The Bushwhacker Wood Stove - Video

For anyone who might be interested, I did a quick demo of how to use Jim Falk's Bushwhacker Stove:

 The Bushwhacker Stove Video

Nice video Jason but, through no fault of yours,  liable to confuse because "Google Ads" showed ads for "woodburning stoves" in a banner.   For most of your video the caption immediately below the screen said "Tiger Stoves £329".  Though I've no doubt the Tiger is an excellent stove if you want to heat your house, lightweight backpacking it ain't. 

Just for the record Jim Falk's site quotes a price of $28.50 for the Bushwhacker.

not sure how big it is but if its smaller than bushcooker (fire cavity) then i reackon it would lots of attention to get a constant burn? (or if woods damp would be a pain too?)

Frum wrote (see)

  liable to confuse because "Google Ads" showed ads for "woodburning stoves" in a banner.   For most of your video the caption immediately below the screen said "Tiger Stoves £329".  .

With Adblock Plus enabled, it doesn't. 

If you don't have Adblock installed but have the neccessary hand/eye coordination skills to use a mouse or trackpad, try clicking on the 'x' on the top right corner of the Google ad. 

Interesting vid, Jason.  Good blog, too.

I emailed J Falk about 4 weeks ago regarding buying a Bushwhacker - His site doesn't accept overseas orders.  Still no reply

Decided to make my own as others on this site are doing.

Hi everyone, sorry about the annoying ads.  As LotC mentioned, you can just close them and get them out of the way.  I have no control over which ads appear. 

 Mole-

When you make your own, would you mind posting some pictures of it?  I'd love to see it.

Monkeyjazz-

It's maybe a little taller than the Bushcooker, BUT, keep this in mind.  You fill it once and let it burn.  You don't keep feeding it.  Once you start putting wood on, it ceases to become a woodgas stove--it turns into a regular convection stove.  I suppose you could keep feeding it if you wanted a long, sustained burn--maybe it just wouldn't be as fuel efficient.  But in that case, the Compact Wood stove is probably a better choice.

I am afraid I totally disagree, either it provides secondary air to burn the woodgas or it doesnt, how you feed it is secondary.

 Feeding little and often will keep a more even combustion mixture of charcoal and volatiles and will allow better burning of woodgas.

I keep hearing that the gasified stove is more efficient than a simple one.  Under what circumstances?  The reason I ask is that my extremely unscientific investigation, which consists solely ofwatching two of Bob's videos plus Jason's produces a clear winner - the simple Honey stove.

All three seem to be about 2 UScups/1 uk pint/500 ml of water.  I adjusted the times to allow for the time between lighting the tinder and starting the stopwatch.  On this basis the Honey (simple) took 7m15s to boil, the Bush Cooker (gasifier) took 9m5s and the Bushwhacker (gasified) took 9mins plus at least a minute between lighting and the stopwatch starting.

I know there will be a great many variables involved in these results and would love to see a fair comparison - which does not mean that I think either Bob or Jason did anything unfair.  Both were just producing honest and helpful videos rather than taking part in a test.

On another thread I was suggesting that I feel that burning the smoke must help efficiency,

The devil is in the other variables:

 a bigger firebox, particularly plan area, filled by a good firelighter, lit with good tinder, and fed steadily with very dry sun warmed finger thickness sticks, with  primary air fed through a good grate of maximum area, with the pot and flames shielded from any wind, on a warm day, using no more than 500 ml of (summer time) cold tap water, using a wide shallow pot ..........

You can overwhelm the difference between a gasifier and a simple stove with other variables very easily.

My little gasifier has boiled 500 ml of cold tap water in 5 minutes from the match, but it was close to ideal conditions. The test is burning wet fuel in rain and strong wind

Hi Derek,

According to Jim (the inventor of the stove), what I said above is true.  Unless it burns from the top down, the wood will not gassify.  It will just burn from the bottom up like a regular wood stove.  I'v tried feeding it once the fuel ran low and found this to be the case.  It was also less efficient and produce a little more smoke. 

Hi Frum,

You're right.  Just becasue I made a video on this stove doesn't mean I think it's the be all end all stove or that it's perfect for every condition.  The video was mostly just to show how to light and use the stove for those interested.  Personally, I don't carry a wood stove.  I'm an alcohol stove person.  But, I like to play with different types of stoves.  So, people can watch this video and take it or leave it as far as I'm concerned. 

Jason Klass wrote (see)

Hi Derek,

According to Jim (the inventor of the stove), what I said above is true.  Unless it burns from the top down, the wood will not gassify.  It will just burn from the bottom up like a regular wood stove.  I'v tried feeding it once the fuel ran low and found this to be the case.  It was also less efficient and produce a little more smoke. 

Well in my experience, Jim is wrong as well. The inventor of the Bushbuddy would agree with me.

All you have to do to get wood to gassify is to heat it a bit and it drives off the easiest burnt components first, in gas form, leaving charcoal until last. So every open fire gassifys wood. The trick is to get oxygen to these gassification products while they are still hot enough to ignite. If you dont you get clouds of white smoke. If the stove preheats the secondary air then the chances of getting oxygen to the fumes while they are hot enough, must be increased.

You are making a distinction between batch fed and continuous fed stoves which I think is totally different.

