Ian Currie on fri 31 may 02
cobalt green
Hi Bob (and also Winston J. Taylor)
One of the useful things the grid method can do is help convert a stoneware
glaze to midfire - e.g. cone 5 or 6. I will use the Reitz Green equivalent
as an example....
You need to understand how the grid method works (see an explanation at my
website below, or you can purchase a copy of "Revealing Glazes - Using the
Grid Method" at the same site.)
The method I used to produce the mid-fire Co/Ti green glazes was as follows:
1. I took a good Reitz Green recipe - mine is based on Hank Murrow's
stoneware Reitz Green, recipe in the book above... Hank will give it to you
for nothing! - and remove any clay and silica from the glaze recipe to
produce "Glaze C" - or Glaze 31... which is the starting point for
developing a grid.
2. I added 30% frit to this starting point and came up with a new starting
point... basically the original Corner C plus 30% frit.
3. Then I used this new Corner C to generate a standard grid... put it on
different clays, thick and thin, and fired it to Cone 5, 6 etc.
The theory is that the 30% frit is a brute force way of getting the melting
points down, and then you simply use the grid to find which combination of
alumina/silica works with the new more powerful set of fluxes. Some will
want to know "which frit" but this is not as important as simply varying
that alumina and silica. Different frits will give different results, but
often NOT VERY different. I often use Ferro frit 3134 or equivalent.
I sent a post to Clayart yesterday which would direct you to the most
interesting results of the Co/Ti midfire set.
Once you understand how the grid method works, the "theory" work for this is
very easily done at my "Calculation Page" at the website below.
Regards
Ian
http://ian.currie.to/
> From: Bobbruch1@AOL.COM
> Reply-To: Ceramic Arts Discussion List
> Date: Thu, 30 May 2002 07:41:15 EDT
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Glaze gurus - cobalt green
>
> Craig: would you have any of those details of the cone 6 derviation of the
> Reitz Green. I used to use the cone 10 Reitz Green when I was in school
and
> would love to use it in a oxidation environment at lower temps.
>
> Thanks, Bob Bruch
>
> <<<<> From: cd
> Subject: Re: Glaze gurus - cobalt green
>
> <<<<Espanola
> NM just over a year ago. One of the grids our class did was a ^6
derivation
> of Reitz Green.
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