|Monthly Tech-Tip |
Recipes show us the materials in a the glaze powder (or slurry). Formulas enumerate the oxide molecules and their comparative quantities in the fired glass. Oxides construct the fired glass. The kiln de-constructs ceramic materials to get their oxides, discards the carbon, sulfur, etc. and builds the glass from the rest. There is a direct relationship between fired glaze properties (e.g. melting range, gloss, thermal expansion, hardness, durability, color response, etc) and its oxide formula. There are 8-10 oxides to know about (vs. hundreds of materials). From the formula-viewpoint materials are thus "sources-of-oxides". While there are other factors besides pure chemistry that determine how a glaze fires, none is as important. Insight-live can calculate and show the formula of a recipe, this enables comparing it side-by-side and with a target formula (or another recipe known to work as needed). Target formulas are opened using the advanced recipe search, choosing the limits batch and clicking/tapping the search button (search 'target recipe' in Insight-live help for more info).
A way of establishing guideline for each oxide in the chemistry for different ceramic glaze types. Understanding the roles of each oxide and the limits of this approach are a key to effectively using these guidelines.
In ceramics, the chemistry of fired glazes is expressed as an oxide formula. There are direct links between the oxide chemistry and the fired physical properties.
In glaze chemistry, the oxide is the basic unit of formulas and analyses. Knowledge of what materials supply an oxide and of how it affects the fired glass or glaze is a key to control.
In ceramics, raw material chemistry is expressed a chemical analyses. This is in contrast to fired glaze chemistries which are expressed as oxide formulas.
Creating Your Own Budget Glaze
How to take a stockroom full of unused materials and turn them into a good glaze rather than try umpteen online recipes that require buying yet more materials you do not need and do not work.
This is the software ceramic technicians need to study, understand, adjust and formulate glazes and clay bodies.