All Earth, 2 fires 5 hot spots!

[Donkey]

This stove is all earthen mixes of one sort of another. The body is mostly adobe bricks with cob. It is insulated with a perlite/clay mix.



First, we laid out the hot-spots. It was decided to stagger the hot-spots so that reaching to the back pot won't burn you.



2 Rocket J-tubes built side-by-side, the closest to the camera is an 8 inch stove, the one in the back, 6 inch.







The only fired brick we used was for the top opening of the feed. It is my experience that if the top edges are adobe (cob), they will be wrecked over time by the wood. Bricks at the top edge of the feed will keep the firebox in good order.





We added in wood storage underneath. This arch passes through to the other side.





To make the heat risers, we placed stovepipe inside of adobe enclosures, packed between with a perlite/clay mix and then pulled the stovepipe out (metal is doomed!)
Here, you can see that the risers are angled, so that the fires will be offset.




























We had some nice stone pieces that served well for keystones in our adobe arches.






Test, a LOT. After the base was built, we ran the stove pretty much the entire time of building the rest.






We insulated in and around the pot holders/hot-spots as much as possible with perlite/clay.






Hot-spots are built to fit a particular pot like a glove. We built the channels like a Lorena stove; pots fit down inside the stove so that heat will flow all around the sides as well as the bottom.


















ALWAYS RUN IT WHILE YOU BUILD IT! This has been my philosophy since the very beginning of my adventures with stovery. It's treated me VERY well.
Yes, you risk burns and smoke inhalation, but if you're paying attention, you can build superior stoves. Use your hands, ears and nose! They are your best guide.












Though the potholes are shaped around a specific pot, reducers can be used to adapt to other pots and pans.















This is as far as we've gotten with this stove. Not documented here yeat is that there will be another, much smaller rocket stove as well; a tiny, 4 inch twig stove will be build into the side. This way, if you just want to boil water for tea, you don't have to start and run the big-guns.
There will also be 2 holders for a variety of beer-can alcohol burning stove that I like so much..

[fzurzolo]

This is awesome! Thanks for sharing, Donkey. I do have a couple questions though,

• Do you have a chimney or are the gasses just exiting under the window at the end? (looks like some smoke on the wall hence the guess)
• How are you forming the channels in the cooktop?  Is it all "solid"  perlite-clay except where the pots are and the connecting channels?  Are you bridging with adobes?
• It seems like you are not minding the potential energy and efficiency loss of using perlite-clay for the riser compared to IFB.  Do you notice a significant improvement with IFB for the riser?  Does the perlite-clay last?

I'm going to be starting my outdoor Rocket cooker build next week so your post was perfectly timed inspiration.  Thanks again!

[Donkey]

Jul 19, 2017 10:01:03 GMT -8 fzurzolo said:

Do you have a chimney or are the gasses just exiting under the window at the end? (looks like some smoke on the wall hence the guess)

There's no chimney. Exhaust goes out the first uncovered hot-spot. If all the hot-spots are covered, it goes out by the wall.

How are you forming the channels in the cooktop?  Is it all "solid"  perlite-clay except where the pots are and the connecting channels?  Are you bridging with adobes?

The sides of the channels are formed with adobes, but the top is sculpted with cob, freehand. A thin plaster of perlite/clay is used to insulate the channels somewhat, though it's not on the ceiling of the channels, so it's likely ineffective but that's OK. The stove still works like a champ.

It seems like you are not minding the potential energy and efficiency loss of using perlite-clay for the riser compared to IFB.  Do you notice a significant improvement with IFB for the riser?  Does the perlite-clay last?

I don't know what IFB is, sorry. I use perlite/clay because it's easy and inexpensive. I don't mind a slight loss of efficiency if I gain in utility and ease. My measure of a stove (or a building or anything else for that matter is "arse value"... The 80/20 rule is my greatest master.

I'm going to be starting my outdoor Rocket cooker build next week so your post was perfectly timed inspiration.  Thanks again!

Good luck with it and don't forget to post your builds here!!

[fzurzolo]

Thanks Donkey,

By IFB I meant insulating fire brick, or soft fire brick, or kiln bricks. But you still answered my question.

And yes, the 80/20 rule rules!  I'd argue that I'm actually a better person because of it 

[DCish]

Love the arch!