compact 6" RMH hybrid with cook top and dutch oven

This photo is just plain cool, some blurr and steam on my lense, but I can see a flying tracer ember, which looks neat even with no photo filter

Maybe titanium or nickel would be a good substitute if my riser prematurely fails, however I've designed my stove very similar to the Zaug stove, which has a 3 years warrantee, and mine has less insulative value and a built in mass, so mine will likely last longer than a Zaug.

Furthermore, my design is a HYBRID, rocket style, shape, whatever you want to call it, it may not be a true rocket by your standards, but it is by the Zaug companies standards.

I want something practical that I can use in my 18x18 underground tiny home. (Which is also a HYBRID home). I want to cook food on it, I want it to last, and I don't want it to melt down, and since I'm already procucing clean emissions (zero smoke) I feel that my design does not require any further insualting. It works, I plan on using it in my tiny dwelling if I finish it in good time. So I can let you know if it outperforms a zaug, or outlasts, or how it works for me in general for my HYBRID multi-use purpose.

well I poured the riser with what perlite I had left, and the similar refractory mix. there is a lower perlite content in this mix, because I'm working with what I had left from the main cast refractory mass around the core in my first mix.

from the color of the fire there it looks like you could be getting excess of 900+ and if you are using regular steel it wont take long for you to see sign of it flaking on the inside. once you see that you know it will be doomed. you can check the the numbers i posted about the different steel types and you will see your steel can not handle temps above 900 F. it wont matter how thick it is, it will brake down over 900 F.

if that happens- which i douubt because of my 60% conductive surrounding mass- will the 2" thick refractory cast riser not suffice?

I would be willing to try titanium or nickel if I had to replace my riser, or if I had to make a design change, but for this prototype in development I wanted to work with what cheap materials I have here at hand... 900+ degrees eh? So that means it IS a real rocket according to what you said earlier

John McDoodle wrote:Maybe titanium or nickel would be a good substitute if my riser prematurely fails, however I've designed my stove very similar to the Zaug stove, which has a 3 years warrantee, and mine has less insulative value and a built in mass, so mine will likely last longer than a Zaug.

Furthermore, my design is a HYBRID, rocket style, shape, whatever you want to call it, it may not be a true rocket by your standards, but it is by the Zaug companies standards.

I want something practical that I can use in my 18x18 underground tiny home. (Which is also a HYBRID home). I want to cook food on it, I want it to last, and I don't want it to melt down, and since I'm already procucing clean emissions (zero smoke) I feel that my design does not require any further insualting. It works, I plan on using it in my tiny dwelling if I finish it in good time. So I can let you know if it outperforms a zaug, or outlasts, or how it works for me in general for my HYBRID multi-use purpose.

John, you take zaug as a point of reference. Have you had one in your hands? Run one? Do you know what they are realy worth? To me, an angled feed tells me straight away that it's a POS. Angled feeds are known for giving sub standard results, with the fuel hanging, and higher emissions than usual with a J tube.

On their site, they claim to have delepped the downdraft movement of air. Yeah sure, and so on. Do you realy know how many they sell? Are you sure it's not a big scam on the internet?

To me, if claiming that they have an efficient stove, they should post graphs by a gas analyser. Stuff you can find here and at Donkey's.

And, they don't claim to have mass inside.

Regarding your emisions, i've tried to explain. Above 400C° and up to 800C° that's the window where dioxins are produced. A normal wood stove produces a tiny amount. A properly running rocket does not. And if you ever feed plastic to your rocket, as some people do, you will produce dioxin and might poison people and animals. That's a reason why we insist. 900C° for a rocket is not nuclear meltdown, but normal behavior.

Furthermore, your exhaust gases, if not looking smokey, or smelling much, might not be as clean as you think. If you're lucky enough to know somebody with a gas analyser, like a Testo 330/II, please get it tested.

Basicaly, we need to keep newbies safe. You're presenting your work here. And some of us think it might not be as safe as you think. We tried to tell you. You're not too keen to listen. Fair play. But we still need to pass the message strongly enough, so another newbie tinkerer, who's a mad welder; will ask himself reading this. "am i following the right way?"

If your thing has enough vermiculite in the mix for the heat riser, it will work. Otherwise, depending on your chimney's draft. When the whole refractory mix is as hot on the inside and on the outside of the heat riser, it will stall the stove. No temperature differential between both sides, means the same presure and same convection on both sides, and the top would act as a siphon in a state of equilibrium.

I've seen the Zaug work very well, and they are guaranteed for 3 years.

I would never burn plastic, I don't care if others do.

Also, Fstyles says my colour of flame indicates 900+ degrees.

John McDoodle wrote:

Also, Fstyles says my colour of flame indicates 900+ degrees.

Farenheit. I'm talking Celcius. 900C° =1652F° Do you have an IR thermometer? That would be intresting, when running without the top, to measure after runing a while the temps Inside and outside the heat riser.

