Advice on a RMH build in Hokkaido Japan

Peter Sedgwick wrote:

Looks like I’m gonna be on snow earlier than expected and the rocket project might have to go on the back burner for a bit.

Peter, what are you doing on snow?

Myself, i work as a chairlift operator, for Serre Chevalier. And i've been doing that for the past 26 seasons. Attacking my 27th this year!
We've had a dump last night, and, i hope they won't call me early! Still plenty to do for my business!

This morning was snow clearing. The wheels of the red toyota are 31 inches!

Satamax Antone wrote:

Peter Sedgwick wrote:

Looks like I’m gonna be on snow earlier than expected and the rocket project might have to go on the back burner for a bit.

Peter, what are you doing on snow?

Myself, i work as a chairlift operator, for Serre Chevalier. And i've been doing that for the past 26 seasons. Attacking my 27th this year!
We've had a dump last night, and, i hope they won't call me early! Still plenty to do for my business!

This morning was snow clearing. The wheels of the red toyota are 31 inches!

Thats a fair amount of snow for sure.

Yeah, got an offer to do some instruction and help with some guiding trough the holidays.
Bit last minute, but will help keep the dream alive, and I always love some time in the trees...

Peter

Hi Peter,   Sorry to hear about your bricks breaking up, but know with your creativity and perseverance, that you will find something that will work.
Liked your DIY paddle mixer. Good job. Would love to have known you as a kid. You probably made your own toys out of bits and bobs of things when others waited til birthdays or Christmas to get uncreative store made stuff.  
For me, I always keep about 1/4" of ash on the bottom of the feed tube and partially along the bottom of the burn tunnel to help insulate the bottom bricks. They are only cement patio pavers and have lasted for 6 years but are like yours, all cracked up and spalling but holding together still. One day I'll replace them. Look forward to your findings.

This thread has been one of the most enjoyable ones I have read on permies.com so far. Between the pictures, the drawings, the dogs, and Mimi, it's been a huge pleasure! And, oh yes, also very educational! Just wanted to give a big thank you for all the sharing, Peter, and also to all the people that contributed their knowledge and advice. What a treasure the whole thing has been!
I'm looking forward to periodic updates. Meanwhile, enjoy the snow and the trees, Peter!

Gerry Parent wrote:Hi Peter,   Sorry to hear about your bricks breaking up, but know with your creativity and perseverance, that you will find something that will work.
Liked your DIY paddle mixer. Good job. Would love to have known you as a kid. You probably made your own toys out of bits and bobs of things when others waited til birthdays or Christmas to get uncreative store made stuff.  
For me, I always keep about 1/4" of ash on the bottom of the feed tube and partially along the bottom of the burn tunnel to help insulate the bottom bricks. They are only cement patio pavers and have lasted for 6 years but are like yours, all cracked up and spalling but holding together still. One day I'll replace them. Look forward to your findings.

Hey Gerry! Think the bricks are just part of the learning process. Still working so we’ll just sort it out when we can.

Always like to try to come up with new and fun ways to do stuff. Will keep going and see where it takes us.

Cheers Peter

Annie Collins wrote:This thread has been one of the most enjoyable ones I have read on permies.com so far. Between the pictures, the drawings, the dogs, and Mimi, it's been a huge pleasure! And, oh yes, also very educational! Just wanted to give a big thank you for all the sharing, Peter, and also to all the people that contributed their knowledge and advice. What a treasure the whole thing has been!
I'm looking forward to periodic updates. Meanwhile, enjoy the snow and the trees, Peter!

Thanks so much Annie.

Means a lot to all of us. The treasure is for everyone to share and learn. There’s always a new adventure right around the corner. For now I’m off to the forest.

Stay free... Peter, Mimi & Chimichanga

So I’ve been away in the mountains for the past 5 days, and still am. However, Mimi has taken it upon herself to keep working on our new rocket. She went out a sourced some seasoned fire wood. Then went ahead and split it all by hand with an ax. Super impressed with her motivation on this. She’s  burning everyday and experimenting with different amounts and styles of burning.

Stove is far from finished and definitely still in bata mode, but it’s changed from an idea, to a drying pile of rocks, and now a working “tool”. One that she is learning to use on her own. She’s been sleeping on it every night with the dogs and says that, with the cushions and blankets, it keeps them all toasty till the morning.

This whole experience has ment a lot to us. Working together to build things, beginning to understand how we can use the natural world around us, and now Mimi learning on her own. We luck to have gotten this opportunity and thank everyone who has helped to make it possible.

Will keep updating and sharing, so we can all learn and find a brighter tomorrow.

Stay free...

Peter, Mimi and Chimichanga

Hip Hip Hooray for Mountain Mimi !  ⚡  (✿◠‿◠)  ⚡

So back at the house with Mimi. She’s learned a lot since I’ve been gone. Giving me instructions now on how and what to burn. Pretty cool.

