carrie or peter jacobson on wed 6 jan 99
Hi Chris, I, too, experimented with those reds a while ago. I tried berry
rust and the tomato red. Both came out, essentially, brown. Not too bad
browns, reddish browns, but I had hoped for, well, tomato red. I fire in an
electric kiln to cone 6.
I did notice one thing: I did tests on porcelain and on red stoneware, and
on the stoneware, the reds were much more pronounced than on the porcelain.
On the porcelain, these glazes were simply brown. Buster Brown shoe polish
brown. Ick.
So if I am thinking correctly, (always a big if), it seems as though some
of the iron in the red clay has helped to bring out the red in the glaze.
So a red iron oxide wash might help magnify the red? I haven't tried this yet.
Also, putting at least the berry rust on more thickly has brought out some
of the red... I actually have come to really like this glaze, it's quiet
and deep...
Best,
Carrie
Carrie Jacobson
Pawcatuck, CT
mailto:jacobson@brainiac.com
Janet Price on thu 7 jan 99
Chris,
Try refiring the "brown" iron reds at cone 04. This sometimes makes
them turn red. Don't know why, but it does. Just put them in with your
next bisque firing.
--
Janet Price, Chief Information Officer
Carroll College, Waukesha WI 53186
jprice@carroll1.cc.edu or jprice@ccadmin.cc.edu
414-524-7120
Judy Musicant on thu 7 jan 99
Chris, and all you cone 6'ers out there,
A real standby iron red in these here parts is Randy's Red:
Flint ---------------------30
EPK ---------------------- 5
F4 Kona Feldspar ---20
Talc ----------------------14
Gerst. Borate ---------32
RIO(Special) -----------15
Bentonite ---------------- 2
I think this is a pretty well known iron red glaze - I know I've seen it
printed in CM and it's a standard around my area. This is a very stable
glaze in that it has a pretty wide firing range and doesn't run. It breaks
nicely over sharp edges, and works very well with a variety of other glazes.
It does vary a little bit in terms of it's being sometimes more red and
sometimes more brown. My experience in getting a rich, rusty red has been
good on both white and red clays (probably somewhat better on red, but still
usually luscious on white). I think I've gotten the best red results when I
slow down the cooling process somewhat (but not too much, or I've gotten
large areas of, too me, an ugly kahki), and don't open the kiln lid to peak
at all until it's completely cool. Good luck.
Judy Musicant
Dee Clay on fri 8 jan 99
Judy,
Is this recipe for oxidation?
Thanks, Diane in Miami
Lori Pierce on sat 9 jan 99
-----Original Message-----
From: Judy Musicant
To: CLAYART@LSV.UKY.EDU
Date: Thursday, January 07, 1999 10:19 AM
Subject: iron reds
----------------------------Original message----------------------------
Chris, and all you cone 6'ers out there,
A real standby iron red in these here parts is Randy's Red:
Flint ---------------------30
EPK ---------------------- 5
F4 Kona Feldspar ---20
Talc ----------------------14
Gerst. Borate ---------32
RIO(Special) -----------15
Bentonite ---------------- 2
I think this is a pretty well known iron red glaze - I know I've seen it
printed in CM and it's a standard around my area. This is a very stable
glaze in that it has a pretty wide firing range and doesn't run. It breaks
nicely over sharp edges, and works very well with a variety of other glazes.
It does vary a little bit in terms of it's being sometimes more red and
sometimes more brown. My experience in getting a rich, rusty red has been
good on both white and red clays (probably somewhat better on red, but still
usually luscious on white). I think I've gotten the best red results when I
slow down the cooling process somewhat (but not too much, or I've gotten
large areas of, too me, an ugly kahki), and don't open the kiln lid to peak
at all until it's completely cool. Good luck.
