Bricks, Kilns, and the First Firing
A month flew by in the blink of an eye as I threw myself entirely into brick production. I gathered bricks from the makeshift kiln and built a proper brick kiln in one corner of the clearing. The temporary one could only produce so many bricks, and making multiple kilns would have required more firewood than we had. Now that I had a real kiln, I could make far more bricks with the same amount of fuel. Stacked in a cylindrical shape topped with a dome, this kiln was far better at trapping heat than the crude earlier version. The improved firing efficiency meant less firewood even for larger batches.
That said, better efficiency didn't solve our chronic firewood shortage. The real issue was temperature. Regular bricks couldn't withstand over 1,100°C, while firebricks needed sintering at 1,200–1,400°C. Firing firebricks in a regular brick kiln would melt it in one go. The materials from the sedimentation process weren't enough for mass production either. For now, I'd have to treat regular bricks as disposable for high-heat jobs.
Even after finishing the brick kiln, foraging branches from the forest myself left us perpetually short on fuel. Trips for firewood slowed everything down. What could I do? We didn't have the money to buy logs. On firing days, I had to tend the fire all day, then block the combustion chamber to smother it and let it cool slowly over 2–3 days. Cooling too fast would crack the bricks, so rushing wasn't an option.
During those long cooling waits, I'd haul the cart through the woods all day, gathering firewood and digging clay for the next round. In spare moments, I taught Clay reading, writing, and arithmetic. She had deft hands but an average head for numbers. Still, after a solid month, she could handle basics. She'd need them later for handling money and inventory.
I kept the sedimentation process running with the jars, too. Seeing piles of kaolin, feldspar, and silica stacking up inside the building gave me a sense of security. At this rate, we'd have enough raw materials for two or three pottery firings.
A little while back, I paid Clay her first wage.
—Clink.
"...What's this?"
"Your pay for last month."
"...! Th-thank you!"
Seeing her check the silver coins in the pouch and bow repeatedly gave me an odd sense of responsibility as her employer.
I also dipped into my subjugation bounty savings to furnish the workshop. For three silver coins, I got a sturdy wooden table; for another three, two wooden chairs with backs. Shelves for pottery would run 7–8 silver, so I put that off. Space wasn't an issue yet—we could buy them once we started selling fired pieces.
After the furniture arrived, I ordered lumber from the general store and had Clay build a kick wheel essential for pottery forming.
"Oh, this looks usable."
"Hehe~."
I explained the design from my past-life memories, and with just verbal instructions, she nailed a working wheel on her second try. Now we just needed the pottery kiln to start production.
Another month passed like that. Finally, we'd accumulated enough bricks for a pottery kiln. Without delay, I started building a small one next to the brick kiln, sized for about eight 10-liter jars at once. I used the same mortar as before—local clay mixed with water. Primitive, but we lacked alternatives.
Like the brick kiln, it was a cylindrical dome. The combustion chamber was behind a jar chamber, separated by tile partitions so flames wouldn't touch the pots directly. Heated air rose to fill the chamber, then escaped through a low rear vent to the chimney. Not knowing exact sizes for the intake and chimney from theory alone, I eyeballed it. I'd refine that with experience.
The finished kiln stood about as tall as me. For heat capacity, I triple-walled it with bricks and packed clay between layers. Glazed pottery needed over 1,200°C—the inner layer would melt each firing, but the outer ones would hold it together.
Looking at the completed kiln, our mountain of bricks had vanished. I jumped straight into pottery making, starting with practice jars for the sedimentation process—we needed lots right away. Since they were originally pots, we could resell them as cookware after switching to settling tanks.
I had Clay prepare the clay body: grind purified kaolin, feldspar, and silica from sedimentation in the household mill, mix at 2:5:3. Blend the coarser feldspar and silica first, then add fine kaolin and stir until uniform. Add water only after dry-mixing to avoid clumping.
Once mixed, knead vigorously like dough. Clay mastered it easily despite being new. Shaping right away would unevenly distribute moisture, risking cracks or breaks in bisque firing. I wrapped the finished body in damp cloth and stashed it in a cool spot inside. After about 7 days aging, it'd be even and less prone to failure.
We had to wait again—no plastic here, so prepping early risked drying out. Once aged, we loaded it onto the wheel. Under Clay's skilled hands, it smoothly formed jar shapes. She didn't disappoint, and her speed improved noticeably.
"You're good at this."
"Really?"
"Absolutely. Best hire I ever made."
"Hehe, thank you!"
By the last jar from the remaining clay, it matched the store-bought ones in quality. She could hold her own in any pottery workshop now.
We dried the finished jars inside the building. Another fortnight wait. I tested magically drying one—it split with a crack. No skipping this step with magic, sadly.
After more brick-making days, we loaded the dried jars for bisque firing. To remove moisture and organics, fire for about 8 hours, seal, and cool slowly over a day.
While they cooled, I made glazes. Essential for waterproofing insides, whether for cooking or settling. No outer glaze to avoid melting on direct flame.
Grind kaolin, feldspar, silica at 1:1:2 into a thick slurry. I also mixed a white fireproof coating for kiln efficiency: kaolin 75, feldspar 5, silica 20. Coating the interior would boost efficiency by 20% and prevent single-use melting.
Stored extras in spare jars and bought a wide brush to coat both kilns.
After cooling, we opened to find two jars shattered from heat. Six survivors. Shards were recyclable as drainage aggregate later.
I had Clay glaze the bisque jars one by one: pour in, roll to coat evenly, pour out excess. A second coat after 3 days would improve waterproofing and sheen, but risked run-off if too thick. I explained pros and cons to Clay. For practice and inner-only, we'd fire some recoated, some not, for comparison.
Then made another batch of eight for bisque, filling the kiln to save fuel. Three broke this time, netting 11 glazed bisque jars.
Preparations complete. Time for glaze firing.