Yes I have a digital laser temperature gun, but I think its only good for so much heat, idk how much, and it needs a new battery lol.

thanks for "keeping me safe" lol, but Fstyles says my colour of flame indicates 900+ degrees, and I would never burn plastic, so that means no poisons, according to you, and 900+ degrees that means that it is a true rocket, according to him.

According to me, you guys should at least let me finish my project before ridicule or judgement, because nobody, including myself, can say how hot my stove will get, what will happen inside, or how long it will last

I'm fairly confident my stove will outlast a Zaug stoves 3 year guarantee. And it will be tested in my dwelling for an entire season. Its not done yet, but hopefully this year rather than next year lol. And even I do have problems with any part of my riser, I'm confident I can still remove the entire riser and replace it with nickel, and/or re-do the firebrick. But I'm very confident that will never happen within the next 3 years...

Thanks eveyone for your great interest and showing me your failures, it takes a lot of man to do that, and I respect you for that. If I fail also, I will share my failure with YOU in return

John, there's a few things some of us can tell you. Expansion of the metal will crack your refractory mortar. That's for sure. If the heat riser's insulation is not enough, it will stall at some point. That's rather usual. And we've all faced it in the trial stages. And if insulated enough, it will start to spall in short order. You know, we've all been through failures. I'm just trying to explain what could happen.

The ash buildup is a result of the burn tunnel not being insulated. Where i'm standing at now, i don't even advocate dense firebricks anymore. But rather insulating ones for the burn tunnel. Even if the strenght and resistance to abrasion isn't the best. I'm aiming at the best efficiency possible.


A well designed rocket can reach 90/92% efficiency in combustion, and good 80 to 90% in heat recovery. And people manage to cook on thoses too. It takes a bit of Learning tho.

dont take my guesstimate from a pic to the bank just yet buddy. you do get to learn what temps are produced from what color flames but pics can be deceiving. if you do in fact have REFRACTORY cement and perlite around the entire core that may just save you from core collapse when the steel spawls apart.

dont be so quick to be so happy about the temps above 900 because thats the temp your type of steel breaks down and the higher it is the faster it breaks down. i wouldnt want to be proud to compare my stove to a ZAUG... its like comparing a Lamborghini to a Volkswagen.

I've been asked to say something here.

Hi!

I have not read every spec of everything written here, but I did skim through it. This reminds me of a long conversation I had with the rather brilliant Peter van den Berg (who appears to already be on this thread).

The conversation goes like this: it is possible to design a rocket system with a lot of metal and have it be okay. It must be a very small system so that the temperatures will probably never exceed 1400 degrees F. Of course, at such low temperatures, it is difficult to get a non-smoky burn - but it can be done.

These forums have a parade of people that went down metal road and made systems that were amazing. For a while. And when the system failed in the middle of winter, they had massive heartbreak.

Rob's system comes to mind:




There has been so much heartache and so many disasters, it seems that there is a very strong push to discourage anybody from using metal in the burn tunnel and/or riser.

I know that we had a lot of people here at my place that were seriously loving on the pocket rockets for a few months - but after they all, universally, burned out their very thick metal tubes - we had to ban the use of this design here. After all: where does that burned metal go? The toxicity put into the atmosphere makes me very uncomfortable.

I think the people here are very much wishing to embrace another enthusiast. And, at the same time, direct your energy to a place that will have a strong positive long term result and not go through all the pain that so many others have gone through.

Thank you paul for showing interest, (weather or not someone drug you into this lol). I respect your opinion and your authority in the community.

I feel that the major differenc between my stove and the "pocket rockets" is that my design is encased in custom mixed 40% refractory 60% conductive concrete. That 60 internal mass will absorb aloof heat, like it is designed to do.

I know its unconventional, but hey, that's why its a hybrid. And I'm happy with my proven clean emissions, as seen multiple times in my burning photos.

If my steel degrades, I will learn from my mistakes and I will remove the lid and upgrade to Nickle

John McDoodle wrote: my design is encased in custom mixed 40% refractory 60% conductive concrete.

not to be mean John but what type of concrete is "conductive" concrete?

Conductive= absorbs and transfers heat, typically causes even displacement of heat throught material/surfaces

Insulative= reflects the heat, does not absorb nearly as much as conductive materials.

Concrete is like a rock. Remember the natives would warm up a rock, and bring it in the tee-pee at night, maybe even sleep with it. That's absorbing conductive mass. The volcanic rock perlite, is the opposite, light in weight (mass) and reflective. That's much more insulative rather than conductive

thanks for your unneeded explanation of what the terms of concrete is. maybe i did not ask the question correctly. let me try again. what type of concrete are you using as the 60%. you have states what the 40% is, what type of cement takes up the rest of the 60%? maybe that is that better?

