Chris on wed 16 feb 00
------------------
Hi out there the story goes like this. After a lot of testing I
came up with this satin matt glaze. It came out very soft to the lips and
green very green. It had 3=25 chrome ox. And .25=25 cobalt carb. as =
colorants,
any way I lost it and my notes. I have tested a lot of other bases but they
all seem to flash tan if the reduction is off just a little. This is the
part that I can=92t seem to fix. The first base never did this=3B if you =
missed
the reduction it still came out green, just not as dark but green. Can
someone out there tell me what is going on here? Help my customers are look
at me funny. Like what do you mean you lost it and can=92t do it anymore? I
feel bad and not to sharp on top of it.
Dannon Rhudy on thu 17 feb 00
------------------
In my experience, greens do not need reduction to be green, and will
be about the same in either oxidation or reduction. Certainly true
of copper greens. Perhaps the =22off=22 color you speak of is related
to thickness of application. Sometimes copper greens will get a
=22tannish=22 sort of look with excessive reduction, where they have
achieved a bit of red from the copper. When the eye sees this mixture
of red/green, it often appears tan or muddy looking.
regards,
Dannon Rhudy
potter=40koyote.com
At 07:53 PM 2/16/00 EST, you wrote:
=3E----------------------------Original message----------------------------
=3E------------------
=3EHi out there the story goes like this. After a lot of testing I
=3Ecame up with this satin matt glaze. It came out very soft to the lips and
=3Egreen very green. It had 3=25 chrome ox. And .25=25 cobalt carb. as =
colorants,
=3Eany way I lost it and my notes. I have tested a lot of other bases but =
they
=3Eall seem to flash tan if the reduction is off just a little. This is the
=3Epart that I can=92t seem to fix. The first base never did this=3B if you =
missed
=3Ethe reduction it still came out green, just not as dark but green. Can
=3Esomeone out there tell me what is going on here? Help my customers are =
look
=3Eat me funny. Like what do you mean you lost it and can=92t do it anymore?=
I
=3Efeel bad and not to sharp on top of it.
=3E
David Hendley on fri 18 feb 00
3% chrome oxide is a tremendously high amount to have
in a glaze. In most glaze bases you get a dark green with
half that amount, or less.
I suggest you try less chrome oxide, for both safety and
aesthetic reasons.
In the Rhodes #32 glaze base (from "Clay and Glazes for
the Potter", Mels' favorite glaze), 1% chrome oxide will
give you tan every time. I call it "cafe au lait".
Since this glaze is very high in magnesium, and low in
silica, this indicates that these are two attributes you do
NOT want your chrome green glaze to have.
--
David Hendley
Maydelle, Texas
hendley@tyler.net
http://www.farmpots.com/
----- Original Message -----
From: Chris
To:
Sent: Wednesday, February 16, 2000 6:53 PM
Subject: Glaze cone 10 green Help?
----------------------------Original message----------------------------
------------------
Hi out there the story goes like this. After a lot of testing I
came up with this satin matt glaze. It came out very soft to the lips and
green very green. It had 3% chrome ox. And .25% cobalt carb. as colorants,
any way I lost it and my notes. I have tested a lot of other bases but they
all seem to flash tan if the reduction is off just a little. This is the
part that I can't seem to fix. The first base never did this; if you missed
the reduction it still came out green, just not as dark but green. Can
someone out there tell me what is going on here? Help my customers are look
at me funny. Like what do you mean you lost it and can't do it anymore? I
feel bad and not to sharp on top of it.
Lorraine Pierce on sat 19 feb 00
Hi David.., and all you claybuds firing multiple loads for student groups...I
know that should I fire chrome green glazes in a ^6 oxidation firing with tin
opacified white glazes, my whites will pink. I have also had the experience of
a zirconium opacified glaze showing a tannish flush when fired in the same
kiln with chrome.
Is there a small percentage of chrome that can be used in a mixed load and NOT
contaminate other glaze colors or must any glaze or underglaze containing
chrome be fired in an 'all chrome' glaze kiln?
One of my students is interested only todays 'fashion' colors and most glazes
and stains use chrome to mute the greens and pale plums and lavenders.
