Fara Shimbo on tue 29 apr 03
Hi, Everyone,
Okay, I give up, I get down on my knees (ooo, you should
hear the sound they make) and cry for HEEEEELP!
I've seen Violet glass. Transparent violet, the color of a
Violet Crayola crayon. Methinks if you can get this color
in a glass, you -should- be able to get it in a glaze, nu?
So I've tried the cobalt-manganese trick, and the Purple of
Cassius trick, and to be honest the closest I've ever gotten
to a real purple was cobalt and erbium....
So, all you glaze gurus out there, is it possible to get
a true fully transparent dark violet/purple glaze? If so,
how does one do it, or where does one start to experiment?
HELP!
Fa
--
===========================================================
Fara Shimbo, Master Crystalliere, Certified Public Nuisance
-----------------------------------------------------------
Shimbo Pottery, P.O. Box 41, Hygiene, Colorado 80533 USA
720.272.0442 7AM to 2 PM, Mountain Time
www.crystalline-ceramics.info www.shimbopottery.com
Silly Science Fiction: http://klysadel.net
===========================================================
Phillip Smith on tue 29 apr 03
Fara,
What temp do you fire.
I have an oustanding violet/purple glaze for C10R.
Phil...
>From: Fara Shimbo
>Reply-To: Clayart
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: Fara Shimbo and the Quest for Purple
>Date: Tue, 29 Apr 2003 08:00:54 -0600
>
>Hi, Everyone,
>
>Okay, I give up, I get down on my knees (ooo, you should
>hear the sound they make) and cry for HEEEEELP!
>
>I've seen Violet glass. Transparent violet, the color of a
>Violet Crayola crayon. Methinks if you can get this color
>in a glass, you -should- be able to get it in a glaze, nu?
>So I've tried the cobalt-manganese trick, and the Purple of
>Cassius trick, and to be honest the closest I've ever gotten
>to a real purple was cobalt and erbium....
>
>So, all you glaze gurus out there, is it possible to get
>a true fully transparent dark violet/purple glaze? If so,
>how does one do it, or where does one start to experiment?
>
>HELP!
>
>Fa
>--
>===========================================================
>Fara Shimbo, Master Crystalliere, Certified Public Nuisance
>-----------------------------------------------------------
>Shimbo Pottery, P.O. Box 41, Hygiene, Colorado 80533 USA
>720.272.0442 7AM to 2 PM, Mountain Time
>www.crystalline-ceramics.info www.shimbopottery.com
>Silly Science Fiction: http://klysadel.net
>===========================================================
>
>______________________________________________________________________________
>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
>melpots@pclink.com.
_________________________________________________________________
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Ababi on tue 29 apr 03
To be honest with you Fara, if you want glossy violet glaze you must take a Mason
stain in the desirable color into gloss glaze perhaps 10% of that stain. I hate it but in
the case of the violet (at least in ^6 ox) it is the only way to get the glossiness
because the high magnesia needed to create the color makes the glaze matte even
when the alumina silica is 9:1 . If you still want a violet glaze call me or e mail me
Ababi Sharon
Glaze addict
Kibbutz Shoval Israel
ababisha@shoval.org.il
http://members4.clubphoto.com/ababi306910/
http://www.milkywayceramics.com/cgallery/asharon.htm
and also
http://www.israel-ceramics.org/membersGallery/personalpage.asp?MID=507
L. P. Skeen on tue 29 apr 03
----- Original Message -----
From: "Ababi"
> To be honest with you Fara, if you want glossy violet glaze you must take
a Mason
> stain in the desirable color into gloss glaze perhaps 10% of that stain.
I hate it but in
> the case of the violet (at least in ^6 ox) it is the only way to get the
glossiness
Oho Ababi, I'm sorry, but that's just not true. To get purple (at ^6ox),
you have to apply color theory to ceramic glaze chemistry. I did this in
college - think I still have some of that glaze here somewhere.....
