Electroplating is an electrochemical process during which the shape of a product is recreated by depositing metal on it. The electroplating method involves coating non-metallic surfaces with metal.
Electroplating is often used in relation to various elegant objects (jewelry, orders and medals, coins, shells, flower pots, sculptures, portraits, etc.). Copper is most often used in electroforming. However, other metals can also be used, including nickel, chromium, steel, and silver.
If all technological requirements are met, it is possible to distinguish a copied object from an original one only by the barrier layer or by removing the original. Moreover, it is quite possible to do all the work yourself at home.
Note! The coating of the copied product must be electrically conductive. If the material lacks this property, bronze or graphite is applied to it.
We take a print from the product that we will copy. To do this you will need some kind of low-melting metal, plasticine, plaster or wax. If we use metal, we treat the item being copied with soap and put it in a cardboard box. Next, pour in a low-melting alloy.
When the casting is completed, we take out the product and subject the resulting form to first degreasing and then copper plating in an electrolyte. To avoid metal deposits on those sides where there is no imprint, we melt the metal in boiling water to obtain a matrix. Fill the form with plaster. The output is a copy.
To create a matrix you will need the following composition:
If the mold is created from a dielectric material, we apply an electrically conductive coating to its surface. The conductor layer is applied either by metal reduction or mechanically, which involves applying flake graphite using a brush.
Even before mechanical surface treatment begins, we grind the graphite in a mortar and sift it through a sieve. The best adhesion of graphite is observed with plasticine. It is most effective to treat plaster, wood, glass and plastic forms, as well as papier-mâché, with a solution of gasoline and wax. When the surface has not yet dried, we apply graphite dust to it, and blow off the adhering substance with a directed air flow.
The electroplated coating is easy to separate from the matrix. If the mold is metallic, we create an oxide or sulfide conductive film on the surface. For example, on silver it will be chloride, on lead it will be sulfide. The film will help you easily separate the mold from the coating. In the case of copper, silver and lead, coat the surface with a 1% sodium sulfide solution to create insoluble sulfides.
When the mold is ready, place it in a galvanic bath connected to an electric current (to prevent the release film from dissolving). First, we coat the conductive copper layer under conditions of low current density.
We will need the following composition:
The operating temperature in the electrolyte bath is 18-25 degrees Celsius. Current density is from 1 to 2 Amperes per square decimeter. Alcohol will be needed to improve the wettability of the coating. A car battery charger can be used as a DC source. We also need an ammeter with the ability to measure current from 0 to 3 or 5 amperes. Usually the chargers already have an ammeter.
Nichrome wire will serve as a rheostat. We wind it on any ceramic plate. A coil from an electric heater will do just fine.
Any plastic container with a volume from 2 to 50 liters, depending on your needs, is suitable as a bath. We use a copper plate as an anode.
Note! The anode area should be approximately equal to the area of the workpieces.
To create a conductive layer for the product, add a few drops of varnish to the bronze powder. It is recommended to use colorless nitro varnish. The varnish needs to be made more liquid, so dilute it with acetone to the consistency of a liquid paint and varnish composition.
We take approximately a 20-centimeter piece of multi-core cable and remove the wire from it. We protect the insulation on both sides of the wire, bend one end of it at an angle of 90 degrees and glue it to the plastic part with instant glue. Moreover, BF glue will not work, as it will dissolve it.
When the items are dry, we degrease them using household chemicals (for example, washing powder). Next, rinse the product in running water or treat it with acetone.
The parts are firmly fixed to the wire. Now they can be dipped one at a time into pre-prepared bronze paint or this material can be applied with a brush. The entire surface must be evenly painted. It is recommended to use insulated wire from the cable, otherwise copper will fall on the bare wire, which will lead to additional consumption of the anode.
After drying the surface for an hour, twist the dried ends of the wires together. The parts must not touch each other. Next, we connect the products to the positive contact and immerse them in the bath. A few seconds after immersion, the copper plating process, visible to the naked eye, will begin.
