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floating blue - cone 5 oxidation

updated tue 6 oct 98

 

Edward Cowell on fri 2 oct 98

Is it possible that Chappel's Floating Blue glaze can lose some of its
vibrancy if it sits around in a bucket for a few years? I have topped up a
couple of times a batch that was originally mixed 3 years ago, and it seems
to be much darker.

Laurie Cowell,
Waterloo, Ontario, Canada

Grimmer on sat 3 oct 98

Hi,

If the glaze has significant soluble ingredients, such as gerstley borate
for example, it's certainly possible that it would change with time. As the
glaze coat dries on the pot, some of the solubles are deposited on the
surface. This would change both the composition of the lower glaze coat and
the surface of the glaze. Many Shino-type glazes take advantage of this
phenomenon, relying on soluble soda for both carbon trapping and red/orange
flashing. I have noticed that old batches of the shino I use perform
differently than a fresh batch.
I'm not trying to be glib or offend this glaze's many fans, but doesn't it
seem that if one can name a glaze problem, "Floating Blue" has exhibited it
at one time or another?

steve grimmer
marion illinois

---------
>From: Edward Cowell
>To: CLAYART@LSV.UKY.EDU
>Subject: Floating Blue - Cone 5 Oxidation
>Date: Fri, Oct 2, 1998, 12:33 PM
>

>----------------------------Original message----------------------------
>Is it possible that Chappel's Floating Blue glaze can lose some of its
>vibrancy if it sits around in a bucket for a few years? I have topped up a
>couple of times a batch that was originally mixed 3 years ago, and it seems
>to be much darker.
>
>Laurie Cowell,
>Waterloo, Ontario, Canada

Greg Lamont on sun 4 oct 98

At 03:54 PM 10/3/98 EDT, you wrote:
>----------------------------Original message----------------------------
>Hi,
>
>If the glaze has significant soluble ingredients, such as gerstley borate
>for example, it's certainly possible that it would change with time. As the
>glaze coat dries on the pot, some of the solubles are deposited on the
>surface. This would change both the composition of the lower glaze coat and
>the surface of the glaze. Many Shino-type glazes take advantage of this
>phenomenon, relying on soluble soda for both carbon trapping and red/orange
>flashing. I have noticed that old batches of the shino I use perform
>differently than a fresh batch.
>I'm not trying to be glib or offend this glaze's many fans, but doesn't it
>seem that if one can name a glaze problem, "Floating Blue" has exhibited it
>at one time or another?
>
>steve grimmer
>marion illinois
>(rest snipped for brevity)

Hi all you Floating Blue lovers out there,

A while back, I received 5 variations on the original Floating Blue recipe
from Ron Roy (thanks again, Ron!) that seek to reduce or eliminate the
gerstley borate--the most likely offender in this recipe. I've tested the
ones that utilize Frit 3134 in place of all or part of the Gerstley
borate--as I had that on hand--find that one of them works especially well:

Ron Roy's Floating Blue #1 (cone 5-6 oxidation)
41 Nepheline syenite
17 Gerstley borate
13 Frit 3134
18 Flint
11 EPK

2 Red iron oxide
1.5 Cobalt carbonate
4 Rutile (milled)

If anyone is interested in seeing the other 4 variations. E-mail me
privately. If I get enough requests, I'll post them to the list.

Regards,
Greg
Greg Lamont
3011 Northwood Dr.
Ames, Iowa 50010-4750
515/233-3442
gdlamont@iastate.edu

Ron Roy on mon 5 oct 98

Steve has a good point here I think - the answer here is to replace some or
all of the GB witha frit - like 3124 - to eliminate the aging problem. I
believe I have done this already - would someone please post a revised
version to the list.

If not I I can do it again - it was a piece of cake. All I need is the
offending glaze recipe.

RR


>If the glaze has significant soluble ingredients, such as gerstley borate
>for example, it's certainly possible that it would change with time. As the
>glaze coat dries on the pot, some of the solubles are deposited on the
>surface. This would change both the composition of the lower glaze coat and
>the surface of the glaze. Many Shino-type glazes take advantage of this
>phenomenon, relying on soluble soda for both carbon trapping and red/orange
>flashing. I have noticed that old batches of the shino I use perform
>differently than a fresh batch.
>I'm not trying to be glib or offend this glaze's many fans, but doesn't it
>seem that if one can name a glaze problem, "Floating Blue" has exhibited it
>at one time or another?

Ron Roy
93 Pegasus Trail
Scarborough, Ontario
Canada M1G 3N8
Tel: 416-439-2621
Fax: 416-438-7849

Web page: http://digitalfire.com/education/people/ronroy.htm