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Low Fire Talc:Ball Clay Casting Mix

Description

Standard low fire ceramic casting body. This is the same recipe as L213.

News

September 2021: The entire industry is phasing out of the use of talc, it is happening suddenly. That means we must change this body. You can find more information on our work at this page (as you will see, this is a work-in-progress, it is not ready for you to just order and expect everything to work as before). Since the new mix described uses dolomite instead of talc, the whiting is not needed (since dolomite contains significant whiting). It is also likely that the amount of sodium silicate (or Darvan) will need adjustment to achieve the desired rheology.

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.

For a 50 lb bag of talc/clay mix (25 talc, 25 ball clay):

  1. Add 10 litres of the water to the mixing tank.
  2. Add 40g soda ash, 120g sodium silicate. Mix for 5 minutes.
  3. Add the 50lb bag of powder, mix for 15 minutes.
  4. Check the specific gravity and add water if it is above 1.8.
  5. 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!

Safety Data Sheet

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Logo Plainsman Clays Ltd.
702 Wood Street, Medicine Hat, Alberta T1A 1E9
Phone: 403-527-8535 FAX:403-527-7508
Email: plainsman@telus.net