|Description:||Calcium carbonate, talc finished gassing|
LOI is not important? Think again!
This chart compares the gassing behavior of 6 materials (5 of which are very common in ceramic glazes) as they are fired from 500-1700F. It is a reminder that some late gassers overlap early melters. The LOI (loss on ignition) of these materials can affect your glazes (e.g. bubbles, blisters, pinholes, crawling). Notice that talc is not finished until after 1650F (many glazes have already begin melting by then).
In Bound Links
A wide range of carbonates are used in ceramics and each of these has its own thermal history. Within that is a range where they decompose to give off...
Ceramic bodies and glazes contain materials that release carbon as they decompose on heating. Clays, gums, plasticizers are examples. These can still be burning out at higher temperatures than most people realize (cone 04 or higher). That burning generates gases, if glazes are beginning to melt befo...
By Tony Hansen
•The secret to cool bodies and glazes is a lot of testing.
•The secret to know what to test is material and chemistry knowledge.
•The secret to learning from testing is documentation.
•The place to test, do the chemistry and document is an account at https://insight-live.com
•The place to get the knowledge is https://digitalfire.com