Judy Musicant on thu 30 aug 07
John,
I've been using the below glaze for several years. It's a shiny Hobart =
Cowles glaze that Lili Krakowski submitted to Clayart some years ago, I =
believe. I fire to a hard cone 5 - cone six bending to about 10 =
o'clock. If it's a bit too thick, it will run if fired any hotter. I =
use Standard 112, and it definitely breaks brown where thin or over =
edges. I think the same is true if it's on white clay. If anyone would =
like to see a picture of it, e-mail me off line.
Lithium Carb. 4.5 =20
Neph Sy. 4.5 =20
Frit 3134 50 =20
EPK 36 =20
Silica (Flint) 5 =20
Black Copper Ox. 2 - 2.5 =20
Tin Ox. 7 =20
Beautiful glossy green, breaking rust. =20
Judy Musicant
PottersGuildNJ.org
Diane Palmquist on fri 31 aug 07
Hi Judy,
I tried many times to send this to you directly but it wouldn't go
through your email server. Anyway I would love to see a photo of this glaze.
I did look on the N.J. guild website and saw a great green glaze on one of
your pieces and wonder if that is the glaze. Anyway you can send the photo
to dlpots@comcast.net.
Thanks!
Diane
----- Original Message -----
From: "Judy Musicant"
To:
Sent: Thursday, August 30, 2007 7:57 PM
Subject: Green glaze breaking brown - cone 5-6
John,
I've been using the below glaze for several years. It's a shiny Hobart
Cowles glaze that Lili Krakowski submitted to Clayart some years ago, I
believe. I fire to a hard cone 5 - cone six bending to about 10 o'clock.
If it's a bit too thick, it will run if fired any hotter. I use Standard
112, and it definitely breaks brown where thin or over edges. I think the
same is true if it's on white clay. If anyone would like to see a picture
of it, e-mail me off line.
Lithium Carb. 4.5
Neph Sy. 4.5
Frit 3134 50
EPK 36
Silica (Flint) 5
Black Copper Ox. 2 - 2.5
Tin Ox. 7
Beautiful glossy green, breaking rust.
Judy Musicant
PottersGuildNJ.org
______________________________________________________________________________
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/
Moderator of the list is Mel Jacobson who may be reached at
melpots2@visi.com
Judy Musicant on sun 2 sep 07
Hello Potters,
Maurice Weitman kindly set up the following site for anyone who wants to =
see a picture of the Hobart Cowles glaze I posted a few days ago - =
http://mopots.com/Judy_Musicant_Green-Brown_Bowl.pdf - it nicely shows =
the detail of the glaze breaking a rusty brown on raised slip =
decoration. Have fun, and thanks Maurice.
Judy Musicant
PottersGuildNJ.org
Ron Roy on sun 2 sep 07
Using that much lithium Carb. is going to be a problem with some clay
bodies - so test it first and look for shivering and crazing happening
together.
It will leach copper into acidic foods - just not enough silica to hold the
copper in. I would not recommend it as a liner glaze.
To stop it from running at cone 6 just add some more EPK - 1%, 2%, 3% -
that will stop the running.
Here is the same glaze with a little more silica but using Aussi Spodumene.
Expansion is very close to the original. If you add more silica to make it
more stable you may lower the expansion too much. In that case simply add
more Neph Sy at the expense of the Spodumene but keep the total alkali mols
at the same level.
If any one tries it I'd like to know how it compares with the original - I
can make adjustments if needed.
Cowles revised green with Spod - RR
-----------------
AUSI SPOD........... 23.00
NEPH SY............. 6.50
F3134............... 51.50
EPK................. 19.00
----------
100.00
FORMULA & ANALYSIS
------------------
*CaO........ .54
MnO2....... .00
*Li2O....... .17
*MgO........ .00
*K2O........ .01
*Na2O....... .28
Fe2O3...... .00
TIO2....... .00
B2O3....... .49
AL2O3...... .42
SiO2....... 2.48
P2O5....... .00
RATIO 5.94 (original is 5.56)
EXPAN 432.26 (original is 433.17)
WEIGHT 280.28
>I've been using the below glaze for several years. It's a shiny Hobart
>Cowles glaze that Lili Krakowski submitted to Clayart some years ago, I
>believe. I fire to a hard cone 5 - cone six bending to about 10 o'clock.
>If it's a bit too thick, it will run if fired any hotter. I use Standard
>112, and it definitely breaks brown where thin or over edges. I think the
>same is true if it's on white clay. If anyone would like to see a picture
>of it, e-mail me off line.
>
>Lithium Carb. 4.5
>
>Neph Sy. 4.5
>
>Frit 3134 50
>
>EPK 36
>
>Silica (Flint) 5
>
>Black Copper Ox. 2 - 2.5
>
> Tin Ox. 7
>
>Beautiful glossy green, breaking rust.
