Soon, Section Chief Tang received news from the factory laboratory that the factory laboratory not only had chemically pure glycerol, but also had a quantity of 8,000 ml. So he immediately asked the laboratory to send 5,000 ml.

Then he took a 6h drawing pencil and a bottle of quick-drying paint from the warehouse of the Equipment Maintenance Department and sent them to Guo Yonghe.

"Expert Guo, all the materials you need are ready."

Wen Qingyan said impatiently: "Can we start repairing the printed circuit board now?"

"It's time to begin!"

Guo Yonghe nodded and said: "But since repairing printed circuit boards is a very delicate job, I still need someone to help me."

Having said this, he looked at Li Weijin and said, "Director Li, go outside and call Hu Dongqiang over and ask him to give me a blow."

He was invited by Hu Changzheng, so it was natural to call Hu Dongqiang in at this time to give him a chance to perform in front of deputy director Wen Qingyan.

Li Weijin did not dare to answer, but looked at Wen Qingyan to see the deputy director's attitude.

"Who is Hu Dongqiang?"

There seemed to be no personnel named Hu in the equipment department in Wen Qingyan's memory, so he asked aloud.

"Director Wen, Hu Dongqiang is a student from the Department of Mechanical Engineering of Zhongtian University and is interning in our equipment department." Li Weijin reported in a low voice.

"Oh, Expert Guo was invited here by his father, right?"

Wen Qingyan nodded, "Director Li, go and call him in!"

Now that Wen Qingyan agreed, Li Weijin naturally no longer hesitated and ran out quickly.

Soon, he brought in Hu Dongqiang who was surprised and delighted.

"Expert Guo, thank you!"

Hu Dongqiang thanked Guo Yonghe repeatedly. He certainly understood how rare the opportunity Guo Yonghe had fought for him was. As long as Guo Yonghe could repair the printed circuit board, he would definitely be credited as Guo Yonghe's assistant.

With this merit and performance, and a little activity, even if Zhang Jianshe is dissatisfied with him, he cannot object to the equipment department keeping him.

"Director Wen,"

Guo Yonghe continued: "The delicate work of repairing printed circuit boards is easily disturbed by outside interference, so the working environment must be very quiet and there should not be too many people.

"So except for Hu Dongqiang, who was the one who started, only two people, Director Li and Section Chief Tang, who are familiar with the equipment and tools of the Equipment Maintenance Section, can stay at the scene. The rest of the people need to wait outside."

“There’s no problem with this!”

Wen Qingyan immediately agreed, waving his hand and ordering: "Director Li, Section Chief Tang, you two stay on site to assist Expert Guo. Everyone else, follow me to the outside lounge and wait!"

Even Wen Qingyan had to go out and wait. Even if Zhang Jianshe was unwilling to do so, he did not dare to say anything. He could only obediently follow other staff in the equipment maintenance department and accompany Wen Qingyan to wait outside.

Seeing Hu Dongqiang carefully running over and locking the door, Guo Yonghe couldn't help but laugh, secretly thinking that this little Hu really did have a wink.

"Chief Tang,"

Guo Yonghe asked: "Your equipment maintenance department should have a low-temperature constant temperature bath and a high-temperature constant temperature bath, right?"

"Yes, yes, both devices are available!"

Section Chief Tang nodded repeatedly.

As the equipment maintenance department of a large state-owned enterprise like Zhongtian Aluminum Plant, how could it not have common maintenance equipment such as a low-temperature constant temperature bath and a high-temperature constant temperature bath?

Soon, he led Guo Yonghe to the low temperature constant temperature bath and the high temperature constant temperature bath.

"Xiao Hu, can you operate this equipment?"

Guo Yonghe pointed to two types of constant temperature baths.

"Yes, yes, I have seen it in the school laboratory!"

Hu Dongqiang quickly replied.

"Okay, then you first pour 2,500 ml of glycerol into the low-temperature thermostat, and use the rapid heating function to heat the glycerol to 180 degrees." Guo Yonghe ordered.

"yes!"

Hu Dongqiang responded and followed Guo Yonghe's instructions.

"Expert Guo, what is the purpose of this step?"

Li Weijin and Section Chief Tang looked at each other. In the end, Li Weijin couldn't restrain his curiosity and asked aloud.

Since Guo Yonghe asked Li Weijin and Section Chief Tang to stay and watch, he naturally did not intend to keep his operations secret.

"Director Li, the disassembly problem is more difficult. Can you dismantle it?"

He explained with a smile: "The special soldered temperature-controlled hot plate device of the low-temperature constant temperature bath and the high-temperature constant temperature bath have exactly the same function.

"The soft soldering joints of the components can be thoroughly cleaned. The glycerol solution has a high boiling point, good thermal stability, and good soldering properties. It is specially used for soldering with a temperature-controlled hot plate device.

"The function of this low-temperature constant temperature bath is called low-temperature heating. After heating the glycerol solution to 180 degrees Celsius, it is soaked in and preheated.

"The temperature reaches one hundred and eighty degrees..."

As soon as I said this, I saw that Hu Dongqiang's operation had been completed, and the temperature on the LCD temperature display on the low-temperature thermostat was rising steadily.

"Xiao Hu, pour the remaining 2,500 ml of glycerol into the high-temperature constant temperature bath, and then use the rapid heating function to heat the temperature of the high-temperature constant temperature bath to 210 degrees Celsius!"

Guo Yonghe ordered.

"yes!"

Hu Dongqiang responded and turned on the high-temperature thermostat again.

"Director Li,"

Guo Yonghe turned around and continued to explain to Li Weijin:

"The heating on the high-temperature constant temperature bath is called melting heating. Because when the temperature of the glycerol solvent reaches 210 degrees Celsius, the solder on the soldered joints that has been infiltrated into the manifold will be dissolved in the glycerol

In the solvent, the integrated block was disassembled from the printed circuit board.

"Because the glycerol solvent itself has good thermal stability and good solderability, after the circuit breaker on the magnetic circuit under the manifold is welded, the manifold is soldered again..."

"That's it!"

Li Weijin and Section Chief Tang suddenly realized that no wonder Guo Yonghe was so confident. It turned out to be because he had mastered the secret of glycerin solvent!

"Expert Guo, thank you for your selfless sharing!"

Section Chief Tang bowed to Guo Yonghe sincerely, "If you hadn't told me this secret, it would have been a difficult problem to safely disassemble the integrated block!"
Chapter completed!