Oven Build pt 2 - the Firebox

After the Storm by OkieRhio.
Acrylic on canvas covered board.

In a previous post, I mentioned that I was given the opportunity to build an earth oven as part of an ongoing project to build a medieval viking village. Today, I'm going to talk about what went into building the base of the oven: the firebox.

The first thing we did before starting the build of the oven out at Knight's Rest Retreat was to decide on a location. When you're dealing with 160 acres of eastern Oklahoma, that means prairie and the beginnings of the foothills for the Ozarks - it's not as flat as you think it is.


Building a Base to Work On


First we cleared out our intended space with a backhoe, and shored up the sides with lengths of old telephone pole that we happened to have on hand. You can see a section of one here, before we were satisfied with placement.

Then we started back-filling to level it all out. The spirit level was put to a lot of use during this portion, as well as for the duration of filling in our area and building our base up to a good solid mass.




A couple of hours of hot, sweaty fill-in, stomping, raking, and adding water (all while measuring and leveling on a regular basis to make sure we were still on track), and we finally had it level enough to actually start building on!



We have since come to the realization that we should probably have laid a concrete slab. While our packed earth base seemed really stable at first, it has since had some settling issues. We plan to correct that oversight when we build the Mark II Oven.


Spacing and Dry Fitting

At this point, we took stock of the fire bricks that we happened to have on hand. These were scavenged from other projects that had been dismantled at Knight's Rest, so we were fortunate enough not to need to purchase any.


We measured the area that had to be covered. The steel plate shown here is what we had decided to use for the floor of our actual cooking space, so we needed to make sure our firebox was large enough to heat the whole thing - but without too much extra room.

Are you sure this is gonna fit right?

We started by dry fitting the fire bricks that were chosen as a floor for the firebox. We also decided to dry fit the edges together to make sure we had our spacing correct.

Trevor squaring up the floor

We leveled as we went, while we were checking on our dry fit and spacing. That was critical to make sure everything fit properly later in the process.





Finally, it ended up looking like what we wanted. It only took us three hours of leveling and dry spacing, a lot of cursing and good-natured horseplay, a couple of bruised knuckles, and a lot of sweat!

Facing the short side away from the firebox opening.

Facing the area where the oven dome will open.

Speaking of Horse Play 

Gussie and the Girls come to say Hi!

Once we'd finished dry-fitting all our bricks, we took a short break... mainly because by that point, the resident horses of Knight's Rest had decided to come investigate what we were doing! Gussie is the Brown and White on the right side of the photo. The others are the Shires raised by Knight's Rest Farm.




Laying Brick

One of our guys mixing mortar

Once our break was over, it was time to start doing some serious bricklaying. Mixing a combination of refractory cement, fine grout, and water gave us our mortar to seal the bricks in place.

Resident Bricklayer hard at it

While we intended to make this a one day project, there is a cliche about "the best laid plans" for a reason: this turned into a project that lasted nearly a month! We worked on getting the brick for the firebox laid well into the that first evening. 

Once we were done with mortaring all the bricks into place, we called it a night. We got together again the next day to start work on the oven dome, and I'll get into how that went on my next installment!