My second question concerns strontium carbonate. I had not used it before and
was surprised at the amount of white material that did not pass through my
screen when I sieved the glaze. My supplier was no help...could not give me
mesh size, producer, manufacturer, etc. I will go ahead and test the glazes as
mixed, but it seems too much is left behind.. the glaze would be very grainy
when applied, if the dregs were mixed in. I believe Standard is the middleman
for my supplier.
Also, I hope someone, please, will send me the URL to the Clayart
Archives...for some reason I am not getting thru using the ones posted in the
Clayart How To from Art Molinaro. The answers I need have no doubt been
covered before. thanks and again,
Thanks, all. Lori in New Port Richey, Fl
David Hendley wrote:
> ----------------------------Original message----------------------------
> 3% chrome oxide is a tremendously high amount to have
> in a glaze. In most glaze bases you get a dark green with
> half that amount, or less.
> I suggest you try less chrome oxide, for both safety and
> aesthetic reasons.
>
> In the Rhodes #32 glaze base (from "Clay and Glazes for
> the Potter", Mels' favorite glaze), 1% chrome oxide will
> give you tan every time. I call it "cafe au lait".
> Since this glaze is very high in magnesium, and low in
> silica, this indicates that these are two attributes you do
> NOT want your chrome green glaze to have.
>
> --
> David Hendley
> Maydelle, Texas
> hendley@tyler.net
> http://www.farmpots.com/
>
> ----- Original Message -----
> From: Chris
> To:
> Sent: Wednesday, February 16, 2000 6:53 PM
> Subject: Glaze cone 10 green Help?
>
> ----------------------------Original message----------------------------
> ------------------
> Hi out there the story goes like this. After a lot of testing I
> came up with this satin matt glaze. It came out very soft to the lips and
> green very green. It had 3% chrome ox. And .25% cobalt carb. as colorants,
> any way I lost it and my notes. I have tested a lot of other bases but they
> all seem to flash tan if the reduction is off just a little. This is the
> part that I can't seem to fix. The first base never did this; if you missed
> the reduction it still came out green, just not as dark but green. Can
> someone out there tell me what is going on here? Help my customers are look
> at me funny. Like what do you mean you lost it and can't do it anymore? I
> feel bad and not to sharp on top of it.
Paul Taylor on sat 19 feb 00
------------------
Dear Thread
Chrome will also reduce to green. Given the right firing and cooling
If you fire fast high and cool down relatively quickly especially
from 1000 c to 600 c your glaze may be the same as ever.
If I had the recipe I would have less chance of being completely
wrong.
Regards Paul T
ps personal replies to tamblin=40go.com as well as ANU. People have been
having trouble with the latter.
----------
----------
=3EFrom: Dannon Rhudy =3Cdrhudy=40paris.cc.tx.us=3E
=3ETo: CLAYART=40LSV.UKY.EDU
=3ESubject: Glaze cone 10 green Help?
=3EDate: Thu, Feb 17, 2000, 9:19 pm
=3E
=3E----------------------------Original message----------------------------
=3E------------------
=3E
=3E
=3EIn my experience, greens do not need reduction to be green, and will
=3Ebe about the same in either oxidation or reduction. Certainly true
=3Eof copper greens. Perhaps the =22off=22 color you speak of is related
=3Eto thickness of application. Sometimes copper greens will get a
=3E=22tannish=22 sort of look with excessive reduction, where they have
=3Eachieved a bit of red from the copper. When the eye sees this mixture
=3Eof red/green, it often appears tan or muddy looking.
=3E
=3Eregards,
=3E
=3EDannon Rhudy
=3Epotter=40koyote.com
=3EAt 07:53 PM 2/16/00 EST, you wrote:
=3E=3E----------------------------Original =
message----------------------------
=3E=3E------------------
=3E=3EHi out there the story goes like this. After a lot of testing I
=3E=3Ecame up with this satin matt glaze. It came out very soft to the lips =
and
=3E=3Egreen very green. It had 3=25 chrome ox. And .25=25 cobalt carb. as =
colorants,
=3E=3Eany way I lost it and my notes. I have tested a lot of other bases but=
they
=3E=3Eall seem to flash tan if the reduction is off just a little. This is =
the
=3E=3Epart that I can=CCt seem to fix. The first base never did this=3B if =
you missed
=3E=3Ethe reduction it still came out green, just not as dark but green. Can
=3E=3Esomeone out there tell me what is going on here? Help my customers are=
look
=3E=3Eat me funny. Like what do you mean you lost it and can=CCt do it =
anymore? I
=3E=3Efeel bad and not to sharp on top of it.
