"Hey everyone, here's the plan. We need a clay furnace, so first we must find the right clay and build a kiln." Lin Yu'an slung a camera across his chest, grabbed his woodcutting axe and a sharpened wooden spear, and set off to search for suitable soil.
From earlier fishing trips he had noted that sediment tends to collect on the inner bends of rivers. Sure enough, on the inside of a curve he found a patch of fine, reddish clay. He dug a handful, kneaded it in his palms, and smiled. "This clay is very plastic and has almost no sand or grit. With a little processing it will make excellent pottery."
The next step was selecting a kiln site. He picked an open, slightly elevated patch about a hundred meters from the bend. It was flat, convenient for collecting fuel and clay, and out of the lowest ground. Using the spear he traced a circle about a meter across and cleared the round working area. "I plan to build a ground level, rising flame kiln," he told the camera. "The fire chamber will feed the kiln chamber from below."
Before building the full kiln he needed to test the clay. Sitting on a flat stone, he pounded and wedged a lump of clay like dough. After many tries and a few failed shapes, he formed a rough, round grate. He set it in a sheltered place to dry. By evening the wind had eased and the piece had hardened slightly, taking on a pale skin. It looked ready for firing.
He built a U‑shaped pit surrounded by stones and started a steady fire. Carefully he placed the dried mud grate across two stones above the flames. "Let's fire this grate," he said. "If it sinters, we have a key component for the furnace."
An open pit will not reach kiln temperatures, but it can sinter coarse pottery enough to test clay quality. He was cautious about heat. "First, you dry slowly to drive out residual moisture," he explained. Even an air‑dried piece contains internal water. He kept the fire moderate so the grate would warm evenly rather than crack.
As the hours passed the grate darkened and the smell of baking earth emerged. Lin Yu'an monitored the flames, stirring the wood to maintain even heat. After two hours he judged that most moisture had evaporated and began to increase the fire, feeding larger logs. The flames climbed and a faint mineral scent rose. Under that heat the clay's minerals change and begin to bind into a ceramic matrix. He planned to hold the stronger fire overnight and into the next day.
Night fell and the pit was the only light in the dark. Lin Yu'an nursed the fire, adding small logs on a careful schedule to avoid thermal shock. He did not allow himself more than short rests. By dawn most of the prepared wood had been consumed. He kept the fire going into late morning; in total the grate baked in sustained heat for well over fifteen hours.
When he judged the high temperature phase complete he stopped feeding the flames and let the embers burn down to charcoal. That residual heat would cool slowly and reduce cracking risk. Exhausted, he returned to the stone shelter for a few hours of sleep.
A chill woke him midmorning. He hurried back to the pit, brushed ash away with a stick, and uncovered the grate. His eyes brightened. The piece had survived. The shape was intact and there were no major cracks or deformation. It lacked glaze, but the texture was solid and ceramic. He tapped it with his knuckles and a clear ringing note answered.
"It worked on the first try," he said, grinning into the camera. "It is stronger than I expected." He handled the grate carefully and stored it in the shelter for later use in the kiln build.
The successful firing proved two things. The local clay can be sintered reliably. His kiln design and firing routine are viable. More importantly, the result raised his confidence for the larger project: making molds and firing bricks for a proper stove and kiln components. He packed the grate away and planned the next steps, satisfied that this experiment had cleared a major technical hurdle.