apex centered within each 3/64" hole was removed with scissors. The resulting tabs were bent inward, and the tent peg was pressed once more against the creases, nearly straightening the tabs. The 29 mm piece was inserted into the 41 mm piece. Inserting the first 5 mm was easy. The 3/64" holes were difficult to insert, but the remainder of the 29 mm piece slid in smoothly.

      The 8 mm piece was inserted above the 29 mm piece, and firmly seated below the cut edge of the 41 mm piece, stopping when the tabs on the 29 mm piece could advance no farther. A fingernail pressed the 3/64" holes into the shoulder of the 41 mm piece. The edge of the 41 mm piece was trimmed to 3 mm above the edge of the 8 mm piece and folded inward with a center punch.

      The burner was tested with 20 ml of denatured alcohol and 2 cups of 43F water in a Halulite Minimalist pot at an outdoor temperature of 48F. There was a slight breeze. The sky was mostly blue with a few clouds. The windscreen and potstand consisted of two Armour beef stew cans. The heat reflector was a 5" diameter aluminum vent cap. After 4 minutes, the water reached 195F, but the rate of temperature increase slowed dramatically. The fuel burned for 6 minutes. The water reached 211F. The pot did not vent steam.

      The burner was tested again without a windscreen or pot, inside a walled shelter. Roughly 20 ml of denatured alcohol was added to the burner. The jets started to form 12 seconds after lighting the burner, and were well formed after 20 seconds. No bubbles were visible. After a few minutes (not measured), the burner made some hissing and sizzling sounds, the jets stopped abruptly, and the fuel that could not drain towards the tabs burned for another 2 minutes and 5 seconds.

      There is a raised ring at the bottom of the burner which traps the last few milliliters of fuel, preventing it from reaching the tabs. An earlier attempt to create drainage resulted in a puncture. Perhaps a circular piece of aluminum foil could be stretched and epoxied across this ring to avoid the two minute simmer after the jets stop.
      I am human and I need to be loved - just like everybody else does

    • Alcohol Stoves

      stoviewander wrote:



      Two 7.5 ounce soda cans were used to build my CHS-Unorthodox alcohol burner, which is based on the Capillary Hoop Stove - Universal by Tetkoba. The top 29 mm and bottom 8 mm cut from one can, and the top 41 mm cut from a second can were used. The 8 mm was measured after cutting. The 29 mm and 41 mm are estimates, based on measurements taken after assembly. The cut edges were filed gently with a flat bastard.

      There are 8 holes 1/32" in diameter in the 8 mm piece. The holes were formed by pressing a center punch at an angle into the thicker aluminum of the can bottom, as close to the side wall as practical, and then drilling the holes inward. With the burner sitting level, the holes are tilted up approximately 25 degrees away from horizontal, and approximately 40 degrees away from a line drawn tangent to the circular cross section of the can (in the horizontal plane, approximately 50 degrees away from intersecting the can's axis of symmetry). The domed portion was removed by scoring with a center punch and tearing with pliers.

      There are 20 creases / ribs in the 29 mm piece. The creases were made by pressing a 1/8" diameter shepherd's hook tent peg into the shoulder and side wall. Twenty holes were punctured with a center punch 6 mm from the cut edge and drilled with a 3/64" bit. A triangle with an approximately 2 mm base and an apex centered within each 3/64" hole was removed with scissors. The resulting tabs were bent inward, and the tent peg was pressed once more against the creases, nearly straightening the tabs. The 29 mm piece was inserted into the 41 mm piece. Inserting the first 5 mm was easy. The 3/64" holes were difficult to insert, but the remainder of the 29 mm piece slid in smoothly.

      The 8 mm piece was inserted above the 29 mm piece, and firmly seated below the cut edge of the 41 mm piece, stopping when the tabs on the 29 mm piece could advance no farther. A fingernail pressed the 3/64" holes into the shoulder of the 41 mm piece. The edge of the 41 mm piece was trimmed to 3 mm above the edge of the 8 mm piece and folded inward with a center punch.

      The burner was tested with 20 ml of denatured alcohol and 2 cups of 43F water in a Halulite Minimalist pot at an outdoor temperature of 48F. There was a slight breeze. The sky was mostly blue with a few clouds. The windscreen and potstand consisted of two Armour beef stew cans. The heat reflector was a 5" diameter aluminum vent cap. After 4 minutes, the water reached 195F, but the rate of temperature increase slowed dramatically. The fuel burned for 6 minutes. The water reached 211F. The pot did not vent steam.

      The burner was tested again without a windscreen or pot, inside a walled shelter. Roughly 20 ml of denatured alcohol was added to the burner. The jets started to form 12 seconds after lighting the burner, and were well formed after 20 seconds. No bubbles were visible. After a few minutes (not measured), the burner made some hissing and sizzling sounds, the jets stopped abruptly, and the fuel that could not drain towards the tabs burned for another 2 minutes and 5 seconds.

      There is a raised ring at the bottom of the burner which traps the last few milliliters of fuel, preventing it from reaching the tabs. An earlier attempt to create drainage resulted in a puncture. Perhaps a circular piece of aluminum foil could be stretched and epoxied across this ring to avoid the two minute simmer after the jets stop.


      SW, you really need to go to the narrower can. The small V8 cans work much better.
      Non hikers are about a psi shy of a legal ball.

    • Alcohol Stoves

      BirdBrain wrote:

      SW, you really need to go to the narrower can. The small V8 cans work much better.


      I am not sure if you meant the to time to boil, efficiency, time to build, or difficulty of building one.

      I am quite happy with the rate of temperature rise while the jets are burning. If I had started with 70F water, it should have boiled in less than 4 minutes, and then simmered for 2 more minutes, or I could have snuffed out the burner and recovered some fuel. I may be able to boost efficiency if I play with the distance between the bottom of the pot and the top of the burner. The burner is almost 1 1/2" tall, and the pot sits about 4" above the heat reflector, for a gap of 2 1/2". I can probably reduce that gap, based on your test results.

      Overall, this burner works much better than any other type of burner I have built. I may be able to heat water faster, or more efficiently, but not simultaneously. This burner has an excellent balance of speed and efficiency, IMO.

      I built the previous version in about an hour and ten minutes. I drilled the jet holes with a Dremel tool, which is faster and easier than using a pin vise and works just as well due to the indentations made with the center punch. I would not try this technique with the CHS-easy, since the center punch would probably tear the aluminum before making an adequate indentation. The pin vise is probably required for the thinner aluminum of the CHS-easy jet holes. How long does building the CHS-easy take for you (neglecting the 24 hours for the epoxy to harden)?
      I am human and I need to be loved - just like everybody else does

    • Alcohol Stoves

      BirdBrain wrote:

      BirdBrain wrote:

      Now you have me curious. Running out to test my stove on 3 cups starting at 68° with 15 ml of Heet to see what my max temp will be.


      Mine made it to 78.3 C in just under 4 minutes. I don't have your pot. I also don't have a Starlyle to compare. Oh well. I am happy where I am.

      Note: I am mixing scales. I started at 68 F (20 C) and went to 78.3 C (173 F).


      I plugged your number into my spreadsheet for comparison. You got a great system there.
      The nice thing about this type of test (not to boiling) is that you get a measurement of both efficiency (proportional to change of temp) and power (proportional to rate of temp change). The other calculated values (time to boil 2 cups, mL fuel to boil two cups) are sort of standard benchmarks that can be estimated from the data. These are only estimates as there are some assumptions that have to be made to do that calculation. Actual data might vary slightly, but being able to get these in a single test is nice.