modular oven - refractory coating

[mrpbjnance]

I just assembled my modular oven... I have some fireclay in which the instructions say to mix with cement....can I use the ready mix concrete that i have lots left over or should i use cement only?

I have the blanket that I will use over the coating and oven so this is just extra to add mass.

Can I also add just a layer of concrete around the oven without the fireclay if I don't have enough? will that help hurt?

[james]

Hey Mike,

My view is that you really only add extra mass to the dome of a Forno Bravo oven if you are thinking about commercial quantities of bread and very large amounts of roasting for big parties. For a majority of home cooking, the standard dome works fine. Note that this is for Forno Bravo ovens, which use the nice (more expensive) refractory material. I can't really talk to other ovens.

I have baked a lot of bread in a non-coated Casa oven -- more than a family could ever eat.

For your mortar, I would recommend making a real fireclay mortar, rather than mixing the fireclay with concrete. 1 part Portland, 3 parts sand, 1 part fireclay and 1 part lime. That works better than "fireclay enhanced concrete (which has sand and gravel as the aggregate -- I'm not sure of how strong the portland mix is).

If you choose to cover the oven, I would not use concrete. It isn't a very efficient thermal product, so I think it would slow down your heat up time and wick heat away from the inside of the oven when you are cooking, and it would not offer a very good extension to your heat holding capability. Overall, not a good trade off.

Hope this helps.
James