Toma opened the kiln after the firing cooled. He used padded tongs to lift out the ceramic collar and set it on a bed of ash.
Sella checked its shape before touching it. The glaze was even, with a firm edge along the lip. She measured the opening twice and compared it with the modular drawing.
“It’s close,” she said. “Good enough for the model. Not for the furnace.”
Toma rubbed a thumb along the edge, careful not to scrape the glaze. One side had warped slightly as it cooled. “The mold shifted when the kiln temperature rose. I can correct it, but this one stays a test piece.”
Gu looked at the curve. “The model collar can be adjusted to fit it.”
“Then we won’t know whether it fits the field joint,” Sella said. “We’ll fit the model to the specification. If this one is outside tolerance, we record that and fire another.”
Toma nodded. He changed the mold, adding a thicker outer lip. Gu showed him where the pressure turned at the return channel. Toma asked whether it warmed and cooled in steady cycles or all at once. Gu answered with the field measurements he had. When he reached the part where he did not know, he said so.
