I want to build an RMH, but I do not know how!

So, you have read all you can find, attempted to search for supplies, your brain is spinning like tires on an icy road...  and it seems you gain no forward traction.
You write on Permies asking for detailed information, and we reply with the information... it's not enough...
You want a detailed plan with every piece and part readily, and cheaply listed, you want to know where to buy supplies in whatever rural location you are located.
I make suggestions on where to locate those supplies ... But, you are not willing to drive several hundred miles to acquire those supplies.
Although there are a few tricky spots on any build where you might not be sure how to proceed there is help easily available.
Permies is a good starting point.  https://permies.com/f/260/rocket-mass-heaters
Matt Walker will offer help to anyone who contacts him, whether you have purchased his plans or not.   https://walkerstoves.com/
Fire speaking will offer guidance.   https://www.firespeaking.com/
At Dragontech I  will help guide you with emails or phone calls, I also offer detailed books on first-time Batchbox building.  https://dragontechrmh.com,    dragontech@blackfoot.net
Peter Berg has a comprehensive website with ALL the information you could want, Peter will also offer help through Permies.  https://batchrocket.eu/en/building
Donkey Pro Boards is a very in-depth technical forum where you can get responses  https://donkey32.proboards.com/

In most cases, all of this help is completely free.
We sell books and videos, and we are willing to privately converse with you.
Somehow, this is not enough help for a good portion of the population.

Not everyone is a confident do-it-yourself kind of person.
Some, just need simple explaining, and the lightbulb over their head illuminates... it really is quite simple.

Others will not grasp the principles of RMH construction no matter how much you attempt to help, they need this built for them.
For those folks attempting to locate an experienced builder, we are few and far away.  It is not cheap to ask Matt, or myself to travel to your location, search out where to purchase supplies, and then drive hundreds of miles to purchase those supplies. After driving hundreds of miles just to arrive at your location...
If money is no object (Transportation, housing, meals, supplies plus labor) then you too, can have an RMH built for you in your home.

A much better idea is to hire a local competent DIYer, who has never built a brick RMH but knows they can with a little help from the pros.
Explain that you want a kickass RMH and then give them all of the free help info that I supplied.
Perhaps, hand them a copy of my book Batchbox Construction for first-time builders.
As much as I like to call this Rocket Science, it really is so simple a caveman could do it.

Not everyone can build things, even when they really would like to.
Complaining that there are no step-by-step all-inclusive plans, that get updated with every little change will not get you an RMH.
All it does is irritate those that are attempting to help.

If you can, then JUST DO IT
If you need some help and guidance then JUST ask.

If you can't do it, then hire someone confident who can learn how, or break out the checkbook and hire a pro.

Otherwise, break out the checkbook and check out https://www.blazeking.com/products/king-classic/  .

That pretty well sums it all up.

Thomas, that black material above the batchbox in your picture - is that an old glass top from an oven, or is it metal?

I think from Burra's build in Portugal, that both are options? If so, do you have a personal preference?

Hi Jay;
Burra's build is a cookstove. She can use either glass or metal, both are good.
I would prefer cast iron so my cast iron skillets could not harm it.
On my build that is a decorative tile top where a soon-to-be-ordered copper tea kettle will sit.

Thomas, your post hit very close to home...

Let me preface by saying, I haven't built a RMH yet, so take my opinion with a grain of salt.  I've tried several times to delve into this subject, often going back to Peter's site, and reading posts here on Permies.  It seems I would just get started and already people would be way over my head and I wouldn't even know what they were talking about.  After reading Thomas' excellent book on batchbox heater core construction, I revisited Peter's site and it's all finally starting to click for me.  I truly and honestly believe that I was just making this way too complicated.  

I'm certain people that have built these put this info out there, but somehow I lost it in the reams of information I was reading.  This is what I wish I understood from the beginning, and someone please correct me if I'm wrong, but this is how I see it now.  This is really as simple as building the batchbox core, of which there are several good ways, and building a box of bricks around it with an exhaust pipe near the bottom of the box.  Obviously there are details, like the size of the batchbox and the correct size for the bell, but that information is readily available.  Beyond that, the hardest part of this, in my mind, is gathering the materials and just getting past the idea that this is too complicated, when, as Thomas said above, "it really is so simple a caveman could do it".

I can understand the frustration people must feel when explaining this stuff over and over again and answering the same simple questions.  This may be small consolation, but please know there are people like me out here that really do appreciate your patience more than you may realize.