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Maurice Weitman on mon 3 sep 07
At 09:04 -0400 on 9/2/07, Judy Musicant wrote:
>Hello Potters,
>
>Maurice Weitman kindly set up the following site for anyone who
>wants to see a picture of the Hobart Cowles glaze I posted a few
>days ago - http://mopots.com/Judy_Musicant_Green-Brown_Bowl.pdf - it
>nicely shows the detail of the glaze breaking a rusty brown on
>raised slip decoration. Have fun, and thanks Maurice.
Howdy,
In the above-mentioned PDF, the recipe for the Val Cushing Satin
Matte glaze which Judy put on the rim of the bowl has a typo which is
my mistake.
I put in "Total 100" when it only added up to 90.
I've corrected the PDF file referred to above to say "90". I will
wait for Judy to verify that the recipe is correct as is, or if there
are indeed errors, I will correct them.
There might be something wrong with the original recipe; Val's
recipes usually add up to 100.
Sorry for the mix up, folks.
Regards,
Maurice
ps Judy, I found a glaze in my Val Cushing handbook that's called VC
Pam Fredericks C6-9 which has the same ingredients as the Val Cushing
Satin Matte Glaze you quoted, but with different, though nearly
proportionally similar amounts. And it adds up to 100. Notice that
it says 6-9...
Yours called for
Nepheline Syenite 40
Gerstley Borate 10
Whiting 10
Lithium Carbonate 6
EP Kaolin 12
Silica 12
total 90
add
Titanium Dioxide 6
Iron Oxide 2-3
and the VC Pam ... wants
Nepheline Sye 44
Gerstley Borate 12
Whiting 12
Lithium Carbonate 6
EPK 13
Flint 13
total 100
add
Titanium Dioxide 11
ROI 4% gives Orange Rust.
I found no other similar glazes.
m
claystevslat on mon 3 sep 07
Maurice --
I use several slight variations of the Cushing "Pam
Fredricks" glaze. It is incredibly sensitive to small
changes -- trying to use bentonite as a suspension
agent is a real problem as even 0.5% very significantly
changes the glaze color and texture. I am fond of, and
sell quite a bit of, the copper carb variation of the
glaze (no RIO, 1 % copper carb) but it runs even more
than the RIO version of the glaze.
At NCECA I told Mr. Cushing I had questions about this
glaze, and even before I told him my issues he asked
if it ran, and said that it was perfectly fired with
a #6 self-supporting cone at about (he bent his finger
to show me the sweet spot) something in the 1:30 to 2:00
range. I can say from sad experience if you get to 3:00
it will run, and drive you crazy. He discouraged the
use of bentonite for suspension, and suggested that
I instead rely on food-grade calcium chloride, mixing
it in water until it was fully saturated, and then adding
the saturated water in the amount of roughly 1 tsp per
1000 g of dry materials -- starting lower and moving
up until the thickness developed.
The green recipe I use is --
Recipe Name: Satin Matte Base -- Rusty Green
Cone: 5-6 Color:
Firing: Oxidation Surface: Semimatte
Amount Ingredient
41.8 Nepheline Syenite
10.4 Gerstley Borate
12.5 Kaolin--EPK
10.4 Whiting
6.2 Lithium Carbonate
12.5 Flint
6.2 Titanium Dioxide
100 Total
Additives
1 Copper Carb
6.2 Titanium Dioxide
Comments: 3% RIO for Rusty Bronze
1% Cobalt Light Blue Green
Very sensitive to bentonite; makes surface overly matte
in small concentrations. Where thick, glossy, runs. Where
thin will run if ^6 reached or exceeded. Lots of crystals.
Where very thin gives some dark grey to silvery effects.
A Cushing Glaze; lots of crystals.
Best wishes -- Steve Slatin
--- In clayart@yahoogroups.com, Maurice Weitman wrote:
>
> At 09:04 -0400 on 9/2/07, Judy Musicant wrote:
> >Hello Potters,
> >
> >Maurice Weitman kindly set up the following site for anyone who
> >wants to see a picture of the Hobart Cowles glaze I posted a few
> >days ago - http://mopots.com/Judy_Musicant_Green-Brown_Bowl.pdf -
it
> >nicely shows the detail of the glaze breaking a rusty brown on
> >raised slip decoration. Have fun, and thanks Maurice.
>
> Howdy,
>
> In the above-mentioned PDF, the recipe for the Val Cushing Satin
> Matte glaze which Judy put on the rim of the bowl has a typo which
is
> my mistake.
>
> I put in "Total 100" when it only added up to 90.
