Hot enamel in jewelry: application technology. Repair of products with enamel Differences between hot and cold enamel

Efanova S.R.

As you know, enamel is a vitreous alloy of silica, alumina and various oxides. By composition, enamels are divided into transparent and muted, they have a large color and tone gradation. The richest palette of alloys has been widely used since ancient times by various civilizations and peoples in decorating metal products and continues to be successfully used to this day.

Since enamel is a glass alloy, it means that it has many of the qualities and properties of glass, and most importantly, it is subject to the same processes of destruction and aging as glass. Over time, under the influence of adverse conditions, the enamel may undergo cracking and delamination; iridescence and corrosion of the surface may begin; detachment of enamel from a metal surface leads to chips, loss and loss. Based on this, the approach to the restoration of various enamels should correspond to the methods of restoration of glass and porcelain.

As a rule, enamel is superimposed on a metal surface. Even if it completely covers the metal, it is impossible not to take this circumstance into account during restoration.

When a metal item decorated with enamel is received for restoration, the metal itself undergoes restoration first. Many enamels are sufficiently chemically resistant and can withstand the effects of chemicals used in the restoration of metals. Although, of course, in this case, this effect should be chosen the most sparing.

If it is required to remove the deformation in the metal, and the enamel has cracks and a tendency to peel off, then it must be carefully strengthened by repeated impregnation with polymers (PBMA, BMK-5, PVB) in order to protect the enamel as much as possible from possible peeling. After elimination of the deformation, the excess concentration of the polymer is removed by its solvent. But this does not mean at all that any deformation is removed when the enamel is strengthened. As soon as there is a danger of cracking and lunges, the process of leveling the deformation stops.

After the restoration of the metal, the restorer proceeds to the restoration of the enamel coating and selects methods according to the state of the enamel. Cleaning of surface contaminants on the enamel will practically be carried out even when cleaning the metal, if the corrosion products were removed. If at the first stage there was no chemical surface treatment, then the contaminants are removed with ethyl alcohol - cleaning, degreasing and dehydrating the surface, preparing it for further work.

Unfortunately, it is not always possible to lighten enamel cracks that are contaminated and have absorbed metal corrosion products. Oxygen- and chlorine-containing chemical reagents used in porcelain restoration techniques (namely, in lightening contaminated through cracks or glaze streaks) are not suitable for use in enamel restoration. The enamel is in close proximity to the metal, which (especially copper and copper alloys) reacts with these reagents, and the contamination of the cracks is not eliminated, but, on the contrary, is enhanced. Therefore, after stabilization of metal corrosion processes, crack cleaning is no longer carried out, and then it is necessary to move on to strengthening processes.

Any destructive process in enamel requires stabilization and conservation. The formation of cracks subsequently leads to delamination and lunges, the loss of not only the appearance qualities, but also fragments of the exhibit itself. Therefore, it is necessary to carefully treat the enamel with strengthening compounds.

The strengthening composition developed at VNIIR (Moscow) has proven itself very well - 25% polymethylphenylsiloxane in toluene. It is characterized by deep penetration, high transparency and colorlessness, high light resistance, thinness of the resulting film, which, if necessary, can be built up and thanks to which it is possible to imitate the gloss of enamel. The refractive index of polymethylphenylsiloxane is practically the same as that of glass.

Polymers - PVB, PBMA, BMK-5 - are also used for impregnation and strengthening of enamel cracks. Choose them 3-5% impregnating compositions and thinners - xylene, toluene. If it is necessary to impregnate white enamel, it should be remembered that PVB, PBMA polymers have low light resistance and turn slightly yellow over time.

The impregnation process is carried out, as a rule, several times, gaining a layer or increasing the concentration of the solution.

Restoration of attacks and loss of enamel with enamel would also be the best way to restore the expositional appearance and integrity of the monument. But, as you know, the enameling process requires heat treatment in the range from +600 to +900°C. In the presence of a damaged, cracking layer of old enamel, the application of new enamel is almost impossible. It is unlikely that a professional restorer would take the liberty of subjecting an exhibit to such heat treatment. Although modern industry (especially Western) allows you to have a large palette of enamels, it is still very difficult to choose the right composition of dyes and oxides to accurately reproduce old enamels.

