As a military fan, Li Xian naturally knows the military system and weapons, and he is even more confident in the artillery-making technology, of course, it is all on paper......

So Li Xian first asked Guan Fengsheng to talk about their artillery-making process from beginning to end.

In the Ming Dynasty, many copper cannons were cast, and the wood clay fan casting cannon [1] was used, and the process was cumbersome, and at the end of the Ming Dynasty and the beginning of the Qing Dynasty, copper and iron cannons were available, and the iron cannon was used to cast the clay cannon, and the specific technique was the lost wax method, that is, the wax was used to make the cannon mold first, and then the mud seal was made into a clay fan. After the mud fan is dry, melt the wax inside, pour in molten iron, and break the mud fan after cooling.

The information that Li Xi read before crossing was simple and clear, but after hearing the real points and specific steps, he realized that he was really talking on paper.

"The real point is in this clay model!"

Speaking of his own business, Guan Fengsheng suddenly lost his usual honest appearance, and his whole eyebrows were flying and his energy was refreshed.

"Choosing mud and mixing mud is a science, and the mud can't be too coarse, and it will easily disintegrate if it's too coarse. It is not good if it is too fine, the water vapor is impermeable, not only the mud fan dries slowly, but also foams more after filling the molten iron, so it is generally a good glue yellow mud mixed with fine sand, and the eight and two match. You have to be careful how much water you add, and you have to be moderate with the wall mud. If you follow the techniques handed down from my ancestors, what kind of soil, what kind of water is used, and what time of day is used, you can pay attention to it! ”

"Ganfan is the most fatal, and this is what worries the gunsmith the most. It's not a simple matter to let the mud dry, the mud fan should be evenly dried inside and outside, the most easy bad thing is that the outside is too fast, and the inside is not enough, so the mud fan is ventilated and dry. ”

Speaking of this, Guan Fengsheng's eyes were leisurely, recalling the past years.

"My grandfather and my father were making cannons for the Shang family when the three feudatories were in rebellion thirty years ago, and I was doing chores on the side, and then the Shang family was defeated, and the family was also implicated, not Brother Li, cough cough...... How to say this. ”

Guan Fengsheng retracted his thoughts and continued to talk about this dry mold.

"If you are in a hurry and you can't grasp it well, then you have to make a fire to dry, but it must be slow to dry over low heat, otherwise the wax in the fan will melt first. If it is a cannon of several thousand catties, it will take three or four months to dry the mold alone, and at least two or three months in the north. If it's just a small cannon, you should be able to do it for more than a month in the spring and autumn in the north, and you have to run for more than two months in winter. Summer is not a good season for making cannons, the mud fan is easy to dry and crack, and the wax inside will melt early. ”

Tian Dayou frowned and interjected: "It's okay to say this season in the north, but our Guangdong is the rainy season, the moisture is too heavy, and it takes a lot more time." If you make a fire to dry, the wax will melt some first, and the waste rate of the cast cannon is very high. ”

These words made Li Xian think of one thing, during the Opium War, Guan Tianpei, the commander of the Guangdong Navy Division, inspected the military defense of Humen Fort, and found that there were many artillery pieces that were unusable, and there was a big pit in the barrel of one of the cannons, which could store four bowls of water.

Guan Fengsheng seemed to be comforting himself: "There is only more modeling and more trying, my father and ancestor built a cannon of several thousand catties back then, but now it is only a small cannon of sixty catties, and there should be a lot less trouble in doing it." ”

He looked at Li Shi, and the worry between his eyebrows lingered: "Two months is still too rushed, even if the mud fan can come out in a month and a half, the rest of the time has to be scraped and polished, and your Uncle Tian and I can take care of seven or eight mud fans at most, and there can only be half of the waste cannons." If it is just to create the appearance of the cannon, the waste cannon can also be handed over. But I can listen to Master Zhong's request, it is to be able to fire a cannon, then even if it is a small cannon, only half of the waste rate is allowed, and this requirement is also very high, in case there is a miss......"

