View Full Version : Alky stove questions
El Toro '94
08-06-2009, 20:18
Don't know if this is the right forum, or if it should be in the DIY gear forum, but here goes.
Just made my first alcohol stove out of a cat food can, can't get water to a boil, can barely get to a simmer. am using 1 oz of slx denatured. Stove lights and burns well, the pot has a tight lid, so I figure its my windscreen, all the configurations I've tried haven't worked. The flames and heat seem to be mostly blowing off to one side, punching intlet and outlet holes only makes it lose heat faster. During my tests the wind was 5 mph max. Any suggestions or solutions would be appreciated.
Hoop Time
08-06-2009, 20:23
I make my windscreen out of those heavy-duty foil oven liners you buy for about 40 cents (2 for .79 last I bought them) in the grocery. I use a hole punch to put two even rows of air holes all around the bottom. Have had no problems with the flame blowing out the side.
Definitely try a good windscreen. Making one out of doubled heavy-duty aluminum foil or an aluminum oven liner is a good way to go. Also, if your pot isn't resting directly on top of the stove, then lower it. The closer it is to the heat, the less heat is lost. Good luck and let us know how it goes.
Dances with Mice
08-06-2009, 20:25
What kind of stove did you make? Is it the type where the pot sits on top of the stove, or did you use a pot stand?
El Toro '94
08-06-2009, 20:31
Stove is the type that the pot sits directly on, so no potstand. The windscreen was msde out of the oven liner, got the idea from Sgt. Rocks website, still no joy on the boil. The wind seemed to blow under the very small gaps between the screen and the concrete.
Skidsteer
08-06-2009, 20:56
Stove is the type that the pot sits directly on, so no potstand. The windscreen was msde out of the oven liner, got the idea from Sgt. Rocks website, still no joy on the boil. The wind seemed to blow under the very small gaps between the screen and the concrete.
So you built a Supercat? Two rows of (14) 1/4" holes or similar? What diameter pot are you using?
http://jwbasecamp.com/Articles/SuperCat2/images/Snow-Pots_1495-600.jpg
El Toro '94
08-06-2009, 21:15
Yes, a supercat, if that's the one in the pic. Pot diameter is 4 inches or so. Walmart grease receptacle/saver. Not the kind I've seen in pics, it looks more like a coffee pot, but it isn't
GeneralLee10
08-06-2009, 21:28
I had the same problem when I started to make them. You just gotta play some more and get some Heet in the yellow bottle. Seems to be a lil cheaper then DA I have several lil stoves. At first it seem as if it was not going my way but the more I messed around with them it got better. Some of them you need to let it prime from what they say. I have now got a tiny one with hardware cloth/wire for a pot stand just lite and set cup on it. Use half of an oz of Heet I can get my water to a boil but I am only using about 10oz of water though. I have came to the conclusion that needing hot food is all in your mind. When working out I did eat all my food cold spinach, chicken, pasta you name it. So why I ask myself do I need to cook a hot meal just a warm drink will do with a cold meal.
El Toro '94
08-06-2009, 21:43
6th test. Got 2-3 bubbles this time, all on one side of the pot. Again, all the heat and flame is being blown to one side in a very light breeze. I can't put any more fuel in, 1 oz comes up to the bottom holes. It's burning fine, the pot isn't snuffing the flame.
What could I be doing wrong with the windscreen? Could it be too close to the pot without snuffing the flame?
El Toro '94
08-06-2009, 23:02
Found a problem, my supercat is burning a full ounce of denatured in a little less than 5 minutes, but don't know why. Anybody have any ideas why my stove is burning out in less than 5 minuted? I xpected it to go 7-9 min. with a full fuel load. Also, flames are blowing down and out under my windscreen whenever there's even a hint of a breeze. that's heat lost. :mad: Getting frustrated.
Wise Old Owl
08-06-2009, 23:08
Found a problem, my supercat is burning a full ounce of denatured in a little less than 5 minutes, but don't know why. Anybody have any ideas why my stove is burning out in less than 5 minuted? I xpected it to go 7-9 min. with a full fuel load. Also, flames are blowing down and out under my windscreen whenever there's even a hint of a breeze. that's heat lost. :mad: Getting frustrated.
I am going out on a limb here, post a pick to www.photobucket.com (http://www.photobucket.com) and then import the picture with the direct path after deleting the http and the pick will load with the insert image button....