In this case, it is proposed not to restore, but to imitate enamel, and for this it is necessary to choose a material that will not only imitate it well, but also be chemically neutral to the metal that serves as the basis for enamel. In this case, the basic principle of restoration is also preserved - the introduction of easily dismantled materials into the exhibit.

Silenced enamels can be quite effectively imitated with mastic based on EO cyacrine with fillers of colored dry pigments. Cyacrine EO is chemically neutral with respect to metals and enamels, has an excellent adhesive ability, practically does not change the color of the pigments introduced. The mastic mass based on cyacrine and colored pigments (chips of colored pastels) is non-shrinking, after quick drying it is perfectly processed with a scalpel and sandpaper. When compiling the color of the mastic, one should only remember that the more alkali-containing substance is in the pigment, the faster the hardening occurs when kneading on cyacrine, therefore, sometimes galmanin (medical powder) must be added to the composition, which contains a small percentage of acid, which slows down the hardening process.

The luster of enamels is perfectly imitated by lacquer coatings, which can be used as: organosilicon varnishes - MCH-7, KO of various grades, Polisil; polymer varnishes - PVB-lacquer, PARALOID, etc. By varying the concentration of varnish solutions, it is possible to achieve imitation in the range from matte to glossy surfaces. The lacquer coating serves not only to imitate gloss, but also as a conservation and protective layer.

By choosing varnish as a binder, one can quite effectively imitate transparent enamels. In this case, Polisil is an excellent base. If we take its 25% or more solution in xylene with the addition of coloring pigments, then a composition is obtained that, when dried, quite accurately meets the requirements put forward. As a rule, such a composition must be applied several times to achieve the desired layer thickness.

No less effective material for imitating enamels with a shiny surface is a two-component acrylic varnish from the German company MAX MAYER. This varnish is designed to cover automotive surfaces, therefore it is chemically neutral to metal, resistant to light, moisture and heat. With the introduction of colored pigments into it, the varnish perfectly imitates many types of enamels.

Enamel-imitating mastics and lacquer compositions not only restore the lost display appearance of museum exhibits, but also act as a protective layer that prevents further destruction of the metal base.

Repair of products with enamel is quite a difficult task and requires special equipment and time.

Most often, when repairing chips and other damage to the enamel, you have to remove all the enamel and recoat.

Enamel can be of different types and therefore the cost of repair depends on many nuances.

Contact the masters from our jewelry network - who are engaged in this service and send photos of your products to them by mail. Then you can find out the exact cost of enamel repair in your product.

Commonwealth Jewelery Map

IMPORTANT! this service can be provided in any workshop (which is possible closer to your home).

You can see the full list of workshops on the "Addresses" page.

Read more about the repair of products with enamel

Enameling has long been used in jewelry making. One of the first mentions of enamel in manufacturing falls on the 12th century BC. We are talking about gold rings that were found in a Cypriot tomb. The finds that were found later date back to the Byzantine era. In the 15th century, enamellers significantly changed the practice of using glass in painting.

The next milestone in the improvement of this technique was Faberge eggs, combining enamel with jewelry. A rare person has not heard anything about Faberge eggs, because these are one of the most famous pieces of jewelry art that combine sophistication, sophistication and individuality. Oriental craftsmen took cloisonne enamel (the process of adding thin partitions to separate colors) to a new level of quality. Artists also used it when creating large frescoes, sculptures, in addition, this is typical for jewelry: bowls, vases.

Today, jewelry enamel is in great demand. Its popularity is largely due to what beautiful and interesting things are obtained when it is used in the manufacturing process, since with its help you can achieve truly unusual shades that compare favorably with trivial ones, while maintaining quality, unlike jewelry.

Unfortunately, cases of enamel abrasion are not uncommon, however, the repair of products with enamel is a well-established process. Enameling is a difficult job that requires a high level of professionalism, knowledge of your business and the ability to get along with enamel. How is enamelling done? To begin with, the enamel is brought to a powder state by grinding. Then it is mixed with pure silver or gold. This mixture is placed on an enameled flat surface and sent to the oven.

When the enamel thickens, it is determined by cells with a thin brush of sable or a professional tool and fired in an oven at a very high temperature (1475 degrees) for up to three minutes. If you mix different shades of enamel and bake several times in the oven, you can achieve an interesting depth of color. All these manipulations are repeated more than once until the enamel reaches the level of the partitions. Now the procedure can be considered successfully completed and the product can be transferred for polishing.