Hearing this, Li Xian also knew in his heart.

"Uncle Guan Tian, we don't need mud fan."

Guan Tian and the others were stunned, their expressions were rich again, and the surprise was not so obvious, what was more was expecting to hear something new, and their state of mind had been gradually honed by Li Shi, and they were no longer as fuss as before.

"So what's it for?"

Tian Dayou still cooperated, and asked at the exit.

Of course, it is an iron model, and it is said that it is thanks to the Manchu Qing officials more than a hundred years later, Gong Zhenlin, who was the same era as Lin Zexu and Wei Yuan.

Gong Zhenlin's iron mold casting method is to first make a mud cannon out of mud, and decompose the mud cannon into four to seven sections, each section is divided into two petals, left and right. Then correspond to each petal, make an outer fan with mud, leave a handle on the outer fan, and there are bamboo shoots that can connect each petal together. Then the molten iron is poured into the inner and outer clay of each petal, and the iron fan of this petal is made.

Next, cast the cannon, fasten the iron fan together with bamboo shoots, fix it with an iron hoop on the outside, brush the inner layer with a slurry to prevent adhesion, and then insert the gun core, pour the molten iron into it, and when it is cooled and formed, the outer flaps of the iron fan are peeled off piece by piece, and the surface is polished and trimmed while the gun body is hot. After that, the mud core is cleaned and the inner chamber is rotated to form.

As long as the iron mold is made, the cost of making a cannon will be greatly reduced, according to Gong Zhenlin's calculations, the artillery silver for casting a thousand catties of cannons will cost a hundred taels for one piece, and the iron mold will only cost a few taels.

Of course, the reason why Li Shi prepared to use the iron mold casting method was not to save money, but to save time. Because the clay fan of the iron mold is made of petals, it takes very little time, and it can be done in ten days at most. And with the iron mold, according to Gong Zhenlin's account in the "Diagram of the Iron Model of the Cast Cannon", forty gunners, if they are in a hurry, can build nine cannons in two days, or a thousand catties of cannons.

Even if they have no experience, there are many places to try, and it will take a little time for the furnace workers in the mine to switch to gunners, but with only four small cannons, it should be extremely easy.

Listening to Li Xian's rough words, Guan Tian and the others also had a little bottom in their hearts, this iron mold casting method is not a high-tech technology, but just a change of thinking, and when they taste the joints, Guan Fengsheng is slightly lost: "My family inherits the craft, it seems that it is going to be abolished......"

The next day, Zhong Shangwei hurriedly transported materials such as ash mortar and many tools by ship, and also sent cannon samples, that is, cannon materials. It has a sketch of the cannon, its dimensions, weight, and an inscription on the barrel of the cannon. Because they are impersonating, that is, replacing the previously discarded cannons, the new cannons must cast the inscriptions of the old cannons. Li Xian paid special attention to it, and saw the text "In the thirty-eighth year of Kangxi, that is, Tian Congdian of the county was supplemented, Meng Zhen, the general manager of the city guard, and Mi Dezheng, the head of the Huangzhai stove", Li Xian thought to himself, Bai Daolong was probably wiping his ass for the former general soldier.

Looking at the cannon diagram again, Li Xian was speechless, this is the so-called mountain splitting cannon, which is actually a slightly larger tiger squat cannon. The shape is twisted and wrapped with an iron hoop, like a hemp flower, and the inner diameter of the muzzle is pitifully small, estimated to be only three or four centimeters, the weight of sixty catties, presumably there is no hope for the quality of the iron material used to make the cannon.

With the cannon sample, Guan Tian and the others also understood the mystery of this iron mold casting method, and it seemed that they would be able to dry it immediately, but their brows were still wrinkled.

The problem lies in the iron, using this kind of pig iron smelted in the mine to cast cannons, which is ironclad and useless.

"Fourth brother, according to the experience of my father and ancestors, this pig iron still needs to be refined, but I don't understand this matter very well......"

