The first glaze is a control, a standard non-fluid clear with copper. The other three are the short-listed ones in my project to find a good copper blue recipe starting recipe and fix its problems (which they all have). The GLFL testers for melt flow at the back and the GBMF test melt-down-balls in front contain 1% copper carbonate. The glazed samples in the front row have 2% copper carbonate. L3806B, an improvement on the Panama Blue recipe, has the best color and the best compromise of flow and bubble clearing ability.
Every glossy ceramic glaze is actually a base transparent with added opacifiers and colorants. So understand how to make a good transparent, then build other glazes on it.
Ceramic glazes melt and flow according to their chemistry and mineralogy. Observing and measuring the nature and amount of flow is important in understanding them.
Ceramic glazes can leach heavy metals into food and drink. This subject is not complex, there are many things anyone can do to deal with this issue
Understanding your transparent glaze and learning how to adjust its melt fluidity, thermal expansion, color response, etc is a base on which to build all your other glazes.
|Recipes||G3806C - Cone 6 Clear Fluid-Melt Clear Base Glaze
A base fluid-melt glaze recipe developed by Tony Hansen. With colorant additions it forms reactive melts that variegate and run. It is more resistant to crazing than others.