shorty core replacing bbr with sidewinder

ok , skip the flying threshold .
I have a square cinder block with  25/25 cm opening I can incorporate in the passing wall, half that, 12.5/25 cm  and half the round hole(to eliminate the below ground area) would be good?

Cerbu Ulea wrote:very helpful, thanks . A flying threshold it's ok? I mean a 2-3 centimeters high bar of thin fire brick just under the front of the roof , So when the door is open the roof does not open directly to the room, I had it in previous build and reduces smells when refueling

The front of my core will look like that, 36/44 cm measures the contour for the frame

1) Am curious, from a brick laying perspective how do you hold this "flying threshold"  in place?
2)  I guess you said before, but by adding this threshold, would you not just be making two thresholds?  with the frame type door as designed by Peter wouldn't you already get this effect?

Just curious,

Scott

easy to make it , a strip of longer brick , mounted in two slots grinded in the top front side bricks above; yes ,I guess the frame will have that effect , I will skip it , Peter also said so

hello, today I want to start the brick work, I will not use a tension frame for the core , for the airframe it is ok 4 studs trough the front wall? a square frame on the inside of the wall around the core would hold them

Cerbu Ulea wrote:hello, today I want to start the brick work, I will not use a tension frame for the core , for the airframe it is ok 4 studs trough the front wall? a square frame on the inside of the wall around the core would hold them

Yes, can be done this way.

this is the first row from the floor, now I added two elements with round holes for cleaning purpose, will be covered with stone corks. The air leaving the bell , goes though the round 17.5 cm (I will grind the edges for better flow , and insulate the floor for it not to count as isa )and another hole which I enlarged to 20 cm by 10 , with a little vertical slit like you said for starting aid .I can have the core lifted 3-4 rows , there is  space up to 1,6 m in height  , maybe 1.7

Cerbu;
The floor does not need to be insulated.
The floor is not counted against the ISA.

I cant tell from the pictures, please say what size is the all tread you used ? are they zinc coated?

1/2"   all thread, stainless steel, zinc would work as well

https://www.youtube.com/shorts/-EceOfPj6vo , sorry ,lot messier than i 've seen , should I clean the dark dust of the wall or it will burn off?

Goodness, that is inside the bell.
Cover it over, nobody will be looking inside the bell

this is the base of the core , an old fire cooking plate 60/62 cm  1 cm+ thick suspended on brick columns at the back , and on the bell's wall in front  

Is that a crack in the slab running from the circle to the back? Is it supported where the crack is, if that is what it is?

yes, that's a crack, supported , but I think welding it will be better, and on the under side it is reinforced from casting with a x corner to corner in a square on the edges, seems I won't get away without buying a weld machine

Money well spent!
Everyone needs a welder.
Or at least know one...

hello, how do you reckon I should lay core's base on the plate? clay&sand , superwool?

Cerbu Ulea wrote:hello, how do you reckon I should lay core's base on the plate? clay&sand , superwool?

Clay and sand, definitely. The superwool won't provide a firm base, too flexible to my taste. The cast iron slab will expand and contract more than the bricks, so a strong refractory cement bond isn't what you want. The clay/sand mortar will allow different expansion rates without trouble.

https://www.youtube.com/shorts/gCjJlYQtW-0
I made the liner too tall about 5 cm taller than listed , should I grind it off?

Cerbu;
What are you calling the liner? There is no part called a liner.
Are you referring to the height of the burn chamber walls?

yes , the part that thickens the walls  after the port , it is noted insulation in the tab 273 mm , it's supposed to be 3 cm above the port 3 sides , fixed , or it may be taller?

OK, I understand where you are referring to.
The riser reduction at the start.
I would say that you need to correct the height; 5 cm ( 2")  is quite a bit higher than Peter's specifications.
Perhaps, Peter will reply.

no hurry , I stop here for about a week, would like to add the 12 mm studs for the frame first

Cerbu, the liner, as I understand it, is now 80 mm above the port. To me, it looks like to be far too much. The point isn't that the liner is too high, it's more that the wider expansion space will become too short. If you are able, take it out and use smaller strips. In your case, 35 or 40 mm above the port isn't that shocking, but 80 mm is definitely too much.

I can grind two sides to 50 with ease , the part above the port I can change the brick piece ;  should I grind at an angle to make the enlargement slower?

Another question please , seeing riser's big thickness, even if covered in superwool  what is the expected time to kick in to a good burn rate?

No, do not angle the edges. I believe Peter intends for them to be square.
A warm core will be at a full burn within 15-30 minutes
The superwool wrap will allow the core bricks to stay hot for a long time.

Cerbu Ulea wrote:I can grind two sides to 50 with ease , the part above the port I can change the brick piece ;  should I grind at an angle to make the enlargement slower?

