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Two Letters Re: Homemade Alcohol Stoves
Mr. Rawles,
The recent article on alcohol stoves made me think of these ultra-lightweight,
portable alcohol stoves made out of soda cans, See this
Wikipedia article.
I have successfully built the original Pepsi-can version using epoxy glue,
as well as the Heineken-can "penny" version. I have not tested them "in
the field" but both work very well indoors, and they have impressive performance,
boiling 2 cups of water in 5 minutes using only 2 tablespoons of alcohol. Those
who have actually used them outdoors say they outperform other small stoves
even in the most extreme of conditions. Even for indoor use, they are a compact,
easily stored backup for cooking.
The stoves are easy to build, but expect to build a few to get the hang of
it and make a well-burning version. Many web sites are available that cover
different versions of the stove and various accessories to go along with it.
For fuel, you should only use methyl or ethyl alcohol. Don't use isopropyl
alcohol in these stoves, as it will cover the bottom of your pots and pans
with soot. Methyl alcohol burns hot and clean, but it is poisonous.
It is available, among other places, as HEET brand engine fuel line de-icer
in auto parts stores
in the red
bottles. (Don't get ISO-HEET, since that is isopropyl alcohol). Denatured ethyl
alcohol is cheapest, and of course Everclear 190 proof grain alcohol works
as well,
but it is quite expensive. Sincerely, - Chris S.
JWR Adds: Denatured ethyl alcohol ("grain alcohol") is much less expensive if bought
in quarts or gallons. It is available at paint stores. Don't buy methyl alcohol (Methanol or "wood" alcohol"), because of its toxicity. Long term exposure to the fumes or just brief contact with the skin can be toxic and can cause irreversible liver damage.
James,
LeAnne's article today has some bad advice and some misstatements in
it - potentially dangerous.
First of all, alcohol will produce Carbon dioxide (CO2) and water vapor (not
carbon MONoxide, CO) only in a perfect (ideal) combustion, with exactly the
correct proportion of oxygen - called the stoichiometric ratio. Any deviation
from that will produce imperfect combustion and CO. Even a perfect combustion
will result in CO2 being produced, the carbon atoms in the alcohol have to
go somewhere. And perfect combustion only happens on chemistry examinations.
A buildup of CO2 can be just as deadly as CO.
Secondly, 70% alcohol is 30% water....and before you get any heat out of burning
the alcohol you need to heat up and boil off the water. Half of the energy
of the alcohol (by volume) is wasted getting rid of the water The water vapor
added to a shelter could be significant. A better choice would be 91% alcohol,
if you had to use isopropyl alcohol. A better choice IMO would be alcohol available from paint stores, boating shops, etc.
For people travelling (backpacking, etc) a higher energy density fuel (gasoline
versus alcohol, with roughly twice as much BTU value
per pound of fuel carried) makes more sense. Alcohol stoves have their niche
but LeAnne's reliance on them
can lead one to dangerous reliance on them in inappropriate conditions. - Flighter
