Kiln Guide

S-cracks, dunting, and blowouts each have a distinct cause tied to moisture, throwing, or cooling speed. Here's how to diagnose which one you're seeing and prevent it.

Crazing and shivering are opposite symptoms of the same issue: glaze fit. One means your glaze expands too much, the other too little. Here's how to tell and fix each.

Crawling makes glaze bead up and pull away from the clay, leaving bare patches. Almost always it's contamination or a too-thick coat. Here's the fix.

Pinholes and blisters both wreck a glaze surface, but they're different problems with different fixes. Here's how to tell them apart and clear them up.

Crazing is the fine spiderweb of cracks in a fired glaze, and it comes down to one thing: the glaze and clay body shrinking at different rates. Here's what causes it, how to fix it, and how to stop it for good.

The file test is a fast, free go/no-go check for blade hardness. Learn how to run it correctly, what a failed test tells you about your heat treat process, and how to diagnose and fix the most common causes of soft blades.