Suggestions Re: Alky stove

[waasj]

I have made my first alcohol stoves and find that it takes 15 minute to get to a boil that can best be described as flaccid. This required filling the stove (got the design from Zenstoves, 30cm tall) all the way, and the boil only lasted for a few minutes until the fuel (denatured alcohol) ran out. Any suggestions on how to improve this?

Right now, I am looking at the option of doubling up. Taking a Crux canister stove out for longer cooking and using the acohol stove for simmering. We all have something we will carry extra weight for, and food is mine. I am willing to sacrifice a few ounces for my meals.

[Odd Man Out]

You will probably need to supply a bit more info. What style of stove (there are tons of different designs). Also it is important to understand that performance is determined by the whole system (stove, pot, windscreen, pot stand, fuel). Also, how much water were you boiling? No way to assess the heat output without having that data. Also, depending on how much water and fuel you use, having the flame go out a few minutes after boil is not uncommon.

Also, from your second paragraph, I suspect that you may not be the best candidate for alcohol stoves. From what you wrote, it sounds like you want to be able to control your stove so you can heat fast to start and then simmer so you can do some real cooking. Each type of stove has its advantages and disadvantages, but for the most part, these are features not found in alcohol stoves. If this is important to you, canister stoves may be your best option. There are many many people using canister stoves for this reason.

I don't know if many people carry two stoves, but that is not out of the question if you want to be able to take advantage of each of the stoves' strengths. If you are new to building stoves, you could consider building a Supercat stove. This is among the most popular style because it is cheap (50 cents for the cat food), ridiculously easy to make (punch holes with a hole punch), and easy to use (no pot stand required). The heat output of this is definitely not "flaccid", but if you want to be able to simmer, you can make a lower-power stove (see Simmercat instructions at the end of this page).

http://jwbasecamp.com/Articles/SuperCat/index.html

The only pop-can alcohol stove I made (and had good luck with) is the penny stove. Instructions are here. Fun to make, but more temperamental than a Supercat.

http://www.jureystudio.com/pennystove/

[Rocket Jones]

I use a Supercat with the GSI kettle and a windscreen made of a length of disposable oven drip pan. In the winter I use a cork trivet covered in foil as a heat reflector and surface protector too. I get a full rolling boil using a little less than an ounce of denatured alcohol, and it takes about 7 minutes with this setup. That's enough water for my FBC meal, a cup of soup and cup of tea. If I'm not drinking hot then I've got plenty for washing up.

[Spokes]

+1 on what Rocket Jones said. I've built my share of alky stoves and almost all of them achieved a boil within 6-7 minutes. I use 3/4 oz. of fuel for most dinners and less for breakfast. Now using the SuperCat almost exclusively because of its simplistic design and no need for a pot stand.

By the limited info provided I suspect you're over-priming the stove......(?).

[cabbagehead]

I sell stoves at BottleStoves.com, and they're made in Massachusetts. They boil in 3 to 7 minutes and then maintain a constant heat that is great for cabbage. You can also stand on them with a full pack.

[Tinker]

+1 on what Rocket Jones said. I've built my share of alky stoves and almost all of them achieved a boil within 6-7 minutes. I use 3/4 oz. of fuel for most dinners and less for breakfast. Now using the SuperCat almost exclusively because of its simplistic design and no need for a pot stand.

By the limited info provided I suspect you're over-priming the stove......(?).

+2 on all the above. The only way to achieve such dismal rusults is to choke off the oxygen getting to the stove. This is a great way to simmer, but not so great when you're trying to achieve a boil.

Most of the stoves I've made required a pot stand. If the pot stand was too short the pot was not in the hottest part of the flame. Most of the instructions I got off of the internet indicated a short pot stand. Increasing the height by 1" will usually significantly increase the efficiency of the stove, as will having at least a 1/4" gap all the way around the windscreen, and having a windscreen that reaches at least 1/2 the height of the pot when it's on the pot stand (or, in the case of the Supercat, the stove itself).

