variation on Heath base

[Fudugazi]

I Was informed by a user in Quebec that he set his hearth on a mix of 33% Crushed Glass, red tile and Rock Salt. This mixture in addition to the usual described substructure. This apparently is a Mexican idea. The rock salt draws moisture out and the tile and glass retain heat in the hearth area. Has anyone heard of this idea.?

[james]

Hello, and welcome.

Great question. I am struck by two thoughts.

First, I have been told many times by pizzaioli and oven builders in and around Naples that they use salt, along with ash, sand (glass is after all melted sand) and who knows what in their hearths. Over time, I think it will be interesting for this group to explore the thermal and insulating properties of traditional materials. Naples has had the unrivalled experience of having great water, volcanic ash, an active volcano, pozzolano concrete -- not to mention great tomatoes, mozzarella and standing ancient Roman ovens which can used as models, which have helped fuel its brick oven heritage. There are commercial oven builders who still fire hand-made bricks in wood-fired kilns.

I am looking forward to learning more, and working our where the basic materials fit. Are they thermal, or insulators? And do they really work?

On a more practical front, modern insulating materials (if you are in a part of the world where you can readily find them) are efficient and cost-effective -- particularly for a home oven. Vermiculite, perlite, insulfrax, and calcium aluminate are findable, predictable and efficient.

That said, if you are interested in exploring the traditional (pre woven ceramic insulation) materials, it will be exciting to see what we can do to help with you oven.

I am sure that the engineers among us will have a great deal to offer.

James

[Fudugazi]

Thanks for your thoughts on that I will keepyou posted if I come up with any furthur info on this theme