The following day, the 11th, Jin immediately set to work on constructing the ultra-large Blow Floater.
"Hmm, just as Elsa said, hauling in materials is so much easier."
Having a direct passageway connected to the underground storehouse made things exceptionally convenient.
"Having a dock dedicated to large-class builds really is wonderful."
Until now, he had either fashioned temporary scaffolding using magi-craft or relied on Daidara to hold things in place. Being able to build while resting the craft on dedicated assembly frames made the work smoother than ever before.
"Put this like so, and this over here... okay....Reiko, hand me those materials over there, please."
"Yes, Father."
"Smith 7, please handle the adjustments on the opposite side."
"Understood."
Thanks to the unprecedentedly smooth workflow, Jin found himself pouring his full effort into the task.
"Th-That's incredible."
"You really never get tired of watching him."
"...Hey, why don't we invite Sion and the others to come watch too?"
"Ah, that sounds like a great idea."
Marcia, Beena, Elsa, and the rest of the onlookers shared the sudden thought.
They acted on it immediately.
"We came, but... what is this place?"
"Jin-san is doing something utterly outrageous again, isn't he...?"
"Wh-Wh-What on earth is this place?!"
Sion, Lordtoss, and Ludmila arrived, utterly dumbfounded.
"Ah... yeah, I know the feeling."
Beena, who welcomed them, gave a wry shrug.
"The truth is..."
Elsa offered an explanation to Sion and the other two.
"What?!"
"A Blow Floater capable of carrying ten tons?!"
"I can't even begin to picture it..."
All three voiced their astonishment.
"Apparently, in the world Jin-nii came from, there were aircraft capable of hauling that much."
"Using the power of wind? That's incredible!"
"Mm. That's why Jin-nii says it can be done here, too."
"Well, that makes sense. It's Jin, after all."
"Jin-sama is truly remarkable..."
While that conversation was taking place off to the side, Jin continued assembling the craft at a blistering pace.
Watching gigantic ingots transform in mere seconds into massive, dish-shaped structures fifteen meters in diameter was truly a magnificent and surreal sight.
And the process repeated itself in rapid succession.
Four circular wings, each fifteen meters in diameter, were arranged to form the vertices of a square.
The structural frame was made entirely of 64 light silver—a lightweight, exceptionally durable alloy.
"With that, the basic frame is complete. Next are the Blow Engines."
Jin fabricated twenty high-output units.
Four Blow Engines were allocated to each circular wing, with the remaining four serving as emergency backups.
"I need to make the propulsion system as well."
To handle forward thrust and directional control, he prepared eight Jet Thrusters of the same design.
Four would provide forward propulsion, while the other four would steer the vessel.
"As for control, a golem brain is the logical choice."
Given the sheer scale of the vessel, Jin deemed autonomous flight assistance essential.
Rather than requiring an onboard pilot, the system would allow someone to simply input a destination and leave the navigation to the craft.
"It won't fundamentally be transporting people, after all."
Jin envisioned it exclusively as a heavy transporter for giant golems like Daidara or large vehicles like the Capricorn.
"We have a bit of leeway with the power output, so maybe I'll make it an enclosed cargo hold instead of using a sling load."
A suspended sling load made sharp maneuvers impossible, and there was always the danger of mooring cables snapping under stress.
Furthermore, an enclosed cargo hold offered the advantage of carrying supplies other than golems.
Thus, he built a lightweight, durable cargo compartment, also crafted from 64 light silver.
Thanks to this addition, the Blow Floater could serve versatile roles beyond simply transporting Daidara.
"All that's left is the color, but let's avoid anything too flashy."
By adjusting the thickness of the surface oxidation film on the light silver, a wide range of colors could be produced.
Jin considered a dark green, but dismissed the idea, feeling it looked too much like a military aircraft.
"Hmm, what should I go with?"
Stumped, Jin decided to consult Hanna, who happened to be standing nearby.
"Hanna, what color do you think would suit this craft?"
Hanna paused in thought.
"Hmm, how about white?" she suggested.
"White, huh..."
Metallic white was nonexistent in raw metalwork; achieving true white required reflecting all wavelengths across the visible spectrum, which on polished metal simply appeared silver.
Naturally, Hanna was well aware of this.
"Why not paint it?" she offered.
"Paint, huh."
"Yeah. And then add red and blue accents."
"Accents... like striping or trim?"
"Yup."
Indeed, Jin had almost exclusively relied on the bare finish of light silver for his exteriors, rarely ever applying coats of paint.
"I wonder if we have any paint on hand..."
Right on cue, Saki strolled over.
"Kufu, I've got just the thing."
Saki announced that she had already developed a specialized paint derived from Ground Spider resin.
"When did you manage that...?"
"Well, I came up with the concept about 370 years ago. But I only perfected it recently."
Melting Ground Spider resin required heating it to roughly 1,600 degrees Celsius. Since the melting point of light silver was 1,668 degrees Celsius, applying it in a molten state was theoretically possible, but practically precarious.
"Kufu, that was the puzzle I had to solve. To begin with, it isn't thread yet inside a Ground Spider's body, right? So I investigated why it stabilizes into a solid thread in the first place."
"Ah, I see."
Inside the Ground Spider's body, the substance was a liquid, solidifying into a stable filament only upon being expelled from its spinnerets.
Saki had researched the precise trigger behind that stabilization process.
"As expected, it was magic."
Ground Spiders were magical beasts that sustained themselves by consuming free ether.
Their bodies were composed of magiatoms, meaning the silk they secreted was inherently made of magiatoms as well.
The thread expelled from their bodies reacted with the free ether present in the surrounding space, which caused it to stabilize—or so Saki explained.
Consequently, silk produced by Ground Spiders living in ether-rich environments like Hourai Island boasted far superior physical properties compared to specimens found elsewhere.
"So, what happens if you have it expel the silk into a space completely devoid of free ether?"
"Oh, you'd obtain the precursor fluid without it hardening."
"Kufu, exactly. It wasn't easy, but I managed to tame a Ground Spider and harvest that raw fluid."
Saki explained that she had named the unsolidified silk fluid "Pre-GST," with GST standing for Grand Spider Thread.
"Though if you don't keep it constantly exposed to an ether eliminator, it instantly turns into Ground Spider resin."
Incidentally, the reaction between free ether and Pre-GST was entirely irreversible, which was why cured Ground Spider resin remained so remarkably stable.
In any case, blending magic dyes into Pre-GST before it hardened yielded a high-performance paint.
"If you apply it in an area enveloped by a Magi-Jammer and then expose it to dense free ether, the paint reacts and cures solid."
The reason for utilizing a Magi-Jammer rather than an ether eliminator was that golems could not operate within the nullifying field of an ether eliminator.
"Under a Magi-Jammer, the suppression of the hardening process is imperfect, giving you a working window of only about ten hours, though."
It came down to the difference between an ether eliminator, which purged free ether entirely, and a Magi-Jammer, which merely brought it under domination, Saki noted.
"No, ten hours is more than enough."
With that decided, Jin resolved to test out the new paint.