Alcohol Stove

You might want to take a look at minibulldesign's Bios stove for more fuel capacity, probably more efficient also. A liter is a lot of water to boil with a cat stove. Depending on how you punched the holes you should be able to get more than an ounce of fuel in it but not much more. Cat stoves seem to work really well for the 2 cup range. If you are boiling that much water on a regular basis you might be better off with a canister stove.

https://www.minibulldesign.com/productcart/pc/viewPrd.asp?idproduct=54&idcategory=2

End2End's thru-hiker stove would also work:

http://end2endtrailsupply.com/Thru_Hiker_Stove.html

Jeff, don’t think an alcohol stove is some easy quick fix where you just pick a design and then get sad when it fails.

I just went through a few weeks (that’s weeks, not days or hours) testing and debugging until I got something I felt was ok for real world use, ie, this is what I was going to cook on for a week, with no fallback.

Here’s what I found: for a liter, you want a pot that has at least 5″ diameter, ideally a bit more. All the stoves guys sort of mumble something about stove widths, and the ones I read, all personally were using flatish 1.3 liter or 1.4 liter pots, and that’s not an accident I can assure you, that’s the ideal size, least heat lost. You can get other stuff to work, narrow pots, I did, but it takes a lot more testing.

You want a Jim Wood type aluminum wind screen, designed to give between 1/4, 3/8, or 1/2 inch extra space on outside between screen and pot. I ended up making an adjustable one so I could test the differences.

The penny stove if used on a wide bottomed pan should have no problems at all boiling 1 liter, which is about 4 cups of water, I got 3 cup boils in my later tests with about 0.75 ounce (1.5 tablespoons). For measuring, I was lucky and found a plastic tube that was about 1/2 thick and clear, then I marked off the tblspoons with lines inscribed. Trying to eye out a normal tablespoon can give a huge range of error I found, so a narrower tube works better.

Although I didn’t test a liter with the standard outward pointing six hole penny stove, with a decent closed pot, cover, and not just windscreen, but a true heat reflector/windscreen, that actually focuses and funnels the heat along the sides of the pot, I don’t see why at sea level, 60 to 70 degrees, I couldn’t get a liter to boil with about 1 oz of real alcohol, that’s stuff like klean-strip green (slx, can order from ace hardware, or Lowes has a green denatured, the green basically means it won’t kill you with toxic fumes when you burn it, unlike say, heet, which is garbage fuel, low heat output and truly vile smell/etc..

With alcohol fuels you need to remember that the closer to the real 95% ethanol you get, the better, since that’s the most heat you’ll be getting. Some user Everclear but that’s really expensive, but the idea is right. But klean-strip green denatured alcohol is a pretty high ethanol content, higher I believe than sunnyside green. And it’s pretty easy to find. I from now on will never use if I can help it any type of alcohol not labeled as ok for fuel, I felt this stuff in my lungs when I was testing it, and the low end stuff, especially heet, is NASTY, and it has very low heat since it’s methanol. So get familiar with this, or just find good green type denatured alcohol.

The penny stoves are not easy to make, and take some practice, trial and error. Hint: vernon ginger ale cans do not have the numbers imprinted on the bottom, just printed in ink, so they seal right. Also, the penny has to be older than 1982 (pure copper), and be reasonably smooth on its edges, or of course it won’t work as a seal. I tried a few version of the cat stoves too, made the bases, but they didn’t burn hot enough for my taste, and couldn’t be made to boil my titanium narrow pot at all.

By the way, pot width is critical, the wider the better, one of these days I’ll pick up a nice evernew 1.3 uncoated pot, wide, but for now, I got a modified penny stove with 5 jets pointing in, 1 to rim, working ok, but it has absolutely garbage performance in the wind, even with a tight aluminum flashing heat shield 6″ high, the turbulence above it from what I can tell just messes with the flames too much. My belief is the standard penny with wide pot is a really good way to go, but it’s a pain to get it made and working, took me a few failures before I finally got one to go.

Or just buy one from some of the great guys you can find out there, save yourself a lot of headache and testing, and get a tried and true design. Some guys make models for all stove types, and their stoves are really hard to make yourself, I looked at the designs of some of them and am not going to be trying those myself since I have other thing to do with my time.

Try MiniBull Designs to start if you want to get a feel for it. Email the guy and tell him your pot size, water quantity you need to boil, and he’ll probably suggest one to you.

Others swear by the Caldera cone stove/heatshield system, but be aware that design only works for the pot it’s made for, specifically, so you are locked into it, not my thing, but a lot of people really like them here who tried, and I guess, failed, to get their own stoves/heatshields working.

