I made three positives in clay of maps of continents. The molds were made out of a 40/60 plaster/silica mix, which was allowed to soak for 5 minutes before stirring, and was de-gassed by tapping the bucket until the air bubbles rose to the surface. I waited too long in this process before investing the clay in the plaster, so the mixture was much more set than it should have been. The molds were made with clay dams.
The molds were dried on September 26th, before they were packed, on the following schedule:
1. 5:00 – 80C
2. 44:00 @ 80C
Argentina was fired in the middle shelf of kiln #2, and India and Africa were fired on the top shelf of kiln #1.
The drying firing does not go all the way up to 100C in order to prevent steam cracks. They were unloaded on Monday September 28th.
All the photos associated with this firing can be found in the following album:
|Multi-fire Part #1|