View Full Version : Pepsi can temp rating.
vipahman
02-01-2006, 13:54
I made a Pepsi can stove a while back and while it works fine for my summer needs boiling 16oz of water, I've never tested it in winter. How well do they perform in winter temps? Would you use them for 0-20 degree, 20-40 degree or 40+ only? What would be the temp at which it just doesn't generate enough BTUs? Thanks.
20+ works fine with denatured alcohol. Isopropyl 90% works but not as good.
Just make sure you prime it well and keep it out of the wind.
Don't know about temps under 20F.
I made a Pepsi can stove a while back and while it works fine for my summer needs boiling 16oz of water, I've never tested it in winter. How well do they perform in winter temps? Would you use them for 0-20 degree, 20-40 degree or 40+ only? What would be the temp at which it just doesn't generate enough BTUs? Thanks.
never had a problem with low temp,just keep it out of the wind at any temp:cool: neo
waskelton4
02-01-2006, 14:55
i used one in probably about 25 - 30 deg weather.. little to no wind and had two issues..
I was using methal alcohol (the gas line antifreeze) and had trouble getting the primer fuel to ignite. I ended up a few times dipping a leaf in some of it and lighting the leaf and then dropping it in the fluid around the bottom of the stove. not a real big deal but kindof a pain.
the other problem was that our water was pretty dang cold so it took more than one fill of the stove to boil.
all that being said.. i haven't used it all that much and the heating issued might be due to me not being THAT familiar with it.
it took much more fuel than the 1/2 oz or 1 oz that lots of folks claim they use per meal.
my $.02
ws
i used one in probably about 25 - 30 deg weather.. little to no wind and had two issues..
I was using methal alcohol (the gas line antifreeze) and had trouble getting the primer fuel to ignite. I ended up a few times dipping a leaf in some of it and lighting the leaf and then dropping it in the fluid around the bottom of the stove. not a real big deal but kindof a pain.
the other problem was that our water was pretty dang cold so it took more than one fill of the stove to boil.
all that being said.. i haven't used it all that much and the heating issued might be due to me not being THAT familiar with it.
it took much more fuel than the 1/2 oz or 1 oz that lots of folks claim they use per meal.
my $.02
ws
i use a small twist of toilet paper as a priming wick,i works great:cool: neo
alcohol has to evaporate to ignite. once it's lit, the pool of alcohol starts to boil and keeps evaporating which makes it burn faster which makes it boil faster (and so on.) this is just like an msr stove's feed tube running across the flame pattern... once it gets hot, it vaporizes the fuel and it quits burning yellow and turns blue...
low temps make it harder for the alcohol to evaporate. the best technique for helping it burn is to keep your fuel bottle inside your jacket in colder weather for a few minutes before you start cooking. also, putting something as simple as a piece of wood or cardboard between the snow/ice and the bottom of your stove will keep the fuel warm... once it gets going, it runs fine. the 'hard part', which is really more 'different' than 'hard', is getting the stove going. once you're running, it burns fine. the additional fuel needed is not so much a matter of 'alcohol has fewer BTUs' as it is the water being colder, and needing to be heated longer to make it boil.
that said, i've never used it below freezing... but the trangia alcohol stove, the original, was developed for use by an army (swedish?) in the cold scandanavian climate.
if you aren't getting a boil on a half oz in 60-70* weather, you're doing something wrong, or your stove isn't working right... 45-60, ok, you may need a little more fuel (because the water's cold)... but it still shouldn't take more than an ounce...
if anyone's interested, white gas has roughly twice the BTUs per ounce as alcohol.
http://www.whiteblaze.net/forum/images/misc/menu_open.gif
http://www.whiteblaze.net/forum/images/misc/menu_open.gif
Below 20 degrees, alcohol will not vaporize. It will put out your match rather than burn. So, when it's that cold out, the alcohol needs to be pre heated, either by keeping the fuel bottle close to your body, or using a wick, or holding it over a flame. Keep alcohol over about 20 degrees, and it will burn.
That being said, consider using a different fuel in winter.
vipahman
02-01-2006, 18:30
if anyone's interested, white gas has roughly twice the BTUs per ounce as alcohol.
If that's so, can I use white gas in an alcohol stove?
Skidsteer
02-01-2006, 18:56
If that's so, can I use white gas in an alcohol stove?
You can...but it is neither safe nor effecient, IMO, and will turn your pot the proverbial black. Not that I've ever attempted such a silly thing...Promise to posts pictures if you try it?
Below 20 degrees, alcohol will not vaporize. It will put out your match rather than burn. So, when it's that cold out, the alcohol needs to be pre heated, either by keeping the fuel bottle close to your body, or using a wick, or holding it over a flame. Keep alcohol over about 20 degrees, and it will burn.
That being said, consider using a different fuel in winter.
