|Monthly Tech-Tip |
These materials have many issues. They can create problems in your glaze slurries (like precipitates, higher drying shrinkage), cause issues with laydown and dried surface and cause fired surface defects (like pinholes, blisters, orange peeling, crystallization). And lithium and barium have toxicity issues (as raw materials). And the lithium, barium and strontium are carbonates, that means carbon burns off during firing (with lithium, for example, 60% of its weight is lost). Yet the oxides that these materials source to the glaze melt, ZnO, Li2O, BaO and SrO can be sourced from frits. In doing that you can solve almost all the problems and get better glaze melting. Fusion Frit F 493 has 11% LI2O, F 403 has 35% BaO, F 581 has 39% SrO and FZ 16 has 15% ZnO. Of course, these frits source other oxides (but these are common in most glazes). Using glaze chemistry you can often duplicate the chemistry of a glaze while sourcing these oxides from frits.
Frits are used in ceramic glazes for a wide range of reasons. They are man-made materials of controlled chemistry with many advantages or raw materials.
Common sense can be applied to the safe use of ceramic materials. The obvious dangers are breathing the dust and inhaling the fumes they produce during firing. Here is a round-up of various materials and their obvious hazards.
|Materials||Zinc Oxide Raw|