Tuesday, 5 April 2011

My Casting Process

Here I am showing the casting process I use to make my Bone China vessels which are later decorated with soluble salts before being fired to vitrification. Thanks to Eugene Hon for the images.

All my moulds are one piece drain moulds made from a paperplaster mix. Instead of the conventional Plaster of Paris spare I use a wide adhesive tape which I place around each mould before casting

Before each session of casting the slip is well stirred and then passed through a small sieve to remove any lumps and to ensure thorough mixing

The slip is then poured, again through the small sieve into the moulds, where it is left to cast for 60 - 90 seconds
 Once the cast has sat for the required time the mould is emptied

And the adhesive tape removed. After draining inverted for about 10 minutes the mould is set upright and the top is trimmed after a further 10 minutes. The pieces are left in the mould overnight and removed the following day.

3 comments:

JoAnn F. Axford said...

Interesting to see your process. I slipcast some of my pieces in porcelain. They are cast for at least 20 minutes before pouring the slip out. I like your adhesive tape collar around the top. I have a couple one piece drop out moulds that I will try that on. Thanks for sharing.

Elaine Bradley said...

The tape is just there to keep the slip from pouring down the paperplaster sides of the mould? One part drop out moulds - you don't use 'spares'? I have tried bone china, it cases so nicely and seems less drama than porcelain to cast with.

John Shirley said...

Hi Elaine
Because I use paperplaster the moulds are often too thin to use a spare, hence the adhesive tape.