K3-en / Photo

July, 2026

Bolt Tower; Ostrava, Czech Republic (N. Kumar)

For decades, the Czech city of Ostrava was known as the "Steel Heart of the Republic," driven by the sprawling Vítkovice Ironworks until the fires went out in 1998, leaving massive steel structures behind to face the slow process of atmospheric corrosion. Instead of erasing this industrial skeleton, the city chose urban resilience by crowning Blast Furnace No. 1 with the Bolt Tower—a landmark named both for its mechanical, bolt-like helical framework and for the legendary sprinter Usain Bolt, who christened it in 2015. This striking structure highlights a beautiful duality of corrosion: the deep, textured orange base features authentic historical oxidation carefully stabilized to honor the city’s working-class past, while the modern crown utilizes engineered weathering steel that intentionally corrodes to form a tight, self-protecting patina, shielding the metal beneath without ever needing a single coat of toxic paint. By letting old rust support new innovation, Ostrava proves that the natural lifecycle of metals can transform a site of industrial decay into a sustainable monument of cultural pride.

June, 2026

Grue – wooden cranes for boats; Umag, Croatia (L. Gašparič)

Grue are traditional wooden cranes once used for storing small boats. The boats were lifted out of the water with steel cables and left hanging on the cranes, protected from the sea. These structures are characteristic of the northwestern coastal region of Istria, particularly in areas with shallow waters and no suitable docking facilities. They first appeared in the early 20th century to accommodate small fishing boats. Today, grue are no longer in use but remain along the coast as part of the region’s maritime heritage and as picturesque elements of the landscape. Over time, the steel components that once lifted the boats have corroded, leaving only a trace of their former function.

May, 2026

Arts et Métiers, Paris, France (I. Milošev)

Arts et Métiers is the metro station on line 11 in the 3rd arrondissement in Paris, opened in 1935. It takes its name from the nearby Conservatoire National des Arts et Métiers (also known as Le Cnam) or National Conservatory of Arts and Crafts, including the Musée des Arts et Métiers, both of which it serves. In 1994, Le Cnam celebrated its bicentennial anniversary. On this occasion, the station was renovated and completely covered with copper plates riveted together, rather than the usual earthenware tiles found in other Paris metro stations. It is the work of Benoît Peeters, a French screenwriter, and François Schuiten, a Belgian designer, authors of the comics series Les Cités obscures. The station simulates the interior of a Jules Verne-style submarine, featuring, in addition to the copper walls, portholes displaying gears and old inventions. All the station's furniture, including name plates, wooden seats, flat tunnel exits, and the lighting, is brown, suiting the decoration style and constituting a unique case in the Paris metro system. The choice of copper is based on its high corrosion resistance in underground environments. Besides, it gives an industrial appearance and »fictional machine« look.

April, 2026

Silent Decay – Microbiological Corrosion Beneath the Sea, C-55 Mine Sweeper Shipwreck, Isla Mujeres, Mexico (A. Koblar, I. Milošev, G. Milošev)

At first glance, an underwater image of a sunken ship appears calm and forgotten by the world – like a frozen moment in time, where the wreck rests in silence and darkness. In reality, however, it teems with life, and an ongoing process of degradation is constantly taking place on its surface. The marine environment is not merely a passive corrosive medium; it harbors a wide variety of microorganisms that actively contribute to the corrosion of metals. This phenomenon is known as microbiologically influenced corrosion. Microorganisms settle on metal surfaces and form biofilms – thin layers in which chemical reactions occur, accelerating the breakdown of the material. Some organisms even use metals as part of their metabolic processes. The result is characteristic localized damage, pitting, and the gradual weakening of the structure.
One of the most well-known examples of such degradation is the wreck of the RMS Titanic. Since its sinking in 1912, it has been gradually decomposed by the bacterium Halomonas titanicae, which feeds on iron and forms distinctive rust-colored structures known as “rusticles.” As a result, the ship’s structure is collapsing at an increasing rate – experts estimate that the wreck could nearly disappear by around 2030. At this time of year, we also remember its first and final voyage, which tragically ended on April 15, 1912. The image of a sunken ship is therefore not only a symbol of a historical event, but also a reminder of the invisible processes that continuously reshape the world around us.

March, 2026

Scenic view from Hong Island, Hong Island, Thailand (L. Gašparič)

Ko Hong (Hong Island) is a small yet enchanting island in the Andaman Sea in southern Thailand, known for its pristine beaches and striking natural scenery. The island is characterized by a tropical climate, with temperatures remaining around 30 °C throughout the year and consistently high humidity. Together with the close proximity of the sea, these conditions create an environment in which metal structures corrode rapidly. A clear example of this can be observed at the island’s viewpoint, situated 109 m above sea level, where corrosion is already visible on the metal railing. This serves as a reminder of how demanding it can be to maintain metal structures in such harsh coastal environments.

February, 2026

Aluminum Hearts, Ljubljana, Slovenia (A. Koblar)

When analyzing the surface chemical composition of an AlSi10MgMn aluminum alloy sample, a surprising motif emerges at first glance – heart-shaped patterns appear across the surface. These shapes are neither random nor merely an aesthetic curiosity, but the result of the growth and rotation of dendrites, characteristic tree-like crystalline structures formed during the solidification of the alloy. When energy-dispersive spectroscopy (EDS) is applied, these “metallic hearts” become even more apparent. Variations in the distribution of chemical elements create a color contrast, where higher pigment intensity indicates regions richer in silicon. This clearly highlights the boundary between the dendrites and the surrounding eutectic matrix. Such microscopic differences in chemical composition are often the initiation sites for corrosion – a gradual and destructive degradation of the metal. Corrosion can be slowed or prevented through the use of protective treatments or by selecting a more suitable material. In this way, the image serves as a symbolic reminder that, much like in human relationships, a long-lasting material requires the right combination of composition, structure, and protection from environmental influences.