=3E=3E
vince pitelka on sun 20 feb 00
> ----------------------------Original message----------------------------
> Dear Thread
> Chrome will also reduce to green. Given the right firing and cooling
In my experience, chrome remains green in oxidation, but often turns brown
in high-fire reduction.
Best wishes -
- Vince
Vince Pitelka
Home - vpitelka@dekalb.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Ron Roy on sun 20 feb 00
Strontium is sold in different ways - mine is grainy as well - push it
through your sieve with a brush - or let sit overnight in water and it will
soften. It will probably soften faster if you use warm water when mixing
your glaze.
RR
>----------------------------Original message----------------------------
>My second question concerns strontium carbonate. I had not used it before and
>was surprised at the amount of white material that did not pass through my
>screen when I sieved the glaze. My supplier was no help...could not give me
>mesh size, producer, manufacturer, etc. I will go ahead and test the glazes as
>mixed, but it seems too much is left behind.. the glaze would be very grainy
>when applied, if the dregs were mixed in. I believe Standard is the middleman
>for my supplier.
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
Cantello Studios on sun 20 feb 00
Hi paul ; that's just it what happen is after coming up with this glaze
through testing many glaze bases I think I gave it to a student and said
this is it try it , keep the card I know which glaze it is .The student said
cool and left never to be seen again. Well I went back to the studio and
mixed up what I though to be the base and guess what I was wrong and I've
been wrong for the last 5 gallons of tests. Let me add hear that I'm no
glaze wizard. So hear is my thoughts what I need is ?
1. A GLAZE BASE THAT IS HIGH Ca0.
2.THE BASE MUST BE VOID OF ANY Mg0. i.e. from my test Mgo. in
reduction seems to turn chrome tan or gold.
3. The glaze must also be void of : Tin ox. > zinc > barium > and
titanium.
( Glazechem ) Chromium (or chrome) (Chromium sesquioxide - Cr2O3) is
a colorant. In
the absence of tin, zinc, lead, barium, or titanium,
it produces greens.
So if these a glaze whiz out that wood like to look at these glaze
bases.
I just pulled out of the hat so to speak. I have not ran any new tests
as a matter of fact I'm not
even sure if there in the ^10 \^11 firing range?
#1.
Kona F-4 63.81 67 %
Flint 13.33 14 % Hazard!
Gerstley borate 8.57 9 %
Whiting 4.76 5 %
Bone ash 4.76 5 % Hazard!
-------- ------
95.23 100 %
Red iron oxide 1.9 2 %
Cobalt carbonate 0.24 0.3% Hazard!
Green chrome oxide 0.48 0.5% Hazard!
Now this is a ^10 Reduction glaze and I do intend to test it. I do
think its what I'm looking for
but the Si02. is to high. I feel this glaze is very glass like, and I'm
looking for satin matt. How
could I matt this down???
#2.
Gerstley borate 11.64 12 %
Whiting 10.67 11 %
EPK 7.76 8 % Hazard!
Lithium carbonate 0.97 1 % Hazard!
Flint 18.43 19 % Hazard!
G-200 40.26 41.5%
Kentucky OM #4 7.27 7.5% Hazard!
-------- ------
97 100 %
Green chrome oxide 2.91 3 % Hazard!
Cobalt carbonate 0.24 0.3% Hazard!
#3.
G-200 42 42 %
Gerstley borate 9 9 %
Frit 3134 7 7 %
Kona F-4 9 9 %
Whiting 9 9 %
EPK 5 5 % Hazard!
Flint 19 19 % Hazard!
-------- ------
100 100 %
Now these last two #2 and #3 are of the top of my head meaning I'm
guessing this is what I need.
The thing is I'm not sure if there any good or even in the ball park.
Could one of you run on
your glaze program and let me know if I'm on the right track.??
Thank You Chris
-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.UKY.EDU]On Behalf
Of Paul Taylor
Sent: Saturday, February 19, 2000 5:36 PM
To: CLAYART@LSV.UKY.EDU
Subject: Re: Glaze cone 10 green Help?
