Li Guodong casts cannons for Zheng Zhilong, and adopts the iron mold casting cannon method. This casting cannon method is produced at a fast speed and can be reused. It is suitable for casting naval cannons.

Iron ore was sent into the blast furnace there. After the fire was opened, the other side was preparing a mud mold for watering the iron mold. Li Guodong did not know the more advanced iron mold sand coating process, but adopted the process of applying soil in the iron mold. First, several pairs of iron molds used to cast cannons were cast, and the cast iron mold was also cast using mud molds.

There are four types of iron molds to be cast, including the iron mold of the twenty-four-pound naval gun, the eighteen-pound naval gun iron mold, the twelve-pound naval gun iron mold and the nine-pound naval gun iron mold. As for casting mortar cannons, Li Guodong does not plan to cast iron molds for Zheng Zhilong. After all, the quantity of mortar cannons is very small, so there is no need to waste time and materials to cast iron molds, and then cast mortar cannons. Using mud molds to cast mortar cannons can meet the requirements.

In fact, the craftsmen had already built the mud mold according to Li Guodong's request. Shortly after the blast furnace was fired, the first batch of four pairs of mud molds that were prepared for casting had been dried and carried in.

Because the furnace temperature is higher than the original blast furnace temperature, it can be directly refined to produce iron, which improves the quality of the artillery. Li Guodong once thought about making steel, but the temperature of the refractory bricks in this era could not meet the requirements of steelmaking, and the technical level of this era could not support the production of converters.

The sand in the timing hourglass leaked out, which means that about three quarters of an hour has passed, which is equivalent to an hour and a half, and the time for iron smelting has come.

"Open the furnace!" The craftsman Lin Shuijie gave the order.

A craftsman opened the furnace door and opened the hole for the molten iron. A stream of blazing and red sticky liquid flowed out from the bottom of the furnace, and flowed into the four pairs of mud molds that were spread out in a row along the brick path. After a while, the first mud mold was filled, and a craftsman pulled the refractory brick with an iron hook to block the first opening. After that, the remaining three mud molds were filled. The craftsman blocked the hole and pulled open the bricks leading to a shallow groove, and the molten iron flowed into the shallow groove. When the iron water cooled, the iron plates were finished.

"These iron plates are of good quality, they are all fine iron! I didn't expect that they could directly train fine iron. This way, it would save a lot of time to build weapons." Lin Shuijie picked up an iron hammer and knocked on the iron plate whose temperature had not yet been completely reduced.

Zheng Xing, who was standing aside and was responsible for managing the craftsman, said: "Since you can directly refine the fine iron, will these irons be used to build bird guns save time?"

"Actually, you can cast the gun barrel directly!" Zheng Zhilong had a sudden idea.

Li Guodong said: "Casting gun barrels can only be made with low requirements such as three-eyed guns. This fine iron is not very exquisite after all, and it still needs to be forged to meet the requirements of making bird guns. Therefore, the gun barrels still need to be forged."

"The mud mold is cold, can you open it?" Lin Shuijie asked.

"It's OK!" Li Guodong nodded.

After the mud mold was opened, the cast iron mold inside was exposed. When the entire iron mold was taken out, Lin Shuijie stepped forward and knocked on the iron mold, and was very satisfied with the quality of the iron mold.

"This iron mold can be used directly to cast a cannon? Can it be reused?" Zheng Xing asked.

"Of course it can be reused." Li Guodong replied.

Zheng Zhilong showed a happy expression on his face: "How long does it take to cast a naval gun by iron mold casting method?"

"A pair of molds can cast a gun barrel in one day, but the barrel still needs to be processed, such as polishing the inner chamber. We need to build a hand-crank boring machine, which is specially used to grind the inner chamber and make the inner chamber smooth. According to this calculation, one gun can be cast in two days. We have four types of molds. As long as there is enough iron ore or pig iron, two guns can be built in one day."

Two cannons were cast in one day. This production speed shocked Zheng Zhilong. He smiled happily and pulled Li Guodong: "When can I cast artillery?"

"Build the boring machine first, and after it is finished, you can cast the cannon."

Zheng Zhilong was indeed anxious. After Liu Xiang turned from his original partner to an enemy, he had already cooperated with the Dutch. Zheng Zhilong knew that the Dutch ships were strong and powerful. For the sake of the Dutch, Zheng Zhilong was so worried that his hair had several white hair. Even if he could not build a large warship, it would be better to put a few more cannons on the turret, or simply build a small boat to carry cannons.

Next, under the guidance of Li Guodong, the craftsmen began to build parts of boring machines. All gears, shafts, bearings and other parts were made of iron. The craftsmen first heated the iron plate, burned red, then cut into the required shape, then cut out the gear teeth, then used the parts to forge, and forged into steel parts, and then polished according to the size.

It is really time-consuming to manufacture an excellent boring machine. Zheng Zhilong has very high requirements for craftsmen. In order to make the parts more durable, these parts took a whole month to make all the parts.

Within this month, Li Guodong and his brothers lived a pretty good life on Kinmen Island. Li Guodong himself occupied two little maids who were serving the bed. Zheng Zhilong enjoyed wine and food every day to entertain Li Guodong and his brothers dresses. During this period, Zheng Zhilong also took Li Guodong to Yuegang.

When you arrive at Yuegang, you can see at a glance that it was once the most prosperous port in the Ming Dynasty.

Since the Longqing switch started, Yuegang has been the merchant warehouse of the Emperor Ming Dynasty. The taxes collected from Yuegang enriched the inner warehouse of the Emperor Ming Dynasty. Unfortunately, by the late Wanli period, the power of the Ming Dynasty had been completely controlled by the civil servant group. After Emperor Tianqi came to power, he had to use Wei Zhongxian to deal with the civil servant group, and finally collected some taxes. After Chongzhen came to power, Yuegang was completely the private territory of Fujian gentry and Zheng Zhilong.

"Brother Zheng, why is Yuegang so depressed? Why is there no trace of a large Taixi merchant ship?" Li Guodong looked around and saw that there was no foreign ship on the long seven-seater dock. There were only a few warships of the Zheng family army and a few small merchant ships of the Zheng family caravan.

Zheng Zhilong snorted coldly: "It's not a good thing that Liu Xiang and Hong Mao Yi have joined forces to do! Hong Mao Yi's warships are showing off their power outside Xiamen all day long! Dongfan and Penghu are occupied by them! Liu Xiang is mixed with Hong Mao Yi, and it's very popular now! If it weren't for dealing with them, why would I have to cast a large-scale cannon?"

Although Yuegang was much deserted, it did not affect Zheng Zhilong's business of making money by taking the Japan route. The Dafu ship filled with cargo left Yuegang and sailed to Japan. When he came back, he transported the ships of brass, silver and gold.

At that time, the Koshu gold mine, the Shimichi silver mine, the Sado gold mine, and the copper mountains of Shikoku Island were far from exhausted. The Shimichi silver mine alone accounted for 40% of the world's silver output! Therefore, Zheng Zhilong's route on the Japan route is also a very profitable route.
Chapter completed!