Hi Judy...I'm very glad to have your Randy's Red Glaze to try...I've been
looking for a good oxidation red. I am not familiar with RIO Special..can
you be more specific? I have been looking for a light, bright orange red
oxide , but my local supplier carries only a spanish red and dark oxide.
thanks, Lori in Florida, New Port Richey
Joy Holdread on tue 12 jan 99
In a message dated 1/7/99 8:05:09 AM US Mountain Standard Time,
huju1404@email.msn.com writes:
> Chris, and all you cone 6'ers out there,
>
> A real standby iron red in these here parts is Randy's Red:
>
> Flint ---------------------30
> EPK ---------------------- 5
> F4 Kona Feldspar ---20
> Talc ----------------------14
> Gerst. Borate ---------32
> RIO(Special) -----------15
> Bentonite ---------------- 2
>
> I think this is a pretty well known iron red glaze - I know I've seen it
> printed in CM and it's a standard around my area. This is a very stable
> glaze in that it has a pretty wide firing range and doesn't run. It breaks
> nicely over sharp edges, and works very well with a variety of other
glazes.
> It does vary a little bit in terms of it's being sometimes more red and
> sometimes more brown. My experience in getting a rich, rusty red has been
> good on both white and red clays (probably somewhat better on red, but
still
> usually luscious on white). I think I've gotten the best red results when
I
> slow down the cooling process somewhat (but not too much, or I've gotten
> large areas of, too me, an ugly kahki), and don't open the kiln lid to peak
> at all until it's completely cool. Good luck.
>
> Judy Musicant
>
What's RIO special? A specific type of Red Iron Oxide?
Joy in Tucson
Stephani Stephenson on wed 13 jan 99
I found that cooling cylcle is very important in development of iron
reds.
My iron reds were gorgeous when I slowed down the cooling cyle, i.e.
when I didn't start pulling plugs and cracking vents....(you know, the
overpowering "I wanna see it NOW" urge!)
My understanding , in semi scientific terms, is that when you allow the
kiln to cool slowly, MORE iron molecules have MORE time at active high
temperatures to bond with MORE oxygen, making them MORE red. Reactions
happen in the kiln on the way down as well as on the way up. A slower
cooling cycle lets those iron reds do the oxygen tango "just a little
bit longer....."
Stephani Stephenson
Nottingham center
San Marcos CA
arcilla@inetworld.net
Diana Pancioli on thu 14 jan 99
Might also be that the iron has a chance to form crystals during a slow
cool.
Diana
On Wed, 13 Jan 1999, Stephani Stephenson wrote:
> ----------------------------Original message----------------------------
> I found that cooling cylcle is very important in development of iron
> reds.
> My iron reds were gorgeous when I slowed down the cooling cyle, i.e.
> when I didn't start pulling plugs and cracking vents....(you know, the
> overpowering "I wanna see it NOW" urge!)
> My understanding , in semi scientific terms, is that when you allow th
> kiln to cool slowly, MORE iron molecules have MORE time at active high
> temperatures to bond with MORE oxygen, making them MORE red. Reactions
> happen in the kiln on the way down as well as on the way up. A slower
> cooling cycle lets those iron reds do the oxygen tango "just a little
> bit longer....."
>
> Stephani Stephenson
> Nottingham center
> San Marcos CA
> arcilla@inetworld.net
>
Cindy Strnad on thu 22 nov 01
Here's the recipe I use for iron reds. Beware:
like all iron reds, it *runs*.
Red Brown ^6 Oxidation
Cheryl Litman
========================
SILICA.............. 28.00 24.56%
EPK KAOLIN.......... 5.00 4.39%
CUSTER FELDSPAR..... 20.00 17.54%
TALC................ 14.00 12.28%
GERSTLEY BORATE..... 32.00 28.07%
IRON OXIDE RED...... 15.00 13.16%
========
114.00
CaO 0.38* 6.67%
MgO 0.44* 5.64%
K2O 0.07* 2.00%
Na2O 0.12* 2.26%
TiO2 0.00 0.02%
Al2O3 0.17 5.52%
B2O3 0.41 8.98%
P2O5 0.00 0.01%
SiO2 2.87 54.57%
Fe2O3 0.28 14.32%
Cost/kg 0.95
Si:Al 16.78
SiB:Al 19.16
Expan 7.00
Notes:
For Blue breaking Purple, add:
Cobalt Carb 3.5
Manganese 0.5
You will notice: No tin, no bone ash. However, I,
too, have noticed the presence of either talc
and/or bone ash in iron red glazes. Unfortunately,
this one requires loads of Gerstley. It's a very
nice iron red, but it does need the re-fire with a
bisque load. I haven't tried a slow cool on this
one--maybe that would work. Because of the running
problem, I don't use this glaze a lot, so I
haven't experimented with it as much as I have
with some others. Also, I haven't tried adding the
Cobalt and Manganese--I had forgotten about that
and will have to try it.