[waasj]

Yeah, I am using a ventilated windscreen/potstand. Next on the agenda is the cat stove.

[Rain Man]

Another vote for the cat stove. Very easy to make and works well. I've built a few dozen alcohol stoves of several varieties. Some worked well, some did not, based on such factors as number of pressurized jet holes, size of those holes, position of jet holes, size and shape of pot, amount of water to be heated, temperature of water to be heated, wind, wind screens, base reflectors, etc., etc., etc.

Just keep practicing until you get results you want. Don't expect a first attempt to be the best attempt.

RainMan

.

[Blissful]

Just a side note - I like my canister stove. After seeing a multitude of burn marks from so-called alcohol stoves on picnic tables and shelters and watching them flair up, I find them hazardous to the owner and the environment. It is only a matter of time before they burn a shelter. But this is my opinion only. Maybe if they are built correctly and used correctly. But too many use their own makeshift ones.

[QiWiz]

You can make a very simple stove that will work well. For example, cut the bottom inch off a soda can and put 3/4 oz alcohol in it. Place on ground. Put the bottom of your pot 1.5 inches above the stove (2.5 inches off the ground). Use rocks, tent stakes, a pot support or whatever to do this. Have a windscreen in place that lets air into stove through multiple paper punch holes or an open quarter circumference on the downwind side of stove. Wrap windscreen so it is no more than a half inch away from your pot. Windscreen should go at least half way up the side of your pot. Light stove. If this does not boil two cups of water in 6 minutes or less, you missed a step.

[zelph]

I have made my first alcohol stoves and find that it takes 15 minute to get to a boil that can best be described as flaccid. This required filling the stove (got the design from Zenstoves, 30cm tall) all the way, and the boil only lasted for a few minutes until the fuel (denatured alcohol) ran out. Any suggestions on how to improve this?

Right now, I am looking at the option of doubling up. Taking a Crux canister stove out for longer cooking and using the acohol stove for simmering. We all have something we will carry extra weight for, and food is mine. I am willing to sacrifice a few ounces for my meals.

Make an "Ion" stove originally designed by the world famous Sgt. Rock. Excellent stove for simmering. Another excellent one is the "kitten Stove" designed by Skidsteer of Whiteblaze. Search their threads for great info on stove design.

[Tinker]

Just a side note - I like my canister stove. After seeing a multitude of burn marks from so-called alcohol stoves on picnic tables and shelters and watching them flair up, I find them hazardous to the owner and the environment. It is only a matter of time before they burn a shelter. But this is my opinion only. Maybe if they are built correctly and used correctly. But too many use their own makeshift ones.

I made an anti-scorch shield from an aluminum oven pan which is just a hair bigger than the diameter of my pot. It goes under my Supercat every time I fire it up. Makes the stove a bit more efficient, too. I cut a small "X" in the middle of the shield and it doubles as a mouse baffle when I hang my bag in shelters (even though I don't use them for sleeping, they're great for cooking and, of course, visiting with other hikers).

[Tinker]

My cookset with ti foil windscreen and anti-scorch shield:

[/URL]

[Odd Man Out]

I made an anti-scorch shield from an aluminum oven pan which is just a hair bigger than the diameter of my pot. It goes under my Supercat every time I fire it up. Makes the stove a bit more efficient, too. I cut a small "X" in the middle of the shield and it doubles as a mouse baffle when I hang my bag in shelters (even though I don't use them for sleeping, they're great for cooking and, of course, visiting with other hikers).

I've used an anti-scorch shield cut from an aluminum pie pan. It had this nice dimpled surface to give it structure with little weight. I've also used a thin sheet of styrofoam covered with aluminum foil. Not only do these protect the picnic tables from burn marks, I think they improve the stove performance as they reflect heat up to the pot and insulate the stove from the cold of the ground.