>
> I've corrected the PDF file referred to above to say "90". I will
> wait for Judy to verify that the recipe is correct as is, or if
there
> are indeed errors, I will correct them.
>
> There might be something wrong with the original recipe; Val's
> recipes usually add up to 100.
>
> Sorry for the mix up, folks.
>
> Regards,
> Maurice
Dolita Dohrman on mon 3 sep 07
This glaze is also in Bailey's ^6 glaze book under Crystal White with
3 variations. I love this glaze for layering. I used to like it all
by itself but have found it is very tempermental. Have you found
that it does not age well? I am finding the crystal white going a
boring semi-gloss cream when thick and a very dry cream where thin.
Not getting the variegation I used to. Also have a hell of a time
with blistering. I once opened a kiln with this glaze sprayed over
with a black glaze on a large bowl and it was beautiful (Mel posted
that one on his website awhile ago). However, I could not believe
when I flipped the bowl over....looked like craters on the moon!
Have taken to spraying the undersides of my bowl very thin. I fire
this slowly and cool slowly. I got used to the running...it can do
absolutely beautiful things when it runs into other glazes,
perferable glossy ones. However, the loss of variegation and the
blisters are killing me!
Dolita
On Sep 3, 2007, at 3:52 PM, claystevslat wrote:
> Maurice --
>
> I use several slight variations of the Cushing "Pam
> Fredricks" glaze. It is incredibly sensitive to small
> changes -- trying to use bentonite as a suspension
> agent is a real problem as even 0.5% very significantly
> changes the glaze color and texture. I am fond of, and
> sell quite a bit of, the copper carb variation of the
> glaze (no RIO, 1 % copper carb) but it runs even more
> than the RIO version of the glaze.
>
> At NCECA I told Mr. Cushing I had questions about this
> glaze, and even before I told him my issues he asked
> if it ran, and said that it was perfectly fired with
> a #6 self-supporting cone at about (he bent his finger
> to show me the sweet spot) something in the 1:30 to 2:00
> range. I can say from sad experience if you get to 3:00
> it will run, and drive you crazy. He discouraged the
> use of bentonite for suspension, and suggested that
> I instead rely on food-grade calcium chloride, mixing
> it in water until it was fully saturated, and then adding
> the saturated water in the amount of roughly 1 tsp per
> 1000 g of dry materials -- starting lower and moving
> up until the thickness developed.
>
> The green recipe I use is --
>
> Recipe Name: Satin Matte Base -- Rusty Green
>
> Cone: 5-6 Color:
> Firing: Oxidation Surface: Semimatte
>
> Amount Ingredient
> 41.8 Nepheline Syenite
> 10.4 Gerstley Borate
> 12.5 Kaolin--EPK
> 10.4 Whiting
> 6.2 Lithium Carbonate
> 12.5 Flint
> 6.2 Titanium Dioxide
>
> 100 Total
>
> Additives
>
> 1 Copper Carb
> 6.2 Titanium Dioxide
>
>
> Comments: 3% RIO for Rusty Bronze
> 1% Cobalt Light Blue Green
>
> Very sensitive to bentonite; makes surface overly matte
> in small concentrations. Where thick, glossy, runs. Where
> thin will run if ^6 reached or exceeded. Lots of crystals.
> Where very thin gives some dark grey to silvery effects.
>
> A Cushing Glaze; lots of crystals.
>
> Best wishes -- Steve Slatin
>
>
>
> --- In clayart@yahoogroups.com, Maurice Weitman wrote:
>>
>> At 09:04 -0400 on 9/2/07, Judy Musicant wrote:
>>> Hello Potters,
>>>
>>> Maurice Weitman kindly set up the following site for anyone who
>>> wants to see a picture of the Hobart Cowles glaze I posted a few
>>> days ago - http://mopots.com/Judy_Musicant_Green-Brown_Bowl.pdf -
> it
>>> nicely shows the detail of the glaze breaking a rusty brown on
>>> raised slip decoration. Have fun, and thanks Maurice.
>>
>> Howdy,
>>
>> In the above-mentioned PDF, the recipe for the Val Cushing Satin
>> Matte glaze which Judy put on the rim of the bowl has a typo which
> is
>> my mistake.
>>
>> I put in "Total 100" when it only added up to 90.
>>
>> I've corrected the PDF file referred to above to say "90". I will
>> wait for Judy to verify that the recipe is correct as is, or if
> there
>> are indeed errors, I will correct them.
>>
>> There might be something wrong with the original recipe; Val's
>> recipes usually add up to 100.
>>
>> Sorry for the mix up, folks.
>>
>> Regards,
>> Maurice
>
> ______________________________________________________________________
> ________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots2@visi.com
claystevslat on tue 4 sep 07
Dolita --
I remember that picture on Mel's page, and was
hugely impressed with it.
