Chapter 1,135 Entering the kiln depends on people, leaving the kiln depends on heaven
The base is fired, the glaze is prepared, and finally the glaze is applied.
Both the inner and outer layers of the blank need to be glazed, usually by dipping the glaze by holding a circle with feet, or by brushing.
The glaze should not be too thin, as it will be difficult to produce high-quality products; it should not be too thick, as it will stick to the bottom.
There is also the application of half glaze, which is a major feature of the lamp-building process.
Because if you apply full glaze at will, it will stick to the bottom due to the flow of glaze water at high temperatures.
In the Song Dynasty, a glaze stop line was specially built on the Xukou lamps to facilitate control of the scope of glazing.
In this process, the most important thing is qualified glaze ore, followed by pine oil firewood.
These two most primitive and simple substances, together with the pine oil and firewood added during the firing process, can be fired into beautiful Jianzhan (crystalline glaze).
Even so, the patterns and colors are randomly formed and cannot be controlled by humans.
Firing porcelain is sometimes very troublesome because there are too many steps.
Of course, all of this can be done in one go, but sometimes, you need to wait.
For example, after applying the glaze, you need to wait for it to dry.
After glazing, place the glaze base in a ventilated and dry place to dry.
You still need to apply glaze after that, because the glaze layer is not thick enough, so you can apply another layer of glaze water after it dries.
The last step is to remove excess glaze water from the glaze base.
At this time, another major process is completed, and then it is fired in the kiln.
Before entering the kiln, it needs to be sprinkled with powder. This is to prevent the sagger from sticking during the firing process. A thin and even layer of refractory alumina powder/quartz sand powder needs to be sprinkled on the sagger.
The kilns built in the Song Dynasty were Changlong kilns, but in modern times, electric kilns are mostly used.
When installing the kiln, electric kilns usually put aluminum oxide on the bottom of the tire to prevent sticking, while dragon kilns are packed in saggers.
After all the preliminary processes have been completed, the green body can finally be loaded into the corresponding kiln and the kiln door can be closed.
At this stage, it is time to start firing the kiln again.
Each craftsman has different firing techniques and different kiln entrance systems. They operate according to their respective techniques. When the temperature rises to more than 1300c, the fire ceases.
It sounds simple, but this step is really the key to the whole process of firing and building a kiln.
Roasting is the kiln firing process that truly determines the appearance and color of Jianzhan. This is a technical difficulty that Jianzhan cannot avoid.
Not only the craftsmen of the Song Dynasty understood the difficulties, but also the modern craftsmen have a deep understanding of them.
Jianzhan must be fired in a kiln at a high temperature of 1200 to 1300 degrees, and must have a good reducing atmosphere.
Today's electric kilns cannot automatically maintain a reducing atmosphere and still require manual control by adding pine oil and firewood.
In the firing process, two factors are the most critical, one is temperature and the other is time.
After the billet enters the kiln, the craftsman must concentrate on carefully controlling the degree of reduction and cannot leave the kiln for a long time, regardless of spring, summer, autumn and winter.
To make the most perfect jianwan, it is necessary to 100% control the temperature in every corner of the kiln during the firing process.
And the duration of each temperature must be accurate to seconds.
But this is almost impossible, so no jianzhan is perfect.
It is for this reason that the firing rate of Jianzhan is very low. "Often great and beautiful things are thousands of miles apart and rely on God to make them perfect."
Therefore, after leaving the kiln, every kiln will inevitably produce defective and defective products, which will be processed on site.
Only products that pass the quality inspection can appear in front of the world and show an indescribable brilliance.
Of course, all this can only be seen after the kiln is cooled after a ceasefire and the temperature in the kiln is lowered.
When the temperature in the kiln drops to the specified temperature, usually below 100c, open the kiln door and the final product will come out!
As the saying goes, entering the kiln depends on people, and leaving the kiln depends on heaven.
Under the baptism of the kiln fire, the lamps that come out of the kiln may be unsatisfactory, or they may amaze the world.
Therefore, after each Jianzhan is successfully born, it still needs to go through a selection process.
Defective lamps will be destroyed after analysis.
The successfully built lamps are registered and stored in the warehouse, and finally appear on the market and are appreciated by people.
Therefore, after reading so many steps, we will know that the steps of building a lamp are closely linked, and they are all "grasshoppers on a rope". If you move one, it will move a hundred times.
Every piece of pottery is hard-won, and contains the hard work of the craftsmen every step of the way and the anticipation and expectation of the autumn water outside the kiln.
And a perfect jianzhan is something that can only be found but cannot be found. The exquisite ones among them are only one in a thousand, one in a thousand.
What is the probability that only one fine product will emerge after firing ten thousand?
Of course, what we are talking about here is high-quality products. High-quality products are perfect jianzhan, not perfect kiln-turned jianzhan.
Such as rabbit hair lamps, golden rabbit hairs, silver rabbit hairs, etc., or simply accidentally firing a flare celestial eye lamp. These treasures often have a one in a million chance of appearing.
When he first started making jianzhe, Chen Wenzhe could only rely on God's will. The most important thing for him was to be familiar with the firing process of this kind of porcelain.
After a few finished products are produced from the kiln and the yield rate is very high, he will start pursuing high-quality products.
So can the flare Tianmu lamp be fired under artificial control?
It's really possible now, but it's very difficult.
It is more difficult to burn and more expensive.
And if the price is expensive, someone must be researching it.
Therefore, Chen Wenzhe can stand on the shoulders of his predecessors, gather the craftsmanship and technology of many masters, and create the high-quality built-in lamps he wants.
This is because black-glazed tea cups like Yaobian Tianmu are rare in our country (complete vessels).
The actual objects are stored in various art galleries and museums in Neon, and are only open to exhibition every seven years.
In fact, there is a fourth and even fifth thing in this world, but the latter ones are all controversial.
For example, the fourth piece is in China and was unearthed in Hangzhou.
In the first half of 2009, ruins were unearthed in Shangcheng District, Hangzhou.
However, it was a remnant vessel, about a quarter of which was lost, but the ring feet were well preserved.
The original shape of the vessel is also quite clear, and the obsidian patterns on the inner wall of the vessel show a dreamlike brilliance.
Although this piece is a remnant, judging from the pictures on display, it is still very beautiful.
Like the collection of Jingjiatang Bunko Art Museum, it is based on bluish obsidian and appears purple-red depending on the angle of light exposure.
This feature is also one of the characteristics of the Yaobian Tianmu lamp.
The three pieces abroad are all in neon, but the only piece in China is a defective product and can only be regarded as half a piece.
Of course, in addition to these three and a half-identified flare Tianmu lamps, there are still some controversial ones.
The obsidian lamps unearthed in Hangzhou were actually controversial when they first appeared.
Everyone knows the origin of the name Jianzhan, but what is surprising is that no Yaobianzhan has been found at the Jianzhan site in Shuiji, Jianyang, Fujian Province for so many years.
Of course, this is just a superficial matter. There should be some fragments of the obsidian lamp in the hands of some collectors in Chizhong Village and Houjing Village.
At least as early as the 1980s, there was a local legend that someone had handled an obsidian lamp fragment.