Building a wood burning oven "The thermal mass"

The 3/16 in steel shell of the oven would not hold enough heat to cook for very long so we needed to add some mass to the structure to act as a heat reservoir. As I mentioned in the beginning we had a boat load of red brick on hand so we are using that. Also a friend had some left over refractory mortar leaving us with this layer almost entirely free. I did elect to mix the mortar with ~50 % sand to avoid cracking since most refractory mortars are used to fill much smaller gaps than I was attempting.

Here is the oven after the first day

Here is the oven a few days later with the rest of the bricks

Rather than trying to brick the top of the dome I elected to cast the last 18 inches or so  with a mixture 

of portland based concrete, with additions of ~30% fireclay and ~5% lime

(I'll let you know how this works in about a week when we begin firing the oven for the first time)

Next time ( in about a week or ten days) We will begin the test firing process so see you then