I found it in Bailey's book as GA-23 -- aka "Rusty Bronze."
He sources it to Judy Musicant, who identified it as a
cone 6-7 glaze, but if I ever got to ^7 with it I'd
expect to find it all on the kiln shelf with nothing
at all remaining on the pot (well, OK, maybe some in
the bottom of a bowl). This is the version with 6.2
percent titanium.
I believe that the 10 percent titanium dioxide version
is an older iteration of this glaze. Some of the
different recipes for this glaze seem to come back
to that change; some depend on whether you calculate
it with everything in at 100% (i.e., they're actually
the same glaze chemically, just expressed with the
colorants 'above the line' vs. 'below the line') and
some are actually slightly different formulae.
I just flipped through the book and can't find a
variation of it identified as crystal white -- I'm
probably looking right past it. (Like Mastering Cone
6 Glazes, I've read and re-read it, and my eyes flicker
over some things that I should be able to find.) What
page is it on?
I've tried the higher Ti concentration versions of this
glaze, but have not been as satisfied with the appearance.
It does run a little less, if my notes are right (my
notes are often poor, and I don't always save test pieces
if I don't like the result) but I got lots of pinholing.
Maybe the 10% version of the recipe is worse for this
than the 6.2%? I have seen serious problems with other
glazes with over 12% TiO2, so that might be an issue.
But when I did those tests I was also experimenting with
bentonite, so maybe that was the problem. I've seen
references in the literature to limiting TiO2 to 15%
or to 8%. I can't say if this might be an issue or
not. {The only glaze I've done a line-blend with
Ti, though (Ian Begg's Clear) is at peak at 6-8%.}
Since I've stopped using bentonite, I've had fewer of
the ageing issues. Also, the glaze is more satiny and
visibly less matte, and colors are brighter. Do you
use a suspension agent? Which one?
FWIW, I find that I get more variegation and a smoother
surface with this glaze in a fast cool than in a controlled
cool. I haven't had blistering problems with this glaze,
so I can't comment on that.
It's good to hear from you -- I remember our little chat
at the show in Louisville fondly. We may be getting a
little narrow on this subject now, so if you want to
continue but to take it off-list that's OK with me.
No sense boring 5,000 potters with it if only 3 or 4 of
us are using this glaze. I have a few snapshots (not
carefully staged pictures, just snaps) of a few of my
experiments with this glaze, let me know if you'd like
to see them. And let me know if size is a problem -- I
can resize them if you can't take big files.
Regards -- Steve Slatin
--- In clayart@yahoogroups.com, Dolita Dohrman wrote:
>
> This glaze is also in Bailey's ^6 glaze book under Crystal White
with
> 3 variations. I love this glaze for layering. I used to like it
all
> by itself but have found it is very tempermental. Have you found
> that it does not age well? I am finding the crystal white going a
> boring semi-gloss cream when thick and a very dry cream where thin.
> Not getting the variegation I used to. Also have a hell of a time
> with blistering. I once opened a kiln with this glaze sprayed over
> with a black glaze on a large bowl and it was beautiful (Mel posted
> that one on his website awhile ago). However, I could not believe
> when I flipped the bowl over....looked like craters on the moon!
> Have taken to spraying the undersides of my bowl very thin. I fire
> this slowly and cool slowly. I got used to the running...it can do
> absolutely beautiful things when it runs into other glazes,
> perferable glossy ones. However, the loss of variegation and the
> blisters are killing me!
> Dolita
D. L. Engle on tue 4 sep 07
If you take it off list please include me as I'm listening in too! And would
also love to see your pictures of it.
Debbie
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG]On Behalf Of claystevslat
Sent: Tuesday, September 04, 2007 12:30 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Green glaze breaking brown - cone 5-6
We may be getting a
little narrow on this subject now, so if you want to
continue but to take it off-list that's OK with me.
No sense boring 5,000 potters with it if only 3 or 4 of
us are using this glaze. I have a few snapshots (not
carefully staged pictures, just snaps) of a few of my
experiments with this glaze, let me know if you'd like
to see them. And let me know if size is a problem -- I
can resize them if you can't take big files.
Regards -- Steve Slatin
Nancy on tue 4 sep 07
Steve
If you take it off list, please include me. I'm reading all the emails
but don't have any input yet
Thanks
Nancy\
D. L. Engle wrote:
> If you take it off list please include me as I'm listening in too! And would
> also love to see your pictures of it.
> Debbie
>
> -----Original Message-----
> From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG]On Behalf Of claystevslat
> Sent: Tuesday, September 04, 2007 12:30 PM
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Re: Green glaze breaking brown - cone 5-6
>
> We may be getting a
> little narrow on this subject now, so if you want to
> continue but to take it off-list that's OK with me.
