Stephanie Wright on fri 2 mar 07
Hi Everybody!
Have not taken photos yet, but thought I would post the results of several
of the glazes I made test batches of. We unloaded the kiln at school
tonight, and results were mixed. We fire ^10 reduction, in a gas kiln.
Although my teacher didn't say so, I do not think this batch reduced much
at all. Even some of our "old reliable" glazes looked different.
Here is what I got. If anyone has suggestions on how to improve, please
let me know! :-)
Byron Temple Orange - Great! Did not run. Was matte, and I would say
leaning slightly more toward brown than orange. I was very pleased with
this one, and we will be making a larger batch for classroom use.
Leach White - Leach base with 15% Zircopax added. Another great one! Pure,
snowy white, glossy, with no running and no visible crazing. We will also
be making a larger batch of this one.
Pinnell Celedon - Very disappointing. Glaze had good application, and did
not run. However, there was no blue/green color to the fired test tile at
all. It came out a creamy kind of pale beige color. Is this possibly due
to lack of reduction? I am going to try this one again. I do not want to
add any blue stain or cobalt, because then it would no longer be a true
celadon!
Apple Blossom - VERY DISAPPOINTING! This was supposed to be a rosy mauve.
Came out instead as a vomity green. Yuk!
Perfect black - Great! True to its name. No problems with running, and
color was shiny and consistently black. Way better than the Mystery Black
we have always used in class!
Purple Haze - Totally bombed! Instead of purple, we got a runny seafoam
green color. It was actually a very nice green, but soooo not what I
wanted! I don't know if this was a reduction problem, or if I forgot to
add something to the glaze. I may try to test this one again just to see.
June Perry's Raspberry copper red - Another huge disappointment! It did
not come out red at all. Rather it was a very dark, muddy brown. Again,
was this a reduction problem? Could it be because I did not have one of
the frits and subbed Gerstley borate?
Emerald Jewel and Sapphire Jewel - Both of these were perfect beauties! I
raised the Chrome slightly in the Emerald. The original recipe was
slightly more teal looking than I wanted. What I got was more of a deep,
rich, almost forest green. And I LOVE the sapphire! Color on that is
actually a slightly lighter tone of blue than the gemstone. Coverage on
both is excellent, glossy, and no running!
Some Bright Green - Not a total loss, but very disappointing. Came out
more of a turquoise/teal rather than green, and was a very flat looking
matte glaze. I might test this one again as well, just to see if anything
changes.
June Perry also has a wonderful base glaze that I have been playing with.
By itself it fires a smooth, semi-gloss, cream color. It is the following:
June Perry=92s Base Glaze
Custer Feldspar 51.71
Soda Ash .2
Dolomite 2.17
Whiting 2.36
Bone Ash 6.59
Zinc Oxide 1.91
Barium Carbonate 4.66
Lithium Carbonate 3.5
Kaolin (Monarch) 16.10 I use EPK
Silica 18.30
Does anyone know if I could use this base with copper red glaze colorants
and still end up with a red color?
Thanks for reading. I am open to comments/suggestions! :-)
Stephanie
Marcia Selsor on fri 2 mar 07
Stephanie,
Sounds like some of yourr kiln did not reduce. Where Pinnell's
celedon is beige, or the copper is green and not red/
Keep going. You are off on a good start.
Marcia Selsor
http://marciaselsor.com
Chris Trabka on fri 2 mar 07
Stephanie,
I have two suggestions.
John Britt's book "The Complete Guide to High-Fire Glazes" - John discusses
various firing schedules and the impacts of light/heavy reduction.
An oxyprobe - It is an indespensible tool to determine exactly what is
going on inside the kiln (how much reduction).
Chris
Veena Raghavan on fri 2 mar 07
Hi Stephanie,
Thanks for posting your results. Very interesting.
Just wanted to let you know that I tested the Some Bright Green and got a
glossy pale green.
Veena
In a message dated 3/2/2007 5:37:36 AM Eastern Standard Time,
brneydgrlie@YAHOO.COM writes:
> Some Bright Green - Not a total loss, but very disappointing. Came out
> more of a turquoise/teal rather than green, and was a very flat looking
> matte glaze. I might test this one again as well, just to see if anything
> changes.
>
VeenaRaghavan@cs.com
louroess2210 on fri 2 mar 07
> Stephanie, are the glaze recipes in the Clayart archives somewhere
> or could you post them?