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
cindy@earthen-vessels-pottery.com
http://www.earthen-vessels-pottery.com
Ben on wed 3 nov 04
If you'd be so kind. What's the trick to getting an iron red, red? I'm =
working with Bailey Red from John Britt's book. Firing cycle's really =
what I'm asking.=20
Thanks,
Ben
John Britt on wed 3 nov 04
Ben,
The best firing cycle I have found is an oxidation cycle with a brief
reduction period at the peak. (I call it O2), See Kaki firing cycle on
page 74.
If you fire in heavy reduction they will be brown. Mild reduction will
give more orange particularly if you oxidize at the peak.
Good Luck,
John
Ron Roy on fri 5 nov 04
Hi Ben,
If you cool em too fast they won't develope the red properly - refire on in
a bisque firing to see if that is the problem.
If so use a slow cool to get em up. Drop to 1000C and hold for a couple of
hours - or drop at 50C per hour till 800C. The longer the slow cooling the
more red usually - but there must be a limit.
RR
>If you'd be so kind. What's the trick to getting an iron red, red? I'm
>working with Bailey Red from John Britt's book. Firing cycle's really what
>I'm asking.
>Thanks,
>Ben
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Vince Pitelka on fri 27 oct 06
> I want to know the mechanism of an iron red; viz., what is is that
> makes it red, and not orange, brown, or black. For example, a local
> potter here has a gorgeous iron red ... with 12% red iron oxide.
> She's also got a tenmoku with 8% red iron oxide. Obviously there is
> something in the composition of the base glazes that is fundamentally
> different, because just 4% red iron oxide doesn't make the tenmoku a
> kaki (I tried it once). So I've looked at her recipe, and other iron
> reds from around the internet (and a book or two), and I noticed that
> most, if not all of the iron red glazes have bone ash in them - which
> I to me appears significant because it supplies P2O5, while the other,
> non-red iron glazes do not. So ... is the phosphorus is essential?
> If not, then what directions should I go to formulate an iron red on
> my own (because I'm not really interested in recipes from others
> except as an academic point)?
Tim -
Yes, that makes sense, except for the last line. All of the saturated iron
red kaki glazes I have encountered have bone ash in them, and I don't know
if it is possible to make one without it. Phosphorus seems necessary for a
good, irridescent kaki, and I can't think of another source. Experimentation
is always fun, and you will learn things in the process, so it's a worthy
endeavor. Experiment away with bone ash content and silica/alumina ratio,
and let us know your results.
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Timothy Joko-Veltman on fri 27 oct 06
Hello all ... until now, I've been a non-subscribing lurker to the
list (ie., I read the archives voraciously), but now I've finally
decided to emerge into the light.
Anyway. Lately, I've trying to formulate an Iron Red for cone 10
electric. Though there are recipes to be found in abundance on the
internet and off, I'm trying to formulate one on my own in an effort
to understand the glaze more thoroughly. But that hasn't kept me from
looking at all the on- and off-line recipes, and one thing I've
noticed is that practically all of them have some amount of P2O5 -
usually supplied by Bone Ash - and appear fairly soft, with alumina
never higher than about 0.35, and frequently less. So ... I have a
couple questions:
1) Do high-fire, oxidation Iron Reds depend on phosphorus? If so, has
anyone tried with Cornwall Stone?
2) Are Iron Reds possible in a higher alumina glazes (ie., 0.5-0.6)?
I guess that was 3 questions, and not a "couple", but who's counting, right?