----------------------------Original message----------------------------
------------------
Dear Thread
Chrome will also reduce to green. Given the right firing and cooling
If you fire fast high and cool down relatively quickly especially
from 1000 c to 600 c your glaze may be the same as ever.
If I had the recipe I would have less chance of being completely
wrong.
Regards Paul T
ps personal replies to tamblin@go.com as well as ANU. People have been
having trouble with the latter.
----------
----------
>From: Dannon Rhudy
>To: CLAYART@LSV.UKY.EDU
>Subject: Glaze cone 10 green Help?
>Date: Thu, Feb 17, 2000, 9:19 pm
>
>----------------------------Original message----------------------------
>------------------
>
>
>In my experience, greens do not need reduction to be green, and will
>be about the same in either oxidation or reduction. Certainly true
>of copper greens. Perhaps the "off" color you speak of is related
>to thickness of application. Sometimes copper greens will get a
>"tannish" sort of look with excessive reduction, where they have
>achieved a bit of red from the copper. When the eye sees this mixture
>of red/green, it often appears tan or muddy looking.
>
>regards,
>
>Dannon Rhudy
>potter@koyote.com
>At 07:53 PM 2/16/00 EST, you wrote:
>>----------------------------Original message----------------------------
>>------------------
>>Hi out there the story goes like this. After a lot of testing I
>>came up with this satin matt glaze. It came out very soft to the lips and
>>green very green. It had 3% chrome ox. And .25% cobalt carb. as colorants,
>>any way I lost it and my notes. I have tested a lot of other bases but
they
>>all seem to flash tan if the reduction is off just a little. This is the
>>part that I canLt seem to fix. The first base never did this; if you
missed
>>the reduction it still came out green, just not as dark but green. Can
>>someone out there tell me what is going on here? Help my customers are
look
>>at me funny. Like what do you mean you lost it and canLt do it anymore? I
>>feel bad and not to sharp on top of it.
>>
Paul Taylor on wed 23 feb 00
Dear Chris
This will teach me a lesson. I suggested you publish the glaze and I am
totally unfamiliar with many of the materials you are using and the sort of
glazes I know about avoid Boron. If you had suggested that you were using
such I would have realized that here I am out of my depth ..
However The glazes look sound enough to me, at high temperature,
testing them on a protected shelf of course.
Just to speculate . It's so much fun to speculate especially when your
not the poor bugger who has to weigh out all the tests. I am wondering if it
is the opel/ matt forming qualities of Tin etc that make the chrome go
red/brown. So an underfired glaze would also not do; since it tends to
crystallize.
I also notice that your own guesses contain not too much calcium. Since
calcium tends to form crystallize as well that's probably for the best.
Good luck it is really heart breaking to have something that works well
and the recipe has gone walk about. I reckon every potter I know searches
for ever through files and draws for the lost recipe.
Regards Paul T
----------
>From: Cantello Studios
>To: CLAYART@LSV.UKY.EDU
>Subject: Re: Glaze cone 10 green Help?
>Date: Sun, Feb 20, 2000, 7:34 pm
>
>----------------------------Original message----------------------------
>Hi paul ; that's just it what happen is after coming up with this glaze
>through testing many glaze bases I think I gave it to a student and said
>this is it try it , keep the card I know which glaze it is .The student said
>cool and left never to be seen again. Well I went back to the studio and
>mixed up what I though to be the base and guess what I was wrong and I've
>been wrong for the last 5 gallons of tests. Let me add hear that I'm no
>glaze wizard. So hear is my thoughts what I need is ?
>
>
> 1. A GLAZE BASE THAT IS HIGH Ca0.
>
> 2.THE BASE MUST BE VOID OF ANY Mg0. i.e. from my test Mgo. in
>reduction seems to turn chrome tan or gold.
>
> 3. The glaze must also be void of : Tin ox. > zinc > barium > and
>titanium.
>
> ( Glazechem ) Chromium (or chrome) (Chromium sesquioxide - Cr2O3) is
>a colorant. In
> the absence of tin, zinc, lead, barium, or titanium,
>it produces greens.
>
> So if these a glaze whiz out that wood like to look at these glaze
>bases.