Been processing lots of wood over the past two days and trying to get a better idea of how our fuel burns. Right now we have switched all of our burning, exclusively, to well seasoned fire wood. It’s been dried for 10 years now. It’s a mix different woods, but mostly Japanese oak and yew wood. We have lots of red yew wood in the area. Was reading that this is good for burning.

Mass now has some long 3cm thick cushions on it and I’ve been sleeping on it the past two nights. Been really warm. Just took some temperature readings on top of the bench under the cushions. It’s says 107C in the middle section of the bench and 98C closer to the dead end of the bench. Have 1-2cm of wheat paste clay plaster on top of fair amount of large flat rocks. Should we think about adding a bit more mass to the top? If so what should we use? Hard to source large thin rocks, so was thinking to use smaller rocks mixed into the same wheat paste earthen plaster.

It’s been almost a month of continuous daily burning now. I imagine the mass we have is almost dry. The outside temperature has been fluctuating over the pass two days from +9C to -5C. Will most likely get cold again soon.

We seem to be able to remain relatively comfortable with the heater running all the time. We will see how it goes as it gets colder. January and February will be the real test.

Heater is serving us rather well, but the house is old, and not well insulated. Beginning to think that the next project may need to be another building, we can live in next year. Extremely interested in berm building and structures that use thermal inertia. Rereading Mike Oehler’s book. The WOFATI concept seems like something to investigate further. Have space in the front that is pretty flat. Could construct something there and then have dirt brought in. Any thoughts on where to get more definitive information and details on WOFATI construction? Can we build one that is big enough for the two of us in a few months?

Probably questions for a separate post, but I thought I’d start here.

Cheers, Peter and the crew
🏔☮️🏔

Peter, do you have strawbales available nearby in the summer.

Peter Sedgwick wrote:Should we think about adding a bit more mass to the top? If so what should we use? Hard to source large thin rocks, so was thinking to use smaller rocks mixed into the same wheat paste earthen plaster.

If you say that your burning all day and your temps are where you would like them to be, then adding more mass would hold heat longer (and take longer to heat up) but they also wouldn't be as high. Really a personal choice at this point and what you would like to achieve.
I've seen whole and pieces of marble counter tops on craigslist and other classifieds online quite frequently. Not sure if you have something like that in your area otherwise your suggestion would work too. Could make an interesting mosaic as your final skin? Tiles would look nice too. It was fun for a while where I made some homemade ones from clay and then fired them in my rocket.

Any thoughts on where to get more definitive information and details on WOFATI construction? Can we build one that is big enough for the two of us in a few months?

I'm sure you've seen the wofati forum. I know they are currently doing temperature tests on it this winter to test the thermal inertia.
I have helped build an underground earthbag structure but was never intended to be lived in. Just for meditation and quiet alone time.

Satamax Antone wrote:Peter, do you have strawbales available nearby in the summer.

Hey Satamax,

Probably not bales per say. Will have to look into it. Do have access to rice straw. Just not sure how much in the spring as the rice cropping season is in the early fall.

Been considering a simple pole frame structure with the timber we have here. Double studded small structure with some sort of stem wall and straw light clay infill on top.

This topic is definitely a conversation for another thread. I’ll start to put some ideas together and make a new topic.

What I can say, so far, that relates to RMHs is, no matter how efficient you make your stove, if the building isn’t well insulated your forever fighting an uphill battle.

Really makes me wonder why previous generations didn’t take the time to find ways to insulate their living spaces in cold climates.

Some places in this house have holes in the walls from something being knocked into them. The previous owners solution was just to put a piece of cardboard with duct tape over it. Temporary fine, but leaving it like that for ten years plus and freezing every winter. Really makes me scratch my head.

Peter
🏔🙄🏔

Hi Peter,

the old guys used to insulate. Often the attic was a hayloft.

Canadians would berm mud against their walls, up to their windows, to add mass and insulation. Thick, real thick walls were used in most of southern europe. Wood walls with wool, moss etc, in the north.

Satamax Antone wrote:Hi Peter,

the old guys used to insulate. Often the attic was a hayloft.

Canadians would berm mud against their walls, up to their windows, to add mass and insulation. Thick, real thick walls were used in most of southern europe. Wood walls with wool, moss etc, in the north.

Good to know. I’ll try to learn more. The walls here are made of paper...

🏔🤔🏔

Gerry Parent wrote:

Peter Sedgwick wrote:Should we think about adding a bit more mass to the top? If so what should we use? Hard to source large thin rocks, so was thinking to use smaller rocks mixed into the same wheat paste earthen plaster.