Cheers,
Tim
Hank Murrow on fri 27 oct 06
On Oct 27, 2006, at 2:16 PM, Timothy Joko-Veltman wrote:
>
> Anyway. Lately, I've trying to formulate an Iron Red for cone 10
> electric. Though there are recipes to be found in abundance on the
> internet and off, I'm trying to formulate one on my own in an effort
> to understand the glaze more thoroughly. But that hasn't kept me from
> looking at all the on- and off-line recipes, and one thing I've
> noticed is that practically all of them have some amount of P2O5 -
> usually supplied by Bone Ash - and appear fairly soft, with alumina
> never higher than about 0.35, and frequently less. So ... I have a
> couple questions:
>
> 1) Do high-fire, oxidation Iron Reds depend on phosphorus? If so, has
> anyone tried with Cornwall Stone?
It would have to be an old source, as far as I know the P2O5 is not in
there any more.
> 2) Are Iron Reds possible in a higher alumina glazes (ie., 0.5-0.6)?
My Shino which can be bloody red is 1.56 Al2O3! Fired in a gas kiln.
The high Al types seem to need the reduction to provoke the body Fe to
color the glaze.
Cheers, Hank
www.murrow.biz/hank
Vince Pitelka on fri 27 oct 06
Tim -
I guess I don't understand the whole premise of your question. Any cone ten
kaki (iron red) recipe should give you a blazing iron red in oxidation.
It's in exessive reduction that iron reds get muddy. It does seem that bone
ash is necessary for good kaki glazes. It's hard to get a good saturated
iron red without it.
Good luck -
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Timothy Joko-Veltman on fri 27 oct 06
> > 1) Do high-fire, oxidation Iron Reds depend on phosphorus? If so, has
> > anyone tried with Cornwall Stone?
>
> It would have to be an old source, as far as I know the P2O5 is not in
> there any more.
>
Ok. I'll be sure check the composition with the supplier, and do some
tests of my own, then.
> > 2) Are Iron Reds possible in a higher alumina glazes (ie., 0.5-0.6)?
>
> My Shino which can be bloody red is 1.56 Al2O3! Fired in a gas kiln.
> The high Al types seem to need the reduction to provoke the body Fe to
> color the glaze.
Shino's are reduction iron glazes, so you can have loads of alumina,
because iron is such a powerful flux.
John Britt on fri 27 oct 06
Timothy,
In this recipe:
ANDERSON RANCH Cone 10
Custer Feldspar 45.00
Silica 20.00
Whiting 7.00
Kentucky Ball Clay 8.00
EPK Kaolin 8.00
Bone Ash 12.00
Red Iron Oxide 13.50
According to Matrix Glaze Software the silica is 0.48. That is about as
high as I have seen with Iron Reds.
Since you are adding 10 -15% Bone Ash and sometimes 2.5 % Lithium
Carbonate (which really helps with the color) that reduces the available
space for other things in the recipe.
For example if you take:
BAILEY'S IRON RED cone 10
Custer Feldspar 47.00
Silica 13.00
Talc 10.50
EPK Kaolin 13.00
Bone Ash 14.00
Lithium Carbonate 2.50
Red Iron Oxide 8.00
And you leave out the Lithium and the Bone Ash the recipe is:
BAILEY IRON RED cone 10 (w/o Bone Ash and LC)
Custer Feldspar 56.28
Silica 15.56
Talc 12.57
EPK Kaolin 15.56
Red Iron Oxide 9.58
The alumina is now 0.74 or so. But now you would have a satiny temmoku or
maybe an Oil Spot.
But it would be easy enough to take a high alumina glaze and try a line
blend with Bone Ash and find out yourself.
The highest alumina glazes I know (except shinos!) are Oil Spots. There is:
BAILEY OIL SPOT Cone 10/11
Custer Feldspar 25.51
NC-4 Soda Feldspar 35.71
EPK Kaolin 15.30
Talc 5.10
Dolomite 5.10
Ferro 3110 5.10
Silica 8.16
Red Iron Oxide 6.00
It has about 0.73 alumina. But if you add the Bone Ash at 10% and the
Lithium Carbonate at 2.5% you get a glaze with 0.46 alumina.