> According to Jim (the inventor of the stove), what I said above is true

Well, although Jim created the instructions for building the Bushwhacker stove (as I understand it), I don't think he invented the gasified wood burning stove.  So it's entirely possible that he's got hold of the wrong end of the stick (not the hot end, I hope...).  There certainly seems to be a lot of confusion about these things...

I found this article to be quite useful, and the associated documents about the Turbo Stove.  However, I don't think these tell the full story, either...  For instance, the Turbo Stove leaves about a 15% charcoal residue.  I'm not sure that I want any residue from my fire...

This Wood Gas Stove, which looks to be a genuine wood-gas burner, judging by that flame pattern, certainly says that you can add fuel as it burns.  Its uses a forced air supply.

Then there's the Biomass Energy Foundation.  Which has a page on gasification, which suggests a continuous top-feed of fuel.  However, this sucks the gas and ash out from the bottom.  A true downdraft gasifier...

or just the raw google search...

I looked at lot of this stuff about six months ago, and never managed to get to a decent answer.

You mission, should you choose to accept it...

FWIW and based on what I've seen from my own attempts to make a woodgas stove I don't think there's a major difference whether you burn down or up.

Initially when I made my mk2 stove which was quite tall I filled it with very small pieces of wood almost to the top (J Falk style) I managed to get it to burn down on the first attempt. On a later experiment I didn't get it to light first time so simply started with a little and added fuel as and when. Both methods worked in a similar way with an almost total absence of smoke and the flame appeared to burn some way above the actual wood (more noticable when burning up Bush Buddy style) the flame also appeared to come from the top vents regardless of whether I used the J Falk method or the Bush Buddy method.

Again FWIW I would guess that J Falks method would provide a more consistant heat output as when you're adding fuel as you go along (Bush Buddy style) there's a tendency for the flame to die down as heat output drops (resulting in a failure to ignite the gas) and then flares up again as the newly added fuel starts to generate more heat. Also when adding fuel you need to be careful not to overdo it or the temperature really drops and there's a lot of smoke, I've had to remove the pot and blow into the firebox a few times to get it fired up again. In one of Jason's other video's he uses a length of silicone tubing with a metal tube on the end inserted into the base air intakes to blow into a hobo stove if required to help it light, that might be a useful addition to my woodstove for getting it going if I overfeed it as it would mean not having to remove the pot.

IMHO of course, I'm no expert on the subject

I have just got hold of a Bush Cooker and have been playing around. I am familiar with the gassification arguments, single load, feeding etc etc.

I feel certain that the actual *conditions* make the biggest difference (ambient temperature, wind, rain, damp/dry wood etc). You might get a few mins difference in boil times with different stoves - but does this actually matter?

In terms of the gassification/top down/bottom up debate, I don't think it matters. If you light a fire in the bottom and stack up the wood it starts as a normal wood fire. At some point the flame front moves from the wood to the secondary air holes around the top. This seems to make a more controlled burn which arguably leaves less ash. Perhaps this is actual gassification everyone talks about. I will try a top down approach too and see if it appears different.

As far as thge Bush Cooker goes, however it really works, it burns wood like a dream. It can boil a big pan (1.5 litres) of very cold water using only tiny twigs (free) in around 10 mins. This is plenty good enough for me.

 I have also played with Esbits and the results are also impressive. These gassify very readily and burns almost immediately from the top air holes. One large tablet (2" square, 1/2" deep?) also managed to boil my big pan in about 10 mins.

So, very happy. A 200g efectively free fuel stove that makes tea in 10 mins.

Next experiements will look at creating a simmer effect by feeding small amounts of fuel to allow slower cooking, and using a meths burner of some sort inside to create a realtively sae 'tent vestibule' cooker.

Oh, and I forgot to mention. I am having a great deal of fun  

Frum wrote (see)

I keep hearing that the gasified stove is more efficient than a simple one.  Under what circumstances?  The reason I ask is that my extremely unscientific investigation, which consists solely ofwatching two of Bob's videos plus Jason's produces a clear winner - the simple Honey stove.

All three seem to be about 2 UScups/1 uk pint/500 ml of water.  I adjusted the times to allow for the time between lighting the tinder and starting the stopwatch.  On this basis the Honey (simple) took 7m15s to boil, the Bush Cooker (gasifier) took 9m5s and the Bushwhacker (gasified) took 9mins plus at least a minute between lighting and the stopwatch starting.

I know there will be a great many variables involved in these results and would love to see a fair comparison - which does not mean that I think either Bob or Jason did anything unfair.  Both were just producing honest and helpful videos rather than taking part in a test.

I watched Both videos this week and have to make the point that Bob lit a bottom up fire and The guy in the video posted by Jason Klassbuilt a fire in the stove and lit from the top. Bob seemed to start a small fire in the bottom and then put more wood in, a bottom up fire. Yet Bob did get the slowing of the fire followed by a sudden increase when flame jets appeared out of the inner, upper holes. This would appear to be secondary combustion of volatiles.

If you read Meecham's article in TGO magazine he decribes his research into the fire lighting techniques for his home-made version of these stoves. His conclusions of his tests (seems to be thorough in past tests) is that you need to build a kind of lattice pyramid of fuel then light the top and leave to work. If this is the case then it is only like a meths stove where you fill up with the right amount of meths required (through experience) and then use before leaving to burn out. At least with a wood burning stove you get a nice fire effect not a dim blue glow.

Frum - was the honey stove timed with wood or meths burner? Silly question I can't remember.

I will be getting the Honey soon and use with wood and meths burner.