What makes purple in color theory? red + blue = purple.
What makes red in ceramic chemistry? Chrome + tin = red
What makes blue in ceramic chemistry? Cobalt = blue
To get purple, take your basic Cr/Sn red gloss glaze and add about 0.25%
(+/-) cobalt carbonate. Et voila! = PURPLE. You DO need a Cr/Sn glaze that
gives you a strong red in the first place, and you will have to experiment
to see how much cobalt to add, but it WILL work. Mine is a dark grape
purple.
This can also be done in reduction firing, by using a Copper red glaze +
cobalt.
L
Ababi on wed 30 apr 03
You are right - I know June Perry has done it.
And I am right too.
And we both right.
To get purple which in my judgment is more red than blue your and June's way.
Violet which I call (in painting) the color that is more blue with a hint of red you get in
ceramics in oxidation by using cobalt and magnesium.
http://members4.clubphoto.com/ababi306910/185990/ fifth slide.
Ababi
---------- Original Message ----------
>----- Original Message -----
>From: "Ababi"
>> To be honest with you Fara, if you want glossy violet glaze you must take
>a Mason
>> stain in the desirable color into gloss glaze perhaps 10% of that stain.
>I hate it but in
>> the case of the violet (at least in ^6 ox) it is the only way to get the
>glossiness
>Oho Ababi, I'm sorry, but that's just not true. To get purple (at ^6ox),
>you have to apply color theory to ceramic glaze chemistry. I did this in
>college - think I still have some of that glaze here somewhere.....
>What makes purple in color theory? red + blue = purple.
>What makes red in ceramic chemistry? Chrome + tin = red
>What makes blue in ceramic chemistry? Cobalt = blue
>To get purple, take your basic Cr/Sn red gloss glaze and add about 0.25%
>(+/-) cobalt carbonate. Et voila! = PURPLE. You DO need a Cr/Sn glaze that
>gives you a strong red in the first place, and you will have to experiment
>to see how much cobalt to add, but it WILL work. Mine is a dark grape
>purple.
>This can also be done in reduction firing, by using a Copper red glaze +
>cobalt.
>L
>______________________________________________________________________________
>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 melpots@pclink.com.
Fara Shimbo on fri 2 may 03
Hi, Everyone,
Got lots of responses to my questions about Purple, and
thought I'd answer them all at once...
Phil Smith, I fire to cones 8-10, depending on the glaze
I'm using. Most are crystalline glazes but I do some (few)
others from time to time. I'd love to try your C10R glaze.
I'll try that Seacrest Purple and see how it works, though
again, it looks very brown. (Although it's a funny thing,
I find as I get older it's become harder for me to distinguish
purple from brown Prismacolors or markers when they're all
jumbled together on the floor because some cat knocked them
all over...)
Ababi, I've tried Mason stains but I've never gotten a true
purple from them. They seem to give me a muddy brownish
purple. I'm looking for the true high-saturation violet
you find in an amethyst. And perfectly transparent too,
which I've never been able to get with a stain (although
here's a hint -- Mason Pansy Purple will go far to keep
your crystals white in a high-titanium glaze).
Lisa Skeen, I've tried several red-blue combinations...
and usually got mud. The best sort of fake purple I
ever got was a combination of CoCO3 and a little CuCO3,
reduced. It was nice but it was only purple from a distance,
and if wasn't transparent. Chrome-Tin reds and pinks don't
seem to "play well with others" in my experience.
Iandol: The manganese wash sounds very promising. Ilene
Mahler gets a lovely Tanzanite color that way. Which leads
to another question: how do you tell if your gas kiln is
fully oxidizing? I have a feeling mine isn't because I
always end up with a little carbon around the top port after
a fire.
Everybody: Neodymium does give a lovely light putple but
I've found generally I can't concentrate it enough in a
glaze to give an amethyst color. It's a hellova flux.
Maybe I'm going at this from the wrong angle ...