Someone else may have the magic bullet you are looking for, but I really
don=92t think you need 0.5 or 0.6 alumina to have a durable glaze! There are=
lots of very durable glazes with 0.48 alumina (celadons and temmokus for
starters). You need good amounts of silica too!
Hope it helps,
John Britt
www.johnbrittpottery.com
Hank Murrow on fri 27 oct 06
On Oct 27, 2006, at 5:23 PM, Timothy Joko-Veltman wrote:
>> > 2) Are Iron Reds possible in a higher alumina glazes (ie., 0.5-0.6)?
>>
>> Hank Replied:
>> My Shino which can be bloody red is 1.56 Al2O3! Fired in a gas kiln.
>> The high Al types seem to need the reduction to provoke the body Fe to
>> color the glaze.
>
> Shino's are reduction iron glazes, so you can have loads of alumina,
> because iron is such a powerful flux.
Say, just want to point out that there is no iron in Hank's Shino. If
one scratches through the intense indian red color, there is white
underneath and right through to the clay body. See the article in CM
here: http://www.ceramicsmonthly.org/mustreads/shinofire.asp for more
on this.
Cheers, Hank
www.murrow.biz/hank
Timothy Joko-Veltman on fri 27 oct 06
Vince, thanks for your reply.
I want to know the mechanism of an iron red; viz., what is is that
makes it red, and not orange, brown, or black. For example, a local
potter here has a gorgeous iron red ... with 12% red iron oxide.
She's also got a tenmoku with 8% red iron oxide. Obviously there is
something in the composition of the base glazes that is fundamentally
different, because just 4% red iron oxide doesn't make the tenmoku a
kaki (I tried it once). So I've looked at her recipe, and other iron
reds from around the internet (and a book or two), and I noticed that
most, if not all of the iron red glazes have bone ash in them - which
I to me appears significant because it supplies P2O5, while the other,
non-red iron glazes do not. So ... is the phosphorus is essential?
If not, then what directions should I go to formulate an iron red on
my own (because I'm not really interested in recipes from others
except as an academic point)?
But the bone ash wasn't the only difference; I noticed that there was
also a fairly low amount of alumina in iron reds I looked at, and so I
though that that too, had a bearing. Then again, maybe not. Hence
the question.
Am I making more sense, now?
Tim
On 10/27/06, Vince Pitelka wrote:
> Tim -
> I guess I don't understand the whole premise of your question. Any cone ten
> kaki (iron red) recipe should give you a blazing iron red in oxidation.
> It's in exessive reduction that iron reds get muddy. It does seem that bone
> ash is necessary for good kaki glazes. It's hard to get a good saturated
> iron red without it.
> Good luck -
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft, Tennessee Technological University
> Smithville TN 37166, 615/597-6801 x111
> vpitelka@dtccom.net, wpitelka@tntech.edu
> http://iweb.tntech.edu/wpitelka/
> http://www.tntech.edu/craftcenter/
>
> ______________________________________________________________________________
> 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.
>
Ivor and Olive Lewis on sat 28 oct 06
Perhaps one way to find the answer is to have one of the mature glazes =
that produces this colour analysed. It would require a way of isolating =
the coloured fraction or one of the hight powered spectrographic =
methods.
Looking through the chemical lists in the CRC handbook does not show any =
compounds of Iron and Phosphorus that are red, Yellow, grey, white etc =
but not mention of red.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
Marcia Selsor on sat 28 oct 06
Michael Cardew explains the matrix development iron reds in Pioneer
Pottery.
I think (its been years since I read this) that the basic ingredients
are iron, bone ash and tin.
So you are correct in your observations.
Marcia Selsor
http://marciaselsor.com
006, at 8:55 PM, Timothy Joko-Veltman wrote:
> Vince, thanks for your reply.
>
> I want to know the mechanism of an iron red; viz., what is is that
> makes it red, and not orange, brown, or black. For example, a local
> potter here has a gorgeous iron red ... with 12% red iron oxide.
