Pottery Firing Failure

Chapter 22: Failed Firing

The air-dried clay blanks had sat quietly in the corner for several days, their color deepening and their texture growing firmer.

They were no longer as fragile as when first shaped; tapping them with a fingertip produced a dull, solid thump, signaling the initial stabilization of their internal structure.

Chen An stared at the two crooked but recognizable forms—the shallow bowl with its warped rim and the wide-mouthed jar with its unbalanced proportions—a sense of ritualistic anticipation and tension surging within him.

Firing was the final step in the rebirth of pottery, the most critical and the most fraught with unknown risks.

Success or failure at this stage would determine whether the clumsy efforts of the past days could truly yield usable vessels, and whether his simple wish to "improve daily life" could take a solid step forward.

He knew well that primitive open-pit bonfire firing had an extremely low success rate, with finished pieces often riddled with flaws.

But for now, he had no other choice. Building a kiln that could control temperature required more complex planning and more materials—far from a one-day task.

He decided to attempt a bonfire firing first, treating it as a "preheating" test for the clay blanks and a hands-on lesson in the firing process.

In the yard, near the kitchen stove, he cleared a small, flat patch of ground.

Using stones and compacted clay, he built a low, platform-like base to serve as the "kiln bed" for the clay blanks. The surface was leveled as much as possible and carefully smoothed with wet clay to reduce the risk of the blanks sticking to it.

Behind the platform, he used the courtyard wall and a few large stones to create a simple enclosure, forming a semi-enclosed space to concentrate the fire as much as possible and minimize heat loss.

He carefully placed the two air-dried blanks on the platform—the bowl mouth-down, the jar mouth slightly tilted downward as well—to prevent residual moisture inside from evaporating too rapidly and cracking the walls during firing.

Around and above the blanks, he began stacking fuel. He had carefully selected dry, slow-burning hardwood branches and split logs, mixed with some easily ignitable dry grass and dead leaves as kindling.

He mimicked the stacking method of bonfires from memory, ensuring gaps between the fuel for airflow, so the flames could burn fully and generate sustained high heat.

Everything was ready. Chen An took a deep breath and lit the kindling with a torch.

Orange-red flames quickly licked at the dry wood, crackling softly and sending up plumes of white smoke. He stayed by the platform, continuously adding more firewood to keep the blaze strong. The flames grew higher, shifting from orange-yellow to a searing white, and the temperature climbed sharply.

Waves of heat hit his face, making his cheeks burn and sweat bead on his forehead.

He watched the clay blanks nervously. At first, their color deepened, and a thin layer of moisture seemed to appear on the surface—a sign of water evaporation.

As the temperature continued to rise, he expected to see the blanks undergo a wondrous transformation—the body sintering, the color stabilizing to a light gray or orange-yellow, the texture hardening like stone.

But things quickly deviated from his expectations.

Signs of failure emerged.

After about an hour, the flames reached their peak. Chen An estimated the temperature was already quite high.

He noticed that the clay bowl, closest to the fiercest part of the fire, began to show obvious changes.

Not the uniform sintering he had hoped for, but localized swelling and blistering—as if gas inside was expanding violently, stretching the unevenly thick walls.

Then came a faint crack—a thin fissure appeared on the bowl's surface!

Chen An's heart sank! He fought down his panic and tried to gently nudge the flames with tongs to distribute the heat more evenly. But it was too late.

As the temperature continued to work its effect, the bowl's fate was sealed.

The crack spread like a living thing, widening, accompanied by a series of popping sounds. The bowl's body collapsed and twisted on a large scale, eventually turning into a shapeless, smoking pile of hard fragments. The unlucky bowl had completely "died in the line of duty" under the scorching heat.

The clay jar fared slightly better, but not by much.

Because it was placed a bit farther away, it received more even heat and didn't suffer violent bursting. But under the sustained high temperature, its body seemed to undergo intense internal stress changes.

After cooling—Chen An had to prematurely stop the firing and risk approaching to rake open the hot ashes—he found that while the jar had largely kept its shape, its surface was covered with a dense network of fine, crisscrossing cracks, like the pattern on a turtle's shell.

A light tap produced a dull, muffled sound, lacking the crisp, solid ring it should have had. The internal structure of the body had clearly been compromised, turning it into a waste product full of hidden cracks and extremely low strength.

Two clay blanks, two failures!

The bonfire gradually died out, leaving only ashes and cooled pottery shards and lumps. The air was thick with the bitter smell of plant ash and the unique tang of earth scorched by high heat. Chen An stood dumbfounded by the messy platform, watching his hard work turn to nothing. A wave of crushing disappointment and frustration, like icy tidewater, instantly engulfed him.

The excitement, the anticipation, the effort... all of it had turned into these two piles of useless fragments. He crouched down, futilely trying to piece together the broken shards, but only felt the coldness at his fingertips and the powerlessness in his heart.

After a long while, Chen An slowly stood up. He silently cleaned up the mess, gathering the shattered pieces and cooled ashes.

He didn't leave immediately. Instead, he sat down by the platform and calmly reviewed the entire process, trying to pinpoint the cause of failure.

- Insufficient and uneven temperature: This was the most direct cause. The temperature of a bonfire, even at full burn, was far below the peak needed to fire qualified pottery (typically above 800°C). More critically, the flame distribution was extremely uneven. The bowl near the fire overheated locally, causing violent expansion and bursting. The jar farther away, while possibly reaching the right overall temperature, suffered from large local temperature differences, generating massive internal stress that led to cracking. A primitive bonfire could not provide a stable, uniform, sustained high-temperature environment. - Oxidation atmosphere control: He realized that in the later stages of firing, a reducing atmosphere (oxygen-poor environment) might be needed to promote the reduction of certain components in the body, giving the pottery better color and texture. An open bonfire, fully exposed to air, was a purely oxidizing atmosphere, which may have affected the final result, though this was not the main cause of this failure. - Defects in the clay blanks themselves: The blanks he had made were inherently uneven in thickness and structure, which undoubtedly exacerbated stress concentration, deformation, and cracking under high heat. But this was an upstream issue; even perfect blanks would be hard to guarantee success with bonfire firing. - Lack of temperature control and insulation: Without a kiln structure, he couldn't effectively concentrate, regulate, or sustain the required high temperature for long periods. Heat dissipated too quickly, and the temperature curve couldn't be precisely controlled.

"Bonfire... no good," Chen An muttered to himself, a hint of bitter realization in his tone. "I need a kiln! A kiln that can seal, control temperature, and provide sustained high heat!"

This thought became clearer and more resolute than ever before. He understood that the birth of pottery depended not only on clay and fire, but also on the tool created by human ingenuity to harness fire—the kiln. This was the necessary step from primitive pottery-making to mature craftsmanship.

Though the first firing ended in total failure, with both clay blanks reduced to dust, Chen An was not completely crushed. This painful failure, in the most direct and undeniable way, revealed to him the technical gap he had to cross on the road to success—building a kiln.

He stood up and took one last look at the cold heap of ashes and broken shards. They were witnesses to failure, but also invaluable lessons. They told him: the trial by fire had not yet been passed, but the path to success was already showing itself in the ashes of defeat.

The next step was no longer practicing shaping, but turning to a grander, more complex project: designing and building his first kiln. This would be a greater challenge than making pottery itself, but for the sake of light, clean vessels and a more convenient life, he had to try.

The wind of the primordial wilderness blew through the small yard, carrying a chill, but it could not extinguish the flame rekindled in Chen An's heart—a flame pointing toward the blueprint of a kiln.

(End of Chapter 22)