GeneralLee10
08-06-2009, 23:12
I don't think you want it more than a 1/4 of an inch from the edge of your pot. If you get the alum foil to close it will burn I've done that a few times with my testing/play-n. I know it sounds and looks very simple which it is, just keep try-n maybe do some youtube searches mite not want to give up just yet.
Skidsteer
08-06-2009, 23:28
Yes, a supercat, if that's the one in the pic. Pot diameter is 4 inches or so. Walmart grease receptacle/saver. Not the kind I've seen in pics, it looks more like a coffee pot, but it isn't
A four inch diameter pot is too small for a Supercat. That's the main problem, no doubt about it.
See the pot on the right in the photo I posted? The one with the scorch marks up the sides?
Four inch diameter.
Found a problem, my supercat is burning a full ounce of denatured in a little less than 5 minutes, but don't know why. Anybody have any ideas why my stove is burning out in less than 5 minuted? I xpected it to go 7-9 min. with a full fuel load. Also, flames are blowing down and out under my windscreen whenever there's even a hint of a breeze. that's heat lost. :mad: Getting frustrated.
Supercats are pretty fast burners.
I don't think you want it more than a 1/4 of an inch from the edge of your pot. If you get the alum foil to close it will burn I've done that a few times with my testing/play-n. I know it sounds and looks very simple which it is, just keep try-n maybe do some youtube searches mite not want to give up just yet.
That was one thing I was going to say. Also, try using less alcohol. Less alcohol comes to a boil faster and you'll get a hotter flame more quickly. Also, I'm assuming that you're not using rubbing alcohol. It's a poor performer.
I routinely boil 16 oz. of water in 5 min or a little less with 1/2 oz. of fuel and have a total of 6-7 min. burn time. This is in summer with both alcohol and water in the 50 degree range.
My pot is a 1.3 liter Evernew titanium one. Pots with a smaller diameter don't catch the flames as well - they go up the sides and only heat the air.
Btw: Just so I don't miss anything - your windscreen holes are on the bottom of the screen, right? I thought so :).
El Toro '94
08-06-2009, 23:45
Don't know how to post a pic, my photobucket-fu is weak. Don't kno how to get a picture into my computer for that matter.
It may be the pot size, but my flames aren't even hitting the pot half the time, they are blowing down and under my windscreen with just a slight breeze, it's like my windscreen is barely blocking the wind at all. Granted, I live on the beach, so it's pretty windy most of the time, but today was relatively calm, 2-5 mph gusts of 10.
Is your pot tightly covered? I use a small rock on many occasions on top of the lid to hold in as much heat (steam) as I can.
El Toro '94
08-07-2009, 00:46
test 9-New windscreen, 6 inch pot, lid, 1/2 oz. denatured. Same result, flameout at about 5 minutes, no boil.
test 10-same new windscreen, 6 inch pot, lid, 1 oz. denatured. Flameout at 6 minutes +/-, no boil.
Noticed some of the flames were yellow at times, mostly when a gust of wind blew. Am not using isopropyl, am using s-l-x denatured alcohol from walmart.
The water I was using is tap water at 75-80 degrees F, about as cold as we can get down here. If I can't get it to boil using lukewarm, I'll have to abandon alcohol as a fuel, as I sure won't be able to boil water that's in the 40-50F range.
Try: smaller holes &/or fewer holes &/or more holes &/or larger holes etc.
The super cats require a fairly fine tuning, at least in my experience. Smaller holes will likely increase the burn time.
I also put just a few drops of "Primer" in a small shallow pan (actually the bottom of a Pringles can) & get better results than without priming. I use no more fuel by priming, & get a boil with 2/3 Oz of fuel. I second the "use less fuel" suggestion, and for the same reason.
My pot is a Fosters Can & works well. My wind screen is a store bought aluminum thing I got as a gift. The whole set up has worked down to around 20 degrees, using near freezing water.