January, 2026

Jester by Drau, Villach, Austria (B. R. Bhagat)

The bronze sculpture of the Faschingsnarr in Villach, Austria, captures the playful essence of the town’s long-standing carnival tradition through the animated form of a jester. Positioned along the banks of the River Drau, the sculpture is regularly exposed to moisture and fluctuating climatic conditions, resulting in natural bronze oxidation and surface corrosion over time. Set against a picturesque backdrop with the Alps rising in the distance, the monument gains a striking visual contrast between art and landscape. The beauty of the surrounding Alpine environment, while enhancing the sculpture’s charm, also contributes to the atmospheric conditions that influence corrosion, illustrating how nature and culture interact in shaping the sculpture’s evolving appearance.

December, 2025

Reflections of the City, Chicago, USA (A. Kraš)

Captured in the heart of Chicago, this mesmerizing view of Cloud Gate — famously known as The Bean — showcases the stunning interplay of light, metal, and atmosphere. Designed by artist Anish Kapoor and unveiled in 2004, the 110-ton sculpture anchors Millennium Park. Inspired by liquid mercury, its seamless curves reflect the city skyline in a surreal, fluid panorama. Built from 168 stainless steel plates, precisely welded and polished until all joints disappeared, the artwork hides a complex truss framework that supports its immense weight and distinctive under-curve. Its mirror-finish surface isn’t just artistic — it’s a tribute to the power of corrosion-resistant materials. The sculpture’s austenitic stainless steel (grade 316L) withstands Chicago’s harsh winters and pollution, preserving its liquid-like brilliance for over two decades. Under the evening lights, the skyline melts across its curved surface — a living reflection of durability, design, and science united.

November, 2025

Dome of Temppeliaukio Church, Helsinki, Finland (L. Gašparič)

Temppeliaukio Church, more commonly known as the Rock Church, is literally built into solid rock. In addition to its iconic rough stone walls, which provide excellent acoustics, the church is crowned by a remarkable copper dome surrounded by skylights that flood the interior with natural light. Inside, the dome is lined with metallic copper wire stretching a total of 22 kilometers in length. On the outside, the copper dome has oxidized over time, acquiring the characteristic green patina typical of weathered copper. Thus, the dome offers a striking contrast between two forms of copper: the bright reddish tone of unoxidized copper inside, protected from corrosion, and the green patina of oxidized copper outside, shaped by natural exposure.

October, 2025

The Fisherman of Durrës, Durrës, Albania (N. Kumar)

Perched at the edge of the Adriatic Sea, the Fisherman statue in Durrës, Albania, is more than a tribute to the city’s maritime heritage. It’s also a living example of how time and nature shape public art. Cast in metal, the figure sits patiently with rod in hand, symbolizing generations of local seafarers. Over the years, the salty sea air has left its mark, forming a green patina that speaks to the statue’s age and exposure. Subtle signs of corrosion on the rod and joints hint at the effects of wind, moisture, and metal interaction in this coastal environment. Surrounded by the sounds of lapping waves and the scent of the sea, the statue stands as a quiet intersection between art, history, and science.

September, 2025

"The Sleeping Puppy" from Zirconium Conversion Coating on Aluminium Alloy, Ljubljana, Slovenia (B. Kapun, A. Kraš)

Zirconium conversion coatings are gaining traction in the aircraft and automotive industries thanks to their ability to improve corrosion resistance and paint adhesion—without the environmental drawbacks of traditional chromate and phosphate conversion treatments. These coatings form via a sophisticated chemical process: acidic solution containing H₂ZrF₆ reacts with the metal surface, initiating localized corrosion (anodic reactions) and an increase in pH at specific sites due to accompanying cathodic reactions (hydrogen evolution and oxygen reduction). This localized rise in pH enables the precipitation of zirconium oxide—a compound typically insoluble at higher pH levels—resulting in the formation of a protective layer. This month’s featured image offers both scientific insight and unexpected charm. Captured using a scanning electron microscope (SEM), the image reveals how the coating mirrors the alloy’s underlying metallurgical structure. The thick, micrometer-scale deposition you see has formed over intermetallic particles (IMPs)—common various inclusions in aluminium alloys that enhance mechanical strength but also act as corrosion hotspots. In contrast, the surrounding matrix shows only a thin, nanometer-scale coating that formed later in the process. To us, the pattern formed on the IMP by the conversion coating strikingly resembles a sleeping puppy—curled up and serene. Even in science, art can emerge when we least expect it!
What do you see?

August, 2025

Corrosion of electrical socket, Dravograd, Slovenia (A. Koblar)

While all materials used in electro installations are made from high-grade and durable materials, they can still degrade due to poor installation process or miss usage. In many accidental cases the main “culprit” can be found in ingenious handyman with a unique way of solving problems. These visionary ideas can often result in severe damage to materials and lose of proper function. One of such mishaps is shown on the picture above, where we can observe a severe case of stainless-steel corrosion. In this case it was caused by strong galvanic coupling between the metallic case and stainless-steel electrical socket holder. Operating conditions were worsened by high level of humidity caused by poor insulation of stone walls (building classified as national heritage) in which the electrical socket was installed. With time, high humidity and exposure to air, most metallic parts used in these sockets almost completely degraded.

July, 2025

Saint Teresa, Prishtina, Kosovo (N. Ajvazi)

Saint Teresa, born Anjezë Gonxhe Bojaxhiu to an Albanian family, is one of the most admired humanitarians of our time. Known for her deep compassion and unwavering commitment to others, she spent her life caring for the poor, the sick, and those often forgotten by society. Through simple acts of kindness and tireless service, she became a global symbol of humility, strength, and love. Her efforts earned her international recognition, yet she remained modest, always focused on the needs of others. In recognition of her life and work, she was declared a saint by the Catholic Church in 2016. For the Albanian people, she is not only a figure of global admiration, but also a beloved daughter of our nation. The sculpture of her in Prishtina, the capital of Kosova, honors her legacy and reminds us that even the quietest voices, when guided by compassion, can leave a lasting mark on the world. The statue is cast in bronze, and over time, it has developed a natural patina as the metal oxidized, adding depth and character to her image.

