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over reduced ^6 copper red?

updated sat 16 jul 11

 

Robin Wolf on sun 10 jul 11


New Oxyprobe is installed, and the first load of test tiles was good. Red.
Lots of Red. Some variation from top to bottom of the kiln, but the wind
was at about 15 to 20 mph. Could really watch the numbers move around with
each gust.



Fired the first load of actual work glazed w/ Oxblood, and it favors more o=
f
a baked bean color than the oxblood. The full kiln was all Oxblood, and of
course, I decided that if a little reduction is good, then heavy reduction
is better. Maybe not a great program to follow! I am interested in seeing
if refiring at least a few of the pieces to see if the color can brighten u=
p
to more cranberry/oxblood.



Any recommendations on whether doing a light reduction would brighten up th=
e
red?



Recipe used is:



Neph 55.33

GB 12.61

Whiting 10.71

Silica 21.35

Copper Carb .39

Tin Ox .99

Bentonite 2

Epsom Salts 1



Started reducing at 1100*F, Oxyprobe showed .83. Held at .83 to .87 thru
1760*, .77 to 1103*C, and .65-.66 to 1213*C. Held at 1210*C for 15 min, al=
l
off, all closed.







Robin Wolf



Robin Wolf Pottery

Kingfisher, OK

405.368.0919



www.robinwolfpottery.com



"Observe the wonders as they occur around you. Don't claim them. Feel the
artistry moving through and be silent." - Rumi

Randall Moody on sun 10 jul 11


What body is this on? I have found that the oxblood glaze that we use at th=
e
arts center is a nice copper red on porcelain and b-mix but goes muddy on
Standard 205 stoneware.

--
Randall in Atlanta
http://wrandallmoody.com

Robin Wolf on sun 10 jul 11


I use ^6 B-mix. The red is slightly "murky". Inside the jars the color is
brighter, with some variations.



Robin Wolf



Robin Wolf Pottery

Kingfisher, OK

405.368.0919



www.robinwolfpottery.com



"Observe the wonders as they occur around you. Don't claim them. Feel the
artistry moving through and be silent." - Rumi

_____

From: Randall Moody [mailto:randall.moody@gmail.com]
Sent: Sunday, July 10, 2011 9:59 PM
To: Robin Wolf
Cc: Clayart@lsv.ceramics.org
Subject: Re: Over Reduced ^6 Copper Red?



What body is this on? I have found that the oxblood glaze that we use at th=
e
arts center is a nice copper red on porcelain and b-mix but goes muddy on
Standard 205 stoneware.

--
Randall in Atlanta
http://wrandallmoody.com

John Britt on mon 11 jul 11


Don't think you have to start at 1100F?!

Johnbrittpottery.com

Ron Roy on mon 11 jul 11


Robin,

Insides would cool a bit slower than outsides - may be a clue there.

RR

Quoting Robin Wolf :

> I use ^6 B-mix. The red is slightly "murky". Inside the jars the color =
is
> brighter, with some variations.
>
>
>
> Robin Wolf
>
>
>
> Robin Wolf Pottery
>
> Kingfisher, OK
>
> 405.368.0919
>
>
>
> www.robinwolfpottery.com >
>
>
>
> "Observe the wonders as they occur around you. Don't claim them. Feel th=
e
> artistry moving through and be silent." - Rumi
>
> _____
>
> From: Randall Moody [mailto:randall.moody@gmail.com]
> Sent: Sunday, July 10, 2011 9:59 PM
> To: Robin Wolf
> Cc: Clayart@lsv.ceramics.org
> Subject: Re: Over Reduced ^6 Copper Red?
>
>
>
> What body is this on? I have found that the oxblood glaze that we use at =
the
> arts center is a nice copper red on porcelain and b-mix but goes muddy on
> Standard 205 stoneware.
>
> --
> Randall in Atlanta
> http://wrandallmoody.com
>

Ron Roy on mon 11 jul 11


Hi Robin,

Slowing down the cooling may help - Tops of kilns cool slower so there
may be a clue there.

If you bisque fire a copper red red glaze you can get more red
crystals to form - that would indicate that a slower cool from 1000C
down to 800C would help - or just an overall slower cool by sealing up
the kiln better.

RR

Quoting Robin Wolf :

> New Oxyprobe is installed, and the first load of test tiles was good. Re=
d.
> Lots of Red. Some variation from top to bottom of the kiln, but the wind
> was at about 15 to 20 mph. Could really watch the numbers move around wi=
th
> each gust.
>
>
>
> Fired the first load of actual work glazed w/ Oxblood, and it favors more=
of
> a baked bean color than the oxblood. The full kiln was all Oxblood, and =
of
> course, I decided that if a little reduction is good, then heavy reductio=
n
> is better. Maybe not a great program to follow! I am interested in seei=
ng
> if refiring at least a few of the pieces to see if the color can brighten=
up
> to more cranberry/oxblood.
>
>
>
> Any recommendations on whether doing a light reduction would brighten up =
the
> red?
>
>
>
> Recipe used is:
>
>
>
> Neph 55.33
>
> GB 12.61
>
> Whiting 10.71
>
> Silica 21.35
>
> Copper Carb .39
>
> Tin Ox .99
>
> Bentonite 2
>
> Epsom Salts 1
>
>
>
> Started reducing at 1100*F, Oxyprobe showed .83. Held at .83 to .87 thru
> 1760*, .77 to 1103*C, and .65-.66 to 1213*C. Held at 1210*C for 15 min, =
all
> off, all closed.
>
>
>
>
>
>
>
> Robin Wolf
>
>
>
> Robin Wolf Pottery
>
> Kingfisher, OK
>
> 405.368.0919
>
>
>
> www.robinwolfpottery.com >
>
>
>
> "Observe the wonders as they occur around you. Don't claim them. Feel th=
e
> artistry moving through and be silent." - Rumi
>

