Alisa and Claus Clausen on fri 23 jun 00
Dear Clayart
I was just going through a raw materials list and I realize I am once =
again confused by materials and translations.
I have three types of feldspars.
Potash
K2O Al2O3 6SiO2 mol. 556
General feldspar, forshammer
(K,Na)2O Al2O3 6SiO2 mol. 540
Soda Feldspar (or soda ash norflot)
NaO.Al2O3 6SiO2 mol. 524
These feldspars I use in my glaze recipes.
But, then I have bags of something also labelled Soda Ash. That is what =
I used for the Soda Ash wash.
It is clearly a different material than soda ash feldspar. It is =
rougher, almost raw salt consitency and hardens
in clumps. What is that? more or less pure salt (natron) NaO?
I do not have a listing for it in my catalogue of materials.
I would appreciate an explanation and the correct names of the materials =
in English.
Best regards,
Alisa in Denmark
Ray Gonzalez on sat 24 jun 00
i looked it up because i have often wondered the composition but never think to look it up... it is definantely not a
spar though. there are actually 5 spars (that we as potters use) as i recall. anyway,
from hamer and hamer: (definantely recommend it!)
soda ash: Sodium Carbonate. Na2CO3. Originally the ashes of burnt sea plants. See Barilla and Kelp. Now the term is
synomous with sodium Carbonate, although this is produced from sodium chloride (NaCl) rock salt by the Solvay process
Sodium Carbonate: Soda Ash. Sal Soda. Na2CO3. the chief source of sodium oxide for glazes. It is highly soluble and
therefore can only be used in frits. It is used in combination with sodium silicate as a deflocculant for casting
slips. See Deflocculation. Until the discovery of Le Blanc and Solvay processes at the end of the 18th and middle of
the 19 c., sodium carbonate for glass making was produced by burning seaweed and salt marsh plants. Hense the name
soda ash. the processes employed now use rock salt and sea water.
hope this helps.
ray
Alisa and Claus Clausen wrote:
> Dear Clayart
>
> I was just going through a raw materials list and I realize I am once again confused by materials and translations.
>
> I have three types of feldspars.
> Potash
> K2O Al2O3 6SiO2 mol. 556
>
> General feldspar, forshammer
> (K,Na)2O Al2O3 6SiO2 mol. 540
>
> Soda Feldspar (or soda ash norflot)
> NaO.Al2O3 6SiO2 mol. 524
>
> These feldspars I use in my glaze recipes.
>
> But, then I have bags of something also labelled Soda Ash. That is what I used for the Soda Ash wash.
> It is clearly a different material than soda ash feldspar. It is rougher, almost raw salt consitency and hardens
> in clumps. What is that? more or less pure salt (natron) NaO?
>
> I do not have a listing for it in my catalogue of materials.
> I would appreciate an explanation and the correct names of the materials in English.
>
> Best regards,
> Alisa in Denmark
>
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