Looking at the windows of expensive jewelry stores, we are delighted with the beauty of products and craftsmanship of jewelers. The art of turning a precious metal into a luxury item in the imagination of many people is a kind of mystery, a special skill that not everyone can master. How are the rings beckoning with their beauty born? What path does the precious metal go from sketch to embodiment in expensive jewelry? What is a flask in jewelry and what is it used for?
Features of the profession of a jeweler
The profession of a jeweler requires not only a creative approach. The jeweler must be careful and patient. There are many nuances in this matter, the observance of which requires extreme accuracy. The jeweler works with high temperatures and hot metal, the danger of this profession requires exposure and physical strength. The master of jewelry is not only a designer who comes up with sketches and works with a file under the bright light of a lamp. He is also a foundry worker who manages with red-hot furnaces and molten metal, lifts heavy gypsum molds and monitors compliance with the technology. The arsenal of the master of jewelry is full of unusual devices about which a simple layman did not even hear. For example, a flask. What is a flask and what is this device used for? This will tell our article.
Flask in jewelry
Despite all the innovations and a high level of jewelry manufacturing technology, many jeweler working methods have remained unchanged since ancient times. The ring casting process, for example, has not changed much. To answer the question about what is a flask, you should find out how the process of casting jewelry.
To make a ring of precious metal, the jeweler uses a special refractory cylinder, into which the hot metal is poured, the molding material is placed and wax blanks are placed. This is the flask.
This device serves to hold the moldable mixture during compaction during the production of the mold into which the precious metal is poured. You can make the flask yourself, the main thing is that it be made of refractory material. Some craftsmen make a flask from a pipe cut or fold it from a sheet of iron. The photo shows a modern metal flask.
A molding compound has already been poured into this flask, inside of which there are wax blanks. The next step is the calcination of the flask in a hot furnace, this procedure takes place in the foundry.
Use of the flask in the foundry
No matter how sophisticated the jewelry as a result, they go through a very harsh path through the red-hot furnaces of the foundry. Here's what the casting process looks like:
- Products come to the foundry in the form of wax blanks, which go through the molding process.
- The wax billet is placed in a special refractory metal cylinder - a molding flask.
- Then the flask is placed in a hot furnace for calcination. The temperature in such an oven can reach 1000 degrees. The wax from the flask is melted, and in this form there is a place for precious metal.
- After calcining the flask and forming a mold, metal is poured into it. The process of casting jewelry occurs in a vacuum, the formation of voids and the ingress of foreign debris into the mold is prevented.
- At the final stage, the caster takes the jewelry out of the flask for casting jewelry and proceeds to its final processing and polishing.
Gypsum flask for jewelry making
What is a gypsum flask? In form, it does not differ from the more common metal. Its only difference is the material and the need for stepwise heating. Plaster flasks are most often used for small jewelry casting, and not for industrial. In order for the casting process using gypsum flask to be successful, the temperature regime must be observed, otherwise the mold will crack and become unusable. This is most conveniently done in a special electric furnace for annealing, since there you can adjust the temperature. Annealing of gypsum flask is carried out in several stages:
- Heating at a temperature of less than 100 ° C. It is necessary to maintain the flask at this temperature for at least an hour.
- Then the form should be in the oven at a temperature of 250 ° C for two to two and a half hours.
- After this time, the temperature should be raised to 450 ° C and annealed the flask for another half hour.
- Only after this can the temperature be raised to a maximum of 750 ° C and annealed for another three hours.
The annealing time depends on the size of the opokich: the longer it is, the longer it takes to anneal it.
Disposable Flask
Having learned what a flask is and how it is used, it is easier to delve into the intricacies of the process. It no longer seems so complicated, rather, interesting and simple. Modern technologies allow you to try to make jewelry yourself at home. The Chinese market offers a wide range of disposable flasks with ready-made shapes. All you need to work with this form is the required amount of precious metal and the ability to melt it. They are used by jewelers who do not have their own foundry, as well as free craftsmen who make jewelry to order.