Monday, September 23, 2013

Cone 6 Glaze - Revisit

After Grace attending 1st Grade and Alex going to middle school, blogging became the last activity that I could reserve my energy to engage. I had abandoned my blog for almost a year. Until last week..........A blog reader posted a question about the Orange Street recipe:
DKat: Could you please tell me if the Orange Street is supposed to add up to 136.5?
I mindlessly replied:
Me: Hi DKat, could you tell me what 136.5 is referring to? Are you asking about a particular material?
Today, another blog reader helped me to point out that:
Powen, What DKat is referring to is the standard practice of listing base glaze ingredients in percentages that add up to 100%. The coloring agents and other additives such as Bentonite come after...............................

Thanks to DKat and Janine pointed out this issue. Please use the recipe as is.
In glaze calculation, after an Unity Molecular Formula was converted to Batch Formula, the recipe should total 100%. For Cone 6 glazes, however, this rule does not always apply to.

Many Cone 6 glazes we use today were converted from cone 9/ 10 glazes, and the easiest way to do so is adding Gerstely Borate or Frit, or replacing a stronger feldspar, ex, Nepheline Syenite or F-4 Feldspar, to the original recipe. This is why the Orange Street does not add up as 100%.

Silica 15.2%
Talc 13.8%
Dolomite 8.1%
EPK 4.5%
Gerstly Borate 17.9%
F-4 Feldspar 46.8%
Red Iron Oxide 12%
Bone Ash 12%
Crocus Martis 6.2%