This is one area where there are many answers but I choose a fairly simple approach that was not mentioned above - light a match and _touch_ the flame from the match to the _surface_ of the alcohol - this locally heats the cold alcohol and gets it burning and the flame quickly spreads across the surface of the alcohol and the stove takes off. I like this approach because you don't have to prewarm the alcohol or do anything overly different. If you don't have a match the same technique can be used by dipping a twig or some pine straw in the alcohol, lighting the twig and then proceeding as if it were the match. The key item in this is touching the surface and don't just toss the match in - dunking the match is not the way to go when it is cold.
If that's so, can I use white gas in an alcohol stove?
no, not really... it will melt... i don't know the specifics, but alcohol burns a little cooler, enabling your pepsi can stove to be made of lightweight aluminum...
however, there is probably a theoretical point just short of meltdown where an alcohol/gas mix MIGHT work... anyone ever try to find it? (not me... i've got enough trouble with my eyebrow as it is...:D )
Skidsteer
02-01-2006, 21:27
no, not really... it will melt... i don't know the specifics, but alcohol burns a little cooler, enabling your pepsi can stove to be made of lightweight aluminum...
however, there is probably a theoretical point just short of meltdown where an alcohol/gas mix MIGHT work... anyone ever try to find it? (not me... i've got enough trouble with my eyebrow as it is...:D )
Patrick gave it a go.
http://www.whiteblaze.net/forum/showthread.php?t=11888
no, not really... it will melt... i don't know the specifics, but alcohol burns a little cooler, enabling your pepsi can stove to be made of lightweight aluminum...
however, there is probably a theoretical point just short of meltdown where an alcohol/gas mix MIGHT work... anyone ever try to find it? (not me... i've got enough trouble with my eyebrow as it is...:D )
I used a mixture of coleman fuel with methanol and then ethanol. Each was about 20% coleman. I had no problems with either melting the pepsi stove or the flame getting out of control. I didn't heat any water--just trying a fuel mix.
If you use pure coleman fuel, be sure you have the local fire department on speed dial. Patrick posted some pictures--these should convince you not to try pure coleman fuel.
Stag
no, i'll pass for awhile... still waiting for the eyebrow to grow back... no sense blowing something up if you can't singe your hair...
thanks for the link to patrick's experiments... seriously, once i get some time, i may tinker a bit with mixing just a little white gas in with the alcohol... i too have a 'bag of stoves' that aren't doing anything but collecting dust as failed experiments... might as well try burning a mixture in them... there has to be an optimum mix where it still acts like an alcohol flame, but uses less alcohol because of the added BTU boost from the white gas...
If that's so, can I use white gas in an alcohol stove?
i would not do it:cool: neo
vipahman
02-02-2006, 17:10
Got it. So alcohol stoves work but not too well around 20F. And I should not use white gas in an alcohol stove. Thanks everybody.
I would then require a ultralight stove for the 0-30F range but I'll post that question in the right forum.
Got it. So alcohol stoves work but not too well around 20F. And I should not use white gas in an alcohol stove. Thanks everybody.
I would then require a ultralight stove for the 0-30F range but I'll post that question in the right forum.
since when has using the right forum ever stopped anyone on this site!?:D go on! ask for a good lightweight gas stove... go on...
MSR Simmerlight is pretty good, from personal use, and i hear great things about the pocket rocket. there are also some titanium heads for gas cylinders, but i know nothing about them.
This past weekend my wife and I spent a night up in the Mt. Rogers area. It was really cold low twenties. While my wife was warming up in the tent (read: shivering and trying to change from damp wet clothes to dry camp clothes) I was fiddling with my alcohol stove. It lit, I put the pot on and went to tend to Kel. After 10 minutes (about the burn time of my stove full) Kel went to check the stove and everything was still cold. But no fuel in the stove. So I busted out the trusty Pocket Rocket and boiled some water. I love that thing. I guess when it is really cold out it is nice to have water come to a boil quickly for that first warm beverage while getting settled at camp. My goal now is to design an alcohol stove system that will work in those temps using a larger fuel capacity (my current one maxes just over an ounce).
most pepsi stove instructions i've seen have a bottom half that's 3/4 inch, and a top half that's about 7/8 inch, or something like that... my first step in the direction of increasing fuel capacity would be to bump the top and bottom measurements up by about 1/4 inch each, which should allow you to use at least an ounce and a half of fuel vs one ounce...
if you're using an ion stove, that same technique would probably work, but both would throw off your potstand height (mine's been tweaked pretty tight, and i'd have to make a new stand.)
I actually have room to bump up size with my stand. I had to make a stand for my last stove since it sat too far from the windscreen/potstand. I'll give it a go... now if only my wife would let me try the stove in the freezer...:D
troglobil
02-07-2006, 15:40
the main problem is than denatured alcohol has a flash point of 55° F. That means it must be raised to thais temp in order to give off vapors to burn, so at low temps it will need to be slighly prewarmed.
Klezmorim
02-07-2006, 15:58
I made several Penny Alcohol Stoves last October/November (collecting the "building materials" was soooo much fun!) and brought one along when the missus and I hike from Springer to Woody the last week of November. Outside temps were in the low 20s F. and the water was cold. I used a titanium Nimblewill stove that I'd made as a pot stand/windscreen. The combo worked great - even in the wind (which nearly blew us off Hawk Mtn.)!