> No sense boring 5,000 potters with it if only 3 or 4 of
> us are using this glaze. I have a few snapshots (not
> carefully staged pictures, just snaps) of a few of my
> experiments with this glaze, let me know if you'd like
> to see them. And let me know if size is a problem -- I
> can resize them if you can't take big files.
>
> Regards -- Steve Slatin
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots2@visi.com
>
>
Veena Raghavan on tue 4 sep 07
I would be interested too, so please include me too, or keep it on the list.
After all, considering some of the things that tend to go on and on, until Mel
calls a halt, or not nearly as pertinent. (No criticism meant, just a
comment!)
Thanks folks.
Veena
In a message dated 9/4/2007 6:22:30 PM Eastern Daylight Time,
dlenglesculpture@EARTHLINK.NET writes:
>
>
> If you take it off list please include me as I'm listening in too! And would
> also love to see your pictures of it.
> Debbie
VeenaRaghavan@cs.com
Clayart SCtag on tue 4 sep 07
I am also interested if you are going off list but you didn't give a
direct address for us to opt in.
Meg
************************************** Get a sneak peek of the all-new AOL at
http://discover.aol.com/memed/aolcom30tour
Anne Doyle on tue 4 sep 07
O.k.,
i guess its safe to say a lot of us are lurking in on this conversation
and interested in this glaze, so please, please don't take it off-list. I
for one would be interested in the photos (if there's a chance of a link
to view tham online) as i'm planning on t4esting this glaze next week and
am more than curious about what others have gotten results-wise.
Thanx!
Anne, in Saint-Sauveur
Dolita Dohrman on wed 5 sep 07
Steve (and all interested parties),
Seems to me we should not take this off-list. This is totally clay
related. Think of all the OT subjects that just go on and on...and on!
I grabbed my Bailey book and realized that I have referred to the
glaze without colorants (GA23) as 'Crystal White' for so long now I
had forgotten that is not what the book calls it. It is indeed the
one on P. 108. This is the version I use and do not add bentonite.
I do use a hand held blender before every use and continue to mix as
I glaze. It does settle out a bit but I do not get any hard-
panning. I have been firing to a hot ^6 but may be changing that as
I have started to use Highwater's Bella's Blend and it does not like
going over 6 apparently. I am interested to see what the glaze does
at a lower temperature. It is tempting to mix a fresh batch and see
if I get the same results I did when I first mixed it.
It is interesting that you like the results better after a fast
cool. I was trying to get more crystal growth wih the controlled
cool and, for awhile anyway, it worked. I went to Ron Roy's glaze
workshop in Canada last year and we worked on this glaze. It is well
worth the trouble. I have not had a chance to test all our
variations but would be glad to share and we could all take one test
but first I have to find all my notes. One thing abut the
running....if you take that away you may very well lose the essence
of the glaze. That is the problem I saw when we were trying to 'fix'
the glaze, it turned into something else entirely. I will send you
some pictures off-list (I really should learn to upload to the
internet site!) and you can see where I am with this. If anyone else
would like the pics, please email me. Please send me your pictures,
I can take large files.
Dolita
On Sep 4, 2007, at 3:29 PM, claystevslat wrote:
> Dolita --
>
> I remember that picture on Mel's page, and was
> hugely impressed with it.
>
> I found it in Bailey's book as GA-23 -- aka "Rusty Bronze."
> He sources it to Judy Musicant, who identified it as a
> cone 6-7 glaze, but if I ever got to ^7 with it I'd
> expect to find it all on the kiln shelf with nothing
> at all remaining on the pot (well, OK, maybe some in
> the bottom of a bowl). This is the version with 6.2
> percent titanium.
>
> I believe that the 10 percent titanium dioxide version
> is an older iteration of this glaze. Some of the
> different recipes for this glaze seem to come back
> to that change; some depend on whether you calculate
> it with everything in at 100% (i.e., they're actually
> the same glaze chemically, just expressed with the
> colorants 'above the line' vs. 'below the line') and
> some are actually slightly different formulae.
>
> I just flipped through the book and can't find a
> variation of it identified as crystal white -- I'm
> probably looking right past it. (Like Mastering Cone
> 6 Glazes, I've read and re-read it, and my eyes flicker
> over some things that I should be able to find.) What
> page is it on?
>
> I've tried the higher Ti concentration versions of this
> glaze, but have not been as satisfied with the appearance.
> It does run a little less, if my notes are right (my
> notes are often poor, and I don't always save test pieces
> if I don't like the result) but I got lots of pinholing.
> Maybe the 10% version of the recipe is worse for this
> than the 6.2%? I have seen serious problems with other
> glazes with over 12% TiO2, so that might be an issue.
