William Bronson

This is what I've gotten done on the exhaust so far.

I wonder if adding it to fermented feed would be good?
I've been giving my chooks oats,  soaked for a few days in rainwater.
I can see adding some cabbage leaves and letting it go for a week,  with some wood pellet char from my TLUD.

Picked up 10 feet of 8" ID double wall pipe for $20 at my favorite surplus store.
Totally worth it.
They even had  a 5 foot length of 10" ID but that was too short anyway.
Couldn't find a tee there but I did get a 90° elbow for the transition from the bottom of bell out the side of the cabinet.
I might build a sheet metal box instead of buying a $13 tee for the base of the chimney.

Work continues on the bell.
There will be a 6 inch "cap" of tamped soil, with a stainless steel steam table pan set into it.
I'm thinking about including an oven right above the firebox.
If I do,  it will probably be a white oven, because making the oven gas tight seems easier than making the door gas tight.  

I googled smoke shelf, and I kinda savvy it.
Better to stick with chimneys that don't need added features.

Great idea,  presented well.
I wonder if you could create a stable vacuum between the two lids for exceptional insulation value.
Items inside the window could one manipulated without opening it via magnets.

thomas rubino wrote:Hi William;
Not a problem to enlarge when you go vertical.
Your 8" is going to be a big beast !  

Wonderful!
Yes 8" is huge for the space, but they say that bigger rockets are less finicky, plus I want to burn pallet slats.
One slat is 40", cut in half 20" , needing at least 24" in the firebox.
Crappy wood, but easy to aquire, process and stack, dry and in bulk.
I will be buying a cordless circular saw just to make harvest easier.
I'm also casting the firebox, and an easily  reproducible  8" batch box seems ideal for more applications, like a bank of bread ovens, heating my enclosed front porch, powering foundry, still or forge...
I figure I can always throttle back.


What do you think about the need for a bypass, given the undersized bell?


Just curious, would a 15" diameter vertical chimney be too much?
I have lots of water heater tanks...

Oh!
I thought the rule of  "maintain system size throughout" applied to the chimney as well?
If it is 10" ID, not a problem then?

Alright, the fiberglass is off the table.
I have a line on some used double walled pipe which should be fine if its the right size.
It might be 10", which would be a shame.

If I go with a perlite insulation, what thickness would be good?


Regarding the tamped soil, I thinking wetting it will help collapse any air bubbles, correct me if I'm wrong.
I also have a reciprocating saw I plan on using to vibrate the forms,to collapse air bubbles.

Stones or brick are preferable from a density viewpoint, but dirt/mud can fill tiny crevices, so I intend to use both.
I think sand would be a great additive, but buying sand by the bag hurts my soul.
I have plans/parts to build a 55 gallon tumbler which would be perfect for grinding bottle glass and ceramic toilets into a grog for these applications, but I won't let myself be diverted with that project.

While we are discussing chimneys, I'm wondering about including a bypass at the top of the bell.
Normally its a no brainer , but my bell will be roughly 3.5290 m2 ISA, as compare to the recommended 8.85 m2 recommended for an 8" batch box.
I intend to tap it to heat as well as the mass, but I'm thinking the relative low ISA might make a bypass overkill.

I've started my bell,  which I call a "dirty metal bell".
Scraps of sheet metal over steel studs,  filled with tamped earth.
The file cabinet, laid on its side, has become a platform to build on.

I've maxed out my firebox,  it will be 28.75" long inside, 125% of the  23" that is normal for an 8" batch rocket.
Because you need 2 inches infringe of and behind the fuel,  I should have space for 24" long fuel.

The footprint of the firebox  plus that of the riser , leave enough floorspace for the exhaust to exit into and through the file cabinet below.
From there it will go through a sheet metal "thimble" and into a chimney.

The rest of the cabinet will hold fire wood,  unless I convert it into a second bell.