Hope something in here helps you, I know I just went through a ton of testing, toxic fume inhalation, etc, to learn what I write here, so maybe if I can help someone skip a few steps, all the better.

Jeff,

I have found the fancy feast stove to be very reliable for boiling 2 cups of water. Boiling a liter is probably pushing the limits of its fuel capacity. Also, what pot are you using?. The stove is more effective with wide, shallow pots. I think the evernew ti .9L used to be Skurka's go to pot.

I am very happy with my White Box Stove and feel confident in recommending it. Inexpensive, tough as nails, easy to use and works great. I also agree with what has been mentioned already in that a wider diameter cook pot the better. And let us not forget that precious wind screen when using alcohol…

There's been lots of discussion on the forums about super cat stoves. Do some googling.

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=42874&skip_to_post=423077#423077

I also was disappointed with mine when I first built it but there are a lot of variables at play, do some experimenting.

<7 minute boil times with 1 ounce of fuel for 2 cups cool water is totally possible if you dial it in.

Also, no offense to the little guys trying to make a living, but I would NOT spend money on what should be the easiest of MYOG projects.

Thanks for the great input everyone. Harald, thanks for the in depth reply. Lots of good info. Looks like I need to tinker around with the alcohol stoves more. My first impression was that I would not want to rely on it on an actual trip. Some of you mentioned pot width. My pot is pretty wide, don't know the width off the top of my head though. I'll take all the ideas you guys gave me and do some more experimenting. Should be fun!

For you that actually use an alcohol stove. Do you feel it saves much weight over a light canister fuel stove? The biggest weight factor would be the fuel. I'm curious how the weight in fuel would compare between the alcohol and canister stoves for boiling the same amount of water.

I was dead set on building a cat stove until I realized I had some REI gift card money and I stumbled across this…http://www.rei.com/product/768603/snow-peak-litemax-stove Snow Peak LiteMax at 1.9 ounces (confirmed on my scale once I got it).

Pair that with a 6.9 oz (says 6.4 on website, was 6.9 on my scale) SnowPeak GigaPower Fuel 110 http://www.snowpeak.com/stoves/accessories/gigapower-fuel-110-gold-gp-110g.html

That is just too good to pass up to me. I like that I can use it on simmer (I don't like to boil my ramen noodles), I like that it is easy on/off, and I like that there is no chance I could accidently kick it over or spill burning alcohol on myself or in the woods.

I would like to know what the weight penalty is for my setup at 8.8 oz for an alcohol stove plus the energy equivalent amount of alcohol fuel. I'm sure it will be a couple ounces but for the added features and simplicity of a canister stove I don't think you can beat it.

I've had the same setup for years Ty Ty and like it except for dealing with the wind and stability issues….but no big deal, just takes more time to get everything right.

I've got a clikstand coming because I want to try alcohol and it's not because of weight…well kind of.

I just hate not being really confident how much fuel is in the canister and on longer trips I always carry one extra. I just want to try being under more control of my fuel and just to have fun with it. Plus I just want to be different;-> Whatever floats your boat.

I love my cat stove for a lot of reasons. First, its very cheap. Second, it feels good to have some MYOG in your kit. Third, its fun and easy to make. Fourth, its very light. Fifth, it pairs well with a heine pot, especially with a tall windscreen. Sixth, you carry just as much fuel as the trip requires (a weight savings). Seventh,…. I'm not likely ever to spend money on a stove when this setup is so good in so many ways. I guess it requires a little more fiddling than a canister stove, but I always look at adjusting the windscreen, etc. as little mini-experiments.

“…unlike say, heet, which is garbage fuel, low heat output and truly vile smell/etc..”

I see a dis-love for HEET here. In theory it looks like HEET has 20% less energy than ethanol. However there are some niceties that makes HEET very appealing:
1. HEET outshines denatured (or SLX) at low temperatures.
2. HEET outshines denatured (or SLX) at high altitude.
3. HEET gives consistent results day in and day out. I struggled with SLX as some purchases resulted in dark yellow flames, and some purchases resulted in requiring more fuel burn time. You cannot predict their mixture ratio. It must be a quality control problem. This is all with the same stove under the same conditions.
4. HEET is cheaper than SLX.

And here’s an interesting observation: HEET or SLX (a true perfect mixture) gives the same burn times for the same amount of fuel (within 10 seconds) at sea level. This is an empirical observation and I do not know the chemistry of why this is so.

And I don’t know where the smell problem is coming. I’m always cooking outside. I don’t smell any fuel; Just my ramen or oat meal. But I could be having a bad nose :P

As a reference, my best results come from the open-jet top-burner pepsi stove and the White Box Stove.
My theory is— if you can boil water at 0F at sea level, then you have a good all around robust stove; and this without priming!

