Angela Davis on tue 31 aug 04
please.
Hi all, and esp John H,
I am going to post my CBR pictures again, Mary and I have been discussing
the specks off list.
http://share.shutterfly.com/action/share/view?i=EeENWLNy3bs3mg&open=1&sm=1&sl=0
As I told her I have a couple of pots from our first batch which show no
specks,
our second mixing has wonderful specks on 2 kinds of unspecked clay.
In fact the clays are the same recipe, we mix it at school and just add RIO
for the red.
I have no idea what causes the specks , they are pale on the red clay and
dark on the white,
and where they are covered with the Varigated Blue they collect the oxide
and go really
dark. I like them and hope to be able to duplicate them in the next batch
so it would be great
to find out what is going on here.
Gaye's specks are in Texas , mine came from Axners in Florida. I am fairly
sure
we are using different clays since we mix our own.
What do you think?
Angela Davis
Now that I re-read Gaye's message I am wondering if she is talking of a
speckled color
or of texture.
----- Original Message -----
From: "Mary K"
To:
Sent: Tuesday, August 31, 2004 10:34 AM
Subject: Re: Cream Breaking Red and Strontium Carbonate
> Dear John,
>
> I would love to know what the graininess is in that recipe (Cream Breaking
Red).....is it the RIO, or do you think maybe it was on an iron bearing
clay? (baby steps, still learning) Mary K
>
> John Hesselberth wrote:
> Hi Gaye,
>
> I would say you got a bad batch, a cheaper/coarser grade, or a
> different material was accidentally substituted when your supplier was
> weighing it out. My strontium carbonate has just a hint of graininess
> when I rub it between my fingers, but it very quickly and easily
> becomes a very fine powder. It disperses easily in glaze suspensions
> and I have never encountered strontium grains in a fired glaze.
>
> Regards,
>
> John
> On Sunday, August 29, 2004, at 01:05 PM, Gaye Sekula wrote:
>
> > Is there a trick to mixing in strontium carbonate? Did I get a bad
> > batch or
> > is it always so granulated? I did a test firing yesterday to ^6, which
> > is
> > what the recipe states, and the strontium grains are still obvious.
> > Maybe
> > I should fire it higher?
> > Thanks,
> > Gaye Sekula
> > San Antonio
> >
John Hesselberth on tue 31 aug 04
please.
Hi Angela,
Until I reread this and noticed you said they were pale on red clay I
was thinking it was poorly dispersed RIO. Now I would have to say I
haven't a clue. Maybe someone else does. You might examine them with a
10x magnifier and see if they look crystalline.
My suspicion, though, is that it is something that is poorly dispersed
and you will have trouble duplicating it.
Regards,
John
On Tuesday, August 31, 2004, at 11:20 AM, Angela Davis wrote:
> I have no idea what causes the specks , they are pale on the red clay
> and
> dark on the white,
> and where they are covered with the Varigated Blue they collect the
> oxide
> and go really
> dark. I like them and hope to be able to duplicate them in the next
> batch
> so it would be great
> to find out what is going on here.
John Hesselberth
http://www.frogpondpottery.com
http://www.masteringglazes.com
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