Maybe what I need to sort out is all the things that _don't_
give you violet and, to paraphrase Holmes, "whatever remains
must be the recipe."
Hmmm. There's got to be a way to get a glossy, completely
transparent, fully saturated violet. Just gotta. Hmmm....
Somebody tell me it can't be done, and then I'll _have_ to!
Fa
--
===========================================================
Fara Shimbo, Master Crystalliere, Certified Public Nuisance
-----------------------------------------------------------
Shimbo Pottery, P.O. Box 41, Hygiene, Colorado 80533 USA
720.272.0442 7AM to 2 PM, Mountain Time
www.crystalline-ceramics.info www.shimbopottery.com
Silly Science Fiction: http://klysadel.net
===========================================================
Ababi on fri 2 may 03
You know what I think?
perhaps this glaze that in ^6 is kind of matte in ^8 will be glossier? I m=
ake is with " I
will send here the "locals" I add here the original recipe and few more. I=
copy from the
clayart glazes at the ceramic web
Glaze Name: Emily's Blue
cone: 6
color:
surface:?
firing:Untested
date: 6/3/96
recipe:
36.56 Custer Feldspar
19.35 Gerstley Borate
11.83 OM-4 Ball Clay
15.05 Talc
10.75 Silica
6.45 Dolomite
100.00 % Totals:
Also add:
4.30 Zircopax
3.23 Cobalt Carbonate
comments:
From the ClayArt Glaze Recipe Database at SDSU.
If you test this glaze and find it useful
please consider resubmitting it to the GlazeBase database.
estimated thermal expansion: 70.11x10-7/=B0C
Unity Formula for Emily's Blue:
0.109 K2O 0.260 Al2O3 2.415 SiO2
0.096 Na2O 0.221 B2O3 0.005 TiO2
0.361 CaO 0.003 Fe2O3 9.3:1 Si:Al Ratio
0.434 MgO
Percentage Analysis for Emily's Blue:
59.98 % SiO2
10.96 % Al2O3
6.33 % B2O3
4.26 % K2O
2.48 % Na2O
8.36 % CaO
7.24 % MgO
0.21 % Fe2O3
0.17 % TiO2
submitted by: Rick Malmgren e-mail: r-malmgren@sjca.edu
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D
I make it a little different. Here is my way recalculated to "your" materi=
als:
EMILY'S PURPLE CLAYART
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Cone 6 1222 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Ferro 3134 23.20
Nepheline Syenite 16.10
EPK 17.20
ultrox 9.40
talc Nital 22.40
Flint 11.50
Cobalt Oxide 3.00
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Seger Weight%
KNO 0.201 4.93%
CaO 0.332 6.97%
MgO 0.467 7.05%
Al2O3 0.281 10.73%
B2O3 0.216 5.62%
SiO2 2.580 58.07%
ZrO2 0.143 6.62%
K2O 0.022 0.78%
Na2O 0.179 4.15%
Al:Si 9.17
Expan. 6.28
ST 363.32
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
I add here another recipe I have adjusted to ^6 try this one too at ^8
violet^6
=3D=3D=3D=3D=3D=3D=3D=3D
NEPHELINE SYENI 41.40 40.59%
DOLOMITE............ 11.70 11.47%
MAGNESIUM CA. 5.40 5.29%
WHITING............. 4.50 4.41%
QUARTZ.............. 27.00 26.47%
GERSTLEY B.... 10.00 9.80%
*COBALT CARBON 2.00 1.96%
=3D=3D=3D=3D=3D=3D=3D=3D
102.00
CaO 0.39* 8.43%w 10.69%m
MgO 0.34* 5.25%w 9.26%m
K2O 0.06* 2.00%w 1.51%m
Na2O 0.21* 4.97%w 5.70%m
SrO 0.00* 0.01%w 0.01%m
Al2O3 0.25 9.92%w 6.92%m
B2O3 0.11 2.92%w 2.99%m
SiO2 2.32 53.19%w 62.90%m
Fe2O3 0.00 0.06%w 0.03%m
Text1 8.64
L.O.I. 13.23
Si:Al 9.10
SiB:Al 9.53
Expan 7.56
Notes: adjusted by Ababi to ^6 from a recipe