AND, it's a bit more expensive, but as fuel, when I can get it, Everclear. This has, or seems to have, a higher BTU than HEET or Denatured with the bonus of being sort of drinkable,,,,, a feature that is important to me as I have a history of (ONE TIME!) nearly accidently drinking my stove fuel. :o
El Toro '94
08-07-2009, 02:41
It must be the stove then. Too many holes I guess. I used the template from zenstoves for my hole pattern, and a paper hole punch like the instructions said, figured it would work. I'm not even close to a boil, just a few small bubbles on the bottom of the pot. All results have been pretty much the same whether I use 1/2 oz of fuel, 1 oz of fuel, narrow pot or wide pot, tight lid, loose lid, windsreen close to the pot, 1/4 inch from the pot. Plenty of intake holes and space in the windscreen. Priming isn't the problem, the stove lights just fine, I wait until I see the alcohol bubbling before I put my pot on, even primed it by spilling some on the concrete under the stove. I get just about the same results every time-no boil for 2 cups, barely a simmer for one cup, flame out between 5 and 6 minutes. I don't kno what I'm doing wrong or you all are doing right.
sheepdog
08-07-2009, 14:05
What kind of alcohol are you using?
Slack-jawed Trog
08-07-2009, 18:16
FWIW El Toro, I'm experimenting w/ Super Cats, too. My second attempt w/ a Super Cat burns 8-9mins on ~1 0z of Heet but won't boil a liter of water. It gets steamy w/ small bubbles on the bottom of the Wally World grease pot but I have to finish the boil w/ another 1/4-1/2 Oz of Heet and a re-light. Instant oatmeal and cowboy coffee just didn't work for me on almost boiled water--more tweaking needed...
I'm also experimenting w/ the Simmer Cat (single row of holes). It burned ~15 mins but I haven't measured (yet) the fl oz of Heet I put into it on the one test burn. Seems like it could work out well even w/ 2 liters of water, if I transfer the almost boiled pot to the Simmer Cat to finish the boil, draw some water for oatmeal/et c., and brew my cuppa cowboy joy. :D
YMMV,
GeneralLee10
08-07-2009, 21:45
It must be the stove then. Too many holes I guess. I used the template from zenstoves for my hole pattern, and a paper hole punch like the instructions said, figured it would work. I'm not even close to a boil, just a few small bubbles on the bottom of the pot. All results have been pretty much the same whether I use 1/2 oz of fuel, 1 oz of fuel, narrow pot or wide pot, tight lid, loose lid, windsreen close to the pot, 1/4 inch from the pot. Plenty of intake holes and space in the windscreen. Priming isn't the problem, the stove lights just fine, I wait until I see the alcohol bubbling before I put my pot on, even primed it by spilling some on the concrete under the stove. I get just about the same results every time-no boil for 2 cups, barely a simmer for one cup, flame out between 5 and 6 minutes. I don't kno what I'm doing wrong or you all are doing right.
Man.... It's not you it's the stove gotta be, I tried making one close to that kind and it was just not for me. So my next suggestion is look at making one out of soda/beer cans. The one I use now is the bottom of a small aluminum spray bottle that my wife had. It can hold 1oz or less nothing more I will post a pic of mine to give you an idea of what I use now.
Skidsteer
08-07-2009, 22:30
I've tried to be nice about it but am I the only one that thinks the Supercat is a piece of crap stove in the first place?
Maybe it's just me but I've never been impressed with the effeciency of it and it has the wind resistance of a Bic in a wind tunnel.
OK. It's easy to make but I've never seen what the big hooraw is. :confused:
GeneralLee10
08-07-2009, 22:45
Skid... I will agree with you it seems to be kinda crappy all the way around. I field tested the one I did make and had one heck of a time even used a Heine Can for a pot.
http://www.whiteblaze.net/forum/vbg/showimage.php?i=35731&c=516
http://www.whiteblaze.net/forum/vbg/showimage.php?i=35732&c=516
http://www.whiteblaze.net/forum/vbg/showimage.php?i=35733&c=516
I posted three pics of what works for me hope it worked.
dreamsoftrails
08-07-2009, 23:12
not enough oxygen
Hoop Time
08-07-2009, 23:27
You might want to try a different design. I have built two Cobra Stoves (http://www.boblog.org/at/cobrastove.htm) now, and had good success with both. I can't tell you exact amounts of fuel to boil because I have not measured it that closely, but the design seems to be pretty efficient. My first one, the holes for the jets were too big, so it burned fuel faster (too fast) and burned too much flame. It actually melted my pot stand and part of my windscreen (though potstand melting may have been from using a different type material than called for in the instructions). The second one I made the jets smaller and it worked much better.
