Scott Weinberg

Mike Oswaldrosnick wrote:I had similar questions about durability, but running a cleaner fuel helped a lot. I use kiln-dried wood from https://onestopfuel.ie/ and haven’t had cracking issues since switching. Consistent moisture content seems to make the burn easier on the bricks and metal parts.

Mike, I was wondering how you determined this boughten fuel has worked better for you.   What were you burning before? And if you had cracking issues, did you replace those particular bricks?

In general, wetter wood, would have a cooler burn with the moisture converted to steam. Or were you thinking this "steam" was the problem?

Just curious.

Scott

The Purpose of a Rocket Mass Stove in my opinion.

A simple review:

Just like everything in life, it (A Rocket Mass Stove)   is not and cannot be everything to everyone.  What it is, when built to the numbers, a extremely viaable wood burning-enviromentaly sound-and quite simply a very stable and consistent heat source.

If you want to go out and look for all the reasons that it won't work you will find them. If you convince yourself you do not have the ability to build it, you will not beable to.  Such is life for some.  Mr. Can't, never did anything, and speaking to your self, "I can't do this, and I can't do that, will simply enforce your ability to not get it done, you won't"   The desire to build is something you either have or don't have.  It can be developed and nurtured with sound advice. Much of that advice is here on the forum.

Can a person develop the skills, learn a trade good enough, find new friends along the way, and end up with a soul warming, house warming endevor?  Absolutely I have friends on this forum site, I will probably never meet, but enjoy them imensely.  .

Can you drop everything, and build over the next 30 days, sure, but you don't have to. There have been many winter projects, started at the beginning of fall and finnished before spring. Nothing wrong with that.

I am off my stump, carry on good folks!

Scott

As this is rather old ( 3 years) Please don't be shy, how has this worked out for you.  

So many threads start out  " this is what I am going to do and it is going to save this X amount"  and then we never hear from again.  So, where does this "great idea" fall into?

cheers
Scott

ps  I am a equal progress comment oriented Person!  Simply meaning, if it is a great idea and has worked out well, then all want to know, and if it didn't work out, that should be stated as well. Learning from dreams of others good or bad, is the basis of true learning.

Well done... gives a warm fuzzy feeling at your progress over the last few years.

Cristobal Cristo wrote:I already commented on this issue stating that there exist quality differences between various IFBs, but now I'm thinking that they should not be used in the wood flame path.
Two vendors/manufactures that I inquired about IFB use in flame path said it was OK, but at the same time it's rather obvious that they are not intended for wood flame path:

1. IFBs are rather new invention, established in industry in the 50s.

2. Industry uses natural gas, propane or electricity to melt, crack, kiln fire.

3. If wood is burnt in biomass power stations or incinerators - high alumina hard bricks are used (I read some paper), because amount of fluxes and detrimental substances is high.

I remember and fully agree now.  This is one of the reasons for my posting of the final results as they have often been recommended to use in locations just like I did.  I am not blaming a soul, just reporting the end results after 3 years of hard burning.

Cristobal Cristo wrote:
My electric ceramic kiln is lined with IFB26, but it's electric and only I converted it to propane and propane exhaust is super clean compared to wood and I use it maybe 10 times per year only, so I may not be able to notice any deterioration.
I just read that IFB/propane kilns may have longevity of 1-5 years in high use environment. High use for ceramics firing would be once per 3 days, because cooling to less than 50 C (safe for glazes) takes me around 40 hours. For quick raku firing (objects are removed hot from the kiln) firings could be more frequent with much more thermal strees.
Masonry heater will be probably fired for let's say 4 months, so with one fire par day it's 120 firings - eauivalent to once per 3 days kiln use schedule. However the fuel is wood with chlorine (bricks don't like it) and various fluxes. Also the temperature in properly built riser is equal and turbulence much higher than in a kiln.

So it looks like IFBs in wood flame path are really being tested by us. I'm really curious about performance of IFB risers built by others.

Excellent deduction for the cause of the problem and end results. While no one has asked, this was not a expansion limiting layup of bricks. Unless they could have walked, I will never know now. But I am doubting it, as the perfectly undamaged bricks were just below and besides the IFB's

Thank you Cristobal Cristo for possible root of the cause.   I would like to add one thing concerning propane heat, and cinder block only flues using standard mortar,  this has been known to cause problems. Though I am not sure the root of the cause. Some flues, as in my case, had cast high clay liners that are working just fine after 67 years,  (no propane every used, simply wood stoves all these years)

regards
Scott

Hello all Rocket Stove builders!

I am going to share an experince basically for one reason and that is simply to tell the good and bad of my past few seasons of the 7"  batch box build.

The good: It worked right out of the gate on the first burn and nearly every burn after,  easy to light, easy to clean and it simply worked.
As most of you that may have followed my various suggestions on stove building, I was and still am pretty insistent on building to the KNOWN working numbers.  (for both the stove and bell)   I don't have any experince with ducted benches thus I never comment on them.

