Yet another wood stove
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Michael Meiser
(mmeiser) - F

Locale: Michigan
Yet another wood stove on 04/03/2011 22:34:03 MDT Print View

Well, there can never be to many wood stoves.

Indeed I've experimented with dozens of different types and designs from forced air, to convection / rocket stoves, to wood gas. As well I've often traveled with whitegas, isobutane, and alcohol, which is a favorite do the ubiquity of alcohol fuel sources like heet and the extremely light weight and simple nature of alcohol stoves like the supercat.

However I keep finding myself coming back to extremely simple wood stove designs.


== Why wood? ==

Like all UL gear it's simply a matter of highly personal issues of style and taste. To each their own.

After doing a 35 day, 1500+ mile bicycle tour / bikepacking trip down the eastern divide in January I realized just how much I loved wood fires. Because I was often following hiker/biker routes with distinct camping spots and fire rings I had a campfire pretty much every night. It was absolutely wonderful.

Indeed for that trip campfires were pretty much essential for melting snow / purifying water and cooking. I would simply have used to much white gas otherwise. As it was I used my white gas stove maybe 4 or 5 times on the entire trip. Only when I couldn't make a fire.


== wood stove pros ==

1) lightweight / no fuel to carry / fuel readily available nearly everywhere

2) better then any other stove for prolonged usage... i.e. multi-course meals / water boiling

3) scalable from cooking stove to campfire given appropriate situations

4) drives bugs away

5) focuses on growing knowledge and skill, not gear or store bought solutions

6) a deeper connection with the wild, i.e. becoming a "wood gourmand" among other things

7) can be hotter / faster cooking then any other stove type. (Absolutely true, more on this later.)

8) great as a general heat source

9) great a a general light source


And I'm sure there are many other big ones I'm forgetting. Feel free to jump in.


== wood stove cons ==

1) smoke does saturate everything

2) soot

3) not usable in a tent / under a tarp


== my wood stove requirements ==

Anyway, my trip got me thinking about finding ways to better integrate fire into general purpose touring and bikepacking so as to further lighten my load and decrease my dependency on refueling.

In order to do so I need a wood stove to be "stealthy" and extremely low impact. The fact of the matter is where I tour (back roads but not back country) and how I tour (fast and light) most of the time I can't have a campfire and if I do have a small wood fire I need it to leave so small a scorch mark (if any) that it's easily covered.

Furthermore of all the wood stoves I've seen I think they are too high maintenance and to small. I'm looking for something that is extremely efficient, but that I can load enough wood into and "abuse" enough that it can burn for at least 30 if not 60 minutes without being attended.

Also... not only do I require a low maintenance stove, but it must also be hot and quick to lite, I'm very impatient when it comes to cooking at times, particularly in the morning. Most of the time I simply skip breakfast for snacking if it comes to carrying more fuel or waiting for a fire to start.

Finally, it of course must be very lightweight and pack very small.

To list my requirements out:

== requirements ==

1) must be extremely hot / boil water as fast as or faster then any other stove type

2) must lite extremely fast (when I need it too)

3) must be extremely light weight

4) must burn for prolonged periods of time

5) must be low impact (little or no scorch mark)

6) must be extremely efficient

7) must not produce a tremendous amount of smoke

8) must pack extremely small.

9) must be scalable, i.e. used with rocks or a log to create a much larger but still contained fire.

10) must be able to lite with and handle wet / damp wood


You will notice that among these requirements is not "sootless". I've not got any hang ups over a pot having a blackened bottom, nor have I found soot build up to be a problem when a stove is hot enough. Indeed I think many of the designs here soot up because they are so small they don't produce enough heet. (more on this later)

The only thing that really bugs me about wood stoves is the smoke smell. I like it, but I often stop in small restaurants and outposts of civilization on my trip and I don't want to scare off their customers.


== yet another prototype ==

This design has been influenced / inspired by Zellph stoves.

http://www.youtube.com/user/zellph
http://www.woodgaz-stove.com/

My nod to Zellph. I like his recent experiments though I prefer a larger stove.


http://www.youtube.com/watch?v=4I4KwrQCp4g


http://www.youtube.com/watch?v=07ZdZfLHoqQ

Specs.

5.85 oz
8" high
5.5 - 6" wide

Consists of three pieces.