El Toro '94
08-08-2009, 12:04
Thanx for all the help everybody. Back to the drawing board. I like the simplicity of the soda can stove, but not the durability issues. I do like the bud lite aluminum bottle idea. Anyone ever boil more than 2 cups of water in one shot with an alcohol stove, or is 2 cups pretty much the limit with 1oz of fuel?
sheepdog
08-08-2009, 13:45
I've tried to be nice about it but am I the only one that thinks the Supercat is a piece of crap stove in the first place?
Maybe it's just me but I've never been impressed with the effeciency of it and it has the wind resistance of a Bic in a wind tunnel.
OK. It's easy to make but I've never seen what the big hooraw is. :confused:
True, but it is an easy stove for a beginner to make. It was one of my first stoves.
sheepdog
08-08-2009, 13:57
Thanx for all the help everybody. Back to the drawing board. I like the simplicity of the soda can stove, but not the durability issues. I do like the bud lite aluminum bottle idea. Anyone ever boil more than 2 cups of water in one shot with an alcohol stove, or is 2 cups pretty much the limit with 1oz of fuel?
Many alcohol stoves will boil two cups of water with 1/2 ounce of alcohol. I usually boil in small batches, 2 cups at a time. Adding twice as much fuel does not necesarilly give you twice as much flame time.
Big Dawg
08-08-2009, 15:16
Where's Zelph... the WB alky stove guru? I'm sure he'll chime in w/ some wisdom soon enough.
My supercat boils 2 cups h2o w/ 1/2 to 3/4oz den.alky w/in 5+/- min., & stove burns for total of 6 to 7 minutes. Not sure what's happen w/ your dilema El Toro?
cutman11
08-08-2009, 20:30
I researched many stoves before making one. I ended up with the penny stove, which is semi pressurized by placing a penny over the central hole. easy to make, when lit with 1 oz of denatured heats 2 cups of water to boiling in 2-3 minutes. the coolest part is the vaporized alcohol shoots out the holes around the edge and looks like a darn gas range burner, even heats the water faster than my gas range at home. Do need a small pot stand (which gets red hot from the heat as well!!
Skidsteer
08-08-2009, 23:01
I researched many stoves before making one. I ended up with the penny stove, which is semi pressurized by placing a penny over the central hole. easy to make, when lit with 1 oz of denatured heats 2 cups of water to boiling in 2-3 minutes. the coolest part is the vaporized alcohol shoots out the holes around the edge and looks like a darn gas range burner, even heats the water faster than my gas range at home. Do need a small pot stand (which gets red hot from the heat as well!!
LOL, that's the funny thing.
Most/many alcohol stoves will boil 2 cups of water in 6-8 minutes; And that's how long it takes most stove top burners to do it too.
Pocket Rockets and Jetboils, etc boil water about twice as fast as you can do it at home in the kitchen.
Kinda puts things in perspective, right? :D
I researched many stoves before making one. I ended up with the penny stove, which is semi pressurized by placing a penny over the central hole. easy to make, when lit with 1 oz of denatured heats 2 cups of water to boiling in 2-3 minutes. the coolest part is the vaporized alcohol shoots out the holes around the edge and looks like a darn gas range burner, even heats the water faster than my gas range at home. Do need a small pot stand (which gets red hot from the heat as well!!
I've made a few of the Penny Stoves my favorite part was drinkin the Hienes, Your comment about the stove looking like the gas burner on a range, was my first thought when I fired it up the first time. The penny stoves are now in my gear closet, and have opted to carry a Cat Stove, I do like it for it's simplicity of design and no pot stand. I have never been able to achieve more than a 4.5 minute burn on 1 oz of fuel and it will just get the water hot enough (just to the point of small bubbles appearing never to a full boil) to make tea, hot coca, coffee, or oat meal. What more could you ask for if you want to see it boil I would suggest to add more fuel 1 and 1/2 oz. should get you to that boil.
HikingIllini
08-09-2009, 14:07
try experimenting with your windscreen. Your problem might be lack of oxygen. I have plenty of AL foil balled up in the recycle bin from different configurations.
Can you bring 2 cups to a boil with no windscreen? If not, then the problem is your stove/pot setup.
Slack-jawed Trog
09-05-2009, 18:06
I think I've got a keeper alky stove. :D
I made a modified Super Cat with a Libby's Vienna Sausage can. With 2 Tbs of Heet I was able to get a recycled 28 oz. can (crushed tomatos) of water to a rolling boil in about 16 minutes, total burn time was about 21 minutes. That'll do pig...