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City of London

The City of London has seen its skyline change dramatically over the past two decades. Long gone are those pictures where one could only see the lonely Tower 42 designed by Richard Seifert signalling the location of the Square Mile in the horizon as if it was the lighthouse guiding the boats up the River Thames.

For those not familiar with the planning process in London and City of London in particular, it could be surprising that a number of skyscrapers have amalgamated within such a reduced portion of land, creating what planners refer to as the Eastern Cluster.

Several factors can explain this phenomenon. First of all, the development plan identifies this area as being able to accommodate a significant growth in office floor space and employment as well as being appropriate for tall buildings. The clustering of tall buildings in this area responds therefore to an attitude from the City of London to enhance the image and its skyline while minimising the impact or extension of the whole transformation.

City of London in the early 2000’s.. We can observe Tower 42 designed by Richard Seifert and Partnersonly accompanied by the Gherkin designed by Foster + Partners.

Saint Paul and the Viewing Corridors

Besides the intention of The City of London to change its skyline there is another factor to take into account to explain the concentration of tall buildings in this area, and this is the protection of the views towards Saint Paul and its dome.

The vistas towards Saint Paul and other strategic landmarks are protected by the planning authorities. The reason for such restriction lies in the necessity to control or preserve the image and identity of these important buildings within their context because of their relevance and significant contribution to the image of London at a strategic level. Nothing that obstructs or undermines views towards these buildings can be built within the boundaries of the so called viewing corridors.

Tall Buildings in the planning pipeline as at 31st March 2018 from Tall buildings in the City of London Part 2, Published by The City of London Corporation; Department of The Built Environment on September 2018.

The Pinnacle, the Economic Crisis and the new commission

Back in 2007 planning permission was granted for a very ambitious scheme that embodied the flamboyant design trends of the time. Such design consisted of a 278m high spiralling tower named The Pinnacle. A short time after, the construction work started. Thus the three storey basement with its foundations and pilings were built followed by the construction of 7 levels of the central core before the economic crash happened. At this point in 2012 works were halted and never restarted again.

Time passed and it wasn’t until 2015 when a prestigious London developer purchased the plot from the previous owner with the intention to build a different skyscraper, more in line with the spirit of the time post-recession. This meant that the design had to reflect a synthetic solution advocating for sobriety and elegance over exuberance and spectacle in order to make the project economically viable for development.

Computer generated image of the design developed for the Pinnacle in the City of London neighbouring the Tower 42 designed by R.Seifert and Partners in the 1970s. Image source via Wjfox2005

Office standards had changed after the crisis and tenants had different requirements so it made total sense to develop a new scheme that could satisfy them. The Pinnacle design catered for a ratio of 1 occupant every 12m2 and after the crisis, tenants were demanding higher density office space thus the new design had to be able to host 1 occupant every 8m2. This meant a 33% of population increase within the building and this in turn, meant that the internal infrastructure of the building had to expand to cater for this population increase.

The greater number of lifts needed became a key factor in the design of the new project. The existing core designed for the Pinnacle proved incapable of providing sufficient service for the tenant’s latest and increased demands. Therefore, it seemed reasonable to demolish and start from scratch. The new scheme was designed trying to reuse as much as possible of the already existing Pinnacle’s basement levels and foundations. This challenge has its implications later on when designing the new structure, and it has shown in the latter design in the form of a series of inclined columns and transfer structures.

One of the biggest transfer structure in the design of 22 Bishopsgate, nicknamed by the design team as the “Rhino truss” for its geometry. It was required in order to transfer the loads from the south east corner columns of the building to the foundations that needed to be utilised from the old Pinnacle design.

Photograph by: Diego Padilla Phillips – Structural Engineer.

The new massing

During the design process, architects go through a series of massing studies and iterations for discussion with planners and developers alike in order to find an optimum design solution that respects the planning conditions and satisfies the client’s aspirations. It has become apparent that the new design for 22 Bishopsgate prioritises standardisation and repetition over singularity and exception.

This strategy not only maximizes the potential return of investment but also to be more environmentally respectful by minimizing the façade area. A minor façade surface not only implies reducing cost but it also allows for a less significant interface between the indoors and the outdoors, reducing the potential energy exchange hence complying with one of the basic principles of sustainability.

Left: Typical 3D printed models produced during the design process by OMA while finding the optimum massing to achieve both the client aspirations as well as meeting the planning requirements.

Right: Computer-generated image of the final design for 22 Bishopsgate inserted within the urban environment, the different height of the steps at the top of the building vary according to the surrounding circumstances.