> She's also got a tenmoku with 8% red iron oxide. Obviously there is
> something in the composition of the base glazes that is fundamentally
> different, because just 4% red iron oxide doesn't make the tenmoku a
> kaki (I tried it once). So I've looked at her recipe, and other iron
> reds from around the internet (and a book or two), and I noticed that
> most, if not all of the iron red glazes have bone ash in them - which
> I to me appears significant because it supplies P2O5, while the other,
> non-red iron glazes do not. So ... is the phosphorus is essential?
> If not, then what directions should I go to formulate an iron red on
> my own (because I'm not really interested in recipes from others
> except as an academic point)?
>
> But the bone ash wasn't the only difference; I noticed that there was
> also a fairly low amount of alumina in iron reds I looked at, and so I
> though that that too, had a bearing. Then again, maybe not. Hence
> the question.
>
> Am I making more sense, now?
>
> Tim
>
> On 10/27/06, Vince Pitelka wrote:
>> Tim -
>> I guess I don't understand the whole premise of your question.
>> Any cone ten
>> kaki (iron red) recipe should give you a blazing iron red in
>> oxidation.
>> It's in exessive reduction that iron reds get muddy. It does seem
>> that bone
>> ash is necessary for good kaki glazes. It's hard to get a good
>> saturated
>> iron red without it.
>> Good luck -
>> - Vince
>>
>> Vince Pitelka
>> Appalachian Center for Craft, Tennessee Technological University
>> Smithville TN 37166, 615/597-6801 x111
>> vpitelka@dtccom.net, wpitelka@tntech.edu
>> http://iweb.tntech.edu/wpitelka/
>> http://www.tntech.edu/craftcenter/
Lee Love on sat 28 oct 06
On 10/28/06, Vince Pitelka wrote:
> Tim -
> Yes, that makes sense, except for the last line. All of the saturated iron
> red kaki glazes I have encountered have bone ash in them, and I don't know
> if it is possible to make one without it.
The original Kaki, Mashiko Kaki, has no bone ash in it. It is
simply made from ground up stone (Ashinuma Seki.) It is pretty low
in P2O5 = .22 So, in the synthetic recipe, you only have .5% bone
ash. Hamada added wood ash to kaki for his tenmoku.
But Mashiko Kaki it ain't a real red kaki. It really isn't
the orange of the Kaki/persimmon either.
Kaki was used similarly to Albany Slip back home. Melts at
SK 4, so was used as a liner glaze in the traditional noborigama. Was
even used to glaze roof tiles.
--
Lee in Mashiko, Japan
http://potters.blogspot.com/
"Let the beauty we love be what we do." - Rumi
"When we all do better. We ALL do better." -Paul Wellstone
Timothy Joko-Veltman on sat 28 oct 06
On 10/28/06, Marcia Selsor wrote:
> Michael Cardew explains the matrix development iron reds in Pioneer
> Pottery.
> I think (its been years since I read this) that the basic ingredients
> are iron, bone ash and tin.
> So you are correct in your observations.
> Marcia Selsor
> http://marciaselsor.com
Marcia,
That's interesting, I had seen some references to tin in iron reds
(ie., in Hopper's "The Ceramic Spectrum"), but interestingly, none of
the recipes I've encountered online have any tin in them. Will
definitely have to try that out.
Thanks for bringing that up ... I'll be sure to check that out.
Vince,
Rereading that "last line [that doesn't make sense]", I realize I
mispoke myself. Recipes are great - but for me, I want a fundamental
understanding of my glazes, not to mention a pride in and
psychological connection to my work, so I look at recipes mostly as
hints for formulating my own glazes.
As for other sources, in Insight's default material database, many of
the wood ashes are listed as containing a significant amount of P2O5.
Of course, mileage *always* varies with ash composition, but this has
given me some interesting ideas.
Again, thanks for your input.
Cheers all around,
Tim
Tim
Timothy Joko-Veltman on sat 28 oct 06
On 10/27/06, Hank Murrow wrote:
> On Oct 27, 2006, at 5:23 PM, Timothy Joko-Veltman wrote:
>
> >> > 2) Are Iron Reds possible in a higher alumina glazes (ie., 0.5-0.6)?
> >>
> >> Hank Replied:
>
> >> My Shino which can be bloody red is 1.56 Al2O3! Fired in a gas kiln.
