View Full Version : Alcohol Stove/Windscreen Tweak
I have been reading as many threads as I could find here at "Whiteblaze" and have looked at most of the website links I found, i.e. Zen Alchol Stoves website, to name but one of several.
On an open jet type pop can alcohol stove, what would be a desirable height of the pot from the top of the stove as well as the diameter of the windscreen. The windscreen I'm trying right now is one where my pot will sit on top of the windscreen.
Here is what I've tried so far.
2 cups of 62 degree water in a 1.1 qt. aluminum pot (cover on).
I used one fluid oz. of denatured alcohol.
My windscreen is 4" in diameter, 2.5" high.
The pop can stove is 1.5" high and from top of stove to bottom of pot when on is 1".
I did my test inside and the stove used up the 1 oz. of fuel never reaching boiling temperature. Actually it hit about 190 Degrees.
I also have one of those brass alcohol stoves from a Swedish Mess Kit and I tried that as well. The results are about the same and so far I'm not impressed, but wondering if it's something I'm doing wrong or in my set up. Any advice would be helpful. Below is a picture of my set up.
After I light my stove, I wait a few minutes and then the flame shoot out the jet-holes. I did notice that as time went by, my flame got bigger coming out of the notches at top of windscreen and slightly up the side of the pot approx. 1/2" or so.
http://i106.photobucket.com/albums/m277/cpaulsb/Forums%20and%20Message%20Boards/P5020001.jpg
SGT Rock
05-02-2008, 15:10
I have been reading as many threads as I could find here at "Whiteblaze" and have looked at most of the website links I found, i.e. Zen Alchol Stoves website, to name but one of several.
On an open jet type pop can alcohol stove, what would be a desirable height of the pot from the top of the stove as well as the diameter of the windscreen. The windscreen I'm trying right now is one where my pot will sit on top of the windscreen.
Here is what I've tried so far.
2 cups of 62 degree water in a 1.1 qt. aluminum pot (cover on).
I used one fluid oz. of denatured alcohol.
Here is the short answer: It depends...
The somewhat longer answer is this: you should tune the height of the pot suport over the stove to where the bottom of the pot sits in the sweet part of the flame. The best point for this in my experience is where the flame starts to turn from blue to orange/yellow. Air flow, amount of fuel burned, pot diameter, stand design, and other factors can change this from stove/pot combo to stove/pot combo.
My windscreen is 4" in diameter, 2.5" high.
The pop can stove is 1.5" high and from top of stove to bottom of pot when on is 1".
I did my test inside and the stove used up the 1 oz. of fuel never reaching boiling temperature. Actually it hit about 190 Degrees.
That doesn't sound good. Something else to consider is the fact you may have too much alcohol to start with - it ain't likely but it is possible.
I also have one of those brass alcohol stoves from a Swedish Mess Kit and I tried that as well. The results are about the same and so far I'm not impressed, but wondering if it's something I'm doing wrong or in my set up. Any advice would be helpful. Below is a picture of my set up.
After I light my stove, I wait a few minutes and then the flame shoot out the jet-holes. I did notice that as time went by, my flame got bigger coming out of the notches at top of windscreen and slightly up the side of the pot approx. 1/2" or so.
Most likely your stand/windscreen design is choking the air flow off to your stove when a pot is in place. Just a theory.
http://i106.photobucket.com/albums/m277/cpaulsb/Forums%20and%20Message%20Boards/P5020001.jpg
Skidsteer
05-02-2008, 16:03
Not enough air as Sgt. Rock said.
Try cutting more and deeper notches in the top of your stand and see what kind of difference it makes.
You'll probably still want a separate windscreen as well.
Thanks gentlemen, I'll tinker with it some more and post back here with some results. Not sure I'll get to it today.
I really like the idea of the low weight with these alcohol stoves, but need tweak this more.
Half the fun of making your own stoves is tinkering with it to get it where you want it.
I remade the windscreen along the lines of something I saw on zenstoves.net. I want to do some more burns with it, but the first test it boiled 2 cups of water on one fluid oz. of denatured alcohol in just over 7 minutes and when I removed the pot, it burned for another 3+ minutes.
Considerable improvement over my first one but I want to see how well this screen holds up. It distorted somewhat. I used flashing aluminum on this one.
http://i106.photobucket.com/albums/m277/cpaulsb/Forums%20and%20Message%20Boards/P5030001.jpg
SGT Rock
05-03-2008, 18:41
There will be some distortion. The thing to remember is not to overload a windscreen that also serves as a pot support. They are generally going to get some distortion but still work.
And once you make one you can always make replacements later. FWIW I gave up on that sort of thing a while back. I found it easier and generaly just as light (if not lighter) to have a seperate pot support and a windscreen.
Right now I'm pretty content with this latest windscreen/pot support. I would imagine that the contentment will be temporary and then I'll want to try something else.
Thanks all for the input on this.
SGT Rock
05-03-2008, 21:01
It will be temporary - you are hooked.
sofaking
05-03-2008, 21:48
Addicts!:eek:
Dances with Mice
05-03-2008, 21:48
I remade the windscreen along the lines of something I saw on zenstoves.net. That is a great looking design (http://whiteblaze.net/forum/vbg/showimage.php?i=5831&original=1&c=member&imageuser=1030). Superb!
I don't know why you went to zenstoves though...
I knew as soon as I found this site I was going to be spending more time in my workshop making things which may lead to breaking some very old backpacking habits where as weight is concerned.
Dances with Mice
Actually I mentioned zenstoves because I did use the windscreen there as a basis for the one only because there was some sort of an instruction to follow for the first time on that particular windscreen.
However, I have seen many of the great ideas here at this site and you can bet I'll be looking at a lot of them very closely. I'm not sure I could improve on anything other than for my own use at this point.
Skidsteer
05-03-2008, 22:46
Dances with Mice
Actually I mentioned zenstoves because I did use the windscreen there as a basis for the one only because there was some sort of an instruction to follow for the first time on that particular windscreen.
However, I have seen many of the great ideas here at this site and you can bet I'll be looking at a lot of them very closely. I'm not sure I could improve on anything other than for my own use at this point.
See Dances? That's what I'm on about!
You need to post real instructions in a real thread for the Kitten stove and your windscreen.
No more of this figuring it out from the photos schtick. Do it for the team man! :p
In all honesty Dances, I didn't see your set up. Don't know how I missed it.
Question is how well does the wire hold up after heating and reheating?
Dances with Mice
05-03-2008, 23:23
In all honesty Dances, I didn't see your set up. Don't know how I missed it.
Question is how well does the wire hold up after heating and reheating?The setup shown in the photo went on a 9 month thru-hike. During that time the wires were replaced once, maybe twice, but I forget how long they lasted. I've never had to replace wires in my weekend-use windscreens but I've made a couple models as I've changed cooking pots.
One feature to consider is the flashing seam - all other plans I've seen use two "C" type folds that hook together. That will cause problems because the strain on the seam is compressive and tends to push the ends together and the seam apart. I made a "Z" type fold on one edge and a straight edge on the other. Then as more weight is applied the seam connection gets stronger.
I just like my setup because I'm a space case and there's no parts to lose. Or rather, there's just one, but I can keep track of one thing. Usually.
88BlueGT
05-04-2008, 03:11
I was just going through the same thing deciding on wether to go with a pot stand and a wind screen seperate or not..... I ended up doing it seperate. I still havent decided on the height yet. I have a thread a few spots down right now trying to get some help with it. I'm going to try and do some testing tomorrow and see what works best...