If you say that your burning all day and your temps are where you would like them to be, then adding more mass would hold heat longer (and take longer to heat up) but they also wouldn't be as high. Really a personal choice at this point and what you would like to achieve.
I've seen whole and pieces of marble counter tops on craigslist and other classifieds online quite frequently. Not sure if you have something like that in your area otherwise your suggestion would work too. Could make an interesting mosaic as your final skin? Tiles would look nice too. It was fun for a while where I made some homemade ones from clay and then fired them in my rocket.

Any thoughts on where to get more definitive information and details on WOFATI construction? Can we build one that is big enough for the two of us in a few months?

I'm sure you've seen the wofati forum. I know they are currently doing temperature tests on it this winter to test the thermal inertia.
I have helped build an underground earthbag structure but was never intended to be lived in. Just for meditation and quiet alone time.

Thanks Gerry,

Yeah thinking a little more mass couldn’t hurt. Cushions seem to make all the difference with the bench. It’s really like night and day. Learning so much everyday just by spending time with the thing. Still not entirely sure what I’m doing all the time, but learning something little by little.

Have seen most of the wofati stuff I think. Would love to start a discussion sometime some to see what could and would make sense. Open to any and all ideas at this point.

Here’s a few images of us today. Spitting wood down for use in the 6” J-tube is pretty time consuming. Will start earlier with this next year for sure. Daily ash clean out looks like this(see photo) Not sure if this is a lot or a little. Do it in the morning before lighting with my hand. Never any soot or black residue on my hands so thinking that’s a good thing.

Peter...✌️🔥✌️

Hi Peter,   Is all that ash coming from just the burn chamber or also from some of the cleanouts? Mine doesn't get a lot coming out of the burn chamber as much as it comes out of the manifold area. Where it does seem to collect in the burn tunnel though is at the back/base of the heat riser. A daily routine for me is to take my cleanout tool and bring that forward and spread it out over the length of the tunnel floor to a depth of about 1/4" to add to the insulative and slight anti-abrasion value it provides. Any extra I just remove.
Keeping the back wall more angular is also said to increase turbulence and mixing of the gases too.
Of course, its all relative to the type of wood you burn and how much you burn in a day. For example, when I occasionally burn cottonwood, the ash is really fluffy and takes up a lot of space than lets say of Doug fir.
Have you looked into "Earthships"? I know they are somewhat similar to WOFATI's and maybe more info on them as they have been popular for quite a while now.

Peter Sedgwick wrote:

Satamax Antone wrote:Peter, do you have strawbales available nearby in the summer.

Hey Satamax,

Probably not bales per say. Will have to look into it. Do have access to rice straw. Just not sure how much in the spring as the rice cropping season is in the early fall.

Been considering a simple pole frame structure with the timber we have here. Double studded small structure with some sort of stem wall and straw light clay infill on top.

This topic is definitely a conversation for another thread. I’ll start to put some ideas together and make a new topic.

Have you thought about retrofitting the existing building with straw light clay?  I don't think there are any impediments to using the rice straw, people do light clay with all kinds of materials, including hemp.  I don't know if hemp is available in Japan, but hempcrete uses lime and hemp and has the added benefit of being a carbon sink.   I have (perhaps unrealistic) visions of redoing our house entirely...  taking off the outer and inner layers and the conventional insulation between and treating the existing wood structure like it was always built for straw light clay walls (or hempcrete), then plastering over them with lime etc. for the breathable walls, insulation, and feeling just a touch smarter than my neighbors.  Tearing out the old materials comes with a footprint, but so does our crummy current insulation and the electrical bills that go with.  Starting over with a brand new building seems like a comparable level of work, and then you still have the old house to contend with.  

Just my two, possibly ill-informed, cents...

-cal

What i have done at my place

Thanks Gerry for all that.

There’s no clean outs in the system right now, so all the ash is from the burn tunnel.  That’s part of the reason we haven’t finished the area around the barrel. Will take the barrel off at some point, but for now seems to be working well. Matt said that won’t need clean outs for the half barrel bench as it will take years for any substantial amount of ash to accumulate and the ash that does settle there will only help to insulate. The transition from the manifold is a massive hole so no clogging issues that I could foresee. Only place that could be an issue, that I could imagine would be the horizontal exit flue pipe inside the half barrel bench. Might angle grind a hole in the end of the bench in the spring to check and then cap and cob over after.

Funny you mention the turbulence. Was thinking of adding a “kick ramp”, out of scrap CFB, at the end of the burn tunnel earlier in the build process, after reading an article Peter V. wrote. (old drawing attached) Noticed that the ash naturally builds up at the end of the burn tunnel kind of in the same way. Maybe leave a bit there to act as a mini quarter pipe ramp for the hot gases to run up?