The Vertical city concept

The 22 Bishopsgate building claims to create a community where people can not only work but also enjoy their spare time. Nowadays companies compete fiercely in a battle to attract the most talented people to work for them and the classic concept of office space has become obsolete.

The new building aspires to become a focus of activity within the City of London, a place which is also infamous for being empty dead during the weekends. It wants to be a point of attraction that can create a social hub out of office hours and that allow companies to attract the most brilliant professionals in the market to join them.

To achieve this, the proposed strategy intercalates zones for different activities at intermediate levels and intertwines art and architecture in the lobbies and around the ground floor in general. Level 2 will be a Food Court that will remain open to the public on the weekends and after 6pm on weekdays after the employees leave the workplace. Level 7 will offer an Innovation Hub for new Tech Start Ups to flourish. Level 25 will include a Fitness Centre. Level 41, the Retreat, will accommodate Spa, Sauna and Wellness Centre, Reading area, Yoga classes and so on. The cherry of the cake, which is always at the top, is the Level 58 Public Viewing Gallery together with the Bar and Restaurant split between Levels 59 and 60, where everyone will be able to enjoy a panoramic view of London from nearly 300m of height. Time will tell if all the intentions of the project become a success and cover the needs of the increasing competitive market and the complex society which we live in.

View from the top of 22 Bishopsgate facing East on a sunny morning with the top of the Gherkin right in front of us a few meters below. At the back we can observe the Canary Wharf skyline in competition with the changing skyline of the City of London.

Photograph by Antonio Moll.

Minoru Yamasaki was born in Seattle, Washington on 1st December 1913. He was a Japanese-American architect whose parents were immigrants to the United States looking for a better life. He is widely regarded as one of the most prominent architects of the 20th century, having designed amongst other renowned buildings, the original World Trade Center Towers in New York City – the tallest buildings in the world at the time.

New Formalism architecture

Yamasaki was a proponent of New Formalism architecture which was an American-style of architecture that developed in the mid-1950s from Edward Durrell Stone’s design for the American Embassy in New Delhi. Stone blended Eastern design concepts with Western architecture to form this new style.

The American Embassy in New Delhi designed by architect Edward Durrell Stone in 1954. The project is recognised as the birth of New Formalism architecture. Photograph by Soumya S Das.

New Formalism includes many design elements from the classical school of architecture such as striving for a strict symmetry in the building’s design, the use of stylised columns and colonnades and expensive natural materials like marble and granite. If the client’s budget does not allow for the use of expensive natural materials, it is acceptable to use equivalent man-made materials to substitute them with.

Reinforced concrete has always played a significant role in New Formalism. Concrete allows architects to design much more liquid, flowing forms and smooth walls that are an essential feature of this aesthetic. Formal landscaping using ponds and fountains in an open central plaza are also crucial elements of New Formalism.

Design of Rainier Tower

All of these elements are present in Yamaskai’s design for the 41-story Rainier Tower, in his home city of Seattle. The building’s disturbing and unique design falls firmly into the ‘love it or hate it’ category.

The Rainier Tower in Seattle designed by architect Minoru Yamasaki. The building’s pedestal base maximises the plaza area below without compromising structural integrity. Photograph by Rsocol.

The structure sits on an eleven-story (121 foot) high, flaring, curved concrete pedestal. The bottom of the base is half the area of the 12th floor and the tower is affectionately known as ‘The Beaver Building’ by locals because it looks like a beaver has chewed away at the bottom.

This narrow profile at ground level only takes up a quarter of a block, which creates space for a much larger plaza and takes up less room in the underground shopping mall below the tower called Rainier Square.

The pedestal design also eased the dreaded ‘canyon effect’ that can funnel wind and accelerate it along streets lined by skyscrapers, making doors very difficult to open. Incidentally, it was this effect that led engineers to the invention of the rotating door.

The reinforced concrete base of the Rainier Tower in Seattle, designed by Minoru Yamasaki, an architect renowned for the style of New Formalism architecture. Photograph by VasSlav.

Structure and resilience

The building has 29 regular floors providing half a million square feet of high-value office space, a ground floor then the pedestal, giving a total of 31 available storeys. The structure is a 5,500 ton steel frame, hung with aluminium cladding, sitting on the reinforced concrete pedestal.

At the time of construction, people were very concerned with the strength and stability of the building. They wondered if the design would be resilient in an earthquake and be able to withstand high wind speeds. It was thoroughly pre-tested by engineers to make sure it would stay standing through the projected earthquakes and storms.