> >> The high Al types seem to need the reduction to provoke the body Fe to
> >> color the glaze.
> >
> > Shino's are reduction iron glazes, so you can have loads of alumina,
> > because iron is such a powerful flux.
>
> Say, just want to point out that there is no iron in Hank's Shino. If
> one scratches through the intense indian red color, there is white
> underneath and right through to the clay body. See the article in CM
> here: http://www.ceramicsmonthly.org/mustreads/shinofire.asp for more
> on this.
>
> Cheers, Hank
> www.murrow.biz/hank
Interesting ... thanks for the link!
Tim
Timothy Joko-Veltman on sun 29 oct 06
On 10/28/06, Ivor and Olive Lewis wrote:
> Perhaps one way to find the answer is to have one of the mature glazes that produces this colour analysed. It would require a way of isolating the coloured fraction or one of the hight powered spectrographic methods.
> Looking through the chemical lists in the CRC handbook does not show any compounds of Iron and Phosphorus that are red, Yellow, grey, white etc but not mention of red.
> Best regards,
> Ivor Lewis.
> Redhill,
> South Australia.
But it doesn't have to be a Fe-P compound ... P could simply ba a
catalyst, or perhaps it's the unusual combination of Fe, P, Al, Si,
and Ca. I imagine there are other possibilities. Analysis of some of
the red semi-precious stones might be of interest as well (not that I
have the resources for this kind of analysis, at the moment).
Cheers,
Tim
Hank Murrow on sun 29 oct 06
On Oct 29, 2006, at 4:09 AM, Timothy Joko-Veltman wrote:
> But it doesn't have to be a Fe-P compound ... P could simply ba a
> catalyst, or perhaps it's the unusual combination of Fe, P, Al, Si,
> and Ca. I imagine there are other possibilities.
I use Ferric Phosphate whenever I want the Iron and the Phosphorus but
not the Calcium that comes in the bone ash. Got a 40# drum from a
chemical company in San Francisco years ago. Can't remember their name.
The cheapest grade will do.
Cheers, Hank
www.murrow.biz/hank
Ivor and Olive Lewis on sun 29 oct 06
Yes, Michael Cardew makes for good reading and makes it quite clear that =
Alkali Earth Oxides should be excluded and there is neither phosphorus =
nor tin in his formulation. He points out that the Iron oxide should not =
dissolve in the molten glaze. Read pp 144-8.
Best regards and good luck with your trials.
Ivor Lewis.
Redhill,
South Australia.
Ivor and Olive Lewis on mon 30 oct 06
Dear Timothy Joko-Veltman ,
True, Phosphorus might be a catalyst. Thinking of the Silicon dioxide =
gems there is Carnelian and Opal gives optical reds of great brilliance.
De Boos et al in "Handbook for Australian Potters" give a Tomato Red (P =
70) that has bone ash.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
Des & Jan Howard on mon 30 oct 06
Ivor
Does the colour necessarily have to be a compound of iron & phosphorus?
It's possible the phosphorus is producing a glass that iron oxide is
insoluble in.
The red of shino glazes comes from iron oxide (haematite) crystals.
Des
Ivor and Olive Lewis wrote:
>Perhaps one way to find the answer is to have one of the mature glazes that produces this colour analysed. It would require a way of isolating the coloured fraction or one of the hight powered spectrographic methods.
>Looking through the chemical lists in the CRC handbook does not show any compounds of Iron and Phosphorus that are red, Yellow, grey, white etc but not mention of red.
>
>
--
Des & Jan Howard
Lue Pottery
LUE NSW 2850
Australia
Ph/Fax 02 6373 6419
http://www.luepottery.hwy.com.au
Timothy Joko-Veltman on wed 1 nov 06
On 10/30/06, Ivor and Olive Lewis wrote:
> Dear Timothy Joko-Veltman ,
>
> True, Phosphorus might be a catalyst. Thinking of the Silicon dioxide gems there is Carnelian and Opal gives optical reds of great brilliance.
>
> De Boos et al in "Handbook for Australian Potters" give a Tomato Red (P 70) that has bone ash.