June, 2025

Flash rust on a carbon steel knife, Varaždin, Croatia (A. Kraš, P. Pahić)

Carbon or Stainless Steel: Who is The Winner in the Battle Against Corrosion on the Plate?
Flash corrosion, as the name implies, occurs rapidly when iron or steel are exposed to air and a thin layer of moisture, resulting in soluble corrosion products that create reddish-yellow stains typical for common „rust“. Rust weakens the metal, leading to flaking, crumbling, and potential structural damage. One example of flash corrosion is when a carbon steel knife (high-carbon steel knife) is not properly dried after use, like the one shown in the picture. In contrast to rust, patina is a protective layer that can gradually form on a knife, preventing further rusting while giving it a distinct dark, matte finish. Exposure to residues from citric-acidic foods like tomatoes and lemons can make patina emerge faster. Furthermore, unlike rust, patina does not affect the taste or appearance of food when cutting. To prevent rust, besides proper drying, regularly applying blade oil can help keep ambient moisture at bay during storage. However, it won't make the knife less reactive when cutting acidic foods. Carbon steel knives offer several advantages over stainless steel knives, such as being sharper, stronger, having longer edge retention, and being easier to re-sharpen. Carbon steel is also more suitable for blacksmithing compared to stainless steel because the latter contains vanadium and chromium, which form carbides, increasing its hardness. Additionally, chromium in stainless steel provides high corrosion resistance. Thus, if you prioritize superior cutting ability, don't mind some rust, and are willing to care for your knife properly, a carbon steel blade may be the right choice for you. On the other hand, if you desire the best corrosion resistance and don't mind performing additional edge maintenance, a stainless steel knife may be the better option for ensuring its longevity.

May, 2025

Corrosion at the edge of the Ocean, Porto, Portugal (M. Mujdrica Kim)

The photograph depicts a reinforced concrete structure shaped like a small boat, located along the Portuguese coast of the Atlantic Ocean. It serves as an intriguing example of the enduring impact of the marine environment on construction materials. The object, which may have once served as an artistic sculpture, now shows clear signs of advanced corrosion. Prolonged exposure to the salty marine environment has led to the degradation of the protective concrete layer, exposing the rusting steel reinforcements beneath. The process of reinforcement corrosion is the result of chloride ions penetrating the porous structure of the concrete and triggering an electrochemical reaction. The formation of rust products increases in volume, further weakening the structure and causing cracks. In addition to reinforcement corrosion, the structure also shows signs of general erosion and mechanical wear on its surface, caused by the relentless action of wind, waves, and marine aerosols. Symbolically, the photograph portrays the interplay of natural forces, time, and material degradation, which is characteristic of structures exposed to harsh marine environments.

April, 2025

Ski-lift, Krvavec, Slovenija (I. Milošev)

Buildings and structures made of metallic materials must ensure safe operation across a wide range of temperatures and humidity levels. The next time you ride a ski lift in sub-freezing temperatures, surrounded by a blanket of snow, you might find yourself thinking about corrosion mechanisms under these extreme conditions.

March, 2025

Jožef Stefan bust, "Jožef Stefan" Institute, Ljubljana, Slovenija (E. Gregori)

The bust of Jožef Stefan, located in the parking area of our institute, is a tribute to one of Slovenia’s most important scientists and a pioneer in physics and thermodynamics. This year, on March 24, we celebrate the 190th anniversary of his birth. Stefan is best known for discovering Stefan’s law, which describes black-body radiation and is considered one of the fundamental findings of modern physics. To this day, he remains the only Slovene after whom a physical law is named. He was also a mentor to the renowned physicist Ludwig Boltzmann. Founded in 1949, the institute bears his name in recognition of his outstanding contribution to global science. The statue is made of a metal alloy, most likely bronze, as evidenced by the characteristic greenish-blue patina on its surface. This patina forms due to the natural oxidation of copper alloys, creating a protective layer that slows down further corrosion. In honor of his legacy, the Jožef Stefan Institute organizes the annual Jožef Stefan Days at the end of March, which this year take place from March 24 to 29. The statue symbolically connects Stefan’s scientific heritage with the institute’s modern research achievements.

February, 2025

Fontaines de la Concorde, Place de la Concorde, Paris, France (I. Milošev)

Two monumental fountains are located at the Place de la Concorde in Paris. The fountains were designed by Jacques Ignace Hittorff in the 1840s in order to honour the maritime commerce and industry of France (south fountain) and navigation and commerce on the rivers of France (north fountain). The major figures of the fountains were made of cast iron, treated through florentinisation or painted with bronze and gold paint. The smaller figures were made of bronze.
Prior to 1828, the primary artificial bronze used for copper and copper alloys was antique green of various shades. A metal coloring called "Florentine bronze" was introduced by a Frenchman named Lafleur around 1828. A variation, Florentine fremé ("smoked" bronze), was introduced by another Frenchman named Camus in 1833. The alloy is typically composed of a mixture of aluminum or tin (<10%) and copper (>90%). Currently, there is no standardized chemical formula for Florentine bronze, as the proportions vary worldwide (source: Wikipedia).

January 2025

Statue of Luigi Galvani, Piazza Galvani, Bologna, Italy (A. Koblar)

Statue stands in the small square of Piazza Galvani, which was named after the scientist to whom it is dedicated to. The famous scientist Luigi Galvani lived and studied in Bologna. His field of research was anatomy and physiology, related to muscle contraction under the influence of electric current. While the monument is made out of marble, a bronze relief with a laurel wreath and scepter is set on the high plinth. After decades of exposure to natural elements the bronze relief is severally damaged and covered with thick layer of patina.

