3079off topic -- diy wood burning backpacking stove
- Sep 30, 2003I have continued messing with this and have a configuration that
might be useful to fire enthusiasts. I will continue refining this
design, but don't expect to uncover major improvements. As with the
Garlington Insulator, I will put together a web page with some
pictures and additional detail. Comments are welcome.
The Garlington WoodGas Stove
After about 2 months building & testing small woodstoves of various
configurations, I stumbled on an easy to build, lightweight stove
(3.5 - 4 oz) that will boil 1 quart of water and hold the boil for
about 10 minutes. The stove is batch loaded, fun to use, and nearly
smokeless when properly fired.
On the negative side, this stove requires a starter fluid and will
blacken your pots. Also, the current version gets hot enough at the
end of the burn to ignite newspaper under the burner, so the stove
should not be used on flammable surfaces.
The design attempts to exploit the "batch-loaded, inverted down-draft
gassifier" wood-burning technique and manages about 1/3 - 1/2 "blue
flame" at peak output. As the gas-burning stage winds down and while
the stove is still quite hot, the flame is mostly blue. Typically,
the stove is burning wood gas shortly after ignition and has a
stable yellow/blue flame within about 1 minute. After about 10
minutes the wood gas is depleted and the stove transitions to
charcoal burning. Charcoal burning continues for about 20 minutes
after this transition.
The stove comprises a steel can, fire grate, stove windscreen, pot
stand and pot windscreen. The steel can forms the body of the burner
and is 3" in diameter and 4 1/2" tall. Primary air holes are punched
at the bottom edge of the can, and secondary air slits are cut about
3" up from the bottom. A fire grate (wire screen) is fitted to the
bottom of the can to allow even distribution of the primary air to
the bottom of the fuel supply. The stove windscreen is made of light
aluminum (disposable baking pan) about 3 1/2" in diameter and 4 1/2"
tall. Slots are cut in the bottom of the stove windscreen to allow
primary/secondary air to enter. The pot stand is fashioned by
bending a coathanger into a clip that slips onto the rim of the steel
can and holds the pot about 1 1/4" above the rim. The pot
windscreen is a piece of doubled aluminum foil that goes from the
ground to at least 1/2 way up the pot.
Find a supply of dry sticks about the diameter of a #2 pencil and
smaller. Dump out the ash from the previous firing, and position the
stove windscreen and pot stand on the stove body. Break up the
sticks into about 1" lengths and throw them into the burner. As the
stove fills, periodically shake/tap the stove to settle the fuel.
When you get close to the secondary air slits, use only the smallest
of the sticks you have collected. Shake/tap down the stove once again.
Spray a small amount of starter fluid (charcoal starter fluid,
kerosene, alcohol, etc.) on the top surface of the wood supply. Do
not use too much, because you only want to ignite the top layer of
wood. (Igniting the lower layers will result in a smokey mess.)
Light the starter fluid. After about 1 minute you should have a good
flame going. Postion the pot on the stand and place the pot
windscreen around the pot.
Caution: If the stove fails to ignite, do not spray additional
starter fluid. There will be hot embers present from your previous
attempt which are capable of igniting the fluid as you spray it on.
This could result in SEVERE injury to you and others. The safe thing
to do is unload the stove, reload it, and try again.
Copyright 2003 Ray Garlington
Air Temp: 55F Starting water temp: 71F
0 Light fire
1 min Water on Stove
5 min Water temp 130F
10 min Boiling
20 min Boiling
25 min 198F
30 186F Charcoal is generating little heat....
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