As you can see, working with enamel is very difficult and requires serious skills and experience. Therefore, to repair products with enamel, you should contact a trusted master who is well versed in the intricacies of his business. A responsible, serious approach is important in order for the work to be done perfectly. With the help of the art of enamelling, the products acquired gloss, charm and chic.

Women try to emphasize their individuality, stand out and attract the attention of others with stylish hairstyles, expensive shoes, manicure and original jewelry. Many choose expensive earrings and rings made of gold and silver with precious metals. Others prefer products with hot enamel or cold. considered unique. Performing the hot enamel technique is considered a refined craftsmanship. Talented craftsmen make jewelry with it irresistible.

Variety with enamel

With enamel, they are distinguished by their special sophistication and beauty. Today, classic, avant-garde, ultra-modern rings and earrings made of silver and gold, decorated with enamel, are at the peak of popularity. Thanks to this original technique, craftsmen place real works of art on bracelets and pendants, worthy of admiration.

Jewelers include creative ideas and experience, combine new metal processing technologies and produce colorful jewelry. The color scheme of these products can be varied. Enamel not only complements crafts, but also protects them from corrosion and mechanical damage. Over time, these decorations do not lose their brilliance and brightness, they are not afraid of moisture, temperature changes and light.

The most important advantage of enamel jewelry is that they are original, emphasizing the individuality of their mistress.

What is enameling

The production of jewelry, covered with a kind of glaze, has been mass-produced. However, such jewelry is handmade. In the original version, each product is different from the other, so they never repeat.

The use of glass, which melts easily, on the metal surface is called enameling by professionals. The composition and application of glaze may be different. There are several techniques for fixing a substance.

History of occurrence

Enamel was used for products even by the ancient Russians. They called her finift. She was decorated not only with jewelry, but also used for arts and crafts: they decorated bowls, goblets, caskets, caskets.

The oldest products with original glaze were found in Cyprus during excavations. Also, traces of this creativity were found in Egypt, India, Byzantium. Since the Byzantine Empire had close ties with Kievan Rus, this technique also came to our region.

In the 10th-11th centuries in the Middle East, ornaments were applied to utensils with hot enamel. The masters of the Byzantine Empire also applied it to the dishes.

Enameling flourished in the 12th-16th centuries. Then the Chinese emperors ordered to combine metal with casting. So enamel began to be applied to copper. For this, a special composition of blue color was created. Later, the technique in blue tones became the property of Chinese applied art. The Chinese enameling technique is popular all over the world. Patterns in the heavenly scale cover not only jewelry, but also caskets, saucers, cups, vases, glasses.

Later, the application of hot enamel began to be used not only for kitchen items, but also framed icons, mirrors, salaries with it. In the 19th-20th centuries, the Art Nouveau style became popular, when decorations and decorative items were decorated with artistic glaze. Chemistry has moved far ahead and thanks to this, experts have developed a whole palette of shades for enamel.

Cloisonne jewelry hot enamel

The most elegant technique of hot enamel is cloisonné. First, a pattern is applied to a copper, silver or gold plate using thin wires. They act as a kind of partitions between which colored glaze is poured.

In the old days, this decoration technique was used instead of precious stones. In India, there are minankari jewelry, in which enamel variegation is combined with precious stones. Hindus also add an ornament made of metal or chasing there.

Exemplary is Chinese cloisonne enamel. What kind of images you will not see on this patterned casting! Here are magical little animals, flowers, petals, bunches of grapes, ornate patterns. Many have enjoyed the enamel floor vases from China!

Stained glass enamel belongs to the partition technique. The principles of these two glazes are very similar. The gaps in the ornament lined with wire are filled with wet enamel. Then the product is dried and fired. To obtain a multi-color pattern, each shade of glaze is fired separately in a muffle furnace. As a result, the fused enamel resembles glass.

The only difference between the stained glass technique and the cloisonne technique is that the first has a transparent structure, if it is raised to the light. Cloisonne enamel has a metal base, so it does not shine through.

Champlevé enameling

The most ancient and easiest to manufacture is champlevé enamel, or "champleve". It consists in creating grooves in the metal. The frosting itself is easy to apply. With its help, colored engravings are made, as well as grandiose images with alternating metal and enamel.

Most often, copper is used as the starting metal, since it is soft and easy to make recesses in it. Their depth can be different, the color saturation depends on it. For the production of jewelry, already stamped blanks with recesses are used, into which enamel of different shades is only poured.

