“The Great Wood Stove Burn-Off”

[Dan Yeruski]

There are three stoves being tested. The Bushbuddy, the bushcookerLT2 and Woodgaz Prototypes. The compact folding Woodgaz was taken out of the tests because the fire box was too large to be able to contain the small volume that exists in 2 ounces of fuel. Smaller prototypes were substituted.

The Bushbuddy and Bushcooker are double wall stoves. The Woodgaz are single wall.

Four tests have been completed with videos.

I'll post all videos here and information concerning specifics once the testing is complete. I'll probably do 2 more tests, possibly 3.

Follow the testing progress here:

<"The Great Wood Stove Burn-Off">

All comments are welcome.

[Mike S]

Now I am far from a gram/efficiency weenie but it seems that the boil times are generally the same under optimum conditions and plenty of fuel. How about reducing the amount of wood?

[Dan Yeruski]

Hi Mike,

If we can get the boil with 2 ounces of kiln dried, then we should be able to get it with dry twigs right?

Someone had to to get off dead center to do some testing. I took the first step. who's up next?

Something to keep in mind. 2 stoves are double wall and the other is single wall.

I'll stick with doing the 2 ounces of kiln dried and do 2 ounces of dry twigs next week. I'll pick some pine twigs out in the woods today and let them dry in my greenhouse till next week. Sound good????

[Mike S]

I think your test are good. I enjoyed watching the videos but since they all performed nearly identical I was thinking of other ways to distinguish performance.

I would think that you could use the same wood but start reducing the amount used. Finding out which stove can consistently boil water with the minimum amount of wood would be a great indicator of performance.

[Dan Yeruski]

Due to spring time planing of fun and games my stove testing has come to an end for now.

The results can be seen at:

http://www.bplite.com/viewtopic.php?f=60&t=4961&p=38376#p38376

Thanks for looking. =)

[Hendrik Morkel]

Not side by side, but in winter and with real wood:

Bushcooker LT II In The Snow

BushBuddy Ultra In The Snow

Ti-Tri Inferno In The Snow

[Antti Peltola]

"I think your test are good. I enjoyed watching the videos but since they all performed nearly identical I was thinking of other ways to distinguish performance."

Me too. However, getting boil with less wood isn't on my list as there is usually more than enough available. How about these two:

1) How long there is usable heat from one load of wood? Longer burn more boiling water without reloading.
2) How is the performance using non-ideal fuel? Usually the wood is not kiln dried out there, and wet wood slows down the beginning of the burn a lot in some models. Getting the test to be fair with all models on this test probably would require some extra thinking like snapping one branch into equal piles for every stove and continue with the next branch so the differences between sticks would not matter too much.

[Ultra Magnus]

I don't mean any offense- but I'm less than impressed with so called "wood gas" stoves that produce tall yellow flames. A true wood gas flame is blue(ish) more resembling a natural gas flame. These stoves, in my humble opinion, are what I'd consider expensive (at least in the case of the bush buddy), well built, and slightly more efficient, hobo stoves…

I chimed in a discussion on the subject over on this thread- http://www.backpacking.net/forum/ubbthreads.php?ubb=showflat&Number=145636#Post145636 and posted some pics of my quest for the blue wood gas flame…

In short, I don't think it's really possible in a backpacking style tin can stove…too much heat loss. In reality, the stoves need insulated combustion chambers, which I'm still trying to figure out a simple clean, easy to make, design.

Just my $0.02

BM

[Jerry Adams]

Does the blue wood gas flame have less soot?

Tried to look at backpacking.net but it said access denied and I was too lazy to continue

[brent driggers]

I look forward to your multichambered, insulated combustion box, blueflame breakthrough.

[Ultra Magnus]

In all reality- a true wood gas flame burns dead clean. During world war two, many cars in Europe were fitted with downdraft wood gassifiers- so the produced gas is clean enough to run an internal combustion engine. http://www.lowtechmagazine.com/2010/01/wood-gas-cars.html

Here's a pic of my stove running at its best. The thing with this stove is that the flame / combustion efficiency changes as it burns. It takes approx. 3mins to warm up, and iirc, this is after about 10mins of burning. https://lh4.googleusercontent.com/__B-y4MyE5YE/TWlOt4Vns_I/AAAAAAAAAVo/89Yvkn7unGI/s512/DSC06091_email.jpg It'll burn for approximately 30 mins on 60 – 70 grams of wood, packed vertically and tightly, about 2 – 2.5" up from the bottom of the 3" x 4.5" soup can combustion chamber.

Here are the rest of the pics from that test burn- https://picasaweb.google.com/bmadau/WoodGasStove?authkey=Gv1sRgCKGf8daH5LK0qwE&feat=directlink

So, it's not soot free, but it's pretty good. Also, I wonder if the kind of wood being burned has an effect on the soot/tar issue. I'm using Douglas fir 2×4's for some level of scientific control for my garage tests, and I'm told that pine trees have lots of tar and resin compared to other woods. Eventually I'll try some good dry hardwoods and see if that makes a difference.

BM

[Eric Blumensaadt]

A good start to a full blown, scientific test of ALL major woodburning backpacking stoves
but…

Let's see the same tests on a CC Sidewinder Inferno and the battery operated Zip Stove.

Since I began asking for this "burn off" I've contended that BOIL times are the best criterion for comparison as they determine overall efficiency. And it is efficiency that we are measuring – efficiency that involves both combustion and conservation of the heat from that combustion.

Again, my money is on any CC Inferno you want to put up against the other woodburners.

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