> But when I did those tests I was also experimenting with
> bentonite, so maybe that was the problem. I've seen
> references in the literature to limiting TiO2 to 15%
> or to 8%. I can't say if this might be an issue or
> not. {The only glaze I've done a line-blend with
> Ti, though (Ian Begg's Clear) is at peak at 6-8%.}
>
> Since I've stopped using bentonite, I've had fewer of
> the ageing issues. Also, the glaze is more satiny and
> visibly less matte, and colors are brighter. Do you
> use a suspension agent? Which one?
>
> FWIW, I find that I get more variegation and a smoother
> surface with this glaze in a fast cool than in a controlled
> cool. I haven't had blistering problems with this glaze,
> so I can't comment on that.
>
> It's good to hear from you -- I remember our little chat
> at the show in Louisville fondly. We may be getting a
> little narrow on this subject now, so if you want to
> continue but to take it off-list that's OK with me.
> No sense boring 5,000 potters with it if only 3 or 4 of
> us are using this glaze. I have a few snapshots (not
> carefully staged pictures, just snaps) of a few of my
> experiments with this glaze, let me know if you'd like
> to see them. And let me know if size is a problem -- I
> can resize them if you can't take big files.
>
> Regards -- Steve Slatin
>
> --- In clayart@yahoogroups.com, Dolita Dohrman wrote:
>>
>> This glaze is also in Bailey's ^6 glaze book under Crystal White
> with
>> 3 variations. I love this glaze for layering. I used to like it
> all
>> by itself but have found it is very tempermental. Have you found
>> that it does not age well? I am finding the crystal white going a
>> boring semi-gloss cream when thick and a very dry cream where thin.
>> Not getting the variegation I used to. Also have a hell of a time
>> with blistering. I once opened a kiln with this glaze sprayed over
>> with a black glaze on a large bowl and it was beautiful (Mel posted
>> that one on his website awhile ago). However, I could not believe
>> when I flipped the bowl over....looked like craters on the moon!
>> Have taken to spraying the undersides of my bowl very thin. I fire
>> this slowly and cool slowly. I got used to the running...it can do
>> absolutely beautiful things when it runs into other glazes,
>> perferable glossy ones. However, the loss of variegation and the
>> blisters are killing me!
>> Dolita
>
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Ron Roy on thu 6 sep 07
Both glazes below are short of silica so I am assuming they are not stable.
The Lithium carb is high enough that it may produce some strange fit
problems on some clay bodies - like shivering and crazing at the same time.
I tried to lower the Lithium carb by adding in some spodumene but had to
take out all the EPK and there was still too much alumina.
I would not recommend it as a liner glaze.
Test well to see if there will be fit problems
RR
>ps Judy, I found a glaze in my Val Cushing handbook that's called VC
>Pam Fredericks C6-9 which has the same ingredients as the Val Cushing
>Satin Matte Glaze you quoted, but with different, though nearly
>proportionally similar amounts. And it adds up to 100. Notice that
>it says 6-9...
>
>Yours called for
>
>Nepheline Syenite 40
>Gerstley Borate 10
>Whiting 10
>Lithium Carbonate 6
>EP Kaolin 12
>Silica 12
> total 90
>add
>Titanium Dioxide 6
>Iron Oxide 2-3
>
>and the VC Pam ... wants
>
>Nepheline Sye 44
>Gerstley Borate 12
>Whiting 12
>Lithium Carbonate 6
>EPK 13
>Flint 13
> total 100
>add
>Titanium Dioxide 11
>ROI 4% gives Orange Rust.
>
>I found no other similar glazes.
>
>m
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
claystevslat on thu 6 sep 07
Dolita --
Yes, it does seem like there is some interest (I thought you
and I were just talking to each other). After seeing the
pictures, my guess is that when you say 'without colorants'
you mean still with the titanium, right? The hand held blender
is a good idea, but it may be contributing to the cratering by
putting air into the glaze (not sure about this, though).
I've used a whisk to get the glaze solids up into the suspension
or just mixed hard and then every pot or two taken a cup and
dipped and poured a few times to keep things moving.
I think that part of the reason why the glaze seems to change
is that if it's not really well mixed, a disproportionate
amount of the Lithium (which is in a water-soluble form) gets
absorbed leaving a thicker suspension with fewer (powerful
melters) Lithium ions. And, as you know, it's hard to keep
it well-mixed.
If you've been firing to a hard six, and your clay isn't
recommended for over 6, that may be an issue as well -- it
may outgas seriously at the hard six, and that could be
putting the craters in the glaze.
