Almost ready!

I have been studying the forum for a few months and I have been thinking about the options available to me to build a rocket stove for my outside summer house.
I live in Scotland and  we can actually have quite nice summer weather !
However I would like to extend the season by adding a little heat into our little summer house.
What I mainly want is a cooking plate to use in place of a smokey BBQ but it would also be nice to have some radiant heat too.

So I have considered a batch box and I was very interested in a vortex stove but I see issues with both of these.

It seems to me the batch box is well tested and designed, well documented and will burn very hot, very fast and very clean but ‘A’ it has a tall riser that would make a hot plate difficult to cook on and ‘B’ the fire only burns for approx one hour, and then goes to coals so not good for cooking on?

The vortex stove looks fantastic but seems a little bit fickle and difficult to set up but I also think it, like all riser less designs needs a strong chimney draft .. ie a tall chimney? I would really love a vortex stove but I don’t think it is developed quite enough at this time?

As I don’t want a tall chimney sticking out of my summer house, I will be limited to about 10’ from the floor to the chimney top.
So I think a J tube might be the best bet, it would be a compromise as I would of preferred to see the fire and I think I might still have to sink the fire box into the floor so the hot plate will not be to high?

However from what I have read I would be able to keep the fire going for as long as I want as long as I feed the fire every 15 minutes so I can cook all day long and perhaps even regulate the temperature? I don’t think there is any other designs that can offer this?

I am open to any suggestions or comments.
I want to build a professional looking and reliable stove with a large hot plate to cook steaks burgers etc
I would be able to build virtually any shape mold or form to produce my stove as formwork is my day job, I am prepared to invest a reasonable amount of money as I will soon be retiring and I intend to party!  

Hi John,    Matt Walkers cookstove seems to be pretty close to what your looking for.

It does require a good external chimney however as that is its main source of draft. He also has a larger version of this stove as well if bigger is what your after.

Thanks Gerry but I really am limited to a 10’ high chimney as it exists from the centre of my 14 x 12’ summerhouse and it just would look awful and out of place  it it was any higher.
The summer house is a ready made wooden construction, concrete base with a centre BBQ and a hood over the BBQ and a short chimney that sicks up about 3’ above the roof.
So I can extend the chimney down but not really  go any higher.
So I want a central feature stove and hot plate that won’t pour out blue smoke, all the windows open up for the summer but we can get a lot of cold windy weather in the winter with a quite a lot of snow on occasions so we would still like to use the summer house in the winter (winter house!)
Anyway I am not sure if you can add wood into Mats stove or if you have to wait for the coals to die right down?

Hi John;
On a Batchbox or on Matts stoves, you can certainly put wood on top of the coals.
A pair of gauntlet welding gloves makes it much easier to not get burnt.
Matt keeps his cook stove cranking all day and I keep both my batchboxes burning the same way.
No need to let them die down if your willing and able to reach a gloved hand into what amounts to a kiln!

Scots John wrote:Thanks Gerry but I really am limited to a 10’ high chimney as it exists from the centre of my 14 x 12’ summerhouse and it just would look awful and out of place  it it was any higher.
The summer house is a ready made wooden construction, concrete base with a centre BBQ and a hood over the BBQ and a short chimney that sicks up about 3’ above the roof.
So I can extend the chimney down but not really  go any higher.

To me that chimney you have sounds perfect. No need to go any higher.
I second Thomas on being able to add wood at any time during the burn. Either a single log or fill it up depending upon how long you need to keep it going.  

Ok thank you for the info, I am probably over reading to much but I thought I read that placing logs on top of coals causes thermal overload (not that I know what that means) and smoke?

Anyhow if my low chimney will work that is something but it does not resolve the problem of the riser height and therefore the cooking top surface.
Also that will only apply if the batchbox is sat on the ground so the fire won’t really be very visible.

Mats designs all seem to use ceramic fibre in the fire box, is that really a good idea? It just seems to me that it will wear down with abrasion and is it not dangerous for your lungs being ‘non body soluble’ so micro fibres can rest in your body for years and then cause major health issues?
Sorry if I seem negative, I honestly appreciate your help I just want to be clear on certain things.

I have watched hundreds of YouTube videos (probably not that many but my wife tells me I have) I love this guys Vortex stove but I am very interested in his old stove at the beginning of this video. What type of stove is that it looks more like the sort of thing I had in mind but I don’t think it has a visible fire?