Thanks, Lou
>
Stephanie Wright on fri 2 mar 07
Lou,
I will gladly post the glaze recipes I tested. See below. Several of them
were from John Britt's book. A few others I found in various places on the
Internet. John's book has been indispensible. Unfortunately, however, I
have no say in how my teacher runs the firing schedule. Although... I have
caught him thumbing interestedly through my book, so there is hope yet! :-)
Stephanie
June Perry=92s Base Glaze
Custer Feldspar 51.71
Soda Ash 0.2
Dolomite 2.17
Whiting 2.36
Bone Ash 6.59
Zinc Oxide 1.91
Barium Carbonate 4.66
Lithium Carbonate 3.5
Kaolin (Monarch) 16.10 I use EPK
Silica 18.30
Byron Temple Orange
Custer Feldspar 49
Cornwall Stone 18
Whiting 18
EPK 6
Ball Clay 9
Red Iron Oxide 6
Zinc Oxide 3
Rutile 4
Leach White
Custer Feldspar 40
Silica 30
Whiting 20
Kaolin 10
Zircopax 15
Perfect Black
Custer Feldspar 42
Silica 22
Whiting 13
Kaolin 8
Soda Ash 3
Zinc Oxide 12
Red Iron Oxide 3
Cobalt Carbonate 4
Chrome Oxide 1
Emerald Jewel
Whiting 24
Custer Feldspar 28
Kaolin (EPK) 20
Silica 28
Chrome Oxide 0.8
Cobalt Carbonate 0.5
Gerstley Borate 5
Sapphire Jewel
Whiting 24
Custer Feldspar 28
Kaolin (EPK) 20
Silica 28
Zinc Oxide 3
Chrome Oxide 0.3
Cobalt Carbonate 1
Pinnell Celadon
Custer Feldspar 24.5
Silica 34.3
Whiting 19.6
Kaolin 19.6
Barium Carbonate 1.9
Tin Oxide 1
Yellow Iron Oxide 0.5
Some Bright Green
Custer Feldspar 45
Whiting 7
Ball Clay 13
Strontium Carbonate 25
Zinc Oxide 10
Red Iron Oxide 1.25
Copper Carbonate 5
Rutile 1
June Perry=92s Raspberry Copper Red
Custer Feldspar 57.87
Whiting 8.76
Dolomite 3.71
Ferro Frit 3134 4.94
Ferro Frit 3195 3.37
Silica 21.35
Copper Carbonate 1
Tin Oxide 1
Red Iron Oxide 1
Apple Blossom
Custer Feldspar 27
Silica 34
Whiting 18
Kaolin 16.5
Talc 4.5
Manganese Dioxide 2
Copper Oxide 0.75
Ron Roy on sat 3 mar 07
Hi Kathryn,
Lithium is a much stronger flux than barium so don't sub that way - leave
out the barium and add in 2.5 whiting.
If you are firing in reduction you probably don't need the zinc oxide by
the way - try it both ways to see.
Some clay bodies - when used with this much lithium carb - will produce
unusual fit problems so test carefully.
RR
>Stephanie, forgive me for asking a stupid question, but if it comes
>from John Britt's book, I can safely assume it's cone 9-10 Reduction,
>correct? also, the first recipe you listed, what if I wanted to
>elimenatee BaCo3, would I use that amt and add it onto LiCo3?warmly,
>Kathryn in NC --->
>>
>> June Perry's Base Glaze
>>
>> Custer Feldspar 51.71
>> Soda Ash 0.2
>> Dolomite 2.17
>> Whiting 2.36
>> Bone Ash 6.59
>> Zinc Oxide 1.91
>> Barium Carbonate 4.66
>> Lithium Carbonate 3.5
>> Kaolin (Monarch) 16.10 I use EPK
>> Silica 18.30
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
sacredclay on sat 3 mar 07
Stephanie, forgive me for asking a stupid question, but if it comes
from John Britt's book, I can safely assume it's cone 9-10 Reduction,
correct? also, the first recipe you listed, what if I wanted to
elimenatee BaCo3, would I use that amt and add it onto LiCo3?warmly,
Kathryn in NC --->
>
> June Perry's Base Glaze
>
> Custer Feldspar 51.71
> Soda Ash 0.2
> Dolomite 2.17
> Whiting 2.36
> Bone Ash 6.59
> Zinc Oxide 1.91
> Barium Carbonate 4.66
> Lithium Carbonate 3.5
> Kaolin (Monarch) 16.10 I use EPK
> Silica 18.30
>
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