alky stove Idea, I need suggestions

I am having fun trying to build an alky stove two so far.

I'm thinking of trying a soda can stove inside a larger can as a wind screen.
I plan to simply use a larger can to place the stove inside of the same as some of the wind screens I see out there only smaller I'm not sure how small I can go with this, I have an almond can which would leave about a half an inch gap.


1 should I make vent holes?
2 how tall should the wind screen be?
3 does anyone even think it will work? LOL
4 how much space should I have between the two cans?

The larger can will have to be larger than a aluminum Heiniken can. Fire needs oxygen to burn efficently. There are tons of alcohol stove ideas online. The penny stove is excellent, But tweaking and testining makes it your own. I personally have best luck with can stove and aluminum wind screen

the problem with using a can as a windscreen, at least with beverage type cans, is that the sidewalls of the cans are very thin, and most of the can's strength comes from the top and bottom rims, which are thicker.

You will definitely need ventilation holes on one side of the bottom, this is obviously the side you will face away from the wind direction.

You will also need to leave at least a 3/8" gap around the pot for the heat and exhaust to escape. The closer the gap, the more efficient the heat transfer, but too little gap will either suffocate the stove, or cause the fuel to condense on the pot. Both bad. The good thing about using something like cans is that they're cheap, so you can play around with it, and experiment with different ideas.

The other problem I've noticed if your windscreen is too close to your stove is that it will reflect too much heat back into the fuel, and speed up the burn rate, which sometimes reduces efficiency. I've done a good deal of tinkering with my alcohol stove of late, and was able to get my pot/stove/windscreen setup weight down to under 2 ounces. I can boil 2 cups on less than a half-ounce of fuel. In relatively calm air, my boil times were in the vicinity of 9 minutes, not fast, but for the overall system weight, and fuel efficiency, I'm fine with it. I also tested it in 20+ mph winds, and was just barely able to get a full boil, which is pretty acceptable performance in my mind.

The pot is a foster's can with the top 1/4 cut off, and a lip rolled into it for sturdiness. The windscreen is a DIY caldera-cone type setup, and the stove is a tealight cup. Total weight for the setup, plus my styrofoam drinking cup is 1.9 ounces. I'll try to snap some pics of the setup, and maybe make a thread about it. I was able to shave something like 6-7 ounces of pack weight over my old stove setup, at the expense of slower boil times, which I'm more than ok with.

I don't think 1/2" will be enough of a gap for the output of a soda can stove and it will choke. Can I ask why you want to use an almond can instead of something like aluminum flashing or tooling foil for a windscreen?

My penny stove/GSI kettle setup's windscreen has a gap of 1/2" and works amazingly well. I can boil 2 cups in 4 minutes on 17ml of fuel. YMMV, but the way I've got the thing setup currently seems to be as close to perfect for the given components as it's going to get, which coincidentally means it's somewhat close to being not enough ventilation, and smothering the stove.

I've found that the best way of optimizing an alcohol stove setup is tinkering, trial and error.

Sounds like the Goya stove by atraildreamer
http://www.backpacking.net/makegear/goya-stove/index.html

He kindly sent me one of them , including two different burners (very well made)
It burned too hot for me. Possibly to do with the fact that we use Ethanol here.
However even diluting the Ethanol with water (by about 15%) it was still too hot.
The dilution works with pressurised stoves like the White Box.
I experimented later on using wider cans as a windscreen , still failed.
Franco

pretty terrible efficiency on that stove, they quote 8.5 min boil time, on a full ounce of fuel. That might be partly due to the absence of any sort of windscreen/heat funnel.

Seems like an overly complicated stove too, especially when compared with a supercat or tealight stove.

I was thinking more about this bit :
"I'm thinking of trying a soda can stove inside a larger can as a wind screen."
I tried several other stoves in that can as well as larger ones (larger can/windscreen) , none of them worked for me.
The stove that atraildreamer sent are standard Pepsi can stoves.
Franco

I think the "tinkering" idea is a good one. I have had so many of the Pepsi can type stoves that I have forgotten what most of them even look like. I have totes full of them in my garage/laboratory...L.O.L. I have done some serious tinkering too. I have probably thirty different configurations of the little Pepsi can stove and none of them work exactly the same, and I have some pretty elaborate set-ups too.(some are such that I would not take them on the trail) I think that the most important thing in a Pepsi can stove is the wall that you build on the inside of the stove that allows the fuel to burn as a gas rather than a liquid and it just seems more efficient. I have a couple of them that will boil 2 cups of water in around three minutes. Then I have others than work great but take as long as 10-12 minutes to get a good boil. Who's in a hurry any way?? Not me. I usually start my stove first and get the water on it while I am setting up my tent. The time works out just about right. Usually by the time that I have my tent up I will have boiling water and it all works out nicely. The choke hazard that Tinny sells at MiniBull is very efficient but doesn't have real good boil times. It usually takes around 10 minutes to boil three cups of water but it takes very little fuel to do so. The thing I like about the choke hazard is that you can boil if you want to do a little cooking rather than just boiling water. It cooks pasta and rice real nicely but it does take a little more time to do so.I guess where I will be going and how long I will be out and what the general weather will be like is what would determine what stove that I would carry with me on any given trip. So times I carry two stoves and that varies as much as the one does. I may carry an alky stove and then as a backup I may carry the pocket rocket with a couple of small canisters, again depending on where I am going and how long I will be out. A lot of times I will carry identical stoves so when the fuel runs out on the first one and I am trying to actually cook something, I will have the second one to continue the cooking process...sabre11004...