December 2024

The Chemistry Christmas Tree (I. Milošev)

In the laboratory, three of our colleagues – L. Gašparič, A. Koblar, and L. Zhang – have set up a special Christmas tree inspired by chemistry. Instead of traditional ornaments, the tree is decorated with Erlenmeyer flasks, round-bottom flasks, and measuring cylinders filled with colorful liquids. Each element is carefully attached to a metal stand with laboratory clamps. The warm glow of lights, gently wrapped around the glassware, creates a festive atmosphere and highlights the vibrant colors of the liquids. Happy Holidays!

November 2024

Photographs from the sculpture exhibition by Boštjan Kavčič "The Return of the Goddess Isis," National Museum of Slovenia, Ljubljana, Slovenia. (A. Kraš)

Patina is a surface layer that forms on copper, its alloys (such as bronze and brass), and other metals due to natural oxidation. Alternatively, it can be artificially created using chemicals and heat to achieve a desired aesthetic effect. Patina enhances the visual appeal of metal by adding color, texture, and depth, often giving it an aged or antique appearance.
At Boštjan Kavčič's exhibition, the bronze sculptures were treated with various patinas to create unique textures and colors, enriching their visual and symbolic qualities. For example, a turquoise patina, created with copper nitrate and ammonium salts, imparts a vibrant blue-green hue, while a jade patina, usually achieved using copper acetate or copper chloride, produces a rich green tone reminiscent of jade. A blue-gray patina is achieved with ammonium chloride or copper nitrate, creating a subtle grayish shade, while an ancient green patina, formed with copper sulfate or other copper salts, mimics the weathered appearance of old bronze. On the other hand, the rare ruby patina is achieved using copper salts and controlled heat, resulting in a deep and striking red hue. A light brown patina, made with ferric nitrate or liver of sulfur, adds a warm, earthy tone to the sculptures. These diverse patinas not only enhance the aesthetic qualities of the sculptures but also contribute to the contemporary reinterpretation of the myth of the goddess Isis, enriching the narrative with a modern artistic expression.

October 2024

WD-40, Ljubljana, Slovenia. (A. Kraš)

Did you know that WD-40, the go-to solution for everything from freeing rusted bolts to quieting noisy doors, owes its name to the "Water Displacement 40th" formula? It took 40 different attempts for Norman Larsen and his team back in 1953 to get it just right. Originally created to protect the Atlas Missile from corrosion, it has since become an essential tool in homes and workshops around the world.
So, the next time you're feeling discouraged by setbacks or mistakes, remember that even the most successful ideas often require persistence and patience. After all, great things are worth the wait! This year WD-40 celebrates 71st anniversary! Cheers to perseverance and never giving up! 🎉

September 2024

The Eiffel Tower during the Olympic Games 2024 (left) and a close-up of the Eiffel Tower (right). (A. Kraš and T. Poženel Kovačič)

Originally built as a temporary structure for the 1889 World's Fair in Paris to celebrate the 100th anniversary of the French Revolution, the Eiffel Tower has since become one of the world's most recognizable landmarks. Designed by Gustave Eiffel, with the help of engineers Maurice Koechlin and Émile Nouguier, the tower was initially intended to stand for just two decades. However, its utility for scientific experiments and radio transmissions quickly demonstrated its importance, leading to its preservation as a cherished symbol of Paris.

Today, the Eiffel Tower remains a proud emblem of the city and has played a significant role in the 2024 Olympics, symbolizing international cooperation and marking another centenary since Paris last hosted the Games. Additionally, Paris also hosted this year's European Corrosion Congress – EUROCORR.

To maintain its structural integrity and iconic appearance, the tower is repainted every seven years with around 60 tons of unique "Eiffel Tower Brown" paint that complements the Parisian skyline while protecting the iron structure from corrosion. This meticulous process is carried out by skilled workers climbing up the construction using brushes to ensure complete and thorough coverage.

Beyond repainting, the Eiffel Tower undergoes regular maintenance and inspections to ensure its safety and stability. Advanced tools and techniques, including drones, ultrasonic testing, magnetic particle inspection, radiographic testing, and ground-penetrating radar, are employed to examine the structure integrity thoroughly. These efforts help to preserve the tower's strength and splendor as a timeless symbol of Parisian charm and human ingenuity for future generations.

August 2024

Statue of Julius Caesar (left) and details of patina and corrosion (right). (A. Koblar)

The statue marks the spot where Julius Caesar is believed to have spoken the famous words Alea iacta est (“The die has been cast”). It was removed and hidden prior to the liberation of Rimini. Later, the statue was rediscovered buried in a ditch and reinstalled in the Piazza Tre Martiri. Due to environmental exposure, it is now covered in patina and shows severe corrosion in some areas.

July 2024

Breakwater, Pula, Croatia (I. Milošev) The breakwater was built in 1914 during the Austro-Hungarian Monarchy to protect the port of Pula and the city from sea tides. Unfortunately, it has been poorly maintained in recent decades, and corrosion has taken its toll and damaged the metal construction.

June 2024

The Edro III Shipwreck, Cyprus (L. Gašparič) A cargo ship, Edro III, ran aground in 2011 northwest of Paphos. The crew was rescued, and the ship was emptied of diesel and marine pollutants. Several studies were conducted on the removal of the ship, which weighs around 2,500 tons and measures more than 80 meters in length. However, none of these plans were executed due to the project's difficulty. In the meantime, the ship is exposed to corrosion in the sea.

May 2024

Boat mooring, Štinjan, Pula, Croatia (I. Milošev)

In the 19th century, Pula was the main port of the Austro-Hungarian Monarchy and the headquarters of the Navy. Many military facilities were built in the Pula area, which are still in use today. Bunkers and ship moorings made of cast iron were built along the sea. The latter still stand today, but have been heavily corroded over more than 100 years.