Unfortunately, the newly built Rainier Square Tower now looms over the original building and, despite the developer’s best intentions to complement Yamasaki’s design, the architectural styles clash in this writer’s opinion.

Nitrogen is a chemical element with an atomic weight of 14.00672. It sits on the periodic table between carbon and oxygen – atomic number 7.

The Earth contains enormous quantities of this element in its atmosphere. When we take a breath of air, standing at sea level, 99% percent of that breath is composed of only two elements, nitrogen (78%) and oxygen.

Current scientific theory is that the nitrogen in our atmosphere was vented from volcanic eruptions during the very early history of our planet.

An erupting volcano emitting a toxic cocktail of gases into the Earth’s atmosphere. The gases released include carbon dioxide, nitrogen and sulfur dioxide.

Discovery of nitrogen

The British botanist, physician and chemist Daniel Rutherford discovered nitrogen in 1772. After various experiments on mice, Rutherford found that the gas was unbreathable and an atmosphere composed of nitrogen could not sustain life. Rutherford also discovered that candles would not burn in an atmosphere high in nitrogen.

The French nobleman and chemist, Antoine Lavoisier, referred to the gas as ‘mephitic air’, meaning that it was noxious to humans. He suggested the newly discovered gas be named, ‘azote’, the Greek word for ‘no life’. However, the name never caught on in English as it was pointed out that all gases except for oxygen are mephitic to humans.

The English name ‘nitrogen’ was coined in 1790 by another Frenchman, Jean-Antoine Chaptal. He took the Latin words ‘nitre’ (potassium nitrate) and ‘gene’ (producing) and combined them to form nitrogen.

Nitrogen’s use in explosives

Nitrogen has had a checkered history since its discovery by Rutherford. We have used it to kill millions of people in wars as nitrogen and its chemical compounds are critical elements in gunpowder and high explosives.

A high explosive contains a tremendous amount of energy that can be released very quickly. To be classified as a high explosive, the explosive reaction must travel through the explosive material faster than the speed of sound.

Handling highly explosive compounds like nitroglycerin is extremely dangerous and the Swedish scientist, Alfred Nobel, experimented with safer ways to do this after his younger brother Emil Nobel was killed in an explosion at the Nobels’ armaments factory in Heleneborg, Sweden in 1864.

Nobel found that when nitroglycerin was absorbed into an inert substance like diatomaceous earth it became safer to handle and easier to transport. He patented his invention in 1867 and called it ‘dynamite’. It was a huge success and along with his later invention of gelignite, afforded Nobel great financial wealth.

Photograph of Swedish scientist and philanthropist, Alfred Nobel (1833-96). Inventor of dynamite and gelignite, he left his fortune to the establishment of the Nobel Prizes.

In 1888, Alfred’s older brother Ludvig died, which led to a rather unfortunate mistake in several newspapers. They published obituaries about Alfred himself, rather than his dead brother.

In one French newspaper, the obituary contained the statement, ‘The merchant of death is dead’, referring to the many armaments factories Nobel had established as part of his business. Alfred was appalled by the thought that this is how he would be remembered and decided to set aside the bulk of his estate for the foundation of the Nobel Prizes. These were to be awarded each year for eminence in the sciences, literature and furtherance of world peace.

Industrial applications of nitrogen

Aside from the manufacture of armaments, nitrogen is a vital component in some products that have been highly beneficial to humanity. For example, most car airbags are made possible by a small, high explosive nitrogen substance called azine. This volatile compound, when detonated, will inflate an airbag in 25,000th of a second and in 2017, airbags had the distinction of saving 2,790 passenger lives in the USA alone.

However, nitrogen’s role in airbags pales completely into insignificance compared to the impact it has had in agriculture. In 1918, German chemist, Fritz Haber was awarded the Nobel Prize for Chemistry for the invention of the Haber-Bosch process that allowed the mass production of synthetic nitrogen fertilizer. The widespread use of these fertilizers has dramatically increased crop yields and been responsible for feeding billions of people and preventing starvation.

A farmer spraying fertilizer on his crops. The global, large-scale use of synthetic nitrogen fertilizers over the past century has completely transformed crop yields.

Today, it is estimated that at least one-third of the entire world’s population is fed directly because of the use of nitrogen-based fertilizers.

Nitrogen is also an element we use at Double Stone Steel in our environmentally friendly physical vapour deposition (PVD) process. We inject tiny quantities of nitrogen gas into our vacuum chambers to enable us to color stainless steel sheets and profiles for our customers.

