Chapter 47 Six Fillings and Six Burnings

With a soft "ding," Lin Sicheng, carrying the sunflower-shaped plate, left the testing room.

Shang Yan snapped out of her daze, leaned back in her chair, and looked quite strange.

Lin Sicheng was unaware that Wang Qizhi had completely betrayed him, so he found it very strange: why would operating the machine cause Professor Shang to be so shocked?

"Professor Shang, what's wrong?"

"Nothing!"

"Oh, then I'll prepare the glaze?"

Is this a sign that they're not even going to act anymore?

At the very least, shouldn't we check the records to see if there are any errors in the voltage excitation, whether the balance signal is stable, and whether there are any abnormalities in the calibration curve?

Muttering to herself, Shang Yan glanced at the computer: Forget it, what's the point of looking at it anymore?

The values ​​in the report are so normal, they look exactly the same as if they were filled in by hand.

Seeing that she didn't say anything, Lin Sicheng took it as agreement and pointed to the material box he had brought from Wang Qizhi's laboratory:

"Teaching Assistant Feng, please prepare the materials."

"Ah, so good..."

Stunned and dazed, Feng Lin, who had been hiding in the corner like a nobody, quickly stood up.

"Senior Sister Li, prepare the glaze... Senior Sister Li?"

After being called twice, Li Zhen finally came to her senses, as if she had just woken up.

That's normal, I'm numb from the shock...

Lin Sicheng glanced at her, then tapped the table: "Write it down!"

Li Zhen blushed slightly and quickly grabbed a paper and pen.

"Base glaze: Natural minerals: 40% lead oxide, 20% borax, 10% each of quartz and feldspar... Oxidizing agents: potassium oxide... calcium oxide... cobalt oxide... copper oxide... iron oxide... arsenic oxide..."

Key points: Melt at 900 degrees Celsius, quench in water to form granules, grind to a fineness of 200 mesh or higher…

"Colored glaze, first, dark green, mixed in eight shades: copper oxide, iron oxide... then medium green... then light green... temperature 800, oxygen-enriched firing, granulation and grinding to 200 mesh..."

"Second, light pink... Third, golden yellow... Fourth, crimson... Fifth, bright silver..."

"Teaching Assistant Feng, prepare the copper base... area... thickness... tempered copper wire, width... length... also prepare Bletilla striata and quick-drying adhesive..."

As soon as Lin Sicheng opened his mouth, Wang Qizhi was stunned: How come the ratio he mentioned doesn't match the one in the test and analysis report?

Analysis of the original glaze sample revealed that feldspar accounted for 35%, while Lin Sicheng's glaze composition only contained 10%.

The report stated that borax accounted for only 5%, but in the new formulation, it accounts for a full 20%.

In particular, lead oxide, which originally accounted for only 10% of the glaze, now makes up 40% in the new formulation.

The key point is that Wang Qizhi doesn't remember which bronze or porcelain glaze was made like this: red lead and borax, used in more quantities than feldspar and quartz.

He frowned, pondering the underlying principles, when he heard a murmur that sounded like a dream.

"He really can... he actually can?"

Turning his head to look again, Shang Yan's eyes were wide open, like hooks fixed on Lin Sicheng's face.

No... you, the teaching assistant, are like this too?

Is it really that exaggerated?

"Professor Shang...Professor Shang?"

"Oh... Professor Wang, please go ahead."

"Why is the glaze ratio so strange?"

Shang Yan sighed deeply: "It is strange, but that's right!"

Wang Qizhi was taken aback: "What kind of statement is this?"

"First, it's about fluxing; second, it's about strengthening the structure; third, it's about maintaining the fluidity of the glaze during the enameling process; and most importantly, it's about matching the copper base, adjusting the coefficient of thermal expansion of the glaze, and minimizing the furnace temperature during the second firing..."

I estimate that the furnace temperature during restoration will not exceed 700 degrees Celsius, and should be able to be controlled between 650 and 700 degrees Celsius. The possibility of the original glaze cracking a second time is not high..."

Wang Qizhi immediately understood: if the glaze was to be added according to the ratio in the test report, the kiln temperature would need to be at least 800 degrees Celsius, but the original glaze layer would definitely crack. So Lin Sicheng simply readjusted the glaze and lowered the kiln temperature.

"But this means the base glaze is diluted many times over. How can the color performance, glaze gloss, and texture be guaranteed?"

"Therefore, he mixed five more colored glazes...which means he had to apply blue at least six times and fire the vessel six times... to achieve a gradient effect and make the glaze layer consistent with the original piece..."

After a slight pause, Shang Yan frowned again: "But as far as I know, so far, only Professor Yang Shiqi and Professor Qi Haonan of the Palace Museum have used a similar method when restoring the Qing Dynasty gilt bronze transparent enamel flower basket clock... Apart from that, there has been no other..."

Wang Qizhi finally understood why Shang Yan was so shocked: this method was very difficult, extremely difficult.

He considered himself a novice, but that was only relatively speaking. At least he was very clear about the effect of temperature on coloring oxidants and color gradation changes.

A temperature difference of one degree can result in a difference of more than ten degrees in the color development coefficient after sintering.

This means that Lin Sicheng increased the difficulty of restoring this disk several times over.

As for whether it will succeed... judging from Shang Yan's ghost-like expression, Wang Qizhi's intuition was that it was unlikely.

