Glazing problem

[Mariam Baramidze]

Hi. That was unexpected, because almost every piece from one firing had the same problem. White clay with transparent glaze. Cone 4.

1. Glaze was not applied thickly,

2. The pieces were clean,

3. Glaze was clean,

4. Cooldown was slow.

Do you have any idea what could cause the similar damage to the pots?

P.S. In some cases glaze slightly has changed the colour and turned yellowish in the damaged area as seen in the photo attached.

[Min]

Is this a commercial brushing glaze, a commercial dipping glaze or a recipe you mixed yourself? How are you determining how thick to apply it? Is this a cone 4 glaze specifically, does your clay mature at cone 4? F it’s mixed from a recipe post it here.
Glaze crawling like you are experiencing has a few main reasons why it occurs. Contamination of pot surface by dust or lotion/oils on hands, glaze application too thick or raw glaze has excessive shrinkage. Reason it’s that yellowish colour where it has crawled into little islands is because it’s thicker there from the glaze crawling together.