Phil Smith on wed 16 oct 02
Corinne,
I'm no guru but I have noticed that the copper in the glaze
will tend to go reddish if fired in reducing atmosphere(excess fuel not
enough air).
Do you have large flames or orange flames blasting from flu?.
Phil:
Pottery by Dai on wed 16 oct 02
Corinne, I think one minute in the sawdust is not long enough to get some
nice copper reduction. Try leaving it in for 5 or 10 minutes, then spraying
it with water to cool it (or dunking).
Dai in Armstrong, BC
dai@potterybydai.com
potterybydai@telus.net
nightfire@telus.net
www.potterybydai.com
Take your work seriously---take yourself lightly. Unknown
----- Original Message -----
From: "Corinne en Ben"
To:
Sent: Wednesday, October 16, 2002 3:41 PM
Subject: how to get turquoise raku
I'm having trouble getting a turquoise colour in the raku proces. I managed
to get turquoise mixed with a copper metallic lustre a couple of times. It
was a beautiful result.
I used the same glaze again and I can't get it anymore, whatever I try. I
only get dark brown,red, maroon. I don't know what to do anymore.
My recipe is :
High alk frit 85%
ballclay 7.5%
whiting 7.5%
+copper carbonate 2-4%
I fire the piece tillt he glaze has melted ( 1000 C), open the kiln, take it
out, hold the piece a view seconds in the air and drop it in sawdust, not
longer than a minute. After this I let it cool in water.
What am I doing wrong?
I'm desperate, and have the idea I tried everything.
John Britt on wed 16 oct 02
Corinne,
Here is the finest Turquoise Raku glaze available:
Chappell RG-5
FritP-25 - 42.5
Frit 3134- 27.4
Lithium Carbonate- 9.8
EPK - 6.3
Silica - 14
Bentontite- 2
Add: 2.5 - 4 Copper Carbonate
It is a great turquoise if allowed to cool before putting in post
reduction. (Alternatively you can spritz it with water.)
Or a great copper luster is reduced heavily in post reduction or in kiln
reduction.
Hope you like it,
John Britt
Penland
Dannon Rhudy on wed 16 oct 02
......I'm having trouble getting a turquoise colour My recipe is :.........
Lower the amount of copper carbonate you are using. For turquoise
raku I generally use 1% copper carbonate. It always comes out
turquoise.
regards
Dannon Rhudy
SusanRaku@AOL.COM on wed 16 oct 02
In a message dated 10/16/2002 11:00:02 PM Eastern Daylight Time,
phsmth@MSN.COM writes:
> Corinne,
> I'm no guru but I have noticed that the copper in the glaze
> will tend to go reddish if fired in reducing atmosphere(excess fuel not
> enough air).
> Do you have large flames or orange flames blasting from flu?.
>
Could it be that the pot is removed from the reduction chamber too quickly?
Susan
SusanRaku@AOL.COM on wed 16 oct 02
Is there a specific time or some visible sign to determine how long the pot
should cool before putting in post reduction?
Susan
In a message dated 10/16/2002 11:04:12 PM Eastern Daylight Time,
clay@PENLAND.ORG writes:
> Subj: Re: how to get turquoise raku
> Date: 10/16/2002 11:04:12 PM Eastern Daylight Time
> From: clay@PENLAND.ORG (John Britt)
> Sender: CLAYART@LSV.CERAMICS.ORG (Ceramic Arts Discussion List)
> Reply-to: CLAYART@LSV.CERAMICS.ORG (Ceramic Arts Discussion List)
> To: CLAYART@LSV.CERAMICS.ORG
>
>
>
>
> Corinne,
>
> Here is the finest Turquoise Raku glaze available:
>
> Chappell RG-5
>
> FritP-25 - 42.5
> Frit 3134- 27.4
> Lithium Carbonate- 9.8
> EPK - 6.3
> Silica - 14
> Bentontite- 2
>
> Add: 2.5 - 4 Copper Carbonate
>
> It is a great turquoise if allowed to cool before putting in post
> reduction. (Alternatively you can spritz it with water.)
>
Corinne en Ben on thu 17 oct 02
I'm having trouble getting a turquoise colour in the raku proces. I =
managed to get turquoise mixed with a copper metallic lustre a couple of =
times. It was a beautiful result.
I used the same glaze again and I can't get it anymore, whatever I try. =
I only get dark brown,red, maroon. I don't know what to do anymore. =20
My recipe is :
High alk frit 85%
ballclay 7.5%
whiting 7.5%
+copper carbonate 2-4%
I fire the piece tillt he glaze has melted ( 1000 C), open the kiln, =
take it out, hold the piece a view seconds in the air and drop it in =
sawdust, not longer than a minute. After this I let it cool in water.
What am I doing wrong?
I'm desperate, and have the idea I tried everything.
Craig Clark on fri 18 oct 02
Susan, the specific time requirement is determined by the type of color
or crazing effect that you are after. The longer that you leave the pot out
in the open atmosphere the more extensive the crazing will be. The converse
is also true. THe use of water changes this dramatically.
The color, in the case of copper carbonate, will generally be in the
"green, aka turquoise" family if you permit the glaze to reoxide completely
before putting it into a light post firing reduction. Just look at the pot
and watch the glaze. When you see the green it's oxidized. How long this
takes will depend upon the size and thickness of your piece (which in turn
affects the rate of cooling) and the temperature to which you have fired.
Just give it a good ten count and go from there.
If you are after the "coppery" look get the pot into the can quickly
with nice billowing flame and drop a piece of paper over it before quickly
closing the lid.
This is a method that works for me. It is one of many.
Hope this helps
Craig Dunn Clark
619 East 11 1/2 st
Houston, Texas 77008
(713)861-2083
mudman@hal-pc.org
If you live anywhere in the vicinity of Biloxi Mississippi there will be a
Paul Soldner workshop there over the weekend of November the 10th at the Ohr
(the mad potter of Biloxi) museum. The cost is $75
----- Original Message -----
From:
To:
Sent: Wednesday, October 16, 2002 10:16 PM
Subject: Re: how to get turquoise raku
> Is there a specific time or some visible sign to determine how long the
pot
> should cool before putting in post reduction?
>
> Susan
>
>
>
> In a message dated 10/16/2002 11:04:12 PM Eastern Daylight Time,
> clay@PENLAND.ORG writes:
>
>
> > Subj: Re: how to get turquoise raku
> > Date: 10/16/2002 11:04:12 PM Eastern Daylight Time
> > From: clay@PENLAND.ORG (John Britt)
> > Sender: CLAYART@LSV.CERAMICS.ORG (Ceramic Arts Discussion List)
> > Reply-to: CLAYART@LSV.CERAMICS.ORG (Ceramic Arts Discussion List)
> > To: CLAYART@LSV.CERAMICS.ORG
> >
> >
> >
> >
> > Corinne,
> >
> > Here is the finest Turquoise Raku glaze available:
> >
> > Chappell RG-5
> >
> > FritP-25 - 42.5
> > Frit 3134- 27.4
> > Lithium Carbonate- 9.8
> > EPK - 6.3
> > Silica - 14
> > Bentontite- 2
> >
> > Add: 2.5 - 4 Copper Carbonate
> >
> > It is a great turquoise if allowed to cool before putting in post
> > reduction. (Alternatively you can spritz it with water.)
> >
>
>
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