The thickness of the copper coating may vary depending on the circumstances, but for small items it will be approximately 0.05 millimeters. The parts are in the bath for 15 hours. The current is adjusted by moving the contact along the nichrome rheostat within 0.8-1.0 Amperes. After copper plating, we increase the current to 2 Amperes. When the curing period of the parts has expired, we wash the items in running water, dry them, and cut off the wire. We clean the wire and prepare it for the next procedure.
The next stage is polishing. For this, a motor equipped with a metal round brush is useful. This job requires a certain skill. The result should be a surface that looks like blackened bronze with some shiny areas. If you cannot immediately achieve the desired result, apply sulfur ointment again, heat the product over the fire and polish it.
For those who doubt the effectiveness of the procedure described above, we suggest doing a test. To do this, you will need a container for electrolyte, where you need to put a little copper. Paint one part with a spray bottle in 2-3 layers in bronze color. Next you need to connect to the battery without using a rheostat. The adapter from the player will also work.
In addition to copper, other metals can be applied to a non-metallic surface, including gold or silver. Silver electroplating can be carried out in one of two ways: chemical or electrochemical. Chemical silvering is produced by immersing the product in a boiled solution of silver. The electrochemical process gives a more reliable result, since the coating is more durable as a result of exposure to electric current. Silver electroplating is widely used in the production of jewelry.
So, electroplating at home is quite possible. The process is quite labor-intensive and requires certain skills, but the end result is worth it.
heat release when electric current passes through the electrolyte.
Filtering the electrolyte should be carried out as often as possible in order to remove sediment from the baths - sludge that accumulates in the form of powdered copper, graphite and dust.
The higher the current density and the more intense the anodes dissolve, the more sludge collects in the bath (this is especially observed when using low-grade anode copper).
As a rule, the sludge settles to the bottom of the bath, but its lighter particles, being in suspension, move to the cathode due to convection, which causes clogging of the galvanoplastic copper.
The sludge, in contact with the copper deposited on the cathode, is incorporated into the metal, leading to the formation of roughness and lumps that interfere with further uniform deposition of the metal. In addition, graphite, used as an electrically conductive layer for molds, also contaminates the electrolyte, is embedded in the metal and contributes to surface roughness. Therefore, filtering the electrolyte is important to create benign copper deposits. Filtration is usually carried out by siphoning the electrolyte through a filter made of cloth, glass or asbestos fiber.
One of the first uses of electroforming was to create decorative sculpture. The technique of galvanoplasty in the 30-40s. XIX century In Russia, a significant number of sculptures were made that have survived to this day (for example, part of the sculpture on the facade of St. Isaac's Cathedral in Leningrad, sculpture in the Catherine Park of the city of Pushkin, etc.).
The sculptor usually creates his work in clay or plasticine. However, the work never remains in these materials - it is transferred to the hands of craftsmen who transfer the sculpture into more durable materials without destruction.
changing over time: copper, bronze or cast iron.
Reproducing sculptures in bronze or cast iron is only possible using the casting method, which, unfortunately, does not make it possible to obtain a sculptural work with absolute accuracy: during casting, the rendering of the smallest strokes deteriorates, and along with them, the manner in which the sculpting is reproduced changes.
In order to recreate a sculpture in metal while preserving all the details of the sculptor’s work, they resort to the technique of electroplating, the field of which, which deals with the reproduction of sculptures, is called artistic electroplating. Reproduction refers to the making of copies of sculptures, executed with full preservation of volumetric dimensions and texture (the nature of surface treatment).
It should be noted that a sculpture is called both the original, sculpted by a sculptor, and a copy obtained from it in some material. The original sculpture is called a model in contrast to the final copy, which is a reproduction. The latter, made in metal using electroplating, is called galvanic reproduction.
The term "sculpture" is applied not only to large monumental works (for example, statues), but also to smaller objects (for example, medals).