April 2024

Rusty Ship, Hulhamale, The Maldives (I. Milošev) Regular renewal of the corrosion protection of ships is important, otherwise the corrosion of the ship's metal hull in the sea progresses rapidly.

March 2024

Dragon Bridge, Ljubljana, Slovenia (I. Milošev) The symbol of Ljubljana is a dragon. Legend has it that Ljubljana was founded by the mythological Greek hero Jason, who stole the golden fleece from King Aitez, then escaped on a ship with his Argonaut companions across the Black Sea to the Danube and Sava all the way to Ljubljanica. Jason fought the dragon that lived at the source of the Ljubljanica river and killed it. The symbol of the dragon, which gradually transformed from a monster into a protector, also adorns the coat of arms of our capital, as it symbolizes strength, courage and wisdom. Dragon statues also adorn the stone bridge in the center of Ljubljana, which was built in 1900 by the architect Jurij Zaninović and is a fine example of Art Nouveau architecture. The bridge was built on the occasion of the 40th anniversary of the reign of Emperor Franz Joseph and was therefore called the Jubilee Bridge. Soon the bridge became known as the Dragon Bridge. Each side of the bridge is flanked by two dragons, which are made of copper, as bronze was too expensive at the time. The surface of the copper dragons acquired a characteristic green patina over time. (Source: visitljubljana.com)

February 2024

Vasa Ship, Stockholm, Sweden (T. Poženel Kovačič) Vasa is a Swedish warship built between 1626 and 1628. The ship sank after sailing roughly 1,300 m into her maiden voyage on 10 August 1628. She fell into obscurity until she was located again in the late 1950s. The ship was salvaged with a largely intact hull in 1961 and in 1988 was permanently transfered to The Vasa museum. The ship was built on the orders of the King of Sweden Gustavus Adolphus as part of the military expansion he initiated in a war with Poland-Lithuania (1621–1629). She was constructed at the navy yard in Stockholm and armed primarily with bronze casted cannons. It was richly decorated and upon completion was one of the most powerfully armed vessels in the world. However, Vasa was dangerously unstable, with too much weight in the upper structure of the hull. Despite that, she was ordered to sea and foundered only a few minutes after encountering a wind stronger than a breeze. During the 1961 recovery, thousands of artifacts and the remains of at least 15 people were found in and around Vasa's hull by marine archaeologists. Among the many items found were clothing, weapons, cannons, tools, coins, cutlery, food, drink and six of the ten sails. The artifacts and the ship herself is giving us invaluable insights into details of naval warfare, shipbuilding techniques and everyday life in early 17th-century Sweden. Today Vasa is the world's best-preserved 17th century ship. The wreck of Vasa continually undergoes monitoring and further research on how to preserve her. Ship sinks in 32 m of water in the stocholm shipping channel. Over the years, Vasa settles in mud and clay. The iron bolts that hold the hull together and the cannonballs on board rust. As a result, iron penetrates the wood. Hydrogen sulfide also penetrates the wood. Waste dumped directly in to the harbour water, during rotting, it produces hydrogen sulphide and consumes the oxygen in the water. This polluted water, low in oxygen, helps preserve the ship. It is difficult for wood-attacking fungi and bacteria to survive. They managed to destroy only few mm of the wood surface. Almost all the objects of wrought iron corroded away while ship was under water. Most of the cast iron objects survived and could be conserved, although they have rusted. Cast iron has a grater carbon content than wrought iron. Even if all the iron corrodes, the carbon structure preserves the object's shape. Vasa's iron was conservated by heating to hight temperatures in hydrogen gas, which converts the corrosion back to metal. The surfaces were then sealed with paraffin wax to prevent new corrosion.

January 2024

Lokomotive series 62, Vrhnika, Slovenia (P. Rodič) Locomotive 62-121 has represented the locomotives of its series at the Railway Museum of Slovenian Railways for many years. From October 6, 2023, it is in a new location at the former terminus in Vrhnika. It was built in 1957, is 9 m long, weighs 48 tons, and reached a top speed of 45 km/h. More information is available here.

December 2023

Genetically Modified Little Mermaid, Bjørn Nørgaard, Langelinie Pier, Copenhagen, Denmark (M. Dlouhy) Crafted by Danish Professor Bjørn Nørgaard from the Royal Danish Academy of Fine Arts in 2006, the bronze "Genetically Modified Little Mermaid" offers a postmodernist interpretation. Unlike its original predecessor by Edvard Eriksen, this rendition showcases a distorted physique—elongated limbs, a hunched posture, and a face lacking distinct features. Part of Nørgaard's "Genetically Altered Paradise," this statue challenges genetic conventions, presenting a whimsical spin on Eriksen's original creation. Nearby, one can find abstract sculptures of Adam, Mary Magdalene, a pregnant man, and Jesus Christ, forming an intriguing cluster of artistic expressions. The statue has not yet been vandalized to this day, maybe this is also the reason why it is not as well preserved as the original.

November 2023

Little Mermaid, Edvard Eriksen, Langelinie Pier, Copenhagen, Denmark (M. Dlouhy) Unveiled in 1913, The Little Mermaid, a gift from brewer Carl Jacobsen to Copenhagen, rests at Langelinie Pier in bronze. The statue is 1.25 metres tall and weighs 175 kilograms. Inspired by Hans Christian Andersen's allegorical tale of a sacrifice for a forbidden love, mermaid gazes towards the shore, longing for her prince, surfacing at dawn and dusk. Jacobsen's fascination sparked from a ballet performance, leading him to commission sculptor Edvard Eriksen for the artwork. The sculpture's inspiration came from ballerina Ellen Price, who played the lead in the 1909 ballet. However, as Price declined to pose nude, Eriksen's wife became the model. Despite enduring vandalism, losing her head twice and an arm once, and enduring paint attacks, The Little Mermaid is always restored, welcoming visitors to Copenhagen's harbor.

