...Why am I looking into this and not simple and available fireproof concrete, well as Peter v. d. Berg states and did research aht if a rocket burner is light and highly insulative, it works a lot better. The better the insulation rate, the higher the temp in the burn tunnel...
So I was thinking, could one make a mix with clay, portland, lime and sawdust?
It more or less sounds like; Stay within the borders of that what has already been used and proven safe to use, and durable.
Don't look any further, for most will be worthless to look at anyway.
Portland/lime combination has been used for ages, sometimes only with lime. This also is mentioned on the traditional oven site.
So, why would this not be good enough for rocket stove cores?
In this combination, gravel normally is used, crushed firebrick or perlite.
Why not sawdust? It would create a honeycomb structure.
Fireclay, the same. I have seen bread ovens in Limburg, 150 years old, made with a clay straw mixture. So again, why not with with sawdust. The HEDON site states that the durability and insulative characters of the clay/sawdust mixture is rather good.Or is this faulty information?