Hannah stove findings
I’ve been playing around with the stove design popularized at the link here:
http://ygingras.net/b/2007/6/a-better-soda-can-stove
Design is simple, yet quite sound. In this design, it’s press-fit, so no glues or tapes is required. However, trying to fit two equally shaped pieces into each other takes quite a bit of practice, but eventually does work. Also, although the pieces may fit, there might still be a tiny air gap that allows for fuel to escape downwards between the pressed-fit pieces… probably not a huge safety issue, but I have observed this happening in one of my stoves.
One issue that people have not answered was whether the stove will work in cold weather. In my tests… depends on the temperature. In minus 20 deg C temps, no. After priming, the flames from the stove is not hot enough to keep the walls of the stove warm enough to pressurize the fuel. It works ok in -10 deg C temps though… however, I’m using it in a protected coffee can that shields the stove from the wind - see picture below. The coffee can has several holes drilled near bottom (0.5 cm above bottom) to allow for oxygen to feed the flames. One hole is set very low, so that I could ignite the priming fuel.
My initial pictures of “first light”. Can’t remember why four pinholes are not ignited… probably because I didn’t put enough fuel in. But for my initial tests, I wanted to be on the safe side and not have too much fuel, just in case it explodes.
Stove is inside a coffee can wind shield. Coffee can has been perforated with holes around 1 inch from the bottom, at 1-2 inch intervals. Perforations are very important if you’re planning to use a coffee can wind shield as it allows a flow of fresh oxygen to enter. Now that I think about it more, I should’ve put perforations onto the top of the can too, to allow for exhaust gases to escape.
Better angle of ignition hole for the priming fuel.
Boiling water on top of coffee can wind shield
Example below is of the stove in the unprotected configuration heating up a test can.
and also heating up a test tin foil container with approximately 1 cup of water starting at 23 deg C. At ambient room temperature of 24 deg C, it took approximately 10 minutes to heat the water up to 85 deg C:
With 35 ml of fuel, I got around 15 mins of usable heating time.
February 3rd, 2009 at 06:08
Hello Larry,
I’m glad that you like the design. For the occasional leak between the two parts, I always fit the top part inside the bottom one. That way if there is a leak, it just becomes another jet. For the temperature issue, I can only recommend that you try other fuels. Methanol packs less energy per gram than ethanol but it is definitely more volatile. Did you try it? I’m not sure if it can work, -20 C is definitely really cold for any kind of alcohol stove. Keep me posted if you find a workable solution.
March 2nd, 2009 at 22:42
Thanks for the tip on reversing the fittings, I’m pretty sure that would work. I have to admit that I omitted an important detail on the fuel I used, which was a fondue fuel from a local dollar store - and there was no details on what this fondue fuel consisted of - whether it was pure ethanol/methanol or a mixture of both.