October 2023

Monuments of Gothenburg, Gothenburg, Sweden (I. Milošev) The annual conference of The Electrochemical Society (ECS) held in October 2023 was after more than ten years organized again in Europe, in Gothenburg, Sweden. ECS conferences are mostly organized in the USA. Gothenburg is a beautiful city, the second largest in Sweden, founded in 1621 by King Gustav Adolf as a heavily fortified trading colony. Gothenburg has a strategic position at the mouth of the Göta River in the North Sea and is today an important port. Gothenburg is also a city of students, as two important universities are located here - Gothenburg University and Chalmers University of Technology. Volvo was founded in Gothenburg and has its headquarters here. There are many beautiful monuments in the city, which attract for their artistic value and placement in the urban space. The green patina of the bronze and copper monuments, created over decades, gives the city a special touch.

September 2023

Granattor, Millstätter Alpe, Austria (L. Gašparič) The iron passage on the mountaintop, with a height of 3.20 m and a width of 3.50 m, is filled with tons of garnet rocks. It is located in the region with the largest garnet deposits in the Alps, and its walls tell the story of the ruby-red precious stone.

August 2023

Boat launching structure, Korčula, Croatia (B. Kapun) The iron structure for boat launching has been severely affected by corrosion. Salt-enriched seawater has caused rust. The presence of organisms such as algae and bacteria has further accelerated the corrosion. Instances like these from nature underscore the impact of natural factors on metallic structures in the marine environment and highlight the importance of using appropriately resistant materials and regular maintenance.

July 2023

Turquoise Cannons at Citadel of Quitbay, Alexandria, Egypt (I. Milošev) The Citadel of Quitbay was built in the 15th century by Sultan Abu Al-Nasr Quitbay on Pharos Island in the Gulf of Alexandria, Egypt. The Lighthouse of Alexandria, one of the Seven Wonders of the Ancient World, once stood on this site, which was destroyed in an earthquake in the 10th century. The monumental fortress, surrounded by the sea, was one of the most important defensive fortresses in Egypt and along the Mediterranean coast. Over time, the citadel lost its military importance. In the 19th century, during the reign of Muhammad Ali Pasha, the citadel was renovated, and the most modern weapons of that time were placed inside the walls - cannons made of copper alloy, probably bronze, that is, an alloy of copper and tin. At the time, copper cannons were more prized than iron cannons because they were lighter, could withstand the stress of firing better, and were more corrosion-resistant. Due to the long-term, almost 200-year exposure to the sea atmosphere, a beautiful turquoise patina has formed on the surface of the bronze. The colors of patinas, which spontaneously form over time on metal surfaces, thus depend on the chemical composition and humidity of the atmosphere to which they are exposed. The green patina on bronze may consist of a mixture of copper chlorides, sulfides, sulfates, and carbonates. The turquoise color is created in the presence of sea salts and ammonia.

June 2023

Self-Portrait in a Cap and Scarf with the Face Dark, Rembrandt, 1633, National Gallery of Slovenia, Ljubljana, Slovenia (A. Kraš) In the context of metal etching, corrosion assumes a deliberate and controlled role. Etching selectively removes the surface of a material using corrosive substances. By protecting the desired parts of the surface from corrosion, only the unprotected areas are removed to create specific patterns. It finds applications in art, printing, and industry. Rembrandt van Rijn, the legendary Dutch painter, printmaker and draughtsman, employed this technique with extraordinary finesse. While the tools, materials, and techniques have expanded significantly since Rembrandt's time, the fundamental principles of etching in art remained the same. Rembrandt's etching begins with coating the metal plate (usually copper) with an acid-resistant substance called the "ground." During Rembrandt's time, the ground was made from powdered bone ash or charcoal and linseed oil The ground acts as a barrier, preventing the acid from affecting areas that should remain untouched. Once the ground is applied, Rembrandt used a needle-like tool called an "etching needle" or a brush to meticulously scratch through the ground, exposing the underlying metal. Subsequently, the metal was immersed in an acid bath typically made of nitric acid, which selectively corroded, i.e. dissolvde the exposed metal. The duration of immersion determined the depth of corrosion and the intensity of the resulting etched lines or textures. This process required precision and control, as Rembrandt had to etch each line with varying pressure to achieve a range of light and shadow effects. After the ground was cleaned, the plate was positioned on the bed of a rolling printing press and covered with a sheet of paper onto which the etching pattern was finally printed. In addition to the ability to produce multiple prints from a single metal plate, existing etchings could be modified by grinding specific parts of the plates and reetching, allowing for changes in the prints. In his self-portrait shown in the picture, Rembrandt's deft etching skills can be observed through the intricate lines that delicately define his face and the folds of his clothing.

May 2023

100 years of corrosion under ground, Godovič, Slovenia (T. Poženel Kovačič) Unfinished railway tunnel close to Godovič was being built in 1916 – 1917, time of the 1st world war. 28 km long railway line between Logatec and Črni Vrh was built by Russian prisoners under Austro-Hungarian captivity. This normal railway line should replace narrow rail which already worked for the aim of supplying the Isonzo battlefield. After the Italian army was defeated in October 1917, Austro-Hungarians stopped the construction immediately. An unfinished 400 m-long tunnel is a technical example of how railway tunnels were built at the beginning of the 20th century. The tunnel stayed unfinished but part of it was later rearranged by the Italian border army into the bunker which was part of the Rapall border line. In 1920 western third of today's Slovenian territory together with Croatian Istria and the city Reka stayed under the control of the Kingdom of Italy. So it remained till 1947. The photo shows the surface of the steel load-bearing element and ceiling after more than 100 years at constant temperature and increased humidity which are typical for cave environments. On exposed surfaces are visible thick layers of iron oxides (Fe2O3·xH2O), a part of the surface is plaster-protected. Water penetrates through the ceiling and therefore also limestone depositions in the form of stalactites are visible.