-Barry
The mountains were made for Teva’s :)

@Harald… funny to read, as I just perfected a design for the evernew.4l Ti mug, (1cup on 10 ml @ 9 min) nice to know there someone else in the east bay, breathing in those fumes in their garage all night! :D

Jeff Gerke, don't want to leave you hanging, and since i have all this stuff sitting around from my tests, here's the results:

12 cm (about 4.8") stainless steel pot I got in china town for about $6, same metal as MSR uses as far as I can tell, just chopped off heavy handle and use aluminium pot grabber. Stainless steal is a much better heat conductor than titanium, so in a sense, this is a very best case test, but aluminium might also give good results. I don't have a 1.3 liter ti pot, but this pot is about the same size as the SnowPeak 1.3 liter, or 1.4, whatever it is, h/w that is are about the same. There's some flame overshoot I can see, so this pot is still really not wide enough, I'd say the evernew uncoated 1.3 liter might be the only one out there that is ideal, except for its lack of a normal lid (come on, expensive ti pot makers, toss in a flat aluminum pot cover with these things along with those totally useless 'frying pans' everyone leaves at home if they know better, a simple alu pot cover can't cost more than a few cents to make)

Matching Jim Wood heat shield/wind shield, about 3/8" space between pot and shield. 6" tall, roughly.

Penny stove, version two, 6 outpointing jets, which means this stove works as its (industrial professional designer) developer intends, the jets heat the can surface which makes the alcohol boil, and the priming works as intended. All inward pointing versions don't work as well for what should be obvious reasons. So this is the standard stove, with pre 82 penny.

Pot stand, bike spokes connected with slightly flattened aluminum tubing, from Ace Hardware, at 2.5 inches, or 1" above edge of stove.

fuel: klean strip green, rated at pretty close to 95% ethanol, though the msds sheets are very vague, so it could also be 90%.

Quantity, first 1/2 oz, 1 tbspn, covering center cup and outer ring, then move penny and let center cup drain. Then add second half oz, same way, except do not move penny.

Water temp, probably 60, outside temp, 70s, 80? not sure.

Time to have 1 liter water hot enough for tea (small bubbles rising), about 7 minutes.

Time to full, roiling boil, about 10 minutes. Time til fuel ran out, about 13 minutes.

This means you can probably get a boil under ideal no wind conditions at about .8 oz, maybe 0.85oz.

I wish I could take this back up to the big sur ridges and test it when the winds really start to rip to see if the outer pointing holes work better in wind than the inner pointing plus one outer pointing, my guess is they do, a lot better, but that's a guess.

Interesting information on the methanol behavior of Heet. Since as I noted, that's some very nasty stuff, which I was feeling strongly in my lungs after just a few stove tests outside in still air, I'll take your word on the altitude/cold features, and since I have access to a very good chemist I can ask him if this is materially or physically possible as fact.

By the way, make sure when you use slx, you use the green, the other stuff is just gunk too, you have no way to know what's in it, that's why slx markets the green as stove fuel, I think it has a more reliable ethanol content, that's my guess. It's possible heet's additives achieve some type of change in burning, hard to say without knowing what's in it, but I won't be testing it, early death isn't in my cards for stove testing, at least not if I can help it. But I do always note empirical data, as a data point, in this case I wonder about the explanation. Might be standard slx has more water, which would make it burn like cr@p no matter what, don't know, I don't plan on using that stuff. It's hard to argue with btu energy content though, so my guess is water is the culprit, but that's only a guess. Since heet is supposed to block water from fuel lines, I'll guess they have the least water they can manage in it, along with all their other goodies.

Jesse Helmick, yeah, those fumes are no fun. What's extra annoying is you really have to sort of hover when testing to make sure it hasn't gone out or whatever.

By the way, one night I actually got some of the symptoms listed in the msds warnings after a very heavy set of testing days, that's when I decided to stop messing around with stuff that's not intended as a fuel and stick to the stuff that is labeled as such, much better results all around for me now with that.

Did you ind your current fuel locally? I'm just about done with my big can of slx… quite and achievement for me!

I asked at Ace Hardware, and they can order it for you, though they only stock the regular slx klean strip at the stores. You can also get it at Home Depot, but I have decided to not recommend or use them anymore, Ace is better at everything and is a local business and the people there actually have a clue about their inventory, ie, I want to support that type of business. I will try to make this the last time I mention HD again.

OSH has it too.

One problem of trying to buy any of this fuel is that you have to find it sold in the can size you want. Some smaller stores won't stock gallons, and the price on quarts is too high. I use a couple of gallons of some kind of denatured alcohol per year.