Batchrockets with no riser at all do exist. They're not on the site as yet, most of my time is gobbled up by experimenting. Those newer cores are called Double Shoebox Rocket, or DSR for short. There are two of those, DSR1 and DSR2. As it happens, DSR2's development has been ready for more than a year, DSR1+ is being worked on as we speak.

A very longish thread on Donkey's forum describes the development of DSR2, https://donkey32.proboards.com/thread/3503/double-shoebox-rocket-mark-ii drawings are released on the same forum.
To save you the time to find these drawings here's the post in which the first is released.
https://donkey32.proboards.com/post/33244/thread
Three others are released further down the above thread, on the following pages.

NB: Have a look at my YouTube channel, there are a number of videos about DSR1 and 2.
https://www.youtube.com/user/peterberg10/videos
The latest one does show very well what it's all about, is fire visability like this what you have in mind?

Thank you for your reply Peter, I am not a member of that forum but I have read about your new design.
Yes that is the sort of thing I would like, a compact stove with a interesting visual effects!
Like I have said I would love the vortex stove but it seems to be a bit sensitive unless you follow the builders exact overall stove design?
Your new version looks very promising but is not actually finished, perhaps I should just wait and see how it turns out.
 

Scots John wrote:Ok thank you for the info, I am probably over reading to much but I thought I read that placing logs on top of coals causes thermal overload (not that I know what that means) and smoke

My understanding of thermal overload is when too much wood gas is being produced all at once that doesn't have enough time to be completely burned so it goes up the chimney and appears as smoke.
Peter has given a description of it here: thermal overload
What I have found that works for me to control this from happening with my batch box when doing multiple loads is to use larger format wood. This significantly reduces the surface area to produce wood gas and really helps to keep the balance of gas to air in check.

Scots John wrote:Mats designs all seem to use ceramic fibre in the fire box, is that really a good idea? It just seems to me that it will wear down with abrasion and is it not dangerous for your lungs being ‘non body soluble’ so micro fibres can rest in your body for years and then cause major health issues?
Sorry if I seem negative, I honestly appreciate your help I just want to be clear on certain things.

If you have ever listened to any of Matt's Stove Chats, he often gets this question and has answered it something like this:
A high mass firebox takes a while to get up to temperatures high enough for clean combustion to occur, whereas an insulated firebox can get there very quickly. Although its abrasion resistance is relatively poor, he feels that the advantage of this alone is well worth it. To compensate, he replaces the 'cheeks' of the firebox once a season.
As far as health concerns, there are many different types of ceramic products out there. The cheaper Chinese ones may be what your referring to.  You have to find the ones that have a low bio-persistence labelling and testing to be sure. Morgan superwool is such a product.

Scots John. All reight beig man?

Well, the builder of the rocket you've posted the video of, has been made by Fox James. https://permies.com/u/250505/Fox-James

He doesn't come here anymore, because of me. He said, i'm too negative. He doesn't seem to have pursued the single vortex path.

https://permies.com/u/250505/Fox-James

I'll send him a message, to see if he's keen on coming back.

Gerry thank you for explaining thermal overload, I am still not convinced about the safety expects of ceramic fibre, in the U.K. we can get body soluble ceramic matting but not body soluble ceramic board.

Satamax, thank you for the links and the accent!
That is a shame about Fox James his work looks great!

I won’t be retiring until the end of summer so I may wait  until there is more development from Peters new project, in the meantime I will keep studying the forum.

A quick update, I managed to contact fox James via Facebook and he sent me this video and answered a few of my questions.
I do like his vortex j tube especially the glass air feed viewing window although I am still not sure about ceramic fibre and my grand children ?
Being logical about it I can’t really see how a ceramic core and riser could possibly effect anyone inside my summerhouse but my main mistake was telling the wife about the potential dangers!
She is right on the case now!!
I don’t particularly want a full size barrel in my space but I am inspired by the design at least something to think about?

Hi John, nice to see you on this forum, I closed down the vortex stove, it was real fun but it did not suit my needs.
It burns too hot for too short a time, the heat pouring out from the barrel was extreme  and just a bit to powerful for my party house.
It was also very fickle and needed to be loaded carefully with super dry wood otherwise it would smoke up the glass!
None of those attributes suit my needs so I reverted to a more basic Jtube

I have run my new fire in a few configurations, all of them run so easily with no issues and plenty of performance.
To be honest the vortex version is very similar to the standard J tube but looks a lot cooler, I just insert a little bit of ceramic fibre to send the flow into a vortex.

This version really is a dustbin and burns anything i put in it, the big fire box last about 30-40 minutes with a standard load of smallish 12” long sticks  but I can keep it ticking over with a single log for a couple of hours at a time.