So how do you know how much fuel is enough?

a few of the stoves I have made don't stay lit or need alot of preheat fuel, I'm not sure what I'm doing wrong, I have worked a few machine shop jobs so I know how to use tools and follow plans I just can't seem to get some of them to work well.

could some one tell me which designs work good? and which will not send a lot of flame up the sides of the pot to melt my gsi lid

Narrow pots:
Chimney stoves work great. Several easy to make ones here: http://zenstoves.net/ChimneyStove.htm

I tinkered for a long time and eventually settled on the penny stove:
http://lmgtfy.com/?q=penny+alcohol+stove

which I use about 90% of the time. Easy to measure, relatively wind resistant, works well in the field.

I'm quite keen on the recent tealight and beercan setups I've seen, especially the one posted here though.

“So how do you know how much fuel is enough?”

My plastic bottles have permanent marker lines showing 1 fl. oz. steps. I usually pour that much per meal (2+ cups). I use the open-jet stove the most.

“a few of the stoves I have made don't stay lit or need alot of preheat fuel, I'm not sure what I'm doing wrong,…”

A few things can cause this:
1. Stove is made too tall. If using a pepsi stove, 1” high works well.
2. using steel or TI instead of aluminum.
3. Or anything else that makes your stove end up being a big heatsink.

-Barry

"I tinkered for a long time and eventually settled on the penny stove:
http://lmgtfy.com/?q=penny+alcohol+stove"

Have you had any problems with your penny stove? What kind of boil times have you experienced? I've read of some really amazing boil times with the penny stove.

I've been considering the penny stove myself, but have heard that there is risk of the pressure forcing the penny off the stove if the stove isn't constructed just right.

No.

That's the attraction to it for me, it's less fiddly and pretty much bozo proof (hi, bozo here..) when used as directed



What they quote on the page is accurate for *CONTROLLED CONDITIONS* if you do the same as what they are doing. you'll note most of the time they are boiling room temp water. Me in the field it's "longer" because I'm usually starting from water that's about 2-4 degrees centigrade instead of 20. But I don't
measure empiricly in the field- I'm out there to enjoy my hike, not obsess over my stove

I do like the fact that it is relatively wind resistant. no you can't use it in a gale with no windscreen, but with a reasonable screen it deals with windier conditions better than a chimney stove which really needs to be in a full cone.

I did a little race once with my brother's caldera cone in the field - no *practical* difference in fuel use or boil time. We both ate at the same time and carried the same amount of fuel




I've made dozens of them and other than screwing up once and mashing the top in and bending things I've never ever seen this. even if the penny were to move you just get a little more flame in the centre. Never seen it be a problem.

The "screwing up and mashing in the top" is less of a problem if you scrounge your heineken cans. In my case a friend and I dug out the shop knife and the 1/64 drill bit and decided to turn sitting by the firepit drinking beer into a stove making bee with a large amount of heineken. Making more stoves was a great excuse to drink three more beers. At least several times in the night there was the modified beauty and the beast quote: "More stoves? What for.. nothing helps..."

I may be WAY OFF here guys. Im kind of a newbie, Ive been camping/hiking for years and years, since I was like 8 yrs old. And Im 26 now. I dont really know a whole lot about stoves, as we usually use the campfire to cook everytime. I know that is not ALWAYS an option, and a stove is great to have In Case of Emergency, or where you cant use the wood yadda yadda etc. But I have just started the whole "Lighter is better" view on life lately.

In Sea Cadets, we used a tuna can with a (326gm)smaller coffee can. Cut into the coffee can, so the tuna can, 1.5X high up can fit through, like a rectangle shape. We used a candle, a votive not a tea light. I can recall putting my black socks in the coffee can, becuase if I packed anything in there (when travelling) it would have been sooty.

Ok, now someone has to let me know if I am off in left field here? Should I just keep my mouth shut or what?


(So, just now I went and researched penny stoves, and man o man, those are neat! Im not good with small little nicky nack things, Im terribly clumsy, and usually have some sort of gash/deep bruise/broken finger each and every summer. I like bigger things that I can have a chance with. But, I wonder if I should still look into something like that....)