My system is not decent

In fact, the process of firing Jianyao Jianzhan is similar, but the final firing results are different.

Humans naturally pursue beauty, and failure is sometimes not a bad thing.

Like firing a silver hare, sometimes you fail and you get a gold hare, and sometimes you really fail.

Such a failed product is a kind of gray rabbit hair. During the firing process, the ferric oxide in the iron-rich liquid phase in the glaze has no time to precipitate for some reason, and a large number of anorthite crystals are exposed on the glaze surface.

The iron content of anorthite crystals is very low, and there is no reflection. It appears gray or light green to the naked eye, forming gray rabbit hairs.

If it is light green, it is the so-called green rabbit hair, otherwise it is gray rabbit hair.

Of course, if your technology is good enough, in the final cooling stage, the glaze is controlled precisely during the cooling process, and when the environmental conditions are suitable, the iron oxide crystallizes, and the temperature is suitable, then a blue-silver luster can be formed.

This is the blue silver rabbit hair, or the blue rabbit hair.

In this way, all the rabbit cups can be fired.

It's just that in this process, gray local tyrants are the most likely to appear, followed by green rabbit hairs, red rabbit hairs, golden rabbit hairs, silver rabbit hairs, and blue rabbit hairs.

It seems very simple to fire these various colored rabbit cups, but when it is actually fired, the quality of the work often changes within a few seconds. If you want to grasp it accurately, you can directly fire the most precious and difficult to burn at one time. It is still very difficult to make fine rabbit hair.

All of this is under temperature control. Whether it is the temperature control in the kiln or the temperature control of the glaze during cooling, it is the key.

The reason why it is said that Jianzhan is difficult to fire is because of these key points, the time is too short, and often a little negligence or delay, the works in the kiln will become another color.

We all know that the Jianzhan pattern is naturally formed in a strong reducing atmosphere after firing at a high temperature of more than 1300 degrees.

But as the atmosphere and temperature in the kiln are different, the markings will also change accordingly, coming and going impermanently, and it is difficult to control.

The firing process is not only about mastering the temperature and atmosphere to make a good Jianzhan, it really needs a little luck.

There is a slight deviation, not to mention silver rabbit hairs, even rabbit hairs with better quality are difficult to burn.

After firing several kilns, Chen Wenzhe was able to grasp the key points.

The firing of Jianzhan, no matter what the final firing is, is actually affected by the four major constraints of blank, glaze, temperature, and reducing atmosphere.

Silver rabbit hair is also severely restricted by these four factors, the first is the restriction of the billet.

The green body must be made of local clay in Jianyang. This kind of clay has a high iron content and is prone to defects such as deformation and blistering at high temperatures.

The chemical and mineral composition of the body has a major influence on the glaze markings.

In the Southern Song Dynasty, other kiln outlets in Fuzhou had poor results, which was directly related to the low content of billet iron.

Then there is the limitation of the glaze, the thickness of the glaze applied to the Jianzhan is the need of the glaze color.

The glaze layer is thin, and the glaze is not black; moreover, the glaze layer is thin, and the rabbit hair markings are short and not smooth.

Thick glaze shrinks a lot during drying, which can easily cause the glaze layer to crack and not stick tightly to the blank, and it is easy to shrink or deglaze when firing.

Glaze thickness has great fluidity at high temperature, so that the glaze layer gradually thickens from top to bottom, and the thickness of the glaze layer is uneven, which has a great influence on the formation of markings;

In addition, it has high fluidity and is easy to cause sticky bottom.

The next step is the restriction of temperature. The firing temperature of rabbit hair is high and the range is narrow.

On the other hand, a piece of silver rabbit hair with smooth patterns and perfect appearance has a narrower firing temperature range.

The kiln temperature is slightly lower, and there are spots on the upper part of the bowl, but no spots on the lower part.

When the kiln temperature is slightly higher, the glaze will flow down and stick to the bottom.

The last is the restriction of the reducing atmosphere. Jianzhan glaze belongs to the iron-based crystalline glaze, and the crystallized substance is iron oxide.

There are divalent iron and ferric iron in iron oxide, and the reduction makes ferric iron into ferrous iron.

Ferrous iron is a strong flux, and it is easy to melt back into the glaze, making the crystalline substance in an unstable state, directly affecting the shape and color of the markings.

The substance that builds the color of the light spots is iron or iron oxide.

The substance that develops color in an oxidizing atmosphere is mainly ferric oxide, which appears yellow, brown, etc.;

The substances that develop color in reducing atmosphere are iron and iron oxide, and the corresponding colors are silver and blue.

Therefore, the firing of silver rabbit hair should be produced under the condition of reducing atmosphere. Of course, blue rabbit hair can also be produced under this atmosphere condition.

Burning silver rabbit hair must be severely restricted by the reducing atmosphere.

In the early stage of firing, it should be reduced to control the shape of the markings, so that they can form filamentous stripes properly;

In the later stage of firing, it still needs to be restored to control the color of the markings. At this time, if the ferric iron is too high, the markings will be gray.

If the ferrous iron is too high, the markings will disappear or even disappear.

Therefore, not only the color of the silver-burned rabbit hair markings is very unstable, but also the shape of the markings will be endangered, affecting many problems such as the slenderness, thickness, and definition of the markings.

There are too many uncontrollable factors in Jianzhan firing, and the range of each factor is extremely narrow.

Ancient kiln workers could only exchange for one or two excellent kilns at the expense of a large number of finished products through the huge number of kilns installed.

Therefore, an excellent silver rabbit hair is extremely rare!

It can be seen that the scarcity and preciousness of silver rabbit hair!

And on this basis, the blue rabbit hairs obtained by accident are of course even more rare, so there is a saying that "blue is rare".

At this time, after firing all the rabbit hair and dripping glaze cups, Chen Wenzhe will next fire the Yaobian cup.

Tianmu glaze is a special member of the porcelain family, and Yaobian Tianmu is the most precious variety.

Yaobian Tianmu is fired with great chance, and the flare under the glaze, which is fired at a high temperature, will shine with colorful halos under sunlight and certain temperature conditions.

This sum of gold, silver, red, blue, blue, and several more colors, needless to say, it must be more difficult to fire.

The most important thing is that there are too many uncontrollable factors, and the range of each factor is narrower, so it is definitely more difficult to obtain Yaobianzhan than Rabbit Haozhan.

Therefore, the Yaobian cup is a well-deserved legendary work among the black glazed tea cups built in the Song Dynasty.

Compared with the Rabbit Haozhan, if you want to get the Obsidian Bianzhan, it is not to make the decoration inside the lamp not to be radioactive, but to form spots.

What Yaobian said is simple and easy to understand, that is, on the black base glaze, there are many irregular, round or nearly round spots of different sizes.

The distribution of spots in the obsidian cup is uneven and without any rules.

A few or dozens of these spots gather together and emit rainbow-like light when illuminated by light. This is the unique product of Jianyao.

As for how it feels to touch, few people can touch the national treasure-level Jianzhan, but some people have touched the modern master-level Yaobianzhan.

The surface of that kind of obsidian lamp is not as clear as it looks, but it is actually flat.

So Chen Wenzhe wanted to learn how to make Yaobianzhan, and it was a good time.