Thank You, Trace;
Excellent synopsis!  
Being overloaded with information, some of it seemingly contradictory, it is easy to make everything seem more complicated than it is.
Trying to wrap your head around an entire build with no prior RMH experience, is enough to make the average person stall and do nothing...
Or ask more questions, becoming more and more confused until you give up on the whole idea.

Now with a little help from my book and your due diligence, you have it figured out.
You have a core, an empty box, you want a bypass for easy starting, and the exhaust comes out the bottom.
Each part of a build is simple and as you build, each new portion fits together.
Once you build your first RMH, even if it is not perfect you will wonder why it all seemed so confusing last winter, sitting next to your box stove and adding wood while reading posts on Permies!






 

Due to the cost, this solid copper tea kettle will arrive sometime before next winter.
It will look outstanding sitting on the tile on top of Shorty.

I have always had a large cast iron kettle on the wood stove.
It produced nice air moisture but you could not drink the rusty stuff.

I'm looking forward to having hot clean water that is still providing moisture but is always ready  to provide a nice cuppa of tea

Wow, Thomas!!! That kettle is downright GORGEOUS!! What's the capacity?

3.1 quarts so nice and large.
Here is a link.
https://www.amazon.com/DEMMEX-Natural-Handmade-Engraved-Stovetop/dp/B07PGVVV1N/?_encoding=UTF8&ref_=pd_hp_d_atf_ci_mcx_mr_ca_hp_atf_d

Thank you! My only other concern is my cast iron stove. Will it melt the copper, ya think?

Hi , Carla;
I sure hope not...
If it does you are having a chimney fire!
Copper melts at just below 2000F.

Y'know... I suppose I could have looked that up, myself, huh?😜 Thank you for both the reassurance and being so nice about it!

Providing a little color in the form of some basic rules based on my journey from not knowing what a RMH was to enjoying the enormous benefits of a batch box masonry heater:

Rule 1 - Everyone that ever started out to build and complete a RMH was the same as everyone else, they never did it before and had no clue what they were getting into. So how did they accomplish it? Those with fear of the unknown invested time to assess their requirements, asked questions and determined a general design that they believe will meet their needs. Be it a J-tube or a Batch Box, a steel drum for maximum quick-availability radiant heat, a masonry bell for maximum storage and slow release of radiant heat, or a bench to both store heat and provide a body warmer to sit on, etc. A little time invested in an internet search of “batch box rocket mass heater” and “j tube rocket mass heater” and then clicking on “Images” in your search engine will provide a quick visualization of many (perhaps too many) different options. But this is a critical time for the first time builder to help determine what they want to build. If you don’t understand the differences between an J Tube and a Batch Box, this is not an embarrassing question to ask, in fact there are no embarrassing or dumb questions… we all started out uneducated and made a commitment to become educated. Once you answer the initial questions of what are my requirements and what style RMH do I think meets my needs, you have overcome perhaps the second biggest hurdle. The first biggest hurdle is as simple as making the commitment to just do it!

Rule 2 - DO NOT expect to sit in your comfy chair looking on Amazon and expect to source the materials you need to build your RMH. As Thomas said, expect to invest the time and money to travel to acquire the heavy & bulky materials needed. UPS will not be delivering the high temperature bricks for your core, the clay bricks for your bell, and probably not the materials for your mortar or the steel for any structural elements. Do expect to spend some time researching where to buy materials. Don’t exclude the opportunity to buy used from Craigslist or Marketplace. People with pottery kilns rebuild their kilns and will often sell their refractory brick. Used clay bricks are often available from buildings that have been demolished. Other materials can be sourced from your building supply stores and steel suppliers. Some of the materials you can source online and have shipped to you. The list of materials needed is not overwhelming, just ask if you aren’t sure. As an example, the main list of materials for my Batch Box is detailed in the first link in my signature below.

Rule 3 - Don’t allow Analysis Paralysis to prevent you from forward momentum. It is really easy to fall into the “over-thinking” trap and allow frustration of the unknown or frustration with sourcing materials prevent you from achieving your vision. Thomas provided links in his initial post to all of the resources anyone would need to answer your questions to overcome over-thinking and keep you on track.

Rule 4 - Expect your project to take more than just a few weeks and be more effort than you may have anticipated. The payback is the satisfaction and dividends you will get back over many years in the future. So I can assure you the effort is worth investing.

Every picture tells a story...