>
Thanks Ivor. I don't have access to that book, but I did find another
"Tomato Red" on the internet ... also contains bone ash, but probably
not the same recipe.
Cheers,
Tim
John Britt on wed 1 nov 06
Tim,
I am sure you know this but just in case, Tomato Red, Kaki, Ohata Kaki,
Iron Red, and Persimmon are often used interchangeably. There are other
official "definitions" of the terms, like Kaki, but in America the recipes
are often the same or very similar.
Good Luck,
John Britt
www.johnbrittpottery.com
John Sankey on fri 13 jul 07
Further to Carol Marians' work
http://www.ceramicsmonthly.org/currentissue.asp
on dwell periods during cooling of iron reds, I've extended her
work by taking microphotos of the various stages. They are up at
http://sankey.ws/glazeiron.html
They show every colour of the kaleidoscope that has been reported
for these glazes, including the blue. They also show the need for
some chemistry expertise, as there are two distinct components to
this glaze, one of which changes only to a small extent in
colours, the other that provides all the bright ones. I'm certain
that small quantities of some elements might reliably change the
appearance of the latter in the directions we want but, not being
a chemist, I don't have the tools to work on that.
I'm going to explore Kevin Balwin's glaze
http://kevinbaldwinpottery.co.uk/glazes.htm
next, to see if I can get more of the reds he shows.
--
(Add 'Byrd' to the subject line of your reply to get through my spam filter)
mudduck on sun 6 dec 09
Does any one know of an iron red glaze for cone 10 reduction that is not =
=3D
so sensitive to application?? I'm currently using Bailey's Iron red =3D
recipe. It is a beautiful glaze when applied just right, but if I get it =
=3D
just a little to thick it's the ugliest greenish brown I've seen. It =3D
would be nice to find one that was a little more forgiving.
Thanks for any help!!
Gene
mudduck@mudduckpottery.net
www.mudduckpottery.net
Carolyn Boeri on mon 7 dec 09
Hi,
I discovered a very nice toasty iron chinese red for cone 6 oxidation that
may be able to be converted to 10 reduction with some tweeking of the flint=
.
I have done that before with temoku the other way around, with not as good
but okay results. the recipe is:
not handy right now, stay tuned.
under the Great Eastern Sun,
Carolyn
----- Original Message -----
From: "mudduck"
To:
Sent: Sunday, December 06, 2009 8:50 PM
Subject: Iron reds
> Does any one know of an iron red glaze for cone 10 reduction that is not
> so sensitive to application?? I'm currently using Bailey's Iron red
> recipe. It is a beautiful glaze when applied just right, but if I get it
> just a little to thick it's the ugliest greenish brown I've seen. It woul=
d
> be nice to find one that was a little more forgiving.
>
> Thanks for any help!!
> Gene
> mudduck@mudduckpottery.net
> www.mudduckpottery.net
>
>
>
Loren JOnes on mon 7 dec 09
I cant say enough good things about Petes Tasty Tomato. The recipe is on my=
website, Last page
http://www.lojoclayworks.com
________________________________
From: mudduck
To: Clayart@LSV.CERAMICS.ORG
Sent: Sun, December 6, 2009 6:50:44 PM
Subject: Iron reds
Does any one know of an iron red glaze for cone 10 reduction that is not so=
sensitive to application?? I'm currently using Bailey's Iron red recipe. I=
t is a beautiful glaze when applied just right, but if I get it just a litt=
le to thick it's the ugliest greenish brown I've seen. It would be nice to =
find one that was a little more forgiving.
Thanks for any help!!
Gene
mudduck@mudduckpottery.net
www.mudduckpottery.net
Edouard Bastarache on sun 20 feb 11
http://ironreds1.blogspot.com/
More to come later,
Gis,
Edouard Bastarache=3D20
Spertesperantisto=3D20
Sorel-Tracy
Quebec
http://www.flickr.com/photos/30058682@N00/
http://edouardbastarache.blogspot.com/
http://www.facebook.com/edouard.bastarache
http://bastaracheblogsarts.blogspot.com/
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