Low Fire Talc:Ball Clay Casting Mix
Description
Standard low fire ceramic casting body. This is the same recipe as L213 (talc and ball clay) but different brand names are employed (KT1-4 ball clay instead of M23 and Pioneer Texas talc instead of Silverline Montana talc). These brands are the whitest commonly available. The KT1-4 is also larger particle size and deflocculates better than the more plastic M23 used in L213 (since the latter is a throwing body).
Preparation
Traditionally people have used sodium silicate and soda ash to deflocculate their slip. However, Darvan is a superior product. We recommend understanding the principles of deflocculation so that you can measure specific gravity and recognize whether a slurry is under or over deflocculated. This will enable you to adjust the recipe for variations in water, materials, climate, etc.
The following is under-construction Nov 6, 2020
For a 50 lb bag of talc/clay mix:
- Add 10 litres of the water to the mixing tank.
- Add 40g soda ash, 120g sodium silicate. Mix for 5 minutes.
- Add the 50lb bag of powder, mix for 15 minutes.
- Check the specific gravity and add water if it is above 1.8.
- Add 1200g of whiting and mix 5 minutes more.
The longer you can mix the slurry there better its properties will be.
Gallery
Ball clay:talc bodies have incredible casting properties. This bowl is 13cm across yet has a wall thickness of less than 2mm and weighs only 101g! It released from the mold with no problems and dried perfectly round. And when fired at cone 04-06 it will stay round!
