Scott Weinberg

Good line, Tom

Benjamin Dinkel wrote:Yeah, it was a couple of hours of unpaid labor in the end. Cleaning up and rebuilidng I obviously didn't charge.
But it was cool to be able to reuse the material, just soak and repeat. . Do any of you have had bad experience with half circle brick arches?

By having such a small compressive face ( the bricks laid flat in your arch ) you are pushing the limits of your thrust line.  The thrust line, is simply from the center of the top of your arch to each outside edge of the arch.  The thinner of the face, the harder it is for this line to stay within the top and bottom of the brick faces or perhaps better said, inside and outside of the arch. Viewing from the end, this line should always be within the inner and outer faces of your brick.

I suppose with the cob hard this would greatly help, but until hard, there would not be much compressive strength at all.

But as you say, only some time has been lost.

Ironically I had a very simple arch collapse today, but was do to my  not holding the above mentioned thrust line stable at the base--  Totally my fault.

I certainly stand corrected, on your intentions, so sorry for that.

With my circumstances being somewhat different than most with tremendous drawing chimney, I will let others chime in on the size comparison of a" J tube to a batch box of smaller size, Although this has been talked about in the past, I am not adept in doing a search for such items, perhaps one of the staff rocket scientist  has all of this already sorted out.

Sometime ago, there was a subject title of  "What is holding you back from building a rocket mass stove" (I am paraphrasing this a bit) And there was a lot of different answers, with one of them being, simply  -People thinking  but not finding   a guide that super defined  exact build BOM for each size.  The problem of course is all the variables.   I would suggest that the numbers are all there for a single bell-batch box, of each size.  But aside from that there are again many variables.

So with that in mind, I will try to attach an example of a 6" shorty, internal unit.  This one was set up for the use of super wool between tiers,  again, so many options but if the pdf comes through on sheet two will be a complete BOM  (Bill Of Materials)  I hesitate a bit on posting this sheet, as one little change can alter so many of the dimensions.  But.............it would get you close.

Take this with a grain of salt, it works very well for some, and not at all for others.   This was derived from a Sketch up file for the shorty 6" size. Interpretation can be different for others.  My way of saying this is NOT gospel  It is entirely a credit to Peter van den Berg of rocket mass fame!  If you have not read all of his excellent ideas on the workings of various stove, this  needs to be done.

Best of success!

Tycer Lewis wrote:

thomas rubino wrote:Hi Ty
Always a good idea to gather your materials ahead of time.
And buying now, rather than later, will save you some bucks for sure.

To help you with the materials, you need a definitive plan for what you will build.
A first-generation 6" Batchbox is quite different than an 8" J-Tube.
Are you thinking of a piped mass? Or perhaps a stratification bell?
What material do you want to work with?
Are you hoping to build as cheaply as possible? Or do you want a beautiful work of art?


Let us know what your plans are.

Thanks for the reply!
Piped cob mass. I know that they are different however I have not done more than watch a few of the videos on the batch box whereas I have read a bunch about the J-tube. If I were to build a J tube, it would be sizedan 8 inch for my application.


Thanks again for your help here! I really want to get that refractory order in the and the pipe ordered ASAP…

You really have to help those that are able to help you by defining better what you intend to build.

You have said " If I were to build a J Tube, it would be a 8" size for my application"  But you do not say if that is what you plan to build,   Could it be a comparable BATCH box?  

With all of the offerings (shown builds on this forum) have you picked one that exactly fits your bill? if so, that will greatly help all of us sort out your bill of materials.  

Now to refine this a bit more, have you picked a J-tube vs a shorty vs anything else ?  Keeping in mind that all of them need to be "shut down or closed" at the end of the burn period"  Will that be a problem as the time of burn can range from 45minutes to two hours, depending on the stove.

I feel the answers for you are out there, but we need you to zero in on the intended end result.  Even down to your available chimney height planned. if you want to get really detailed.

Best of success.

All of these are most interesting in the perceptions of danger and all the rest.

Probably not much on here, but if like myself, a small private plane is a great thing, but often proves the saying, "if you fly by air, have time to spare"  As far as the big planes go, 99% of frequent flyers would say, it is all in the mind set. Basically it will go the way you precieve it will go. Greatly or Poorly.

As far as bags, go, rules are rules, but for good reasons,  i.e. if there is only X height under a seat, then there is nothing one can do to change it. With the vast majority of travelers making it work, then perhaps a person who doesn't think it will work for them, shouldn't be trying to do what they already know won't work.  I am not trying to be mean.  Just a simple fact in life.

Lastly, while when things go badly on a aircraft, they are really bad, the odds/chances are so slim that it is not worth talking about.  Everytime your on a two lane road, just think how many times you meet someone going 55 mph or more, where only 1/2 of the deviation or seperation  is controlled by you == it is or could be a scary thought if you dwell on it.   When you step back and understand the newspaper/radio ways, What makes more sensational headlines, one airplane crash or 500 car crashes.  ( the spread could easily be bigger than that ) but the airplane news will win every time.

Stay safe everyone.
Scott

Cristobal Cristo wrote:

Scott Weinberg wrote:[But I am hear to say, I used what I thought was the best "insulating fire brick" I could get my hands on in the states. And after a few years these have started to break down

Scott, do you remember what brand and model of IFB you have used?
The insulating bricks in my gas kiln do not show any wear, but at the same time I use it sporadically, but at higher temperatures. I always inquire if IFBs that I purchase can work in flame path.