Have looked into earthships a bit. Tons of tires at automotive repair shops and construction companies around the area. Not sure if they are “free”, but could ask. My biggest concern after ingesting that route is the number of people saying tiers are an absolute nightmare to pack. Maybe could come up with a system where the tiers are used as a non load bearing stem wall filled this pumice or perlite. Then create a sill for a double pony wall above the tiers so that we could infill with SLC (straw light clay)

Just some ideas. Keep saying this, but probably should open as another thread in the building forum soon. Only relation here to RMHs is the lesson that you need a well insulated space to really take advantage of this “efficient” heating system.

Have all kinds of kooky ideas and things I think might be worth trying in my head. Look forward to sharing in the near future.

Thanks again for always taking the time to advise and contribute.

One love...Pete and the gang

🏔🏔🏔🏔
🏔👨🏻‍🔬👩‍🏭🏔
🏔🐕🐕🏔
🏔🏔🏔🏔

Hey Andrea,

Yeah the idea of retrofitting an old house with straw light clay is really what got me started on the whole eco thing. Just seems like a really cool and affordable way to insulate a space. It’s non load bearing so don’t have to be overly concerned with structural stuff, don’t have to be limited to bail availability and preshaped blocks, clay makes it fire resistant, and sounds easy to do. I’m sold!

So we found a house with lots of land for pretty cheap and we moved in. But after looking at the structure and thinking a bit I came to the realization that maybe this house is not really laid out for SLC. There’s a lot of apposing roof pitches that drain water right onto the sides of the house. (See attached image below) This makes it a bit more tricky I think. Need to incorporate an additional “floating” siding, that incapsulates the building, “rain screen”. More logistics. Plus the idea of living in the space as we work on it might make us, especially me, go totally crazy. Sawdust and junk in our rice cooker etc. More logistics.

The house right now only has well water on an electric pump. No shower, no washing machine, no working toilet. Still going outside. (topic for another conversation)

Retrofitting this house is possible with some planning and a bit of imagination. We both feel that this space is not only ours, but hold the memories of past generations. We feel obliged to hold onto as much of that as we can. Only time will tell us how the history of this space can live on and bring happiness and fulfillment to future generations.

In the mean time, I got the idea to build a smaller space from looking at the old storage shack in the front yard. Old man, Shoji san, (RIP) built the shack with a neighbor many years back in a few days (my estimation) It’s simple round pole construction with wavy steel siding on it. Most of the poles are rotted out at the base and the only thing keeping it standing is probably the siding at this point. But none of the beams are rotten and I even climbed on the roof a few weeks ago to patch some holes. Things not moving anywhere unless there’s a tornado (no tornadoes here).

So I figured if the old farmer guys can build this, we can do something similar and take steps to avoid the rot etc. Add a stem wall and trade the steel siding for SLC infill. Throw a RMH in for heating, cause now we know how to make those. (Thanks Permies)

This would give us something to live in temporary as we decide what to and how to do the old farm house. A smaller project to help continue to build our skills and understanding of the materials around us. Much less daunting and feasible for us I feel.

Hempcrete sounds cool and there is so much of it growing wild in the wood up the road that we could build a town with it. Japan use to use it extensively before the war. Only obstacle now is that if I try to use it I’ll most likely get arrested. Laws have changed (thanks General MacArthur)
Legal hemp is extremely expensive and again, would probably raise red flags.

I’ve read that stinging nettle could be substituted for hemp and may actually work better, but I’m no expert. Just know I could plant tons of that with no issues what so ever.

Now that we are totally and completely off topic I’ll call it a wrap.

Always love two cents, there’s mine...

Thanks so much for your ideas. Please feel free to keep adding.

Cheers and beers...Peter and the fam🙏🏼

Satamax Antone wrote:What i have done at my place

Cool!

That mean you just stack bails on the outside of the building and replace them when they rot?

Peter

Peter Sedgwick wrote:

Satamax Antone wrote:What i have done at my place

Cool!

That mean you just stack bails on the outside of the building and replace them when they rot?

Peter

Well, i am meant to fix and render thoses. But you know how life gets in the way!

Hey folks...🧵👜🧵

Here’s something that MIMI and I whipped up the other day. Needed a way of moving firewood quickly and easily from one place to another.

Just came up with a drawing of what we wanted and then put some wood on a bath towel to figure out the right size for us. It’s really a personal preference at that point. Then just cut and fit some sticks for handles.

This is way better than a cardboard box, and if you have some extra fabric laying around it can be made on a home sewing machine in an hour or so.

Working really well for our needs, so I thought I’d share.

Cheers Peter and crew...🌲🧺🌲

Peter Sedgwick wrote:Hey folks...🧵👜🧵

Here’s something that MIMI and I whipped up the other day. Needed a way of moving firewood quickly and easily from one place to another.
...

