A flameware body being tested for thermal shock. Is this a joke?

Thursday 28th July 2016

A recommended flameware recipe from a respected website (equal parts of 35 mesh grog, talc and ball clay). Looks good on paper but mix it up for a surprise. The texture is ridiculously coarse. Recipes like this often employ fire clays and ball clays, but these have high quartz contents (in a test like this a ball clay vessel could easily fail in 5 seconds). But this one is surviving still at the 90-second mark. Or is it? While porcelain pieces fail with a spectacular pop of flying shards, these open-porous bodies fail quietly (note the crack coming up to the rim from the flame). There was an intention to create cordierite crystals (the reason for the talc), it is hard to say whether than happened or not. But the porosity of 12.5% would be difficult to deal with. On the positive side, you could likely continue using this vessel despite the crack.

Pages that reference this post in the Digitalfire Reference Database:

TSFL Thermal Shock Failure, Grog, Thermal shock, Flameware

This post is one of thousands found in the Digitalfire Reference Database. Most are part of a timeline maintained by Tony Hansen. You can search that timeline on the home page of digitalfire.com.