When Guan Fengsheng said this, his eyes were extremely bright when he looked at Li Shi, as if he was waiting for him to come up with the know-how of steelmaking.

In this business with Mr. Zhong and Mr. Bai, there is no need to use steel, and the conditions for steelmaking are still insufficient, not to mention coke, the refractory bricks that Li Shi wants have to depend on the progress of Wu Tantou......

"Fourth brother, you have already made a batch of kaolin bricks, which are indeed more fire-resistant, according to your statement, I have used it to build a new brick kiln......"

When asked about the specific situation, Wu Tantou said it as if squeezing toothpaste, Li Shi frowned and asked why he didn't say it earlier, Wu Tantou was still very aggrieved.

"Didn't the fourth brother want some silica bricks? I thought about getting that out and talking about it, but it seemed a bit of a problem. ”

Nonsense, of course it's troublesome, kaolin refractory bricks are only a little stronger than the existing refractory bricks, it's just a transition, and you have to rely on it to burn dolomite bricks and silica bricks, Wu Tantou is busy with Li Shi's own plan, but the matter of taking over the cannon building is involving the quality of pig iron, and Li Shi has to pull him up.

"In addition to burning charcoal and bricks, what else can Wu Tantou help?"

Guan Fengsheng and Tian Dayou were very puzzled, Wu Tantou pursed his mouth, straightened his waist disdainfully, looked at Li Shi, and waited for Li Shi to correct his name.

"How to make pig iron, I understand, but I have to build a new furnace, not to mention the things in front of me, I also have to help Wu Tantou in the things I am preparing, and he will still be a great hero if he wants to make steel in the future."

Li Xi said as he spoke, Wu Tantou smiled hehehe, and finally felt a little embarrassed, and scratched his head in embarrassment.

How to improve the quality of pig iron in the mine, Li Xi also knows in his heart, of course, he has to thank a number of traversal farming texts that he has read before. The specific method is to add slag materials such as limestone and quicklime to remove the phosphorus and sulfur impurities in the pig iron. However, because the current iron-smelting furnace is a refractory brick with the surname of acid, the impurities generated by the reaction between the slag material and the molten iron will react violently with the acid component of the refractory brick, so it is necessary to use the refractory brick with the surname of the medium or alkali surname to build a new furnace.

Wu Tantou got out the kaolin bricks, that is, clay refractory bricks, just right.

"There are still so many ores in the mine, don't mine for now, Uncle Guan is responsible for the iron mold and iron materials, Wu Tantou is responsible for building the iron furnace and the new iron smelting furnace, Carpenter He is responsible for building the fort and making the workpiece, Uncle Tian organizes the manpower, and manages the progress ......."

It's just a small four-splitting cannon, but a lot of things have followed behind, speaking of which, this is a good opportunity to climb the science and technology tree and accumulate experience, technology and talents, of course Li Xi will not let it go, and try everything that can be tinkered with. Master Zhong scratched his head and would not have thought that his business was sent to the door, but he was used by Li Shi to "borrow chickens and lay eggs".

It's just that there are too many things, so you have to pay attention to management, Li Xi had to assign these four uncles, and the four of them didn't have any objections.

"If you are in charge of a stall, you can't do it if you don't have money in your hand, so you can divide the ...... each person first. Fifty taels of silver, well, I'll divide fifty taels ......."

Then Li Xi finally fulfilled his dream of sharing the spoils, and the four of them looked at each other, and they all didn't understand why these four brothers were so afraid of holding a lot of money in their hands.

"This kind of money that does not distinguish between public and private has to be cleared up as soon as possible."

None of them could have imagined that Li Xi just didn't have confidence in his own frugality......

[1: The casting process of the bronze cannon in the Ming Dynasty, first the wooden fan and then the mud fan, it can be seen that people are dizzy, or the iron cannon casting process is much simpler, and the copper cannon or something, so I will not mention it. 】