William & Susan Schran User on mon 11 jul 11


On 7/10/11 6:35 PM, "Robin Wolf" wrote:

> Any recommendations on whether doing a light reduction would brighten up =
=3D
the
> red?=3D20
> Recipe used is:
> Neph 55.33
> GB 12.61
> Whiting 10.71
> Silica 21.35
> Copper Carb .39
> Tin Ox .99
> Bentonite 2
> Epsom Salts 1
> Started reducing at 1100*F, Oxyprobe showed .83. Held at .83 to .87 thru
> 1760*, .77 to 1103*C, and .65-.66 to 1213*C. Held at 1210*C for 15 min, =
=3D
all
> off, all closed.

Robin,
Why are you starting reduction so early?
I start reduction (pushing in damper slightly to create back pressure at
bottom spy hole) at 1800F - 1850F.
Reducing too much earlier may be trapping some carbon under/in the glaze
that may cause the muddiness.

We use a glaze similar to yours:
Davis Copper Red ^6 reduction
Nepheline Syenite =3DAD 38
Custer Feldspar =3DAD 8
Whiting =3DAD 9
Gerstley Borate =3DAD 15
EPK =3DAD 7
Silica =3DAD 23
Tin Oxide =3DAD 1.5
Copper Carbonate =3DAD 0.5

Here's a great article that will help you understand how the red color is
formed in copper red glazes:
http://digitalfire.com/4sight/education/copper_red_glazes_115.html

Bill
--=3D20
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com

David Woof on fri 15 jul 11


Robin asks: would brighten up=3D20
the red>
=3DA0
Hi Robin=3D2C=3D20

For now=3D3B set your fired stuff aside=3D3B fire a new load=3D20
and watch to see if and what the colors develop or change to at stages of t=
=3D
he cool down. This is an education in itself.
You could work with this idea through many tests and firing/cool down sched=
=3D
ules.
=3DA0
Some reds are white or patchy red at shut down and=3D20
develop those lush reds during cooling.=3D20
This is a very important factor to be investigated when testing glazes.=3D2=
0

During cool down is where reduction may be the most=3D20
effective=3D2C and glaze reactivity is active at surprisingly lower temps.=
=3D20

You will get differing results during controlled cool downs=3D3B=3D20
and or firing up and down during a cool down.=3D20
Keep good records which include external atmospheric=3D20
conditions=3D2C which it is common to see change several times=3D20
during the complete firing and cooling cycle. Be a detective write it all d=
=3D
own=3D2C loading patterns...are other glazes also in the load that will mos=
t =3D
likely impact your results.

Ref=3D3B Coleman's beautiful full kiln loads of perfect cherry red pots in =
th=3D
e Geil Kiln ads. He was very willing to publish his glaze recipes=3D3B but =
th=3D
e "old fox" didn't say much if anything about firing schedules. I think it =
=3D
was Pete Pinnell who shone a bright light into his darkened cooling kiln an=
=3D
d watched his copper reds really turning red.=3DA0 Mel and Joe Koons were w=
or=3D
king with iron reds and asking the questions as to the effect of controlled=
=3D
cool downs. Success!!!! I'm not sure of the chronology but wood fired redu=
=3D
ction cooling was also being explored. Other folks took off from the sharin=
=3D
g of these ideas and the circles keep widening.

Your Oxyprobe is a great tool in this but it is not a magic wand unless you=
=3D
=3D20
understand the proper incantations.=3D20
Do you know why the same glaze may look different when on the outside or=3D=
20
inside of the same pot?=3DA0 This is a basic bit of understanding to build =
on=3D
. Ron mentioned this last week=3D3B did you catch it and the far reaching s=
ig=3D
nificance of this?

It is easy to just give you my answers=3D3B or parrot the "truths"of others=
=3D
=3D2C and rightly we must share our information=3D2C but I also think too m=
uch =3D
of this alone as just "crowding around the same fishing hole" when there is=
=3D
a whole new world out here of yet undiscovered wonder.=3DA0=3D20

So I compliment you on your willingness to try=3D2C think=3D2C try things=
=3D2C qu=3D
estion and ask.

Keep it going and keep us posted.

I love it when folks follow up from asking advice by later posting their re=
=3D
sults and perhaps new discoveries.

This stimulates the "think tank" aspect of Clayart=3D3B where when formulat=
in=3D
g a reply it can inspire further thought and the teacher becomes the new st=
=3D
udent if they put their egos in their back pocket and sit down to consider =
=3D
and ponder the possibilities of what we yet do not know.

This was the old Clayart that I came to love=3D2C support and respect.=3DA0=
The=3D
"Old Timers" here (a good long list of names) are still displaying this at=
=3D
titude of teachable humility while they share and instruct. True Mentors.

Misneach=3D2C

David Woof

=3DA0
=3DA0
=3D