Simon fire insulated fire brick, nearly white in color ( not that makes any difference)  Again I am not blaming the brick, and perhaps this is a one case deal, I could get the exact details, but have decided in my case, it will be hard-high rated fire brick only. As all of those have survived very well.

I will check to see if they had a fire temp rating later today.

Scott

sara ventura wrote:

I am unsure what type of insulating firebricks you have there. Better to use just hard firebricks for the entire core. The riser is the part that's heat stressed most of all, especially the liner in the lower half. Thin strips of insulating firebrick, I feel scary about its durability.

I have located a high temp materials factory that offers:

Insulating firebrick G-26 -
Dimensions: 230 x 114 x 64 mm
Maximum temperature: 1430ºC
Alumina: 56%
Characteristics:
Excellent insulating qualities.
Mechanical and temperature resistance superior to group 23 bricks.
High purity.
Thermal shock resistance.

Firebrick AL40-
Dimensions: 230 x 114 x 64 / 76 / 20 / 30 / 40 mm
Maximum temperature: 1420ºC
Alumina: 39-41%
Characteristics:
High purity.
Low iron content.
Good mechanical resistance.
Excellent resistance to thermal shock.

I'm trying to avoid ceramic wool as much as possible, I was going with the insulated firebrick for the riser, so I don't have to add extra insulation outside. Keeping the ceramic blanket at minimum when directly exposed to gases.

I"ve had a look at your drawing of the core, and question arose. The depth of the firebox, is that a fixed figure because of the bell depth?

I've drawn 50 cm because the depth is the lenght that has more tolerance, and I'm thinking in the type of wood I'll be using.
Most of the times the horitzontal cuts of the wood are at an angle, length is always irregular. So extra depth to make sure I can fit any kind of cuts in the box load.

I know things are different around the world but when I ever hear about insulating fire brick being lighter and ect. I have to let folks know.  As many have read, about my 7" batch box,  it has worked just fantastic, And because of the tremendous draft, can get to perhaps hotter than most. On the third the burn.

But I am hear to say, I used what I thought was the best "insulating fire brick" I could get my hands on in the states. And after a few years these have started to break down, while the hard fire brick has NOT SHOWN any problems. (same stove)  This was not caused by thermoshock, abrasion from fire wood, nor anything else I can think of.   and Simply used in the riser.  Not the end of the world by any means, but still some maintaince that I was not planning on doing this summer.  This is no fault of the design, simply these bricks could not handle what I was asking of them.

Am pretty sure if I had done the exact same thing with hard fire brick, with wrapped insulation, I would still be 100% good.

Again, results may very, but this is just my case as stated.

cheers
Scott

T Cool wrote:Peter,



According to that article you need to add some pillars inside of Pepper Shakers! More mass practically.

I think this shows that in 1928 there was a difference of opinion and lots of them. Certainly true with just about anything of that time.  Our abiilty to test ( Peter's to be suspecific ) sure does help in todays world.

May Maglock wrote:I live in WI. I'm planning on building a simple one-story (shed roof) timber frame addition (12' by 26') this summer to our small old farmhouse. The addition will attach to the long side of our house (26'). I am not an experienced builder or timber framer. I've completed two workshops, and read a lot of books, but no more experience than that.

With all of your reading, certainly the foundations for your location or soil types have been covered? Something as important as this, now would not be the time to decide that there must be a better way, most but not all, books cover what works for your area. But certainly what is good for your area, may not work for southern latitudes and so on.

May Maglock wrote:We are on a tight budget and also prefer to not use manufactured components whenever possible.

We are using red pine timbers we've cut and milled ourselves. 8x8 posts and 8x10 beams.

If I am reading this correctly, you are getting things lined up pretty well for the above ground supports? Just need to nail the below ground stuff?

I

May Maglock wrote: am wondering about using four foot deep holes with compacted gravel and either stone or cement block on top, with the piers located underneath the house posts. We would use anchor bolts to attach to black locust 8x8 sills on the perimeter (2x8 block locust joists). We'd then attach the posts to the black locust. Does this work? Is it stable enough? Will it hold the load of the addition? Or do we really need posts going into the ground for stability or other reasons?

Thanks for your thoughts on this.

By digging down as you describe with stone or cement block built up to make a level based top, what is your proposed method to have every pier level?  As Tom mentioned, the sannen tubes really can help tremendously in this reguard, Set them as perfectly as possible, then decide where the level line is, cut to this line and fill the tubes. If this goes against your desire to not use commercial products, your cement blocks fall into that catergory. Stone will never get to a perfect level without concrete,  so I am just proposing cutting to the chase.   Much of this has to do with your longevity plans, if your shooting for 10 years vs 100, makes a big difference.   Knowing if your in silt, sand or extra rocky country makes a big difference as well.  

Best of success.

Gilbert Fritz wrote:To make this work economically, I'm going to need to learn to make my own wooden handles. I know that riven wood is stronger than sawn. Does anyone know of a book or website which covers the process of riven tool handle making from log to handle?

Gilbert, it has been 5 years, have you developed any skills to merchandise? if so which has been the most wanted in your neighborhood? profitable?

Did you end up becoming a handyman by choice or neccessity?

Inquiring minds want to know.