I'll try to send you a sample picture of some not-quite-
completely healed crates from my last firing -- used the L&L
fast glaze ramp to ^6 (which has drifted a little due to the
age of the thermocouples so it doesn't quite reach ^6) and
a 14 minute soak at top. The cone came down to the 2 o'clock
position, the curve just starting to show, and you can just
see the pinholes curing. As I wrote (off-list) earlier today,
I think the solution may be firing to a very slightly lower
temp, just enough to bring the glaze to the glass surface
that will heal, and to hold at that temp just long enough
to heal.
We should remember, though, that the glaze is a little
different in each iteration. The Rusty Bronze version
has 3% RIO, which is slightly refractory at ^6 oxidation.
The green has 1% Copper Carb, which is a flux at ^6 ox,
at least in larger concentrations -- and VC/PF is such
a 'tippy' glaze that it may be influenced by much smaller
changes in the Cu concentration.
Lots of cone 6 glazes have about 65% silica. Bentonite
has just about that. Cone 6 glazes generally run 6 from
6 percent alumina to about twice that. Bentonite runs
higher; about 22% as I recall. So the high-alumina nature
of VC/PF becomes an issue in adding bentonite, which is
usually close enough to the targets for a glaze in Si and
Al both that adding a percent or even two doesn't change
things too much. VC/PF is just tempramental like that.
Best wishes -- Steve S
--- In clayart@yahoogroups.com, Dolita Dohrman wrote:
>
> Steve (and all interested parties),
> Seems to me we should not take this off-list. This is totally clay
> related. Think of all the OT subjects that just go on and
on...and on!
> I grabbed my Bailey book and realized that I have referred to the
> glaze without colorants (GA23) as 'Crystal White' for so long now I
> had forgotten that is not what the book calls it. It is indeed the
> one on P. 108. This is the version I use and do not add bentonite.
> I do use a hand held blender before every use and continue to mix
as
> I glaze. It does settle out a bit but I do not get any hard-
> panning. I have been firing to a hot ^6 but may be changing that
as
> I have started to use Highwater's Bella's Blend and it does not
like
> going over 6 apparently. I am interested to see what the glaze
does
> at a lower temperature. It is tempting to mix a fresh batch and
see
> if I get the same results I did when I first mixed it.
> It is interesting that you like the results better after a fast
> cool. I was trying to get more crystal growth wih the controlled
> cool and, for awhile anyway, it worked. I went to Ron Roy's glaze
> workshop in Canada last year and we worked on this glaze. It is
well
> worth the trouble. I have not had a chance to test all our
> variations but would be glad to share and we could all take one
test
> but first I have to find all my notes. One thing abut the
> running....if you take that away you may very well lose the essence
> of the glaze. That is the problem I saw when we were trying
to 'fix'
> the glaze, it turned into something else entirely. I will send you
> some pictures off-list (I really should learn to upload to the
> internet site!) and you can see where I am with this. If anyone
else
> would like the pics, please email me. Please send me your
pictures,
> I can take large files.
> Dolita
Dolita Dohrman on fri 7 sep 07
I make GA 23 just as it is stated in the book.
> Steve wrote: The hand held blender
> is a good idea, but it may be contributing to the cratering by
> putting air into the glaze (not sure about this, though).
I wonder if there is truth to this. I use the blender with all my
glazes and this is the only one giving me some trouble.
> Steve wrote: If it's not really well mixed, a disproportionate
> amount of the Lithium (which is in a water-soluble form) gets
> absorbed leaving a thicker suspension with fewer (powerful
> melters) Lithium ions.
I really feel there is an aging problem with this glaze. I am
definitely going to mix up a new batch. I know I mix this enough
before I use it. I have not used the green or the blue version in
awhile and am going to run a test on those two. They have been
sitting on my shelf for months. The Rusty Bronze is behaving the
same as the the GA 23 base (which I refer to as Crystal White). Both
are a very evenly colored semi-gloss unless sprayed very thin, and
then they are just dry.
I do have to say that all of the variations of this glaze are
excellent layering glazes.
I saved an old Clayart email from Jason Hooper. He adjusted the
glaze to eliminate some of the running and stated that it did not
change the surface of the glaze. He did a vinegar test and found no
change after 2 days. I don't think he will mind if I post it here:
Variation on GA 23 (Crystal White)
Neph Sy 40
Gerstley Borate 10
EPK 12
Whiting 10
Lithium Carb 5
Flint 15
Titanium Dioxide 6
I am going to find my notes from Ron Roy's glaze workshop and post
some of those recipes. I am also going to learn how to use flickr so
I can post some pics. I have save an old post that gives
instructions. This old dog can certainly learn new tricks!
One thing I did want to mention is that I find the fast glaze program
on the L & L way too fast (is there such a thing?). 4.55 hours just
seems too short. The slow glaze program is 7.53. That seems about
right for a fast glaze to me....am I right? Educate me, please!