Transparent or through enamel

This glaze is used in jewelry with precious metals. It can be gold, platinum, silver. Such a metal covered with transparent enamel will shine through it and shine very strongly. The colors of the product will be very juicy. The metal under the transparent glaze does not tarnish and is protected from mechanical damage.

opaque enamel

This glaze is also called opaque. Apply it to copper and tompak. Silent or opal enamels are distinguished by a huge range of colors, due to which the metal alternates with the color of the glaze.

There is also something in between translucent and deaf enamelling. At different angles of incidence of light, it changes from transparent to opal, resembling the play of light with modulations.

Hot enamel technology

Hot enamel jewelry has been used for a long time, although the process of making them is considered time-consuming. This type of enameling is a leader in the manufacture of jewelry and other products. Such a glaze is firmly attached to things, because it is baked in specialized ovens (muffle) and kept at a temperature of 600-800 ° C. Then the product can be cooled, cleaned and polished.

At first glance, the process seems simple, but patience for such a case does not hurt. In its initial form, the enamel has the form of a powder. It includes specially selected charge materials: quartz sand, chalk, feldspar, clay. Also in this composition are soda, borax, potash and excipients. The presence of dyes, oxidizers, opalants in it is mandatory to obtain an opal state.

First, in a special container, dilute the enamel powder with water to the density of sour cream. Then this mass fills the desired areas of jewelry. Before firing, the product is dried to release air bubbles. Under the influence of temperature, the enamel fuses and becomes like glass (transparent or deaf). Then the craft is polished and amenable to re-firing. The end result is a perfectly smooth surface.

For multi-colored and cloisonne glazes, firing is done strictly alternately. White enamel is fired the longest, followed by pink and blue. Then fill the cells with green and black glaze. Red glaze is considered less heat-resistant, it is kept the least.

The enamel mass is poured very evenly to make a flawless surface. Depending on the complexity, hot enamel jewelry can be fired from 5 to 100 times. It is necessary to monitor the firing time and temperature very precisely. This is how unique masterpieces that exist only in a single copy are obtained.

Types of cold enameling

Cold enamel is peculiar fiberglass, easy to apply. There are three types of cold enamelling:

Tricks of choosing quality products

Enameling is a painstaking process, so jewelry using this technique is not cheap. They are considered premium products. When buying jewelry with enamel, you should pay attention to the presence of cracks, chips, scratches, bubbles. Gold is most suitable for it, because it does not deform when heated. Sterling silver hot enamel earrings look great. Copper gizmos are also quite in harmony with vitreous glaze. The storage and wearing of enamel jewelry requires the following rules:

Differences between hot and cold enamel

Hot enamel is more durable and the price is higher than cold enamel. In cold enamelling, there is another technique - enamel. After its application, it spreads in multi-colored patterns, like gasoline on water. There are some sort of colored streaks.

Hot pouring is more even because it is strong. On cold enamel there are irregularities, since it is not polished. Still hot glaze shines brightly.

Cold mixes also have advantages. They are characterized by simplicity, unpretentiousness, plasticity. For the manufacture of such jewelry does not require special tools. Cold enamelling is suitable for all alloys.

Enamel on gold and silver

Stunning collections of gold and silver jewelry with enamel make the hearts of the most sophisticated connoisseurs of beauty tremble. Among the huge selection of earrings, rings, bracelets, the harmony of juicy shades, faceted gems pleases the eye. Classics in the form of black and white are also in trend today.

Silver with enamel look simply masterpiece. Coated rings are produced massive and refined. They sometimes encrusted stones. Original sets with enamel will become a decoration for girls of any age and status. Smooth, even rings look great like wedding rings, on which a Greek pattern is applied.

Who produces hot enamel jewelry

Feminine colored jewelry is represented by several Czech ones. The most famous of them is Style Avenue. Czech specialists are experimenting with cloisonné cold enamelling.

Italian products with glaze are popular. Here are the most famous firms: Damiani, Bulgari, Garavelli. Italian crafts surprise with their shapes in the form of flowers, buds and butterflies.

Products received the name minankari. Shades in them pass very smoothly. It is suitable for pendants and rings.

In Russia, silver jewelry by Sunlight is especially popular. The surface of this enamel is very smooth, and the ornaments are made in smooth lines.