Scott Weinberg

Jackson Bradley wrote:I get somewhat confused on the longevity of the different parts for the different types.

I can't quite wrap my head around what I'll need to replace/clean, about how often it will need replaced. That seems to depend on the type of RMH. I have read through your masonry build in the large building, the Wisner's materials, Thomas Rubino's projects, etc. I have seen where some of the metal components need to be replaced and some of the bricks crack and need replaced, etc.

I understand a factor of that would be climate dependent due to the amount it would be used (wood burned). The larger masonry heaters seem like what I would work up to in my residence but practice building one on in my accessory building.

Longevity?  Lets flip this a bit, and look at the numbers,  so we have a outdoor stove that cost 10 times more and burns 10 times more wood (ok, lets cut that to 5 times more wood)  and still needs repairs after a few years, at the mercy of electricity and dealership cost.  vs rocket mass stoves that probably and possibly need some general maintained cost of a few dollars per year

Tom has clearly shown what hard burning, looks like and how he handled it.

I am on my third year of burning, and while I think I can detect some future repairs, they appear to be minor. and while I am trying to get a better video, I can honestly say, no hotter fire has burned in a standard wood stove.  I can heat a 1/2 round rod, to deep red in less than 3 minutes and cherry red in 7 minutes so hot it is.   I have been a proponent of building a stove where the entire core burn unit could be replaced without touching the bell. This was not hard but has not been needed. But I probably will do this again. Just takes a bit of planning.

Excellent post Glenn,

I would like to add to this a bit.

1) any in the Midwest with basements, you have great potential room, if you have a chimney that goes with the house.   Heat rises nicely. and yes it might not be a center piece, I think many will enjoy this especially if you have a window on your door ( easily done )

2) insurance- I bet I have heard 100 times from home owners that they feel they could not get insurance if they have this built by themselves or a contractor, So I ask why?  other than hearing  " because that is what I heard "  I have yet to have someone tell me, this is a non-insurable unit, causing the house to be uninsurable.   Better yet, show me.  So I have to presently believe this is a classic case of  Somebody said that somebody said, that somebody said, it can't be done.  Which generally plays out that it was never a fact, I don't mind to be proven wrong, but simply have not seen this yet.

  To back this up further, for every reason that a classic wood stove with smoldering fires that might be producing a potential chimney fire, I can show you why that is simply not true with a rocket mass stove.

3) Time, everyone seems to be short on time, but, for every hour spent gathering wood, for a Rocket Stove, you can get 2-5 times more usable heat, plus if you add in all the easy to gather woods ( throw away boxes at nearly every lumber yard, construction sites, storm damaged areas,  that are in fact FREE )

This of course is just food for thoughts, but the 1st step of any job, is starting, whether that is in the planning, cleaning, or constructing. But, if you don't have time to do it right, when are you going to have time to do it over?   Might as well, start with a great plan and follow through.  Tom of Dragon Tech just showed what got done with a great mission and determination.

Best of success!

Glenn Herbert wrote:I agree that a ducted mass would continuously lose heat with any amount of residual draft. I think a stratification chamber would be more dependent on details of the configuration. If the combustion core exit (riser top or secondary chamber exit port) is near the top of the stratification chamber, then it will be introducing cooler air and diluting all the stratified hot air remaining. If the core exit is low in the stratification chamber, it can move more directly to the chimney exit and leave the hot upper part of the chamber undisturbed. This is assuming that draft is restricted from full burn-time flow and does not "jet" at all.

As many may know, I have tremendous draft, even when the stove is not lit.  and this is nearly all the time.  Yes, even in summer.  Thus it can be concluded, that if something ( air ) goes in it has to come out, and of course if it comes out and makes it through the bell or any other part of the mass, it is just the law of physics, that X degree cooler air, will gain temp if allowed to travel through, X degree of warmer environment.  The speed of such can be expressed as CFM (cubic feet per minute)   Thus the tiniest level of inlet, left unchecked but having a clear shot of air travel, can loose just as much  heat as loosely sealed but large area of air inlet. such as a door.

Perhaps one of the easiest ways of knowing, is simply when you shut down your stove, before the wood is completely coaled out, and it is nothing but ash in the morning.  Something allowed this to burn. i.e  air entering your stove burn chamber.  Basically if you have a great drafting stove, you will also have a stove that wants to just keep the cycle alive, ( heat going up )  And of course, this can be simply tested, if your exit pipe is very warm 3 foot from your stove, it is getting that way from flowing heated air.   I have come to believe that some will simply migrate up the flue, but stiving for the lowest CFM will save a great deal of heat.

