Ivor and Olive Lewis on mon 1 may 06
Good suggestion David.
I really should not have to explain this, but:
Seat Earths that underlie Seams of Coal tends to be highly refractory, =
They are one of the best sources of Fire Clay, which, as you know,does =
not readily melt at top stoneware temperatures. In fact it is a regular =
ingredient in cone ten to twelve glazes
Now folk on Calyart like to talk about wood firing and ash glazes and it =
has been explained to us that Ash and Ash Glazes made from residues of =
vegetable matter tend to melt exceptionally well because they contain =
vast amounts of Flux. Stuff such as Potash, Soda, Magnesia and Lime.
Eons of time ago, vast forests of ferns and other exotic prehistoric =
plants had their roots in soil. As part of their metabolism they sucked =
soluble salts containing our fluxing compound out of the earth. So, =
depleted and then buried, that soil became the layers of rock which =
underlay seams of coal. Provided it has not been heated above about 350 =
deg C it can still be ground up and mixed with water to make an =
excellent plastic clay.
Compris ?
Best regards,
Ivor
David Beumee on tue 2 may 06
Wonderful, Ivor and Hank! Thank you. Great stuff!
David Beumee
-------------- Original message ----------------------
From: Ivor and Olive Lewis
> Good suggestion David.
> I really should not have to explain this, but:
> Seat Earths that underlie Seams of Coal tends to be highly refractory, They are
> one of the best sources of Fire Clay, which, as you know,does not readily melt
> at top stoneware temperatures. In fact it is a regular ingredient in cone ten to
> twelve glazes
> Now folk on Calyart like to talk about wood firing and ash glazes and it has
> been explained to us that Ash and Ash Glazes made from residues of vegetable
> matter tend to melt exceptionally well because they contain vast amounts of
> Flux. Stuff such as Potash, Soda, Magnesia and Lime.
> Eons of time ago, vast forests of ferns and other exotic prehistoric plants had
> their roots in soil. As part of their metabolism they sucked soluble salts
> containing our fluxing compound out of the earth. So, depleted and then buried,
> that soil became the layers of rock which underlay seams of coal. Provided it
> has not been heated above about 350 deg C it can still be ground up and mixed
> with water to make an excellent plastic clay.
> Compris ?
> Best regards,
> Ivor
>
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