Insulating an oven hundreds of years ago

[Thailandnotes]

I'm planning to build an oven here in Thailand when a friend comes to visit me in January. I'm wondering if anyone on these threads has used traditional ways to insulate an oven. There is mention of a clay insulation for ovens excavated in Italy, but I'm wondering if anyone has considered rice husk ash. It is a common ingredient in hibachis here in Thailand.

"Rice husk ash, an agricultural waste material, is available in large quantities in the rice paddy growing countries of the world at little or no cost. This ash is highly porous, mostly silica and possesses refractory and thermal insulation properties. It is therefore an attractive starting raw material for the manufacture of low to moderate cost thermal insulations for dryers, ovens, kilns and furnaces, including those employed in the ceramic industry."

[Laku]

Re: Insulating an oven hundreds of years ago

I think I've read some where that Pumice has been used in some parts of Italy as insulator in ovens.

[david s]

Re: Insulating an oven hundreds of years ago

I think I've read some where that Pumice has been used in some parts of Italy as insulator in ovens.

Yes, I've heard that too. Pumice was also used by the Ancient Romans in the construction of the Pantheon dome. They used the pumice, carted all the way from Pompeii to Rome, for the upper sections of the concrete dome. Being so light it was a suitable aggregate for the job. They knew what they were doing, it is an awe inspiring building.
Give the rice husks a go you may be on to something. It may work even better if the rice husks were used unburnt.

[azatty]

Re: Insulating an oven hundreds of years ago

Ash is generally a good insulator. How much you need for an oven...who knows? Probably just fill an enclosure the same way vermiculite and perlite is used.