When burning let it roar, when not, shoot for the lowest snore.  A true sleeping dragon so to speak.

Best of success.  
Note- if any of the areas that need to be sealed up, never gets over 500 degrees F, some silicon sheets come in handy for air stoppage. And can last for years. Just like the stoves themselves, a little ingenuity can go a long ways.

3rd year for the stove, where does the time go.

Thought I would do a quick share/update  I fired up the stove, 10/26/25 for the first time this fall.  Had it all cleaned up internally from this past spring, so no dampish ash or other things to deal with (damp basement application)

Almost scary how quickly, things sprang to life with the mighty roar,  used by pass until I felt it was HOT, then closed off after 2 minutes.after than a success was determined. I design my cast-less top a little differently now adays, but this one is working just fine.  Video, might not be so good, a winter project to figure out how to do better.

Cheers all, and stay warm.  Also completed my 50th harvest season yesterday! Pretty good feeling with record corn yields for me on most fields.

Thanks Tom for all your excellent promotion work and show casing the bling.

Some of asked,  

How long have I done?      Nearing 20 years now
Have things changed?        Absolutely, with now very intense colors and coatings
Fonts?                                  Anything and everything
Limits?                                  Not many.  unless you want alum, brass or gold

Just an example of last winters work, I do 10's of dozens in the winter, in a room next to my 7 inch rocket stove.  Detailed below.

Scott

Matt Todd wrote:

thomas rubino wrote:
I am very happy to report the highest temps my arch has risen to are just over 400F!!!  (Success!)

Do you have any measurement on what your core exhaust temperature is reading?
Reason I ask is, I'M BUILDING A SHORTY IN A BRICK BELL TOO!

One final detail I'm working out is the internal chimney. Planning to do the "plunger tube" style of chimney into the bell. But my Shorty core will flip the exhaust to shoot out the back wall of the riser stub so I can put an oven on top of the firebox. The potential issue being hot exhaust shooting horizontally right at my plunger tube. My DSR2 build has a black stove pipe plunger tube and I intend to do the same here. Just a little worried about it being directly in the exhaust path.

I know around the world and even in the same country as the USA folks have different terms for different things.  In this case, what part of the stove are you considering "a plunger tube"  And presuming this is inside a bell, does this effect somehow the workings of the stove vs a bottom of the bell exhaust outlet?  Am curious about if this is something some have not seen, or if this is just different terminology.

Thanks in advance.
Scott

Cerbu Ulea wrote:2 tons I think its a  fair guess, fire bricks seam heavier ,  3 kilos each?  some in the top bell plus the core , the sand was say 10 buckets, and the old terracotta tiles count I think, is it a good number? It stays warm 36 +  hours this time of year, but one fire a day I prefer now

Well there you go, no need to argue with success or even 2nd guess it.  I honestly feel that every stove is a success if it burns clean, heats what was expected of it and looks nice to the builder.   Beyond that is sizing,  We truly have numbers for those kinds of calculations or those that can answer those types of questions.

cheers

Cerbu Ulea wrote:please help me calculate the mass of my stove , single skin yet, it has aprox. 400 bricks at about 2,7 kilos each , the core has thin mortar but in the bell's walls there is a lot of clay & sand , add also the number of the fire brick in the core , which I did not weigh

Looks like you know what you used, thus I would add it up.And you will have your answer.  for example- 400 x 2.7Kilo  for 1080 kilos
And you know how much clay and sand

Thus you already have your answer..

[quote=Timothy Norton
It is that time of year where I am cleaning my household boiler (not a RMH) and I started to read up on the maintenance needs of other systems. I decided to explore a bit about RMHs but was having issues finding anything.

It sounds like it may be minimal if its a batchbox or a bell.

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Yes, indeed the maintenance is LOW, and with proper clean outs, easy.    Long ago, I invested in a ash vac intended for a wood stove.  the kind that has a metal pail, a fire proof hose, fire proff filter, and although it can suck up some small coals, really no need for that. I use simply to clean the burn chamber, rather than pulling out the ash and scooping up.

back to the vac--

This unit has enough ash filtration to it, that it can easily clean just about any rocket mass stove offerings, although as stated, there will be little of that. I can easily go every 3rd year, if I want to.

If you meant having trouble finding anything on RMH's, this location should have everything you need.  Be aware there are lots of suggestions on the internet, about RMH's that come forth after one day of burning, often have lots of metal involved, or even concrete for burn chambers.  I think you will find on this site, a much more practical aspect, where use of fire bricks, and clay based mortars. for building stoves for years and years of use. I certainly intend for mine to last 15 years or more.

Best of success.