Louis H.. Katz on tue 22 aug 00
Hi Clayart,
One of my students is talking about Raku Casting Slip. Anbody have any great ideas
on how to make such a beast?
Louis
Jonathan Kaplan on tue 22 aug 00
>Hi Clayart,
>One of my students is talking about Raku Casting Slip. Anbody have any
>great ideas
>on how to make such a beast?
>Louis
Louis:
You need to formulate your casting body with a balance of 50 parts plastic
materials and 50 pats non-plastic materials.
I would use a mix of 2 fireclays such as Hawthorne 30 mesh and Green Stripe
200 mesh. Add some Goldart or Roseville and some ball clay. As this body is
fired between cone 04 and cone 06, I would suggest that on the non-pastic
side you have talc and wollastonite, and finally, some fine mesh grog or
Mulcoa should do the trick.
Less water is needed for a casting body. For 100 gallons of liquid slip,
you will need 1000 pounds of dry mix and approximately 50 gallons of water.
Notice those ratios. I would start under 50 gallons and then bring your
speciific gravity to where it needs to be.
I prefer to avoid sodium silicate/soda ash deflocculation systems,
preferring Darvan 811 across the board. We measure in millilitres and a
good starting point , that works for us, is for 1000 pounds take 15-22% of
that and make it millilitres. So for 1000 pounds a range would be 150-220
ml of Darvan 811/ You will need to adjust for the viscosity.
Let me know if I can be of more help.
Jonathan
Jonathan Kaplan
Ceramic Design Group LTd/Production Services
PO Box 775112
Steamboat Springs, CO 80477
(970) 879-9139 voice and fax
http://www.sni.net/ceramicdesign
UPS: 1280 13th St. Unit13
Steamboat Springs, CO 80487
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