Making Your Own Ceramic Slip

White Slip Recipe (cone 04)
INSTRUCTIONS FOR MAKING YOUR OWN SLIP

The first time you make slip it all seems mysterious, it is very important that you measure carefully and keep a written record of what you have done. There are seasonal variations in the talc, and possibly in the other ingredients; so it is important to know what you have done in the past and be consistent. First figure out how many gallons your slip mixer will hold. It is easiest to make 25 or 50 gallons as you will not have to weigh the slip components. Test slip with a hydrometer, or scale, it should read 1.75, and weigh 14.5 lb. per gallon. (a hydrometer measures the amount of water versus solids- we will cover this subject in another post)

50 GALLON RECIPE

1. WATER -27 gallons- the warmer the better
2. SODA ASH -4 OZ. DRY
3. BARIUM CARBONATE 3 oz. DRY (use only if water is mineralized or salty)

Dissolve Soda and Barium in hot water and add to water and allow to stir with mixer running add your Clays.
These clays are all dry in bags.
4. KT OM4 —– 100 LBS. 2 BAGS (Or 4 bags of KT-1-4 which is a premixed Ball Clay)
(a Kentucky Ball Clay that fires at cone 04-white)
5. KT #1 SGP —– 100 LBS. 2 BAGS(another white clay. Tennessee Ball Clay cone 04)
When the mix seems too thick start adding the Sodium Silicate a little at a time
6. Sodium Silicate –12 to 18 OZ. LIQUID
7. TALC 2882 —– 300 LBS. 6 BAGS add the talc with the mixer running. If it clogs up at the top, Turn the mixer off and use a stick to help mix it in. (This part gets to be tiresome but you have to battle your way through it.)
8. Let the mixture mix for as long as possible and then rest overnight.

WHAT THE COMPONENTS DO: Soda Ash and Sodium Silicate are Deflocculates. `They make the particles of clay all repulse each other (like two north poles on a magnet). Proper deflocculation allows the use of less water to make the slip a liquid, this keeps the molds from getting too wet. BALL CLAY: The OM4 and SGP or 1-4 are called ball clays, they are the actual clay in the formula. TALC is the main ingredient, it is magnesium silicate and it’s function is to prevent the glazes from crazing and to make the bisque white.