of Ruth Ballou rballou@bellatlantic.net
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
Now back to the ceramic web:
There were 3 more "Emilys"
Glaze Name: Emily G. Purple
cone: 9
color:
surface:matt
firing:Untested
date: 6/3/96
recipe:
41.00 Potash Feldspar
12.00 Colemanite
7.00 Dolomite
15.00 Talc
5.00 Tennessee #5 Ball Clay
20.00 Silica
100.00 % Totals:
Also add:
2.00 Cobalt Oxide
2.00 Bentonite
2.00 Tin Oxide
Unity Formula for Emily G. Purple:
0.137 K2O 0.247 Al2O3 2.967 SiO2
0.060 Na2O 0.250 B2O3 0.003 TiO2
0.369 CaO 12.0:1 Si:Al Ratio
0.435 MgO
Percentage Analysis for Emily G. Purple:
64.60 % SiO2
9.14 % Al2O3
6.31 % B2O3
4.68 % K2O
1.34 % Na2O
7.50 % CaO
6.34 % MgO
0.07 % TiO2
Possible Health Hazards: Talc: wear a NIOSH approved dust mask when handli=
ng dry
material Silica: free silica-wear a NIOSH approved dust mask when handling=
dry
material
Here's a ^9 Emily G. Purple I used to use 15 years ago. Maybe it is the sa=
me one you
are looking for. It has a wonderful buttery texture and is very purple. su=
bmitted by:
Elizabeth Beth Fusaro e-mail: elfusaro@freenet.scri.fsu.edu
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
I am not so sure about high fire glazes. It seems to me that it has too m=
uch silica. Try
to remove some it might be glossier.
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
Here is the version for ^8 of Emily
33.33 Custer Feldspar
17.71 Gerstley Borate
15.62 OM-4 Ball Clay
13.54 Talc
13.54 Silica
6.25 Dolomite
100.00 % Totals:
Also add:
4.17 Zircopax
3.12 Cobalt Carbonate
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
In the ^10 version they forgot to add the colorants
41.00 Potash Feldspar
12.00 Gerstley Borate
7.00 Dolomite
15.00 Talc
5.00 Ball Clay
20.00 Silica
100.00 % Totals:
Keep glazing
Ababi
---------- Original Message ----------
>Hi, Everyone,
>Got lots of responses to my questions about Purple, and
>thought I'd answer them all at once...
>Phil Smith, I fire to cones 8-10, depending on the glaze
>I'm using. Most are crystalline glazes but I do some (few)
>others from time to time. I'd love to try your C10R glaze.
>I'll try that Seacrest Purple and see how it works, though
>again, it looks very brown. (Although it's a funny thing,
>I find as I get older it's become harder for me to distinguish
>purple from brown Prismacolors or markers when they're all
>jumbled together on the floor because some cat knocked them
>all over...)
>Ababi, I've tried Mason stains but I've never gotten a true
>purple from them. They seem to give me a muddy brownish
>purple. I'm looking for the true high-saturation violet
>you find in an amethyst. And perfectly transparent too,
>which I've never been able to get with a stain (although
>here's a hint -- Mason Pansy Purple will go far to keep
>your crystals white in a high-titanium glaze).
>Lisa Skeen, I've tried several red-blue combinations...
>and usually got mud. The best sort of fake purple I
>ever got was a combination of CoCO3 and a little CuCO3,
>reduced. It was nice but it was only purple from a distance,
>and if wasn't transparent. Chrome-Tin reds and pinks don't
>seem to "play well with others" in my experience.