Working really well for our needs, so I thought I’d share.

Cheers Peter and crew...🌲🧺🌲

We had one of those when we lived in our house that was only heated with a wood-burning stove. So helpful! Ours wasn't homemade, though. My children always called dibs on it when it came time to lug in the daily firewood supply - there was quite a bit of lugging! Wish I had known about RMHs back then. :-) Thank you for sharing the plans for the carrier!

Peter Sedgwick wrote:Funny you mention the turbulence. Was thinking of adding a “kick ramp”, out of scrap CFB, at the end of the burn tunnel earlier in the build process, after reading an article Peter V. wrote. (old drawing attached) Noticed that the ash naturally builds up at the end of the burn tunnel kind of in the same way. Maybe leave a bit there to act as a mini quarter pipe ramp for the hot gases to run up?

I remember a while back (maybe in a podcast) Erica Wisner saying something about how Peters kickback was designed this way because he had considered this area to be just a dead space (or something like that) which is why the ash tends to just build up there. However, if you look at his design, it also includes a tail that redirects the gases back on themselves for better mixing. Not sure if the ramp alone would do much but worth a try.  

Peter Sedgwick wrote:Have looked into earthships a bit. Tons of tires at automotive repair shops and construction companies around the area. Not sure if they are “free”, but could ask. My biggest concern after ingesting that route is the number of people saying tiers are an absolute nightmare to pack. Maybe could come up with a system where the tiers are used as a non load bearing stem wall filled this pumice or perlite. Then create a sill for a double pony wall above the tiers so that we could infill with SLC (straw light clay)

Not so much promoting eathships as much as taking things that use a similar concept in design and function and applying that info into what you want to achieve. Also, because they have been around for a while and lots of books have been written about them, there should be more info to pull from.

Peter Sedgwick wrote:Have all kinds of kooky ideas and things I think might be worth trying in my head. Look forward to sharing in the near future.

I was just thinking the other day how much I missed your drawings. Thank you for them.
You have taken a project and turned it into a lifestyle where everything 'touches' each other in an uplifting and complimenting way, not only for your family but to all those that read your posts.
Keep the spirit alive!

After reading your post on making your own wood carrier, I was inspired. I remembered I had an old canvas tent in the shop and borrowed our community sewing machine and presto!
One modification I made was to put some push pins in through the handles to keep them from sliding out of the carrier. I thought of just sewing them in permanently (or having one end with velcro) but this was one of those 'get er done' kind of projects. Thank you for the inspiration!

Totally cool Gerry,

Thanks for the info. Didn't think about the earth ship stuff that way. Thanks for pointing it out. Will do a bit more research.
Might be a bigger project than we can handle for this coming spring, but always good to start thinking about and planning.
Will see how we pan out in the coming months.

Did see Peter's wave shape ramp in his explanation of how to create turbulence in a J-tube burn tunnel, but couldn't really think of a way to create the shape, he was suggesting, with rigid ceramic fiber board.

Your version of the firewood hammock looks even better than ours. Well done. Like the addition of the push pins on the ends.
I just left ours extra long with the bark still on the birch branches we used. Think the friction is enough to hold them in place for now.
Just grabbed the first semi straight sticks I could find from a pile of brush we cleared earlier in the fall. Might incorporate your idea if we upgrade to straighter finished handles.
To be honest I misinterpreted your comment about velcro the first time I read it and it made me think of a way to lash the to handles together quickly. Here is a quick sketch of my idea.
Just drill some holes and double over a thin piece of paracord or leather etc. with a stick or a dinosaur tooth, for a clasp. That way you can keep the bundle closed even when you're not holding it. i.e. doesn't spill out all over the room.
(See attached sketch)

Today I decided to try Matts suggestion for an air intake regulator. Still trying to figure out how and when to use. Was using split bricks before, but Matt suggested using an upside down pan to cover the feed tube.
I'll be the first to admit, I really don't know exactly what I'm doing here and I have no idea how to find the coveted holy grail of Peter's Goldilocks air intake ration. (See attached)
This however is what I did notice, when I use a sauce pan instead of fire bricks:

1. Easier to limit air(O2) intake than blocky hot bricks
2. Less chance of sparks flying out of the feed tube and setting your uninsured house on fire.
3. Potentially keeping more heat in the fire box
4. Seems to make it easier to do compete burns of large wood logs at higher temperatures. When I look under the inverted sauce pan the flame/burn is running much higher and consuming more of the wood than when sticks are just surrounded by split bricks
5. Looks super DIY:)
6. Less likely that our dogs, Chimi and Chunga, will be able to pull burning sticks out of the fire when no one is looking, again house on fire. Not the look we're going for:)

I'm not a rocket scientist, but with the research I've done and the observations I've made I have come to the belief that a J-tube system, by nature of design limitations, will never allow you to really fine tune your air intake ratios to the extent that you can with a more refined design, like a batch or double shoe box etc. However It seems to me that this kind of experimentation can be extremely useful when trying to better understand the world of fire and how it works.

