Paul on wed 5 may 04
Hello,
I am looking for some advice on how to prepare a small batch (10,000
gram) of cone 10 casting slip for a special project. I have read through
the archives but there is a lot of different opinions there. The main
question is how much sodium silicate to use (I don't have any darvan 7
or soda ash and don't plan to buy any since I have two full gallons of
silicate) and what would be a good recipe? On digital fire, I read that
they suggested 25% each of ball clay, kaolin, feldspar and silica as a
formula so I was thinking of trying it; and about 40% water should be
added. Does this sound like it would work? If anyone has some advice to
give I would me most thankful to hear. Thanks!
Paul B
Falmouth,KY
Roger Korn on thu 6 may 04
I've had ocassion to make casting slips out of several throwing bodies. My approach is:
1. Add dried clay to water until a slip of about 1.75 specific gravity results (one liter weighs 1.75 Kg). This will be really thick - too thick for casting.
2. Prepare a deflocculent consisting of 1/2 sodium silicate and 1/2 soda ash, by weight. You will need less than 2% deflocculent compared to the slip weight.
3. While stirring the slip, slowly add deflocculent until the slip "suddenly" thins dramatically. Then add just a little bit more deflocculent.
Try casting a piece - if the slip is too thick, add water, if it is too thin, evaporate water.
And by the way, keep notes of the successful mixture (water, clay, deflocculent). You WILL want this info again, probably years from now.
Roger
Paul B wrote:
I am looking for some advice on how to prepare a small batch (10,000
gram) of cone 10 casting slip for a special project. I have read through
the archives but there is a lot of different opinions there. The main
question is how much sodium silicate to use (I don't have any darvan 7
or soda ash and don't plan to buy any since I have two full gallons of
silicate) and what would be a good recipe? On digital fire, I read that
they suggested 25% each of ball clay, kaolin, feldspar and silica as a
formula so I was thinking of trying it; and about 40% water should be
added. Does this sound like it would work? If anyone has some advice to
give I would me most thankful to hear. Thanks!
Paul B
Falmouth,KY
--
McKay Creek Ceramics
In OR: PO Box 436
North Plains, OR 97133
503-647-5464
In AZ: PO Box 463
Rimrock, AZ 86335
928-567-5699
Kathy McDonald on thu 6 may 04
Pottery supply house makes a good one
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG]On Behalf Of Roger Korn
Sent: Thursday, May 06, 2004 8:23 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: CONE 10 CASTING SLIP HELP NEEDED
I've had ocassion to make casting slips out of several throwing bodies. My
approach is:
1. Add dried clay to water until a slip of about 1.75 specific gravity
results (one liter weighs 1.75 Kg). This will be really thick - too thick
for casting.
2. Prepare a deflocculent consisting of 1/2 sodium silicate and 1/2 soda
ash, by weight. You will need less than 2% deflocculent compared to the slip
weight.
3. While stirring the slip, slowly add deflocculent until the slip
"suddenly" thins dramatically. Then add just a little bit more deflocculent.
Try casting a piece - if the slip is too thick, add water, if it is too
thin, evaporate water.
And by the way, keep notes of the successful mixture (water, clay,
deflocculent). You WILL want this info again, probably years from now.
Roger
Paul B wrote:
I am looking for some advice on how to prepare a small batch (10,000
gram) of cone 10 casting slip for a special project. I have read through
the archives but there is a lot of different opinions there. The main
question is how much sodium silicate to use (I don't have any darvan 7
or soda ash and don't plan to buy any since I have two full gallons of
silicate) and what would be a good recipe? On digital fire, I read that
they suggested 25% each of ball clay, kaolin, feldspar and silica as a
formula so I was thinking of trying it; and about 40% water should be
added. Does this sound like it would work? If anyone has some advice to
give I would me most thankful to hear. Thanks!
Paul B
Falmouth,KY
--
McKay Creek Ceramics
In OR: PO Box 436
North Plains, OR 97133
503-647-5464
In AZ: PO Box 463
Rimrock, AZ 86335
928-567-5699
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