For sh**s and grins, I decided to make a stove out of a couple of 24oz. Heineken cans. Wow, what an improvement! Two ounces of fuel burned for 23 minutes. I'm sure the stove will hold three ounces for a good half-hour burn. I'll try it and report back.
Here are a couple links if your interested:
http://www.csun.edu/~mjurey/penny.html (http://www.csun.edu/%7Emjurey/penny.html)
http://www.thru-hiker.com/workshop.asp?subcat=2&cid=9
The Penny Stove looks cool. I've seen that site before but I'll probably try and make one to that design this time around (have a couple of heinies waiting for me at home anyways). the 24oz. cans seem interesting too. Since I'm usually out with my wife I might just like that extra burn time. Thanks for the links.
I actually have room to bump up size with my stand. I had to make a stand for my last stove since it sat too far from the windscreen/potstand. I'll give it a go... now if only my wife would let me try the stove in the freezer...:D
she's gotta sleep sometime....:D
Skidsteer
02-07-2006, 19:09
This past weekend my wife and I spent a night up in the Mt. Rogers area. It was really cold low twenties. While my wife was warming up in the tent (read: shivering and trying to change from damp wet clothes to dry camp clothes) I was fiddling with my alcohol stove. It lit, I put the pot on and went to tend to Kel. After 10 minutes (about the burn time of my stove full) Kel went to check the stove and everything was still cold. But no fuel in the stove. So I busted out the trusty Pocket Rocket and boiled some water. I love that thing. I guess when it is really cold out it is nice to have water come to a boil quickly for that first warm beverage while getting settled at camp. My goal now is to design an alcohol stove system that will work in those temps using a larger fuel capacity (my current one maxes just over an ounce).
I've not had any problem bringing my water to a boil at temps as low as 25 degrees F. with homemade alcohol stoves thus far and most of my stoves hold no more than 1 1/2 ounce. But, if I were having trouble, one solution would be to bring a Trangia. It'll hold @ 3 ounces and for large quantities of water/low temps it would be tough to build a stove to rival it's effeciency, IMO. Just an idea.
I've looked at it and read nothing but great reviews of it. But I have 2 stoves already that I have "paid" for. I like the challenge of building one. This was also my first go around with an alcohol stove on the trail. I have yet to decide whether or not that is going to be the stove of choice for our thru in 2007.
I built a simple alcohol stove last night and tested it at 26F, no wind. Using denatured alcohol (HEET), it brought 2 cups of water to boiling in 12 minutes, and continued the boil for 8 minutes. Pretty basic construction using two pop cans and a swiss army knife.
http://cruisenews.net/backpacking/BeerCanStove.html
vipahman
02-08-2006, 12:16
Mine took 9 minutes at 40F. Yours 12 minutes at 26F. So, while the time is going to increase in more than a linear curve, it is definitely possible to infer that at around 12F, it will take at least 15 minutes. IMHO, that's a loooong time to wait especially at those temps.
If it even works at 15F. I think I would go with a woodburner under 20F. At least you should be able to find dry wood fuel.
Our situation was everything was wet and frozen. It was raining like crazy on saturday till about 1 or so when it changed to sleet, hail, then snow. I think my stove worked but didn't have the capacity to boil the water, I also had more than 2 cups of water in the pot. The stove would boil 4 cups at home but that is with an ambient temp of 67 degrees. Anyhow I'm excited to see that some of these stoves have the capacity to work in the low temps. Thanks for sharing the knowledge.
Nightwalker
02-09-2006, 19:34
Our situation was everything was wet and frozen. It was raining like crazy on saturday till about 1 or so when it changed to sleet, hail, then snow. I think my stove worked but didn't have the capacity to boil the water, I also had more than 2 cups of water in the pot. The stove would boil 4 cups at home but that is with an ambient temp of 67 degrees. Anyhow I'm excited to see that some of these stoves have the capacity to work in the low temps. Thanks for sharing the knowledge.
Try here (http://www.minibulldesign.com/fs2.htm). Scroll down to the Sith.
I might make one similar to the sith. I like the primer wick system. Thanks for posting.
Klezmorim
02-14-2006, 13:42
Just a quick update: my Penny Alcohol Stove made from 24oz. Heineken cans burned 43 minutes on 3oz. fuel (+.5 ounce for priming). It took 5.5 minutes to get a pint of water to boil; 11 minutes for a quart.
atraildreamer
05-20-2006, 08:23
I used a mixture of coleman fuel with methanol and then ethanol. Each was about 20% coleman. I had no problems with either melting the pepsi stove or the flame getting out of control. I didn't heat any water--just trying a fuel mix.
If you use pure coleman fuel, be sure you have the local fire department on speed dial. Patrick posted some pictures--these should convince you not to try pure coleman fuel.
Stag
Update your will and get your affairs in order before igniting...:banana