It's getting close to the time when we need to open a new thread to discuss rocket topics that no longer fall into the category of "Help me! I don't know how to make a RMH..."

Many questions and topics rolling around in my head, but I'll leave you with that for now.

Thanks as always...

Peter and the crew

Peter;  I beg to differ... You and Mimi are indeed Rocket scientist's.    Your posts no longer are "help me now I don't know what to do next" ... now you are innovating , learning, planning on how to improve things...  Indeed You Guys ARE ROCKET SCIENTISTS!  
Congratulations... your certificate might show up if you wait long enough... until then please keep posting.  I expect in the future to see photos of all the new RMH's that you are consulting on being built!

thomas rubino wrote:Peter;  I beg to differ... You and Mimi are indeed Rocket scientist's.    Your posts no longer are "help me now I don't know what to do next" ... now you are innovating , learning, planning on how to improve things...  Indeed You Guys ARE ROCKET SCIENTISTS!  
Congratulations... your certificate might show up if you wait long enough... until then please keep posting.  I expect in the future to see photos of all the new RMH's that you are consulting on being built!

Thomas, you don’t have to beg. I’ll take the compliment as it comes...🥳

BTW, please include in the care package ,with our certificate, one extra large pack of food stamps, and one Testo 350 Handheld Control Unit for Exhaust Flue Gas Analyzer.

Thanks in advance, Peter

P.S. don’t really have a problem talking to girls, I live with three of them. The real issue is, they have to spend most of the day listening to me talk to myself...👨🏻‍🔬

Peter,   My handles were made from old broom handles I had lying around. Perhaps a bit thick for people with smaller hands but at that moment it was easier than tromping through the woods to find just the right ones. Also, the holes that I left for hands are a bit small. As I was using it yesterday, I found that I liked to slide my arm through one hole and then grab the other handle with my hand and use my other arm to load the carrier. When I get a moment, I think I will do this....perhaps make it rounded too. I'm not that good at it but I find using a sewing machine kind of fun.

One thing I love about my RMH is that its never quite complete. There's always something different to discover on how to do something a little different and not be limited by a manufactured product or 'tied to the grid' in any of its operation. In a way it helps me keep mindsets from sticking and developing attitudes and opinions that can be limiting.

Thank you for listing your air intake observations. I agree....we do need some kind of thread, wiki,.... whatever (other than search function) to find these little tidbits of information that can help a lot of people and not have to repeat, repeat, repeat them over again. Books are great, but updates are limited to many years inbetween.

I agree with Thomas. You and your team are true (mad) Rocket Scientists! ...out of the box and into the fire!
Thank you for the pie!

EDIT: After watching your video, it gives me a whole new meaning to 'giving' pie to someone else!  Excuse me, but I think I'll go take a shower now...  

No problem Gerry...🎂👨🏻‍🔬👩🏻‍🔬🎂

Link:  https://youtu.be/V5OgLLkWUV4

Peter,   Forgot to ask: Your photo "More complete burn with cool blue flames...🔥" shows a pretty nice looking feed tube with no perceivable cracks. Did you repair/ replace them or is it just not visible in the photo?

Gerry Parent wrote:Peter,   Forgot to ask: Your photo "More complete burn with cool blue flames...🔥" shows a pretty nice looking feed tube with no perceivable cracks. Did you repair/ replace them or is it just not visible in the photo?

Haven’t replaced the bricks yet...🧱

Pealed the top layer of the floor brick up and just filled with ash to make the floor flat. Back wall brick is snapped in half and now the top half is just resting on the bottom half. Think I’ll try remixing a new batch of refractory cement and recast the two broken bricks with the half bag of refractory cement I have left over before trying to find other stuff. Maybe add some Chimichanga hair to the mix as James Fox suggests. Also much less water on the next batch. Still a bit stumped on how much vibration is necessary. Not enough and you end up with air bubbles. Too much and you run the risk of separation in the aggregate I believe. Might have vibrated too much, as my brick photo indicates...🤔

Right, left and front bridge brick still alive, kicking and fully functional...👊🏾💪🏾👊🏾

Will elaborate on these topics soon as I begin to consolidate my ideas and questions. So much to learn, experiment with and share. Excited about it all, as this give us more options and opportunities moving forward.
For a lack of a better expression, “SUPER COOL”

Happy days... Peter and company 🏔✌️🏔

P.S. blue flame is pretty to look at but is that a good sign or bad one?