Dolita
Jason Hooper on sat 8 sep 07
The green version of the VC Pam Fredericks glaze was definitely too dry for me,
and it leached out the copper very easily with vinegar. Maybe the application
was too thin.
Anyway, I decided to try and make a functional version of the glaze - mostly by
bumping up the amount of silica which seemed too low. I reformulated to use frit
instead of GB, and switched to spodumene to reduce the COE. This is what I ended
up with, and it looks great in green because of small white crystals. I use a
slow cooling schedule. It's still a little more fluid than I would like, so I'm
fine tuning the amount of lithium carbonate at the moment. It suspends really
well in the glaze bucket - it's a little odd, but you get used to it.
Recipe Name: VCSM Satin Green spodumene
4 Nepheline Syenite
14.5 Frit--Ferro 3134
30 Spodumene--Gwalia
10 Whiting
1.5 Talc
3 Lithium Carbonate
19 Kaolin--EPK
17 Silica
99 Total (yes that's 99 not 100)
6 Titanium Dioxide
2 Copper Carbonate
Here's a picture of a teapot using this glaze:
http://www.southpawceramics.com/Mugs%20&%20Cups%20&%20Teapots/slides/Teapot%20-%20Round%20-%20Satin%20Green.html
If this URL breaks, just go to my home page and browse the gallery for 'satin
green' pieces.
It also gives a nice white with a slight purplish tinge in grooves if you use 1%
RIO instead of the copper.
Because it is a satin matte I think it's little rough for a cutlery surface, so
I still tend to use a simple gloss as a liner glaze.
cheers,
Jason
Dolita Dohrman wrote:
> I saved an old Clayart email from Jason Hooper. He adjusted the
> glaze to eliminate some of the running and stated that it did not
> change the surface of the glaze. He did a vinegar test and found no
> change after 2 days. I don't think he will mind if I post it here:
> Variation on GA 23 (Crystal White)
> Neph Sy 40
> Gerstley Borate 10
> EPK 12
> Whiting 10
> Lithium Carb 5
> Flint 15
> Titanium Dioxide 6
--
Jason Hooper
512 789 2463
http://www.southpawceramics.com
Ron Roy on sat 8 sep 07
Hi Dolita,
7 hours for a cone 6 glaze seems too fast to me - it may work with some
glazes but most would would suffer from that fast a firing.
RR
>One thing I did want to mention is that I find the fast glaze program
>on the L & L way too fast (is there such a thing?). 4.55 hours just
>seems too short. The slow glaze program is 7.53. That seems about
>right for a fast glaze to me....am I right? Educate me, please!
>Dolita
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
John Hesselberth on sun 9 sep 07
On Sep 7, 2007, at 9:39 AM, Dolita Dohrman wrote:
> One thing I did want to mention is that I find the fast glaze program
> on the L & L way too fast (is there such a thing?). 4.55 hours just
> seems too short. The slow glaze program is 7.53. That seems about
> right for a fast glaze to me....am I right?
Hi Dolita,
My firings take about 8 hours to get to peak temperature in my L&L
using the ramps we suggest in MC6Gs. Then the slow cooling (firing
down) adds another 5-6 hours. Total time: about 14 hours from
starting the kiln to shut off at 1400F. I never use the built in
"fast/slow" programs. I just find the end point too unreliable. I set
my own end point temperature and confirm it by watching cones. If you
are going to fire up faster than I do, make sure you have a good soak
at peak temperature to let the kiln and the pots even out. And of
course the peak temperature has to be adjusted depending on the
length of the soak so you don't over or under fire. I strongly
recommend you use the computer but confirm with cones--they are the
gold standard.
John
John Hesselberth
www.frogpondpottery.com
"Man is a tool-using animal....without tools he is nothing, with
tools he is all" .... Thomas Carlyle
Fred on thu 13 sep 07
---- Ron Roy wrote:
>Hi Dolita,
>
>7 hours for a cone 6 glaze seems too fast to me - it may work with some
>glazes but most would would suffer from that fast a firing.
>
>RR
>
>
>>One thing I did want to mention is that I find the fast glaze program
>>on the L & L way too fast (is there such a thing?). 4.55 hours just
>>seems too short. The slow glaze program is 7.53. That seems about
>>right for a fast glaze to me....am I right? Educate me, please!
Dolita,
I have an L&L 23T and my slow glaze cycle is 9 Plus hours. Perhaps there is a flaw in
your Kiln? I don't use the fast glaze cycle --instead program the MC6 cycle into the Kiln.
>>Dolita
>
>Ron Roy
>RR#4
>15084 Little Lake Road
>Brighton, Ontario
>Canada
>K0K 1H0
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots2@visi.com
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