Oxygen is everywhere, and we tend to think of it in its gaseous state – approximately 21% of the planet’s atmosphere is composed of oxygen. But did you know that oxygen also makes up as much of the Earth’s mass as iron? Iron and oxygen each comprise 32% of the planet we live on.

A satellite photograph of Earth. Oxygen is a major constituent of the planet’s mass and is the third most abundant element in the universe after hydrogen and helium.

Oxygen and the human body

Amazingly, as you sit reading this article on your computer, you are made up of approximately 65% oxygen. In fact, 96% of your body is made up of only six elements: oxygen 65%, carbon 18.5%, hydrogen 9.5%, nitrogen 3.2%, calcium 1.5% and phosphorus 1.0%. Therefore, a person weighing a modest 70 kilos, will contain 45.5 kilos of oxygen.

There are 94 naturally occurring elements found in nature and the human body contains an impressive 60 of those elements. Some of them have no known use in our bodies and some can be fatal to us in larger quantities like mercury, for example.

Discovery of oxygen

In 1772, the Swedish chemist Carl Scheele was successful in isolating the gas from air. Unfortunately, Scheele did not publish his results for another seven years and he was not credited as the discoverer. This late publishing of results became a habit with Scheele, earning him the nickname of “hard-luck Scheele” because he made a number of chemical discoveries before others without receiving the plaudits.

It was the British clergyman and chemist, Joseph Priestley, who was given recognition as the discoverer of oxygen. He published his findings in 1774 on how he had isolated the gas and called his discovery, ‘dephlogisticated air’. Phlogiston was thought to be a substance in all materials found on earth and oxygen was thought to be air that had this element removed. However, in reality ‘phlogiston’ did not exist.

Portrait of British scientist Joseph Priestley by Ellen Sharples (1769-1849). He is largely credited as the discoverer of oxygen having isolated the gas in 1774.

Renaming the gas

The French nobleman and chemist, Antoine Lavoisier, was opposed to the accepted phlogiston theory to which Priestley clung for the whole of his life. Priestley visited the French scientist shortly after his discovery and told him about his experiments and how he had liberated the new gas.

Lavoisier was intrigued by his English counterpart’s discovery but doubted the phlogiston theory and set about conducting his own quantitative experiments to discover if the new gas was in fact a chemical element. His research proved this to be the case, giving the first correct explanation of how combustion works in the process.

In 1777, Lavoisier renamed the gas ‘oxygen’, which means ‘acid-maker’ in Latin, as he mistakenly thought that oxygen was required to produce all acids. The new name gained in popularity and eventually entered the English language despite some resistance from English scientists loyal to Priestley and his original discovery.

Lavoisier later claimed to have discovered oxygen independently of Priestley but this was largely refuted by the scientific community and the aristocratic chemist later died on the guillotine in the aftermath of the French Revolution, charged with tax fraud.

Reactivity of oxygen

Oxygen is a very reactive element, and it will oxidise with most of the other elements. This natural oxidisation process is essential for stainless steel as it forms a thin protective coating on the surface of the metal. The layer is well adhered and does not flake off like rust.

A close-up shot of a marine-use stainless steel handrail. The metal is alloyed with chromium which reacts with oxygen to form a corrosion-resistant layer on the surface. Photograph by Southern Rigging Supplies.

This protective coating will stop the stainless steel from oxidising further and no more rust will form on the surface. If the protective oxidised layer gets scratched or damaged, it will immediately start to reform over the exposed area.

Oxygen is an essential element in the physical vapour deposition (PVD) process we use at Double Stone Steel. We inject tiny quantities of the gas into our vacuum chambers to enable us to color stainless steel sheets and profiles, anything from blue and green to more exotic pink, emerald and rainbow.

I went for my annual flu shot today. The nurse that gave me the jab was highly skilled and I did not feel the actual injection at all. I had a closer look at the needle she had just used, and honestly, it was extremely small.

This tiny stainless steel needle was produced using a technique called tube drawing. Tube drawing is the type of simple industrial process that we all take for granted.

Light 2.5ml Syringe With 21G Hypodermic Needle by RayMed. The hollow needle used is made from stainless steel and produced through an industrial process known as tube drawing.

Development of hypodermic injections

If flu shots had existed in the late 17th century and I had been friends with the polymath, Sir Christopher Wren, I could have popped round his house for my injection as he was one of the very few people in Europe experimenting with hypodermic injections at this time. Wren was experimenting on injecting his unfortunate dog with various liquids, including beer and morphine, using equipment he had made himself.