>
> I just pulled out of the hat so to speak. I have not ran any new tests
>as a matter of fact I'm not
> even sure if there in the ^10 \^11 firing range?
>
> #1.
> Kona F-4 63.81 67 %
> Flint 13.33 14 % Hazard!
> Gerstley borate 8.57 9 %
> Whiting 4.76 5 %
> Bone ash 4.76 5 % Hazard!
> -------- ------
> 95.23 100 %
>
> Red iron oxide 1.9 2 %
> Cobalt carbonate 0.24 0.3% Hazard!
> Green chrome oxide 0.48 0.5% Hazard!
>
> Now this is a ^10 Reduction glaze and I do intend to test it. I do
>think its what I'm looking for
> but the Si02. is to high. I feel this glaze is very glass like, and I'm
>looking for satin matt. How
> could I matt this down???
>
>
> #2.
> Gerstley borate 11.64 12 %
> Whiting 10.67 11 %
> EPK 7.76 8 % Hazard!
> Lithium carbonate 0.97 1 % Hazard!
> Flint 18.43 19 % Hazard!
> G-200 40.26 41.5%
> Kentucky OM #4 7.27 7.5% Hazard!
> -------- ------
> 97 100 %
>
> Green chrome oxide 2.91 3 % Hazard!
> Cobalt carbonate 0.24 0.3% Hazard!
>
> #3.
> G-200 42 42 %
> Gerstley borate 9 9 %
> Frit 3134 7 7 %
> Kona F-4 9 9 %
> Whiting 9 9 %
> EPK 5 5 % Hazard!
> Flint 19 19 % Hazard!
> -------- ------
> 100 100 %
>
> Now these last two #2 and #3 are of the top of my head meaning I'm
>guessing this is what I need.
> The thing is I'm not sure if there any good or even in the ball park.
>Could one of you run on
> your glaze program and let me know if I'm on the right track.??
>
> Thank You Chris
>
>
>-----Original Message-----
>From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.UKY.EDU]On Behalf
>Of Paul Taylor
>Sent: Saturday, February 19, 2000 5:36 PM
>To: CLAYART@LSV.UKY.EDU
>Subject: Re: Glaze cone 10 green Help?
>
>
>----------------------------Original message----------------------------
>------------------
>Dear Thread
>
> Chrome will also reduce to green. Given the right firing and cooling
>
> If you fire fast high and cool down relatively quickly especially
>from 1000 c to 600 c your glaze may be the same as ever.
>
> If I had the recipe I would have less chance of being completely
>wrong.
>
> Regards Paul T
>
>
>ps personal replies to tamblin@go.com as well as ANU. People have been
>having trouble with the latter.
>----------
>
>
>----------
>>From: Dannon Rhudy
>>To: CLAYART@LSV.UKY.EDU
>>Subject: Glaze cone 10 green Help?
>>Date: Thu, Feb 17, 2000, 9:19 pm
>>
>
>>----------------------------Original message----------------------------
>>------------------
>>
>>
>>In my experience, greens do not need reduction to be green, and will
>>be about the same in either oxidation or reduction. Certainly true
>>of copper greens. Perhaps the "off" color you speak of is related
>>to thickness of application. Sometimes copper greens will get a
>>"tannish" sort of look with excessive reduction, where they have
>>achieved a bit of red from the copper. When the eye sees this mixture
>>of red/green, it often appears tan or muddy looking.
>>
>>regards,
>>
>>Dannon Rhudy
>>potter@koyote.com
>>At 07:53 PM 2/16/00 EST, you wrote:
>>>----------------------------Original message----------------------------
>>>------------------
>>>Hi out there the story goes like this. After a lot of testing I
>>>came up with this satin matt glaze. It came out very soft to the lips and
>>>green very green. It had 3% chrome ox. And .25% cobalt carb. as colorants,
>>>any way I lost it and my notes. I have tested a lot of other bases but
>they
>>>all seem to flash tan if the reduction is off just a little. This is the
>>>part that I canLt seem to fix. The first base never did this; if you
>missed
>>>the reduction it still came out green, just not as dark but green. Can
>>>someone out there tell me what is going on here? Help my customers are
>look
>>>at me funny. Like what do you mean you lost it and canLt do it anymore? I
>>>feel bad and not to sharp on top of it.
>>>
| |
|