Hi Peter, as I see it the mold was leaking quite a bit. So some of the water disappeared during the all-important solidifying phase. Vibration time is depending on the type of refractory castable. Rule of thumb for most of the DIY available kind is this: vibrate until there's water on top with what I would describe as "fat-eyes", like on hot soup. After vibration is done, don't move the mold while hardening, in normal circumstances that would be 8 hours although I always left it overnight. You found out yourself the mix should be quite dry like crumbly, moist earth. Vibrating will take care of compacting it.

Most of my castings since the eighties were done this way, covered with a plastic sheet to hold the all-important water in, the casting will get hot so drying out is a real risk! Submerging the hardened cast into a bucket of water for some hours seems to result in better quality. Drying and curing should be done carefully before ramping up to maximum working temperature.

Peter van den Berg wrote:Hi Peter, as I see it the mold was leaking quite a bit. So some of the water disappeared during the all-important solidifying phase. Vibration time is depending on the type of refractory castable. Rule of thumb for most of the DIY available kind is this: vibrate until there's water on top with what I would describe as "fat-eyes", like on hot soup. After vibration is done, don't move the mold while hardening, in normal circumstances that would be 8 hours although I always left it overnight. You found out yourself the mix should be quite dry like crumbly, moist earth. Vibrating will take care of compacting it.

Most of my castings since the eighties were done this way, covered with a plastic sheet to hold the all-important water in, the casting will get hot so drying out is a real risk! Submerging the hardened cast into a bucket of water for some hours seems to result in better quality. Drying and curing should be done carefully before ramping up to maximum working temperature.

Thanks for the insight Peter.

I will incorporate your advice into our cast the next time I get to doing a layup. Temperature here is on average below 0C and not the optimal environment for casting I believe.

At present I’m using a product by AGC Asahi Casters, a well established brand here that is readily available to the general permies. Most likely will look into more specialty items in the future. Do you have any advice as to what I should be looking forward in a refactory castable product for the purpose of lining a rocket feed tube?
i.e.- minimum temperature resistance requirements, additives like aluminum or silicates etc

I’ve also ended up with a fair amount of ceramic “dust” from cutting my ceramic fiber board core. Would it make sense to experiment with this as a additive to future castables, for its insulation value? (similar to the way you would use perlite) If so, any thought on recipes/ratios?

Lastly, while we are on the topic of castable, I am rather curious about the possible use of geopolymer castable materials. I understand that they are still being tested and that their refactory properties are greatly dependent on the ingredients used and the accuracy of the individual curing process.
However, do you think they could be used safely, as an alternative to ridged, delicate and costly CFB products in the near future?

Although we are rather new to the world of rocket mass technology, I am extremely intrigued by our finding to date and very much interested in continuing my experimentation. Sharing our successes and failures, so that everyone can learn and grow.

Clean burning energy seems like a good place to start...

Cheers, Another Peter🏔✌️🏔

@Peter S.,
What I've learned over the years is things like this: don't add anything other than water to the mix and quite sparingly with that. If it says refractory castable or something along that lines on the bag the resulting product answers to specifications. Anything what you do to change the end product runs a huge chance of ending up in a cast that doesn't live up to specs anymore in the unfavorable sense of the expression. Adding stainless steel needles of specific size could end in a higher tensile strenght, I don't know about dog's hairs. In some kinds of castables there are small polypropyleen fibres mixed in which will melt away when in use so it forms small cavities. Don't try this yourself, rely on the manifacturer for ingredients for it's highly unlikely you could change the specs for the better.

For our purposes, a specification temperature of 1200 ºC would be sufficient. Real heavy castable has a specific weight of nearly 3 kg/liter, the insulative kinds lower than 2 and some of the lightest 1.4. The lighter the softer, the kind I used weighs in at 1.92 kg/liter.

I don't know much about geopolymers, only that it should be done with really basic materials and a very ehrrmm... esoteric process. That process is the main stumbling block, so I did stick to the known to work materials, saving me from becoming a materials experimenter instead of a wood burning developer.

@Peter V.

Well put and extremely logical. Thanks for the explanation.

When we started the core build portion of this project I consulted with Matt and others here as to weather or not we should insulate the CFB (ceramic fiber board) heat riser. Everyone said that we could, but it was not necessarily.

After burning our stove for a month or so, I have grown curious to know what additional insulation on the heat riser and around the portion of the burn box on the inside of the manifold might do. The core is not taking up very much space relative to the internal surface air of the burn barrel and manifold. Although I haven’t measured for clearances, I imagine we could add a few more centimeters of insulation without interfering with air flow.

Is this curiosity something which might be worth tinkering with and if so any thoughts on insulation materials? (Morgan’s super wool is too expensive and have only found it sold in large rolls here so far)

Thanks in advance,

Peter and crew...🥽🤓🥽

Peter Sedgwick wrote:P.S. blue flame is pretty to look at but is that a good sign or bad one?

