If you want to make enamel, you have to place the porcelain according to the procedure before you start firing the kiln. At this time, the temperature inside the kiln mouth rises sharply.
And the temperature rise is also very particular.
Especially when entering the kiln for the second time, when the lines are being fired, the temperature at this time should be controlled at 850°C.
The entire heating process takes 5-6 hours.
During the heating process, the initial heating rate should be slow to reach 150°C to allow the oil and water in the pigment to evaporate smoothly.
The temperature rises quickly in the mid-term, causing the overall temperature of the porcelain to quickly reach 650°C.
In the later stage, the temperature rises slowly to 850°C, and the gemstone pigment is completely melted, making its expansion coefficient close to that of the ceramic glaze water, and the entire heating process is slow-fast-slow;
The last step is to cool down. When the temperature reaches the predetermined 850°C, the heating is stopped to allow it to cool down naturally.
The entire cooling time varies according to the season.
The cooling time is 15 hours in summer and autumn, and 7-10 hours in winter and spring.
During the entire slow cooling process, the expansion coefficients of the gemstone pigments and the ceramic glaze water are close to each other, so they are completely fused;
This is still the first firing line, and there will be four more firings in the kiln.
The second step is painting and firing. The first step is to burn the background color. After the background color is painted, it is naturally dried in the shade and then fired in the kiln.
The conditions for drying in the shade, as mentioned before, are also very troublesome.
The next step is to enter the kiln for the third time, this time for color matching and firing.
The first step is to apply color, and then dry it naturally in the shade.
Depending on the painting surface and the richness of the colors, the number of color registration and firing needs to be repeated 5-10 times.
The more times it is fired in the kiln, the lower the firing temperature, and the firing temperature of overglaze paintings is controlled between 600°C and 850°C.
This process is repeated until the final firing is completed.
It is very easy to make a pen holder. Of course, in order to avoid waste, you cannot open the kiln once and fire only one pen holder.
For a batch of enamel-colored porcelain, he tried his best to select simple shapes to make, and Chen Wenzhe soon made dozens of them.
With so many enamel-colored porcelains, as long as one-tenth of them are successfully fired, his work will not be in vain.
In the process, he also carefully formulated many secret recipes, all of which can be directly exchanged for money in the ceramic market.
If nothing else, just pure kaolin, not everyone can prepare it.
Now everyone knows that the mineral soil used in firing porcelain bodies and painting enamel bodies is kaolin.
But what kind of kaolin is used, few people know.
If you want to make high-quality enamel white bodies, the first step is to prepare pure kaolin clay.
Kaolin is resistant to high temperatures. Only by firing pure kaolin can the plain tire produce a "white as jade" effect, and is it suitable for painting directly on the plain tire.
Therefore, pure "kaolin" is used to fire the porcelain body and paint the enamel porcelain body.
How pure is it? Choose one pound out of a thousand pounds!
Of course, the choice here is definitely not selection, but preparation using unique technology.
In addition to this most basic kaolin treatment, the next step is to prepare the plain "high temperature glaze"!
White tire tread glaze is a special high-temperature glaze.
Glaze is a substance made from quartz, feldspar, borax, and clay, diluted with water, and applied to the surface of porcelain before being fired.
In the third step, you need to prepare porcelain body painting enamel pigment blending oil
The pigment blending oil used in the enamels of the Qing Dynasty was Dolmen oil imported from ancient Persia, which has been lost for many years.
But Chen Wenzhe had seen palace enamel porcelain, and through the glaze on it, he could see how ancient Persia prepared this kind of Dolmen oil.
Unfortunately, if you want to prepare this kind of Dormen oil, you must also use raw materials from Persia, which is now the country of Lavida.
Of course, it should be possible to make it by selecting mineral materials with similar element content.
However, it was different after all, so Chen Wenzhe didn't cause too much trouble.
Nowadays, there are special high imitations of the enamel glaze blending oil, which can definitely be used on ceramic works for daily use.
When used on high-end porcelain, special enamel glaze and oil must be used to achieve the best painting effect.
You must know that the porcelain body painting of enamel colored porcelain is its essence. At this point, the foundation is the glaze blending oil, then the glaze, and finally the painter.
No one of these three is more important. It can only be said that if you do not do any one well, you will not get good works.
For example, in the last step, when you first start painting, the enamel paint cannot adhere to the ceramic base glaze.
If you forcefully paint some works, the colors will definitely peel off on their own after firing.
It can be said that there are pitfalls everywhere, and the firing may fail if you are not careful.
If you want to successfully bake, you must first know where the pits are so you can avoid them.
The first step is to prepare the blending oil. The high imitation palace enamel pigment blending oil now synthesized uses a variety of vegetable oils.
Such as: camellia oil, camphor tree oil, etc.
Of course, it is definitely impossible to mix them without any rules. Instead, after many experiments and proportional configurations, a higher quality palace enamel pigment blend oil was developed.
This not only solves the color problem, but also balances the expansion coefficients of the ceramic glaze and the enamel material, breaking through the adhesion problem between the enamel material and the ceramic glaze.
The final enamel fired will definitely be more delicate and beautiful than the enamel inherited from the Qing Dynasty.
And this is still the blending oil, and the most important pigment blending formula.
At this step, the most important thing is to develop a non-toxic pigment blending formula.
At this point, the results of modern scientific tests are a bit strange.
It has been established that porcelain with painted enamel is non-toxic.
However, laboratory tests revealed that the enamel pigments of Qing court porcelain paintings contained excessive amounts of lead, arsenic, and borate.
Of course, the content of lead, arsenic, and borate in the current porcelain body painting enamel pigments is far lower than international standards. Therefore, the fired porcelain body painting enamel porcelain vessels can be used with confidence in various occasions;
The last key technology step is definitely the firing of porcelain body painted enamel.
The method and technology of firing enamel on porcelain bodies are many times more sophisticated and complex than firing other porcelains such as blue and white porcelain, pastel porcelain, etc.
In particular, the temperature requirements are higher, and the melting points of enamel pigments are uneven. A complete porcelain body painted enamel art must be fired repeatedly from high to low, and the white body can be completed.
Most people don't dare to try this kind of porcelain because the cost is too high.
But Chen Wenzhe is different. He has inheritance experience, and he can even see the final firing effect of the porcelain he made.
Because based on inherited techniques, he knew exactly what these works would look like in the end.
Generally speaking, this batch of works, fired according to strict ancient techniques, will eventually show an effect that is bright in color, as warm as jade, with dewdrops on flowers, down on butterflies, and as thin as an egg curtain.