Paulette Carr on thu 24 mar 05
I, too, have been working with iron glazes, but at ^9ox in an electric=20=
kiln. I have had some real success with temmoku and tea dusts, but I=20
am currently struggling with a kaki =96 or iron red glaze =96 Bailey=92s =
Red.=20
No matter what I do =96 apply thickly, thinly, refire to ^9, refire to=20=
^04 with slow cooldown, I get a liver color =96 or a dirty mustard from=20=
the bisque firing. I have written to John Britt, and he suggested that=20=
this glaze needs to be fired higher.
I have checked the archives, and read many, many posts concerning iron=20=
reds. What get my attention is that many of you are able to obtain at=20=
least one iron red (Berry Rust) at ^6 in an electric firing. This=20
suggests to me that the iron should be able to go red with a slow ^9=20
firing and slow cooldown, and may require a bisque refire.
I am not stuck on Bailey=92s Red, specifically, just on obtaining a good=20=
kaki. Berry Rust was tested under high fire conditions, with good=20
visual results, apparently, but unfortunately, this glaze has low=20
Al2O3 (.29) and SiO2 (2.69) for a ^9 glaze, even using Craig Martell=92s=20=
modifications. Bailey=92s Red does have a higher Al2O3 (.34), but a low=20=
silica (2.51). These values I obtained from my Insight calculations. =20=
Another interesting glaze in John Britt=92s book is Persimmon 2 with=20
Al2O3 and SiO2 (3.43). This seems like it would be a more stable=20
glaze. I have not tried it yet, but will in my next firing.
Additionally, I read in an archived post from Carol Tripp who=20
referenced Paul Lewing, that you need a really red iron oxide, so=20
yesterday I purchased Spanish red from my local supplier, as well as=20
yellow iron. I don=92t really have a feel for the difference among iron=20=
sources. Is it a distribution of iron compounds, or concentrations, or=20=
what??? I will try these recipes with the Spanish red.
Now to my question. Has anyone been able to obtain an iron red glaze=20
by firing in an electric kiln with cone 9 down? May be I am focused on=20=
the wrong things. I would be very grateful for any insight.
Thanks!
Paulette Carr
Paulette Carr Studio
Member/Potters Council
St. Louis, MO
Ken Chin-Purcell on thu 24 mar 05
It's not khaki, but you can see my iron red here:
http://www.bungalowpottery.com/glazes.htm
I consider this glaze still in progress. The recipe is:
F-4 FELDSPAR 46.5
OM #4 BALL CLAY 6.5
TALC 5.5
BONE ASH 10
FLINT 14.5
IRON OXIDE RED 9
WOLLASTONITE 7
BENTONITE 1
I fire to cone 9 way down and a conrolled cool:
Fire up to 1260 C, 60C/hr last hour, hold 15 min
Drop to 1120 C, 120 C/hr, hold 50 min
Cool to 750 C, 70 C/hr
I plan to do the "Currie Thang" with this glaze, vary alumina and silica.
-- Ken Chin-Purcell
www.bungalowpottery.com
dannon rhudy on thu 24 mar 05
Paulette said:
Now to my question. Has anyone been able to obtain an iron red glaze
by firing in an electric kiln with cone 9 down? May be I am focused on
the wrong things. I would be very grateful for any insight.......
Paulette, I have two really good iron reds, one for cone 9, one for
cone 6. There are a number of factors involved in achieving good
iron reds, but -
give me your recipe. I may have a useful idea for you, but don't know
until I see what is in your glaze.
regards
Dannon Rhudy
Kathy McDonald on fri 25 mar 05
Subject: Re: Problem obtaining Iron Red at ^9ox
Paulette said:
Now to my question. Has anyone been able to obtain an iron red glaze
by firing in an electric kiln with cone 9 down? May be I am focused on
the wrong things. I would be very grateful for any insight.......
Years ago I used to use a glaze called Ohata Khaki that fired to a great
iron
red at cone 9 in an electric kiln.
It was also nicer(redder) if you refired it to cone 06 after the cone 9
glaze firing.
If you want me to go back in my old notebooks for this recipie I am sure I
have
it. Please post me offlist.
Kathy
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Fred Hagen on fri 25 mar 05
Kathy, I would be interested in your recipe as well --could you send it to me?