If you check page 1 photos, you will see 3 different types of conductive mass. My mix is composed of a conglomerate of all 3. But for the record, approx 30% of mix is fireplace mortar, another approx 30% of my refractory mix 6000 PSI HD fiber enforced concrete (mixing those gives me my 60% conductive mass). The remaining 40% of my DIY refractory mass recipie is pure volcanic perlite. Its a home-brewed recipie where I take other peoples diy firebirck and use the best from others results. Same as how I designed my hybrid, using pros from different designs, making a practical design, with not many "cons". F styles, I enjoy your input, can we communicate via purple moosages also so we can both speak more freely, as we both clearly would prefer? I've tried but I don't know how

Thanks again for the interest in my first hybrid project

Fstyles:

30% fireplace mason mortar
+ 30% 6000 PSI HD fiber enforced concrete
= 60% massive

60% mass
+40% refractory volcanic perlite
=john's DIY refractory firbrick mix recipie

John McDoodle wrote:Fstyles:

30% fireplace mason mortar
+ 30% 6000 PSI HD fiber enforced concrete
= 60% massive

60% mass
+40% refractory volcanic perlite
=john's DIY refractory firbrick mix recipie

i sent you one of those non private purple mooses that they say they dont read, not that i care if they do and if i wanted something private i would talk to you in person with all electronics off and in another room. but i digress... it looks to me but correct me if im wrong... that 6000psi fiber mix you got going on there seems to me it may be high strength Portland cement with aggregate and fiber? you seem to use the term "refractory" very loosely. i want to let you know "Portland" is not "refractory RMH" material and will spawl the moment the steel breaks down if it has not already started to spawl as we speak and will fall out like powder when the steel breaks down. im sorry to be the barer of bad news my friend.

also perlite is insulative, not refractory. perlite is basically tiny puffs of volcanic glass that has air pocket fluffiness that gives it the insulative property and if too close to the center of your heat riser it will sinter or even melt.

No portland cement here... I listed my ingredients multiple times...


I am currently trying to remove my new cast riser mould, what a chore... I split it open and taped it closed, for easy removal, but its not removing easy at all lol. I have a steel barrel type sleeve for the outside of my cast riser also, since my 8" idea got upgraded to a 10" outer diameter. More pics to come soon.

believe me when i tell you i used REAL refractory cement with perlite (actually too much perlite) my first heat riser and un-be-known to me after i made the decision to upgrade my heat riser to a more insulative custom design when i took my heat riser out i noticed only after a few burns it was melting and turning my refractory perlite mix to powder. i have pics and may post them. i do have pics of my new upgrade step by step though and it is 10x faster start... i mean 0( zero) to dragon in 30 seconds... no joke! much hotter burns and i thought i was getting hot burns before. im afraid i might melt the top of my barrel now.

That's good man, I'd like to hear more about your upgrade, hey, I might have to upgrade my riser also according to the general population here. And that's okay with me. Like I said, bear with me, I'm learning. I like to learn by doing.

John McDoodle wrote:That's good man, I'd like to hear more about your upgrade, hey, I might have to upgrade my riser also according to the general population here. And that's okay with me. Like I said, bear with me, I'm learning. I like to learn by doing.

you can read about my entire system over here. First Rocket stove heats water with pics

Fstyles:

I got your message, thanks. I did also send you a couple "purple moosages".

I also saw your system. I like the water-as-a-mass idea.

How does the 10" duct around the riser hold up? I will be doing the same concept with mine. It was supposed to be 8", but I upgraded to 10"

The 30% 6000 PSI HD is classified as "concrete" by "sakrete"

The other 30% is classified as fireplace mortar.

The word cement comes after the word portland, but I did not use any of either "portland" or any "Cement". I used "concrete" and hi-temp mortar.

I think cement is different than concrete, and I agree, I would not use portland cement either. However I did use concrete and fireplace mortar, if that makes any sense...

John McDoodle wrote:Fstyles:

I got your message, thanks. I did also send you a couple "purple moosages".

I also saw your system. I like the water-as-a-mass idea.

How does the 10" duct around the riser hold up? I will be doing the same concept with mine. It was supposed to be 8", but I upgraded to 10"

its no longer 10". i added another 4" to the circumference to the outside heat riser duct and it works so much better. maybe you should try my refractory cement paper mache idea on your heat riser. make a real refractory cement slurry. i have doubts your cement you call refractory is actually refractory. refractory cement cost $26 for a 1gal pale and if you are buying a 30 - 50lb bag of so called refractory cement for $12 or so i have serious doubts its real refractory cement. refractory cement does not come with aggregate in it for sure.

my idea here goes. i mentioned this on my RMH page.
make a refractory cement slurry and soak high temp fiberglass or rockwool in the slurry thoroughly and then paper mache it around your steel heat riser. then put your 10'' or more duct around the heat riser tube you just paper mache'd with refractory cement slurry fabric and then fill the air space in between the heat riser and duct and you have your self a super heat riser even after your steel breaks down.