Thanks for the update on the bricks. However, I'm not even going to make a comment on them with "@Peter V" on board. (I guess that's his new 'street' name).   :)
As for the colours of the flames, I found a site that simply describes what they mean, what temperatures they represent and chemical constitutions. In this case, blue is your friend.
flame colours
BTW, I have almost the exact same setup for distributing the heat in my place, except I removed the stand and placed it higher up...its remote controlled so no reaching required.

Peter Sedgwick wrote:When we started the core build portion of this project I consulted with Matt and others here as to weather or not we should insulate the CFB (ceramic fiber board) heat riser. Everyone said that we could, but it was not necessarily.
After burning our stove for a month or so, I have grown curious to know what additional insulation on the heat riser and around the portion of the burn box on the inside of the manifold might do. The core is not taking up very much space relative to the internal surface air of the burn barrel and manifold. Although I haven’t measured for clearances, I imagine we could add a few more centimeters of insulation without interfering with air flow.
Is this curiosity something which might be worth tinkering with and if so any thoughts on insulation materials? (Morgan’s super wool is too expensive and have only found it sold in large rolls here so far)

-The CFB should take the brunt of the heat so a lower rated insulation could probably be used. If your looking for simplicity and quickness, perhaps a wrap of rock wool batt insulation would do the job. It could be cut lengthwise to reduce its thickness (if needed) and then secured with hardware cloth.
-Many years ago I made a quick fire brick heat riser, encased it in sheet metal and then filled the space with loose vermiculite - I didn't have perlite at the time. (similar to how you insulated your chimney). Yes, it did settle but good for a short term test. I used my shop vac to suck out the vermiculite when I was done and used it many times over.
-Now that you know how your stove functions (drafting in particular) you could see if the added heat retention the insulation gives you increases the differential enough (heat inside the riser vs outside the riser) to make up for the loss of space and drag that it may have on the exhaust.

Wow Gerry,

Your link was pretty intense and extremely informative. Almost too much for one sitting. Think I’ll have to read it like 6 time, before I can honestly say that I “read it”.

Thanks.

As for insulating the stove...
I’m really one of those people that always thinks, “yeah, but what happens if you do...?” The person that constantly raises his hand in class and asks a million questions to the point where the teacher says “shut up and just memorize the formula for the exam”.

It often gets me into trouble, but also often gets me new ways of looking at and/or understand things. I’ve been that way since I was little. Think it’s just hard wired somewhere in my mother board.

At times I’ll hold myself back, and repeat in my head the old saying, “If it ain’t broken don’t fix it”. But then there’s the other me that says, “if it ain’t finished then keep on breaking it until you understand what makes it brake”.

Everyone starts on an adventure, like that of learning how to build a rocket mass heater, with there own goals in mind.
My goals are evolving and so is the path that is leading me there. Think that’s really what makes the whole thing exciting.

It’s part of the journey Mr. Gerry. Thanks so much for helping to shine a light on that path.

Let’s keep braking things and see what happens...🤘🏽👁🤘🏽

Peter

I have found that studying rocket stoves can be very frustrating, it is not something that has been developed and perfected by a large company with unlimited resources ... so many questions don’t have conclusive answers that can easily be found out!

Obviously we have Peter V who seems to be so dedicated and helpful and has a great understanding but I assume he has limited time and budget  to help his development.

There would seem to be many approaches and many potential ideas out there but it is all done by independent people or small groups of self funding enthusiasts.

In my short time association with rocket stoves I have seen a lot of progress, as more folk get involved and design different ideas ranging from the most basic fugal but successful attempts, to stunning  high budget, high efficiency large house designs.
However I can’t help but think there is far more to come........

Peter Sedgwick wrote:Wow Gerry,
Your link was pretty intense and extremely informative. Almost too much for one sitting. Think I’ll have to read it like 6 time, before I can honestly say that I “read it”.

I thought it was a pretty simple description, so when I went to go look at the link I posted I saw what you meant. Not sure how that one happened but here's what I really wanted to show you:
fire colours   As a double check, there should be a picture of a boy sitting in front of a roaring campfire at the top of the webpage.

The picture you posted looks like Mimi is being held hostage by the one-eyed anti-RMH terrorist group known as 'Big Oil'...... Should we send in the troops to rescue her?

You truely are a student of life Peter. This picture of Gary Larson's  The Far Side came to mind:

EDIT:  I removed the picture after discovering that Gary Larson just opened a new webpage The Far Side and has a copyright on all his pictures not to be displayed without permission from the copyright holder. Didn't think it was worth emailing him so instead I provided a link to his site instead. Its worth the mouse click !