But based on his understanding of Lin Sicheng: the more you think it's impossible for him, the more likely he is to be...

Just as he was making wild guesses, he heard a "click" sound. Wang Qizhi looked up and his eyelids twitched involuntarily.

Lin Sicheng actually pried the fish tail off the bottom of the plate?

No... we haven't even started repairing it yet, and you're already causing trouble?

"Lin Sicheng, what are you doing?"

"To test the safe furnace temperature range, right?" Lin Sicheng asked matter-of-factly. "Didn't we agree on that before?"

Yes, that's true, but you didn't say you wanted to pry up such a big piece?

Well, it's already been pried off. Anyway, if he can't fix it, there's always Professor Lin as a backup plan…

Wang Qizhi waved his hand, indicating that he should continue.

Lin Sicheng proceeded methodically: design, pattern, cutting, attaching, welding, correction... Basically, he used copper wire to cut and copy the pattern of the two fish onto a new copper plate, based on the pattern on the bottom of the plate.

It sounds simple, but it still left Wang Qizhi and Shang Yan completely stunned.

First, it's about precision: use pliers to straighten and cut, then use tweezers to bend it, and you've pinched out the required curve. Then stick it onto the copper plate, and it fits perfectly.

As Lin Sicheng had requested, Feng Lin was supposed to cut off the excess thread or patch up any minor gaps. But with both fish nearly finished being assembled, she stood there, unable to move a single finger.

Secondly, it was fast. From drawing the base design to welding and making corrections, Lin Sicheng assembled more than a hundred copper wires of various sizes in less than an hour.

The key point is that the ratio of the pattern to the bottom of the basin is almost one to one... It feels like Lin Sicheng has a ruler in his eyes.

Shang Yan looked at it for a long time, then sighed: "Professor Wang, if you were to pinch it, how long would it take you?"

Two to three hours...

Thoughts raced through his mind, and the words were already on the tip of his tongue when Wang Qizhi suddenly stammered, "Why would it need to be measured in hours?"

Shang Yan was stunned for a moment, then pursed her lips: You've confessed without being asked!

I asked how long it would take, not how many hours.

Just then, Li Zhen prepared the base glaze, and Lin Sicheng began applying the blue enamel. Shang Yan and Wang Qizhi were completely focused, not even blinking.

Seeing the blue gun (a glazing tool) in his hand, as if it had grown an extra finger, and the glaze powder seemed to have a spirit, automatically flowing to where it should flow, Shang Yan was speechless.

I was just laughing at Wang Qizhi, but now I realize I'm not much better myself.

Just as she was secretly sighing, Lin Sicheng asked Li Zhen to start the furnace. Shang Yan narrowed her eyes slightly: The most crucial part is coming.

Glaze is applied, the vessel is placed in the kiln, fired, allowed to cool naturally, and then removed from the kiln... Glaze is applied again, and the vessel is placed in the kiln again...

This happened repeatedly, six times in total, and it was already the second day.

Actually, by the time the blue light is applied, no assistants are needed, but Feng Lin and Li Zhen didn't leave. At most, they would take turns napping in the adjacent rest room during the three or so hours when the temperature dropped.

Shang Yan and Wang Qizhi had no choice: they couldn't possibly cancel both days of classes, could they?

But the two of them timed it perfectly, arriving at the conference room just before the final furnace firing.

Only Li Zhen and Feng Lin were in the laboratory, their heads facing each other, staring at the sunflower-shaped plate on the table, seemingly studying something.

"Are you here too early?"

The two exchanged a glance, then Wang Qizhi looked around again, "Where's Lin Sicheng?"

Li Zhen and Feng Lin quickly stood up and greeted him, "Professor Wang, Lin Sicheng went home this morning."

Wang Qizhi was stunned: "What is it?"

"He went home... It was right after the last time he went into the furnace, you were in a meeting, so he didn't dare call you... But he told you before he left:"

When the time is up, just let it cool to room temperature before opening the oven, then place the pattern at the bottom of the basin, and take a picture. If there are any problems, he'll come over immediately... We've already taken the picture, but he hasn't come yet..."

Does that mean there's no problem?

Wait... how can this kid be so carefree?

Even just for a sample, it took two whole days...

Cursing under his breath, Wang Qizhi walked to the desk, glanced at it casually, but his eyelids couldn't stop twitching:

The basin's walls were a bluish hue, and two koi carp lay side by side, one with a head and tail of fiery gold, its scales shimmering like stars on its back. The fish's head poked above the water, creating ripples.

The other fish, ranging from red to pink, had a slightly arched body and its tail stirred up tiny whirlpools, with a few drops of silvery water suspended in mid-air.

Being pretty is secondary; the key is the vivid, lively, harmonious, and congenial feeling it evokes… Wang Qizhi felt that the two fish at the bottom of the basin were born to look like this.

He even felt a little regretful. If he had known it would be so successful, he should have had Lin Sicheng do the repairs directly instead of testing some samples.

He sighed, preparing to ask Shang Yan for her opinion, but as soon as he turned around, he suddenly leaned back: "No, Professor Shang, are you exaggerating?"

The person remained motionless, their eyes unblinking, as if they wanted to gouge their eyeballs out and embed them into the two fish.

He muttered to himself, "Six times filled, six times burned... That clock in the Forbidden City was only burned five times..."