Thanks Fred Hagen
Kathy McDonald wrote:
Subject: Re: Problem obtaining Iron Red at ^9ox
Paulette said:
Now to my question. Has anyone been able to obtain an iron red glaze
by firing in an electric kiln with cone 9 down? May be I am focused on
the wrong things. I would be very grateful for any insight.......
Years ago I used to use a glaze called Ohata Khaki that fired to a great
iron
red at cone 9 in an electric kiln.
It was also nicer(redder) if you refired it to cone 06 after the cone 9
glaze firing.
If you want me to go back in my old notebooks for this recipie I am sure I
have
it. Please post me offlist.
Kathy
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Daniel Semler on fri 25 mar 05
Hi ya,
I use this glaze, Ohata Kaki quite a bit. We fire gas to cone 10 either
oxidation or reduction. In ox. it will go a lovely red with light speckling. In
reduction it can gun metal and will be darker, particularly on iron bearing
stonewares. I currently, usually use it on porcelains or white stonewares in
oxidation. It takes layering with a good dark tenmoku well too.
The recipe Ken Chin-Purcell posted is a somewhat similar composition. Ken, I
think the example you showed is on an iron bearing stoneware ? I can only just
see the cup bottom peeking out below the glaze. Have you tried it on a white
body ? By the way, I like your pallete, you have some really good looking
glazes.
Thanx
D
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Ken Chin-Purcell on fri 25 mar 05
It's actually on Continental Clay's high fire white stoneware.
I need to mix up a new batch. The first batch hardpanned after
sitting for a week or two, so I added some epsom salts.... too much!
Now I have red pudding. Yes I realize I could add some sodium
silicate, etc., but I think it's best to start over.
I've also gotten curious about using a "redder" iron oxide, so I think
the next batch will be a test using Spanish RIO (and more bentonite!).
If I get anything better I'll report back.
-- Ken C-P
> The recipe Ken Chin-Purcell posted is a somewhat similar composition. Ken, I
> think the example you showed is on an iron bearing stoneware ? I can only just
> see the cup bottom peeking out below the glaze. Have you tried it on a white
> body ?
Paulette Carr on fri 25 mar 05
Dannon said:
give me your recipe.=A0I may have a useful idea for you, but don't know=20=
until I see what is in your glaze.
Dannon,
The recipe for Bailey's Red was published in John Britt's book, but he=20=
posted it on Clayart in last August, so I feel ok about posting it=20
again.
Bailey's Red
Custer Feldspar 47.0
Talc 10.5
Bone Ash 14.0
Lithium Carbonate 2.5
EPK 13.0
Silica 13.0
+ Red Iron Oxide 8.0
=09
I have pictures of the test tiles, and if you would like to take a look=20=
at them, I will send them under separate cover. If you need my firing=20=
schedule, I will send that as well.
... I wonder if the iron is too low here...
I have just made up Kavanaugh's Berry Rust (below) and Persimmon 2 from=20=
John's book (and have asked permission to post it or give it to you),=20
with Spanish red iron oxide. Both of these glazes contain Gerstley=20
borate, no Li, and bone ash and red iron oxide. Persimmon 2 is in=20
range for target formulas for a ^9 glaze, but Berry Rust is low in both=20=
SiO2 and Al2O3. I will be able to let you know how these look in about=20=
a week.
Kavanaugh's Berry Rust [^7-10ox]
Nepheline Syenite 18.2
Talc 9.1
Dolomite 9.1
Bone Ash 9.1
Gerstely Borate 9.1
EPK 18.2
Flint 27.30
+ Red Iron Oxide 9.1
Thanks, again, for taking a look at this, and for any guidance you can=20=
give me!
My best,
Paulette
Paulette Carr
Paulette Carr Studio
Member/Potters Council
St. Louis, MO
Paulette Carr on fri 25 mar 05
Ken wrote:
It's not khaki, but you can see my iron red ...
Ken,
Thanks, as usua,l for sending me another great glaze. I am indebted to
you for the clear and Tea Dusts, and you were the one person that I
couldn't find at NCECA to thank for your glaze help ... So ... many
thanks for your generosity!!! Even when a glaze did not fit my clay
(crazed), it did push me in the right direction. While I am testing
other iron reds, I will prepare this one and give it a try. I will let
you know how it goes.
Maybe someday I can say thanks in person.
My best,
Paulette Carr
Paulette Carr Studio
Member/Potters Council
St. Louis, MO
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