Cone 6 Reduction Electric Kiln Firing in Saggars
I have recently carried some successful trials using saggars to produce cone 6 copper red reduction glazes in an electric kiln. I generated a reduction atmosphere by adding a small amount of black iron oxide mixed with powdered charcoal to the bottom of a saggar with a test piece painted with Selsor red copper reduction glaze (see formula in "The Complete Guide to Mid-range Glazes " by J. Britt pg 100). I started with a copper red cone 6 glaze because it is easy to see if there is reduction; r
Which reminded me of an early paper on local reduction.
One of the most interesting ideas was the use of a SiC containing engobe/slip which then influenced the colour of a SiC-free glaze applied over the bisqued piece.
- They give combinations for copper reds at cones 012 and cone 9.
- They suggested that silicon carbide achieves reduction effects over this remarkably wide range by only reacting when in contacted with liquid glaze.
I haven't seen this idea mentioned elsewhere (an