From the point of view of reproduction technology, the spatial (volumetric) nature of the sculpture’s outlines is of utmost importance. On this basis, sculpture is usually divided into one-sided and multi-sided.
A one-sided sculpture is intended to be viewed from positions located on a central axis perpendicular to the background plane. One-sided sculpture includes bas-reliefs (low relief) and high reliefs (in high reliefs the convex image protrudes strongly above the background plane).
Multi-sided sculpture
The bas-relief of St. Petersburg (panel) is made by galvanoplastic deposition. The main material for their manufacture is copper, which is then coated with another metal to give the product greater expressiveness and completeness. The end result can compete with real works of art. The bas-relief is a wonderful gift that no painting can compare with, although there are some =)
We pay attention to every detail and work through every detail, manufacturing products using modern equipment. It is these factors that help us significantly reduce the production time of products and improve their quality. The souvenir products we produce are distinguished by their quality and durability.
Our bas-reliefs are distinguished by their variety of shapes and precise elaboration of each element.
Currently, metal products are used both in everyday life and in various industries. Metal is widely used in design art and performs not only a decorative, but also a protective function. Metal products are distinguished by excellent characteristics, such as strength, reliability and pleasant appearance. This material is multifunctional and practical, which is why metal products are so popular.
Thanks to the use of injection molds, the production of large quantities of goods is simplified. Artistic forged products add elements of luxury to the interior. Jewelry does not lose its relevance, still remaining the favorite gift of any woman. A bas-relief on the wall can transform the interior and add a touch of originality to everyday life.
The manufacture of complex products requires the presence of craftsmen of various qualifications, as well as the investment of time and money. Significant cost reductions and productivity increases are achieved through the use of galvanoplasty. Thanks to it, it becomes possible to recreate the exact shape of an object; the process occurs due to the decomposition of metal solutions by electric current. Thanks to electroplating, it is possible not only to recreate exact metal copies, but also to strengthen and decorate existing surfaces by coating with nickel, gold or silver.
A striking example of a product obtained in this way can be a bas-relief; the lines of the resulting product are impeccable and precise, the product takes on an elegant appearance. A bas-relief made in this way is much more profitable to buy than a product made by any other method.
By choosing us, you can be confident in the quality and timeliness of the product. Our specialists are able to recreate elements of any complexity, and art masters are able to offer non-standard and fresh solutions.
Particular attention is paid to the production of bas-reliefs, special techniques are used.
In this article we will tell you how icons are made using the electroplating method. And first, let's start directly with what it is - galvanoplasty?
The method of creating copies using the electrolytic method was discovered by B.S. Jacobi 100 years ago. This process was called, in a complex word, galvanoplasty. We will not provide detailed technology here; you can find it on the Internet or by reading specialized literature, we will describe only the most basic.
In short, galvanoplasty is the electrochemical growth of a thick layer of metal in a liquid electrolyte. In this article we will be interested only in copper, although other metals can be grown by electroplating.
So there is an anode and a cathode. To completely confuse everything, a plus is connected to the anode, and a minus to the cathode. Copper ions move from the anode to the cathode.
To remember once and for all what needs to be connected where, you can simply remember that positive charges are attracted to negative ones. Copper ions are positively charged, therefore they will be attracted to the negative terminal of the power source.
Let's consider the process of making galvanic copies using the example of a copy of a toroid for a transformer made of plasticine. After making the mold, stripped copper wiring is laid around it, from which the copper build-up will begin. It can be seen in the photographs below.
Then, a conductive layer is applied to the copy, in our case it is a special graphite in aerosol packaging (Graphit 33, kontakt chemie), it is convenient to apply and it has a resistance of hundreds of ohms, which will be optimal.
Due to the fineness of the graphite particles, all irregularities are immediately visible. Whether this is good or bad depends on the case. Since the copper will be thick, all the irregularities will be overgrown.