>Iandol: The manganese wash sounds very promising. Ilene
>Mahler gets a lovely Tanzanite color that way. Which leads
>to another question: how do you tell if your gas kiln is
>fully oxidizing? I have a feeling mine isn't because I
>always end up with a little carbon around the top port after
>a fire.
>Everybody: Neodymium does give a lovely light putple but
>I've found generally I can't concentrate it enough in a
>glaze to give an amethyst color. It's a hellova flux.
>Maybe I'm going at this from the wrong angle ...
>Maybe what I need to sort out is all the things that _don't_
>give you violet and, to paraphrase Holmes, "whatever remains
>must be the recipe."
>Hmmm. There's got to be a way to get a glossy, completely
>transparent, fully saturated violet. Just gotta. Hmmm....
>Somebody tell me it can't be done, and then I'll _have_ to!
>Fa
Fredrick Paget on sat 3 may 03
There is a purple color that is used in making low fire decals for
ceramics. They say it is based on gold.
See: http://www.beldecal.com/ceramic.cfm #0365.
Testing this might be a bit expensive.
Anybody know about the use of gold chemicals in glazes?
Fred
From Fred Paget, Marin County, California, USA
John Hesselberth on sat 3 may 03
Hi Jon,
They can be semi-transparent or translucent, but I haven't seen one
that is transparent. They are transparent enough, though, to look
quite different on white vs. tan stoneware.
Regards,
John
On Saturday, May 3, 2003, at 01:07 AM, Jon Singer wrote:
> whether Cr+Sn can be used to make transparent glazes?
http://www.frogpondpottery.com
http://www.masteringglazes.com
Jon Singer on sat 3 may 03
Lisa Skeen rightly points out that she didn't say "stain" when she
mentioned
Cr-Sn. My apologies. (I tend to think of the Cr-Sn and Cr-Al pigments as
being generally similar to the kinds of stains potters frequently use,
and in fact
you can actually buy some of the Cr-Sn combinations as commercial
stains --
for example, Mason 6000 through 6006.)
I haven't tried Cr-Sn; but as I say, I have not been able to get
transparency
with Cr-Al (except in a high-Boron glaze that dissolved it, and fired
out to
a sort of snotty yellow-brown color); can anybody say, one way or the
other,
whether Cr+Sn can be used to make transparent glazes?
Cheers --
jon
PS: Judging from the analysis of Emily's Purple (thanks, Ababi!) it is
indeed
a Mg-matte glaze, and that rules it out for this particular
application. OTOH,
it might be interesting to see whether the purple color can be had
without the
matte surface in a glaze with _relatively_ high Mg content, and I will
definitely
be trying this. (Many strange things affect the colors of transition
metal ions!!)
Liz Gowen on sun 4 may 03
The purple colors in china paints come from gold but are fired at a much
lower temp.018 and of course are expensive. I have put it on after
highfiring a piece put it is not that clear purple but not bad.
I have used a crimson stain with a glaze from one of coopers books ^6.
The color respnse can be good, transluscent to transparent where thin with
good color but is fickle as to application. I only did color tests with it
and then put it on hold. Think the glaze needs a bit of tightning up esp for
verticles ( my experiment was for carved tiles) Looking at a tiny mug I made
yrs ago with a red white and blue combo some of the cross overs look
purplish. I still have some glaze made so will play with it a bit and let
you know.
I have seen a chinese vase transparent turquoise vase with transparent
grape lifesaver handles so it must be able to be done . I had searched for a
while then forgot about it. you have repeeked my interest.
Liz Gowen NJ
> There is a purple color that is used in making low fire decals for
> ceramics. They say it is based on gold.
> See: http://www.beldecal.com/ceramic.cfm #0365.
> Testing this might be a bit expensive.
> Anybody know about the use of gold chemicals in glazes?
> Fred
>
> From Fred Paget, Marin County, California, USA
>
>
____________________________________________________________________________
__
> 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
melpots@pclink.com.
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