1) 1/2" wire cage main body
2) aluminum windscreen
3) 1/2" wire cage screen on the bottom

Rolls up easily in my 700ml pot with plenty of room for the rest of my cook kit including:

1) titanium light-my-fire spork, i kept breaking the plastic

2) 3-4 oz of alcohol (optional)

3) small bic lighter

4) a platypus bladder cut down to .60oz to make a large cup/bowl/mug (like a ziplock, but free standing and more durable)

5) a supercat stove (optional)

6) zip lock with cotton balls, twine and/or other natural fire starting materials

I'm fairly pleased with the way this burns, can boil 2-3 cups of water in 3 minutes when it's going good. Indeed this is without a lid which I find unnecessary with a campfire or stove such as this unless ash is an issue.

This rapid boil time is not surprising given the stoves size. Most stoves featured here are 3-4" wide and the stove sits on top. This limitation in size drastically cuts down on heat and convection, especially when a pot is placed on the top. It's then that most stoves tend to cool down and produce a lot more soot because of the incomplete combustion.

Indeed this stoves size is key as my 700ml pot can simply be set in the fire without impeding or choking the convection... as can a kleen canteen or other container.

What's more new wood can even be placed in around the pot while it's cooking.

I have learned from my experience with campfires that there is no need for a traditional stove top or pot hanging setup. There is always a way to securely set a pot right on the coals or in the fire. Indeed I find this to be more secure then most stoves which can be easily knocked over and have never spilled a pot of water setting it in or on the fire.

In fact I'm so comfortable I'll often set my cup of tea or coffee right back in or on the edge of the fire between sips to keep it hot.

What's more setting the pot in the fire is the key to extremely rapid boil times.

First, putting the pot in the stove top right on the fire protects the pot from the wind

Second, this vastly improves the surface area which is in contact with flame.

Thus the actual flame is NOT hotter then isobutane, whitegas or even alcohol (as is evident by it not being blue) but there's much more flame all around the pot producing much more heat transfer and significantly improved boil times.

In short... wood can make all other stoves seem bulky, slow and clunky.

In my opinion. ;)


== Weight / size ==

Though large and just a prototype this weighed in at 5.85oz. Not bad considering.

The aluminum windscreen alone is 2.75oz. It should hold up well, but is overly heavy and will eventually need to be replaced with some thin titanium which will be far lighter, thinner and more heat resistant.

What's more it's pretty versatile. The windscreen is removable and usable for other purposes and it can be opened up in a 3/4 or half round shape as a reflector for a larger fire (not that it wouldn't melt until i replace it with titanium).

And of course the windscreen can be used with another stove if one is carrying two stoves for versatility... i.e. alcohol and wood... as I often do.

Right now for the prototype cage I'm using galvanized 1/2", will be replaced with some like stainless steel in time.


== quick start?? ==

I've been experimenting with quick start options for when I'm in a hurry, i.e. a quick breakfast.

As with all things good and true about bushcraft and going ultralight getting a fire going quickly and efficiently is more about skill and experience then gear.

That said, the quickest option is to use a tiny tea light type stove or improvised piece of aluminum foil with a 1/4 oz of alcohol in it.

I find this more then enough to get even damp wood going fast.

Simply light the tealight stove and set the stove over it.

Just an FYI though... I melted down my supercat stove using it in this manner. It gets hot under there.

well, I think that sums it up.

If you've got anything to add, any critique, any other stoves or threads exploring stoves like this I'd be grateful.

Edited by mmeiser on 04/03/2011 22:37:12 MDT.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Yet another wood stove on 04/04/2011 08:01:27 MDT Print View

That's a nice design

I keep reading about wood stoves, I gotta try that out

It seems like you wouldn't use very much wood compared to a campfire, for those of us that feel guily burning up all the bits of wood in the wilderness

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Yet another wood stove on 04/04/2011 13:49:51 MDT Print View

There are many places where wood burning is forbidden due to forest fire danger.

--B.G.--

Michael Meiser
(mmeiser) - F

Locale: Michigan
Re: Re: Yet another wood stove on 04/04/2011 22:57:33 MDT Print View

First, my appologies for not posting a pic or two. I thought the videos would appear visibly in the thread. I guess this post was a little underwhelming. Will try to post some photos inline when I get the chance.

@Jerry Adams (retiredjerry), regarding efficiency: Yes these would stoves use a tiny, tiny fraction of the wood a campfire burns. It's a big part of their charm. A single three foot branch could burn the whole evening. A handful of sticks can make dinner.