Make no doubt about it, I have relied heavly on the advice of Tom of Dragon Fame. Fox James and his great experiments and of course Peter van den Berg  who without him I might be still rubbing two sticks together.

The bad:  Late last season during my monthly inspection I noticed a piece of IFB laying on the inside floor of my bell, but all was working well so didn't think much of it, later I found another  and this kept going... but all was working so I was only puzzled.

So finally on 9/25/2026 I took off the face plate of my bell, (very easy to make, worth every bit of time to construct, as with it off I can crawl right in if need be)
and what I found was very simple, anything I built with good hard fire brick was perfect, anything I built with IFB (Simon Brand) which was all of the riser and some re-enforcement pieces was simply junk, (cracked, broke, or completely out of place)  I doubt I will ever use those again. If I feel something needs extra insulating power, I can always add some of the Mineral wool, or many other product out there that seem to hold up well if this don't have to touch the wood.

I am sure other bricks might stand up better, but I am never going to take the risk again.

So now the really good.  Everything is repairable, (replaceable) the bell is in great shape, and the mineral wool inside was good too. Without the large face plate this would require reworking the bell to some extent, (never fun) This is not bad.

Final explanation of the breakdown of the IFB's--- This stove is run hard, I can often heat a 1/2" dia  (12-14mm) metal rod to a glowing red in less than 5 minutes and just guessing, the IFB's even though they were rated for extreme temps, simply did not hold up. Perhaps even shifting slightly during heating phases. Again, I don't know for sure, and I don't really care now, as the riser is completely out of the bell in 30 minutes of time, and the rebuild will take place.

WARM regards to all.

This can be as complicated or as simple as you want it to be.

in the very simpliest terms --- Burning wood that is 10% moisture vs 25%  produces about 83% as much heat.  Again this is a very simple calculation of just calculating how many pounds of wood your actualy burning.  90# vs 75#  if your starting with 100#   If your calculating in metric, the same 83% comes forth.  

Ironically this 83% figure remains about the same with good oak vs poor cotton wood. If you start with the same wood and maintain the same spread in moisture, the figure does not change much.
Likewise the effcieny of the stove does not effect the number much.

WE can wish for better, and precieve it to be better, but in this case, just not to be.

Now for a bit more complicated, for every pound of water your converting to steam, cost you 992 BTU's.   So above this is 15 lbs of water for every 100 pounds.
So  an additional 14, 000 btu's out the flue.  No getting around it.  If it is there (the moisture)  and your wood burned, then it consumed the BTU's to turn to vapor.  

Stay warm folks, and let the suns drying power in the summer give your stove heating power in the winter.

Scott

Benjamin Dinkel wrote:Thanks for the input.
I really wanted to use the inclined fire bricks but thought it wouldn’t work on shorty because they would be in the way of the exiting exhaust out of the riser, wouldn’t they?
Do you remember the reason for not using the shelves in a permanent build?

The brick at 2.5" thick would be below the exiting exhaust. The smaller the size of the stove the shorter the two top brick would be, still cut for the taper as the other stove photos shown in this forum subject.

thomas rubino wrote:Apparently, the shelves aren't reliable in the long run.
For short-term use or on a build with easy access to the core, they would be fine.
Perhaps in your warmer climate, they might last indefinitely?

I originally thought first-gen batchboxes required a flat roof, but Peter oked the peaked design.
I suspect that it would work on Shorty as well.

I have always built a peaked roof for the burn chamber-  the trick is simply in that you don't let bottom base side slide any where (out) .  NO different than a buttress, if the bottom can't slide it can't fall in.  If y our using a tension frame, just utilize a part of the frame on each side of the base of the peaked roof. thus one angle cut on one end of the brick and one angled cut on the base side.

If you need photos, let me know and I will look them up. I think this is/was shown in my build a few years ago, but attached to my postings.

if you don't have a brick saw, then I would suggest casting instead.  

Scott

Gary Throop wrote:Oh, wow!  I just found this guy on YouTube!  A total inspiration!  He looks as old as I am and look what he did!  If he can do this, so can I!

Has anyone seen this?  Any comments?  Suggestions?  Criticisms?

Gary

While we will probably never know, I would like to know what the ISA is/was and size of stove itself  5"-6" or 7" and this would give a correlation number that we know today because of Peters work, that really works well.  Who knows, this build might have been spot on.  

On a side note, those kinds of bricks with the holes, can be or should be filled, as that is a mass gain of very little cost, and I am not talking about a sand filling, sand simply insulates far to much!

Over the years, I have changed my thoughts on good working stove and that is simply- "It should work for years and years with little maintenance"  Probably one of the biggest reasons that the simple bell, single or double has really took hold the world over.  It is a grand design, that is easy to predict, easy to build, and works well for years.