–B.G.–

I love ACE, they dont have everything, but the one I've gone to my whole life, (pete's ace in castro valley) has the best staff ever, they know what they have and can get, and will really try to help you with your project…

bob, yea there's always a give and take, which is why I usually just go to the big box stores :(

An alcohol stove is a "matched system". It takes some playing to find what works best for your own application. OK, it takes A LOT of playing to find that out, but its fun, for a while. Most people like the idea of making something cheap and functional themselves, so they play around with alcohol stoves at some point. Many go back to cannister too for ease, reliability,simplicity, speed.

The system includes the pot, the stand (if any needed), the windscreen, method of priming/lighting, etc. You must have a good windscreen, that provides air for flame without losing too much heat. The windscreen retains heat around the pot. In very breezy conditions you may need to use your sleeping pad as a big second windscreen to be able to use an alcohols stove at all.

Supercats work well for wide pots, and can be fast. They can put out a scary amount of flame. They are not as efficient as some others due to this, but they are fast for the right pot. Speed might be important if you want to use one 2cup pot to boil water for 4 people,but to do that you would want a cannister that boiled it in 3 min
. For most, you are doing a single boil and who really cares if it takes 4 min or 10 min? Use the one that uses less fuel, which isnt the supercat.

"
By the way, make sure when you use slx, you use the green, the other stuff is just gunk too, you have no way to know what's in it, that's why slx markets the green as stove fuel, I think it has a more reliable ethanol content, that's my guess."

Dont know if it is always the same, but my experience with the Kleen Strip Green was horrible. Yes it has more heat due to higher ethanol content. It also left a NASTY STICKY brown varnish like residue on the pot. (that has never totally come off) Absolutely unnaceptable. SLX burns totally clean without a bit of soot. Best for backcountry use is of course Everclear, since you can use to steriize a bad wound, or drink, or use a fuel,and is non-toxic.

Barry P wrote: 1. HEET outshines denatured (or SLX) at low temperatures.
2. HEET outshines denatured (or SLX) at high altitude.
3. HEET gives consistent results day in and day out. I struggled with SLX as some purchases resulted in dark yellow flames, and some purchases resulted in requiring more fuel burn time. You cannot predict their mixture ratio. It must be a quality control problem. This is all with the same stove under the same conditions.
4. HEET is cheaper than SLX.

Barry,

How does number two above work? How is it that HEET works better than SLX at high altitude?

HJ

“How is it that HEET works better than SLX at high altitude?”

At high altitudes I have noticed HEET to be much easier to light than SLX (mostly Ethanol).
I’m not a chemist but here’s my theory:
HEET Vapor Pressure: 97 mmHG
HEET Vapor Density: 1.1
HEET Boiling Point: 148F
Ethanol Vapor Pressure: 59 mmHG
Ethanol Vapor Density: 1.59
Ethanol Boiling Point: 173F

Here we have HEET boiling sooner and producing vapor. It’s amazing how the vapor is such low density but pushes out at a high pressure (as seen in the specs above). Combine that with low pressure (in high altitude) outdoors and the HEET vapor wants to shoot far. It’s kept contained by the pot on top of it. I.e., HEET does not require much push/oomph to get a flame going. How’s that for technical jargon? Likewise, the Ethanol is going to need a little more boost to get the vapor shooting out the stove’s holes. How much more boost— I don’t know how to calculate.

Also it has been cooler at high altitudes when I cook. So I might have a temperature mixed in with the pressure effect.
This might explain why my partner’s stove (same pepsi stove as mine but uses denatured) keeps going out at high altitude.

-Barry
The mountains were made for Tevas :)

Interesting ideas. I'm not sure what exactly is going on, but if HEET works better, then HEET works better. Can't argue with actual on-the-ground experience.

By the way, SLX can vary, but it's roughly equal parts ethanol and methanol with a dash of methyl isobutyl ketone thrown in (up to 4%). Since SLX has so much methanol (up to 50%), I'm surprised that there's much difference between HEET and SLX. Maybe the methyl isobutyl ketone does something to the vapor pressure? Dunno. Way beyond my chemistry knowledge.

HJ

What is the definition of high altitude?

Above 6000 meters, or what?

–B.G.–

Actually, the thing I'm curious about is if the stoves were the same (or at least roughly the same). We could be attributing something to the fuel when in fact it is the stove that is the issue.

HJ

From Wikipedia:

Mountain medicine recognizes three altitude regions that reflect the lowered amount of oxygen in the atmosphere:

    High altitude = 1,500–3,500 metres (4,900–11,500 ft)
    Very high altitude = 3,500–5,500 metres (11,500–18,000 ft)
    Extreme altitude = above 5,500 metres (18,000 ft)

Works for me.

HJ