April 2023

Washington Monument, Washington D.C., ZDA (I. Milošev) Washington Monument in Washington D.C. honors George Washington, the first president of the United States. The hollow, Egyptian-style obelisk, 170 m high, was completed in 1888 and is made of marble, granite, and bluestone gneiss. It was the world's tallest structure between 1884 and 1889, after which the Eiffel Tower overtook it. The obelisk is topped with a pyramid made of solid aluminum with a weight of 2.85 kg. Aluminium was chosen because it is light and resistant to corrosion. In the 1880s, aluminum was expensive and a rare metal used primarily for jewelry. The aluminum pyramid was the largest aluminum casting of its time.

March 2023

Tourmaline corrosion, Salzburg, Austria (A. Kraš) Corrosion, in its broadest sense, is the gradual deterioration of a material as a result of its interaction with its surroundings. Corrosion is more than 90 % electrochemical in nature and is most commonly associated with industrially manufactured metals, though it is also observed in other materials. The common denominator for corrosion of all materials is a local defect in materials, whether it is represented as the grain boundaries, outer or inner edges, mechanical damage, etc. The image depicts the corrosion of gemstones named tourmalines, the most complex silicate minerals composed primarily of aluminum and boron cyclosilicates. It is seen that the preferential dissolution i. e. corrosion, happens on crystal defects. Deep holes were formed in an otherwise perfectly preserved crystal.

February 2023

Gold and silver ores, Salzburg, Austria (A. Kraš) Due to a stable electron configuration, noble metals, including gold, silver, platinum, palladium, rhodium, ruthenium, and osmium, resist chemical reactions, including corrosion. This also reflects in resistance to various weathering processes, which is why noble metals are often found in their free elemental state in nature. In contrast, non-noble metals are typically found in the form of isolated pockets where natural chemical processes reduce their ores, leaving behind small flakes or inclusions of pure metal. Here we come to the exact origin of corrosion process, as a natural tendency of a refined metal to return to its original, thermodynamically stable state of ore. The main corrosion products are thus compounds found in ores, particularly oxides and hydroxides, occasionally accompanied with chlorides or sulphates.

January 2023

Corrosion on the exterior of cans, Ljubljana, Slovenia (S. Stavber and A. Kraš) Many reactive (aggressive) organic compounds are stored in double packaging and usually refrigerated or even frozen. The inner packaging is made of a specific material, while the outer packaging is usually made of metal cans for transportation and safer storage until use. The interior of the cans is often coated with materials that protect against corrosion, and the space between the inner and outer packaging is filled with non-flammable and chemically stable material. This protection is sufficient for safe transportation and short-term storage of aggressive chemicals. However, the exterior surface of the protective cans is still exposed to an aggressive corrosive atmosphere that is always present in chemical storage areas. After prolonged and inappropriate storage of such chemicals, significant corrosion of the packaging (see picture) and surfaces of the storage area (e.g. refrigerators) occurs. Therefore, the advice is to use aggressive chemicals as soon as possible and dispose of unused ones. Another option is to purchase extremely expensive, specialized, and adapted refrigeration equipment.

December, 2022

Anodic (left) and cathodic (right) protection, Vrhnika, Slovenia (P. Rodič) [LEFT] The metal construction of city lights is exposed to various external conditions (e.g., cold weather, snow, and moisture), so adequate corrosion protection is needed. One of the protection methods is with a zinc strip, which is fixed on the lower part of the metal construction and buried in the ground. This provides long-lasting corrosion protection. [RIGHT] The cathodic protection measuring point is often observed in nature (yellow concrete sign). But the most interesting part is hidden under it, as it indicates where underground pipelines (e.g. natural gas) are. They are connected with cathodic protection, which enables durable corrosion protection of metal pipes.

November, 2022

Diatoms on the coating surface, Adriatic sea, Slovenia (B. Kapun and I. Milošev) Biofouling is a layer of micro/macro organisms formed on artificial or natural surfaces such as ships and piers upon immersion in aquatic, mainly marine environments. The biofouling process starts within a few minutes after immersion due to physical interactions between the surface and organic molecules (proteins). This conditioning film is the starting point for further attachment and growth of micro- and macrofouling. We conducted field testing of sol-gel coated Al-Si alloys in the Adriatic Sea to test their resistance against corrosion and biofouling. Electron microscopy image shows diatoms formed at the coating surface after 1 month of immersion. A diatom (diatoma) is a group of microalgae. Diatoms may have different shapes, but most are broadly bilaterally symmetric, as in the photo. Diatoms are surrounded by a cell wall made of transparent, opaline silica SiO₂, usually ornamented by different patterns. Like plants, diatoms convert light energy to chemical energy through photosynthesis and generate 20-30 % of the air we breathe.

October, 2022

Tramway tracks on the road, Berlin, Germany (A. Kraš) Due to the lower construction costs associated with the use of tram/railway tracks to carry back electricity, complete isolation of the rail metal surface as a means of corrosion protection is less feasible. Corrosion pits on railways tend to form rapidly and fortunately, merge quickly on the large surface rather than growing deeply. This results in general corrosion, where material loss, unlike localized attacks, does not pose a threat to construction integrity. Rust formed by general corrosion provides a certain degree of corrosion protection after some time, which, when combined with proper maintenance and inspection, can ensure safe railway operation for many years, if not decades.

September, 2022

A ships' bow, Nerezine, Croatia (A. Kokalj) The remains of a ship on which large stones were placed in order to sink it and make a pier out of it. Only the bow protrudes from the water, which is already quite corroded.