I second Thomas' remark on this.

Cerbu Ulea wrote:Another question please , seeing riser's big thickness, even if covered in superwool  what is the expected time to kick in to a good burn rate?

Thomas is right again, although in general the burn turns smokeless in about 5 minutes, assuming a warm core. In a stone cold core, that would take about 10 minutes. As soon as the rumbling sound is heard, the afterburner function has kicked in and smoke will disappear, just like that.

thanks all for the replies, I look forward to finish as close to your tab and advises as I can , fire it , than if you wont mind i'll ask what to do with the air intake after the fire is out , but coals still red, cooking inside the core I saw you wrote is a good option, maybe you have a testo diagram of the embers faze

Cerbu Ulea wrote:...than if you wont mind i'll ask what to do with the air intake after the fire is out , but coals still red, cooking inside the core I saw you wrote is a good option, maybe you have a testo diagram of the embers faze

In general, during the coaling stage lots of CO is formed and sent up the chimney. On the other hand, the heater is at its hottest so quite a portion of the heat is going to the great outdoors and heating the birds.
I am using this method: when the fire is in its coaling stage and no more flames are to be seen, I close the air inlet completely. The coals will die down due to lack of oxygen, rather quick in fact. A generous layer of coals is kept in the firebox, very good to start the next fire on. In Europe, this is called the Austrian method. It is assuming that there's no chimney damper, only an airtight door, otherwise carbon monoxide could get into the room. Without such a chimney damper the chimney is still pulling, so anything that's harmful will be exhausted in a harmless way.

And to round off, why is it good to start a new fire on top of a layer of charcoal? The self-ignition temperature of wood is about 320 ºC (608 ºF), while charcoals' is significantly lower. So, loading the firebox on top of coals *and* lit from the top will result in a good fire in a surprisingly short time span. Just because the coals will ignite easily, the fire creeps from the back to the front in short order. After the burn is done and the fire dies down, about the same layer of coals is left behind, to start the next fire on.

but being hot I suppose a bread would cook on the extinct coals, i'll try , it is not a must

Cerbu Ulea wrote:but being hot I suppose a bread would cook on the extinct coals, i'll try , it is not a must

You are absolutely right on this. A friend of mine bakes his own bread, using the firebox of his mass heater to that purpose during winter. He's placing a stainless steel grid on legs over the coals, so the bread in its form is elevated above the coalbed itself.

https://www.youtube.com/shorts/AkEffDvnqro
I'm splitting an oak and a horse chestnut tree I was given this January, would this piece be too big ?

Cerbu Ulea wrote:I'm splitting an oak and a horse chestnut tree I was given this January, would this piece be too big ?

To build a fire in a lukewarm or cold heater, in that case it's too big. When fed into a hot firebox with somewhat smaller pieces around it, it would be consumed in short order. The following is an old video, taken from a first generation batchrocket. Nevertheless, the Shorty design is equally capable of this.

nice , mine being a sidewinder affects somehow the position of the top lighting pattern , or the position of the air slits?

Cerbu Ulea wrote:nice , mine being a sidewinder affects somehow the position of the top lighting pattern , or the position of the air slits?

Both of those aspects are the same as in a normal straight Shorty core. This has been tried and tested thoroughly, already over a year ago. In general, the aerodynamics of this core are very specific, it will function even without a door at all. Even the reversed sidewinder showed exactly the same behaviour during the workshop in France this spring. Much to my surprise, I might add.

this is the core covered in superwool
https://www.youtube.com/shorts/8MV6Jv_spOQ

what temperatures am I to expect in the air frame? for now it is sealed with  tape rated 175 degrees Celsius

Hi Cerbu;
If it were burning season, I could give you an exact temperature at which my airframe runs.
I suspect that the 175 °C  (347°F) gasket is not enough. The doors on my first-generation batchboxes  run 400F-500F ( 205-260 C)
I can tell you that the 7"x7" door glass on Shorty gives off the most radiant heat.

the seal between the frame and the core's edge it is half inch super wool, but as for now I still got no weld machine the frame is two piece cut and bend pipe sealed with tape , hope at least it lasts the tests

Why a test?
The door frame is fully designed by Peter; no need to test it.
I would not light that stove off with just tape holding it together.
If you have no welder yet, could you take your frame to someone who does and have them tack-weld it so it can not fall apart when/ if your tape fails?
You can purchase a welder and finish welding it yourself after testing your core.

I am sure the design is good , the tests to run the heater I look forward to. Newish town for me here, hardly know anyone. It is quite solid ,bent from a single piece of cut pipe , except the the small piece above the inlet , that could indeed fall if the tape fails. Should l just make small curing burns and monitor the temperatures, or just wait to weld it myself?