Wood gas stove advice.

[NarzaCyst]

Hey all.

Decided to make a Wood Gas Stove today after making a very successful beer can stove last year.

So I used x2 Kenco tins I'm varying sizes.

So..... I'm far from any expert clearly, but I noticed a couple of things.

Pretty difficult to get these things ignited, and PROBABLY , due to poor craftsmanship, they don't keep a flame for long.

Now. I think both of these issues are down to poor craftsmanship whereby the outer tins bottom holes are too small and not allowing enough oxygen in from the bottom to feed the inner tin.

This is the constructed item.

All holes on the inner tin are of the same size as the outer, which you can see.

I thingk the inner tins holes are fine as I had more than plenty wood gas burn through the top vents as you can see below.

Now, asking for advice please.

Should I increase the size of the outer tins holes to increase air flow as I feel the stove was lacking oxygen from the initial burn! I'm more than happy with the output of the stove once it's up and running, or should I persist with the difficult startup of the stove and cheat and use non natural fire starters?

Just for the record, issued a lighter in this case with birch bark with kiln dried wood to get this thing going.

When I had ignited the birch bark, my plan was to place the wood on top to start the process, however the birch bark kept going out after dropping it into the bottom of the inner tin. (Hence my assumption on the outer tins holes being too small) In the end, I had to place the kiln dried wood inside the inner tin initially to build the height, and then igniter the birch bark again, and place on top to get the thing started. Like an upside down fire.

Thanks in advance.

 

[Macaroon]

An upside down fire is precisely what you're supposed to have with one of these; they're properly called a Top-lit Up Draft gasifier, which is why you'll often see them refered to as t.l.u.d.'s on the 'net. lay the fire inside the combustion chamber to just below the gas outlets, and light it from the top, the fire will burn it's way down through the stack of material with the smoke being drawn down through the fuel and back up the cavity to come out of the gas holes and there to be ignited. It's not really a fire that you aim for, the first stage is called pyrolisis (sp) and then you have the true burn up top as the gasses come through. You'll find that fatwood and pinecones are great for getting a hot burn going initially, and when your initial fuel stack is used up you can poke more in as you need to, but from above.

The whole gasifier thing, whilst being very simple in principle, can be a bit of a "dark art" until you develop a feel for itand then you'll find it goes very smoothly (mostly ) I can use mine as easily and almost as quickly as I can an alcohol stove and it's my preferred brew kit when out, almost daily usage and most days more than once.

There's yards of info and vids for these, and a good place to start is to hit "Zen Stoves" with the search engine of your choice...............Have fun!

Just to add, there's no such thing as cheating; use whatever works to get you going at the start of your adventure with these. I found vaseline-soaked cotton perfect at the start, and carry it with me all the time, sometimes I just want to drink a brew without playing around with stuff.

 

[NarzaCyst]

Many thanks Macaroon. Much appreciated.

One thing though, should I increase the size of the external tin holes or not? During the burning / gasifying stage, it was top notch, but I did notice that I had large coals once the flame had burnt out.

Now, I see this as a good point when wanting to add more fuel and increase the burn time, these coals were so good, that adding wet fuel worked and was ablaze in less than a minute.

The bad point is, it will take time to turn these coals into ash, therefore, taking longer for the stove to cool down.

I own a honey stove, and this cools down extremely quickly.

Am I just wanting something that is not possible?

Thanks in advance.

 

[Macaroon]

Those coals, although they look big and bright, will lose their heat very quickly indeed - it takes my home-made ss jobby no time at all to cool down and usually by the time I've finished my brew the whole shebang is cool enough to pack.

I wouldn't change anything on the stove 'till you've played with it a good bit more, it sounds to me as if you've got it somewhere near, but I'd strongly advise you to do a good bit of reading on the whole subject so as to get a good feel for the basic principles, and just go somewhere and brew up as often as you can; you'll soon get the hang of it!

There is a formula for the area of the holes on both containers in relation to their volumes, but I can't remember it offhand and can't find it to link to at the moment but I'll post it if I stumble across it.

 

[NarzaCyst]

Macaroon, many thanks for your advice, much appreciated. I shall have a read around regarding the principles. If you happen to stumble on that article, it would be greatly appreciated.

Shall have a play with it next weekend, if the rain ever let's up.

Many thanks once again.

 

[GJBC]

looks Great Alex. i known you will tinker to get it spot on.

G

 

[UKAndre]

Hi All

Search YouTube for Four Dog Stove Company. There is a detailed set of videos on how to build one of these as well as examples of his own titanium "Bush Cooker". Loads of good and entertaining material. Loved the "Gopher Stove" once you get it going you gotta go for more wood!! Also lots of links to all sorts of American old school gear suppliers too.

Enjoy