August, 2022

Copper and brass in everyday life, Ljubljana, Slovenia (I. Milošev) Drinking coffee brewed in a džezva (coffee pot) and served in a fildžan cup with a cube of sugar and ratluk (Turkish delight) is a special experience. Coppersmithing - the tradition of making these objects from copper or brass - goes back centuries in Bosnia.

July, 2022

Summertime, Red sea, Egypt (I. Milošev) Ships need efficient corrosion protection in seawater in the form of paints and coatings, especially those more exposed parts.

June, 2022

Richard Serra: Installation in Guggenheim Museum Bilbao, Spain (M. Dlouhy) Richard Serra is an artist of sculptural minimalism. His works of art are enormous round metallic configurations like one represented in the picture. The weathering steel he uses is frequently referred to as COR-TEN. Material of this type is resistant to atmospheric corrosion because of its chemical composition. When exposed to a real environment, it forms a protective oxide layer, creating the look of a "weathered" surface while protecting the surface from further damage. With the passage of time, such steel develops a rust-like appearance.

May, 2022

Galvanization of steel, Ljubljana (A. Kraš) During galvanization, as molten zinc cools down, snowflake-like or six-fold star patterned crystal grains, named „spangles“, develop on the surface of steel. It is believed that lead presence as impurity in zinc ore causes spangling and as such, spangles served as an indicator of steel protection in history. However, with today's zinc refining processes, lead is removed, and spangle-free galvanized steel surfaces can also be obtained.

April, 2022

Underwater Corrosion, Sharm el Sheikh, Egypt (G. Milošev) The wreck of the Thilstegrom is one of the most famous diving sites in the world. It is located in the Sharm el Sheikh area of Egypt at the depth of 30 m. Thilstegron was a British cargo ship bombed by the German army in 1941 in the Red Sea. The photo was taken in 2019 by Goran Milošev, and the diver is Ingrid Milošev.

March, 2022

Stairs Fence, Koper (B. Kapun) A special form of corrosion called galvanic corrosion often occurs at the junction of two metals. Galvanic corrosion occurs when two dissimilar metals are immersed in a conductive solution and are electrically connected. One metal (the cathode) is protected, whilst the other (the anode) is corroded. .

February, 2022

Remains of the railway bridge, Kranjska Gora (N. Lešić) The Jesenice-Trbiž railway line was completed and opened in 1870, and it was taken out of service in 1966 due to the dilapidated infrastructure. The picture shows an iron construction of the bridge, which is well eaten away by rust due to a lack of protection. The term rust refers to surface oxidative damage to iron, where various amorphous reddish-brown iron (III) oxide hydrates are formed.

January, 2022

Roofs in Paris, Paris, France (I. Milošev) Paris is famous for its grey zinc roofs. By decree of Napoleon III, zinc began to be used in the mid-19th century, as it was available in Moresnet mines. The renovation of Parisian roofs was entrusted to Baron Hausmann, who, with the introduction of characteristic elongated windows and zinc roofs, completely transformed the appearance of the city, which to this day remains one of Paris’ greatest attractions. The protective matt patina on zinc protects the roofs from weathering. The production and installation of welded zinc roofs are extremely demanding and the know-how of the Paris roofers is placed under the protection of UNESCO World Heritage since 2019.

December, 2021

Lost shopping cart, Kotor, Montenegro (M. Poberžnik) In environments with many microorganisms, microbes can form biofilms on the surface of a wide range of materials. Within biofilms, a microenvironment conducive to corrosion processes can be established. This type of corrosion is called microbial corrosion or biocorrosion.

November, 2021

Weathering steel, Štanjel (I. Milošev) The stairs at the viewpoint in Štanjel Castle are made of so-called weathering steel. It is a family of low-carbon structural steels, we call it also, corten (COR-TEN), which contain small amounts of copper, chromium, nickel, phosphorus, silicon and manganese. Upon air exposure, a protective layer that is resistant to weathering is formed on the surface and the structure, therefore, does not require painting. So it is not about harmful rust but protective patina. Earthy colours of these protective layers of rusty patina are liked by some, not by others.

October, 2021

World War I military trench, Sabotin (L. Gašparič) Sabotin is a 609-meter high hill above Nova Gorica. For the purposes of the First World War, the land was heavily excavated. The summit was an important defensive point that defended Gorizia until August 6, 1916, when after a short and bloody battle, the mountain was captured by the Italians. The post-war degrading iron remnants due to corrosion still remind us of the horrors of war from more than 100 years ago.

September, 2021

Haizearen orrazia, San Sebastian (M. Dlouhy) Haizearen orrazia, is from the Basque literally translated into The Comb of the Wind. It is a collection of three iron sculptures by Eduard Chillid. The Basque Country is particularly well known for its metal industry, especially iron ore mining and steel production, which are still among the predominant industries in northern Spain.

August, 2021

Galvanic corrosion on top of Rašica, Rašica (A. Kraš) On top of Vrh Staneta Kosca, which is better known under the name Rašica hill, stands a 17 meters high Kamnik Battalion memorial tower placed there in 1957. The tower, that has been already affected by the galvanic corrosion, offers a splendid view of the surrounding hills and mountains, especially the Kamnik-Savinja Alps as well as the entire Ljubljana basin.

July, 2021

Upper Funicular Railway Station, Ljubljana castle (I. Spajić) More than a century-old idea of a funicular railway to Ljubljana Castle was realized in 2006 and has carried more than 4.5 million passengers to date.

June, 2021

View at the train station, Ljubljana (L. Gašparič) On June 2, Slovenia celebrates the Railwaymen's Day. On this day in 1846, the first train arrived on the Slovenian territory. On this occasion, we are dedicating this month's photo the railway industry.

May, 2021

Uvala Luka, Rakalj, Istra (I. Milošev) A ship from the Second World War adds a special atmosphere to the beautiful bay Luka. Years in seawater have left inevitable consequences on the metal structure.