Rocket Stove Adventures

Part II: Level, you elusive devil.


In The Book, there is a mere few sentences about starting on a level surface. Of course, it is common sense. The stack and burn tunnel need to be straight and smooth, so, level.

However simple the idea, the task was in no way easy.  Our floor started out level, tamped drain rock. Then we made cob and built walls in there. Over time, globs of cob fell and built up. We walked over them and stomped out cob on top of them, forming little hills and valleys that had to be scraped level without disturbing the drain rock below. Not easy.

So, I am dedicating this entire post to the topic The Importance of Being Level.

Marble base (it's a all about that...)

We dumpster dive for chunks of granite and marble. Laid out with mortar, this one-inch marble will collect heat under the stove and lend it to the floor.


Kind of a shame this beautiful stuff will be below floor level. (The floor will be a cob floor with a beeswax finish.)

Earthen mortar

We mixed small batches of mortar in one of Nathan’s water drum troughs, usually used for soaking clay. Mortar is made of strained construction sand and clay. The sand needs to be sharp and fine, aka masonry sand.

Pea gravel

Nathan used an old kitchen strainer he scored at a thrift store.


We used the course sand to set the marble slabs.


And spent hours trying to get them level.


At Last! The Rocket Stove Construction Begins

Part One: The Mock Up

First of all, this whole idea we got from Ianto Evans, stove-master and co-founder of The Cob Cottage Company in Coquille, Oregon.

Here is where we begin. This is our mock-up furnace. It’s for an 8″ stove pipe system. After we mortar it together, we will up-end a 55-gallon steel drum over the stack.

It took a couple tries to get it just right.

We build a fire in the feed, or fire box and got air is drawn through the J-shaped chamber and up the flue.

The test fire

It will meet the barrel and be forced downward through the stove pipe, which will be embedded in “thermal batteries” where the heat will be held and slowly released.

Rockin heat

Thermal batteries will be formed into benches and a bed. I’m excited to say goodbye to cold sheets. But I get ahead of myself.

Stop! Get back!

What happens when you fling a pair of Carharts overalls over the cob wall in winter and leave them there until early summer?

Carharts with Yellow Jacket

Something find it cozy and starts a family. In this case, no baby robins, no nest of startling disease-carrying but totally adorable deer mice, no. We got Yellow Jackets.

Yellow Jackets' nest in the cob wall

I admire these brightly dressed and fierce carnivorous pollinators. From a distance.

Yesterday, upon removing the overalls from the wall, the wasps flew out, past Nathan (owner and disturber of Carharts) and unleashed their rage on our sweet bulldog, who had no idea where the attack came from and why.

Wake Robin

Luckily, it was not a big, well-established nest (yet) and he escaped with just a few stings.  But he cowered in the kitchen with the rest of us for what was left of the afternoon. Nathan was stung a couple of times. I ran at the first sign of buzzing.

Every time we opened the door, huge guard wasps would hurl themselves toward us, so we had to slam the door shut while they buzzed angrily against the glass.

We re-watched season one episodes of Game of Thrones, roasted coffee, made jam, then dinner, still the wasps stood guard. Finally, the rain fell harder, the sun moved off of the property and they settled… back into the wall. But they let us walk by (even the dogs) with just an increase in buzz volume and pitch as long as we keep walking.

We were hoping the disturbance would make them want to move away, But they seem perfectly happy in our cob wall. A whole matriarchal society that I have to slaughter. Sad, but we must finish the walls this summer, wasps or no.

The Coffee Nook


Our first batch of cob for the season started the coffee nook. The large, opening, SSE-facing window will be set in a small wall of cob atop a salvaged marble sill. In front of that, a fir slab counter. The foot of the bed (nest-shaped and heated from the exhaust of the rocket stove) will serve as a bench. A”coffee rocket” will be built right into the wall next to the window. So, sliding out if bed for a cup of coffee is that: just a slink under the covers to emerge in the other side, light up the rocket, and grind the beans.

Labor Day: Free Labor!

Slapped on a few batches with friends this weekend. We are at a critical point where built-in furniture needs to be planned, windows and doors installed and sculptural detail decided upon. So, a few carefully placed batches took us a long way. So grateful for friends lending energy and time that will live in the walls.

Stomping it out
Little cobs
Squishing it on
Up go the windows