Alisa Liskin Clausen on sun 5 mar 06
On Sun, 5 Mar 2006 14:01:02 +0000, May Luk wrote:
>Hi Alisa;
>
>Yours are very similar to Bill E's stormy lavender
>blue, but less stormy?
>
>I put your recipes into Glaze Master and I have a
>rough calculation for my own comparing purposes. I'm a
>bit slow, so I need to put the recipes in context and
>think out loud. Please allow me to indulge.
>
>I checked out Zircopax is 0.22 CaO and 34.28 SiO2 in
>unity. Your three glazes are not all of the same
>class- quite a bit of variables amongst them. If all
>of them gives you pink specks, zinc is not the only
>contributing factor because only Mike B Shiny Clear
>contains zinc. >
Hi May,
I was not considering Zinc to be the catalyst. I think that we are getting
misunderstood on my typo in the original post. I only mentioned Zinc when I
meant Tin, as to
what was fuming the Cobalt under glaze on the tests where I added Tin to
the bases.
The bases are different and that was also part of the purpose of my testing,
to see opacity in different types of bases.
However, the pink specs were an added surprise in the stripes of just pure
Cobalt wash. The specs. are all very similar in the color and form.
At first I was thinking mostly about Dolomite/Magnesium, as Cobalt often
goes pinkish lavender there. Looking at the bases,
this idea did not hold too much water, because the specs. are very prominent
in Mike Bailey's Shiny Clear, and as your table
shows, little MgO there. Cobalt and Zircopax can often result in what I
call Medicine bottle blue, a white blue.
I am inclined more along the lines that is a lucky episode for lack of any
other information at this
point in time! I used a whole new batch of Cobalt and this is the first time
I have seen the specs. However, I understand
from others who wrote to me, that they have seen them also, in different
firing environments as well.
I am making a lot of test tiles at the moment because I am clean out and my
24 hour gas station still will not stock them.
Thanks May, and I will get some photos soon.
Best regards from Alisa in Denmark
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