When making icons, special blanks (waxes) made of special jewelry wax are used as “blanks”, on which a conductive layer is also applied. The blanks are an exact copy of the future icon, which will be obtained at the end of production, and therefore small irregularities and roughness on it are unacceptable. The photo below shows two icon blanks made of jewelry wax, St. Nicholas the Wonderworker and the Mother of God of Vladimir.
The electrolyte contains sulfuric acid, which in our country of idiots is classified as a precursor, which means it cannot be found on the open market. We'll have to get it. You can get it as an electrolyte for car batteries. The acid concentration is not important to us.
So, the composition of the electrolyte for work without stirring from the book by Kaznayachey B. Ya, “Galvanoplastics in Industry”
CuSO4 (copper sulfate) – 200g/l
Sulfuric acid (by mass of pure H2SO4, must be recalculated depending on concentration) – 30 g/l
Ethyl alcohol – 5g/liter (to increase wettability)
Operating mode – 1-3 A/dm^2 at a temperature of 18-20 degrees.
The growth rate of copper at this current density is 220 nm (nanometers)/minute. That is, to obtain 1mm of copper it will take 4545 minutes, or three days. With twice the current density, the time will be half as long. It's simple.
So, let's prepare all the ingredients, I'm getting ready to make three liters of electrolyte:
Dissolve. First, pour in vitriol, pour distilled water into it, wait for it to dissolve, it’s better to mix (you’ll have to wait quite a long time!). After this, add sulfuric acid. The acid needs to be poured like this:
Be sure to add acid to water, and not vice versa, and preferably using a glass rod with constant stirring. Technical vitriol contains carbonates, so be prepared for the acid to hiss upon first contact with the solution.
Let the solution settle a little (when adding acid, some of the vitriol may precipitate - its solubility decreases) and filter it. I filtered through regular cotton fabric. I know that this is bad - it dissolves, but there was nothing else. In principle, you can simply let the electrolyte stand, then all the dirt will settle to the bottom, and then drain the “tops”.
I made the electrolysis bath itself from a piece of a 6-liter mineral water bottle.
During the process of dissolving the anode, fine copper particles fly off it - the so-called sludge. This sludge, floating through the solution, ends up on the mold. Due to such inclusions, the copper on the workpiece does not grow evenly and dendrites appear. In industry, in order to prevent sludge from getting into the general solution, either casings made of special acid-resistant fabric or PVC boxes are used. I decided not to go too far from the bottle theme, and made a box from another mineral water bottle.
It’s easy to do - bend a liter bottle until you get a rectangular profile and poke a 100W soldering iron many, many times. The main thing is that when this box is lowered into the solution, the waterline is in a place that is not riddled with holes. Naturally, the bottom should not be full of holes either.
We load the workpiece. In my opinion, it is better to first pour the electrolyte into the bath, and only then immerse the mold.
Now the most important thing is to increase the copper. The extension itself consists of two stages - tightening and the actual extension.
Tightening - coating the entire workpiece with copper is carried out at low currents, usually up to 1A/dm^2. Personally, I first start with 100 mA/dm^2 and gradually increase it to an ampere, because at the beginning the conductivity is distributed very unevenly and hydrogen bubbles may appear in the pestle of the wire, which will spoil all the copper.
Extension. Everything is relatively simple here - turn on the maximum current and wait for the process to complete. The main thing is not to forget to feed our copper-eating monster.
End of tightening process. The total current is 1A, and the density is 0.64A/dm^2:
Immediately after finishing electroforming, half of the toroid looks like this:
The process of making icons using the galvanoplasty method is completely identical. A conductive layer is applied to the wax blank, then a layer of copper of the required thickness is deposited on it through an electrochemical process. If necessary, a layer of silver can be applied on top of the copper, resulting in an icon that looks like silver.
The only drawback of production is toxicity, since the technology uses chemicals.
Galvanoplasty only looks complicated on the surface, but in practice everything is quite simple. This method allows you to create documented accurate copies of bas-reliefs, coins, coats of arms, medals, emblems, etc. Widely used in restoration.
.jpg)
