Slip casting is a process of creating ceramic forms by casting liquid clay (slip) into plaster molds.
This process is most useful when you want to make multiples of a form. The molds enable you to create identical copies.
In the classroom, slip cast multiples can be used to….
-create multiples of a student’s ceramic artwork (for gift giving or a new sculpture of multiples)
-create identical starting forms that students will manipulate to create their own unique artwork
- try out different glaze techniques on
- allow experimentation without the fear of “ruining” the artwork
All you need for slip casting: Plaster mold, Clay slip, kiln
Necessary items if you want to make your molds: five gallon bucket, plasticene ( non hardening clay), Vaseline /liquid soap, hammer , chisel/screwdriver,
Plaster and slip are available at most ceramic supply centers. I listed some local suppliers on the resources page in this packet.
Plaster comes in a couple different types. Pottery plaster is the standard and readily available at ceramic supply stores. Casting plaster is only necessary if you want to make extremely detailed pieces. I go with the cheapest and it works fine for classwork.
Just as clay comes in many forms, so does slip. The texture and chemical content of the slip dictate what type of clay body it forms. Clay slip bodies range from fine delicate porcelain to coarse strong stoneware. Your firing temperature depends on the content of your slip.
For normal classroom use I use low fire white casting slip.
It is available in premixed 2gallon bags from most ceramic supply stores. It usually runs about 8 dollars a bag.
Four gallons is enough for a class of twelve to make at least two ten inch hollow forms.
HOW EXACTLY do you CAST SLIP?
First, you need a mold made of plaster. It must be plaster because the plaster absorbs the water from the slip.