My vaccination against the flu would have been a whole lot more traumatic as Wren’s standard equipment was comprised of various animal parts! Bladders from animals, like sheep and pigs, were used as syringes to hold liquids and then he sharpened a goose-quill or a porcupine-quill for the actual needle. I can only imagine the horror of having an injection in this way!

Thank goodness for tube drawing that allowed for the invention of small steel needles by an Irish doctor, Francis Rynd (1801-1861).

Dr. Rynd gave the first injection with his invention on 3rd June 1844 to one of his patients, Mrs Margaret Cox. He gave her four injections, consisting of fifteen grains of morphine dissolved in one drachm (3.6ml) of creosote, directly into her supra-orbital nerve. The treatment worked and her severe pain dissipated within a few minutes.

The technique of tube drawing

Tube drawing is an industrial process designed to precisely reduce a tube or wire of a larger dimension to a smaller dimension. The desired smaller dimension is achieved by drawing the original-sized hollow tube through a metal die of a smaller size. Tube drawing works on many material types including steel, stainless steel, copper, aluminium and even glass.

The tube drawing process will often include the use of a mandrel or plug on the inside surfaces of the tube. The mandrel’s function is to help reduce the thickness of the original tube’s wall. If the finished tube’s wall thickness is not critical, the process will not use a mandrel. The name for tube drawing without a mandrel is tube sinking.

Typically, on a single pass through the die, drawing the tube over a stationary mandrel can practically reduce the material by 35-40 per cent.

A diagram illustrating the process of tube drawing. This technique allows for the manufacture of precision quality, hollow cylindrical products by drawing a tube through a smaller metal die. Image courtesy UKCME, University of Liverpool

One of the challenges found in tube drawing is the production of heat through friction. This problem is reduced by using a long mandrel when drawing the tube and good quality cooling lubricants.

Production of steel pipe

Pipe and tube have been in increasing demand since the 1800s. In 1815, William Murdock invented a lamp that was designed to burn coal gas and he was appointed to supply this system to the whole of the City of London. The main problem he faced was sourcing inexpensive steel tubes. Murdock, being an inventor, came up with a very creative way to solve this problem. He used the discarded rifle barrels from old muskets to form a continuous pipeline for the coal gas.

His lighting system proved successful and stimulated the demand for long, inexpensive metal tubes. The first economical method for producing cheap piping was patented in 1824 by James Russell. Russell’s method was in production for a year or so until Comenius Whitehouse replaced it with a much more efficient method that is still the basis of pipe-making procedures today.

Water flowing through a steel pipe. Precision sizing of metal pipes is done using a production technique known as tube drawing that was first used in the 19th century.

In Whitehouse’s method, thin sheets of metal got passed through an opening in a die. The die was cone-shaped and curled the edges of the material towards each other. The two sides were then welded together to form a pipe.

Nickel is an element, and it has an atomic weight of 58.6934. Nickel sits in the periodic table between cobalt and copper – atomic number 28. It is a beautiful color being mainly silvery-white with gold tones.

A piece of the chemical element nickel (Ni). Nickel is resistant to corrosion and is used pre-eminently as an alloying metal in nickel steels and nickel cast irons.

There is an abundance of this element on Earth. Nickel is the 23rd most common element in the Earth’s crust at around one part per hundred but the metal is 100 times more concentrated below the Earth’s crust, than in the crust itself.

The inner core of Earth, around 2,400km across, is thought to be a solid sphere consisting of an alloy of iron and nickel. Nickel makes up about 20% of the inner core.

The Earth’s outer core is about 2,260 km thick and is the only liquid layer of the Earth. The outer core is also thought to compose mainly of iron and nickel with the nickel content again, around 20%. The movement of this outer molten core gives the Earth its magnetic field, which makes life on Earth possible by shielding us from cosmic radiation.

Discovery of nickel

The name nickel is from the German word, ‘kupfernickel’, which loosely translated means ‘devil’s copper’ or ‘copper demon.’ German miners mining copper were the first to discover nickel bearing ore, but at the time no-one could extract anything useful from it apart from a green pigment to color glass.

In 1751, around 100 years after the initial discovery, a Swedish alchemist, Baron Alex Fredrik Cronstedt began studying the mineral found in this ore. He was trying to isolate copper but was unsuccessful. However, he did eventually separate a new silvery-white metal which was later named ‘nickel’. He was the first person to refine and isolate nickel, and in doing so, discovered a new element.

Major deposits of nickel

30% of the world’s available nickel is found and mined in Canada, in an area called the Sudbury Basin. This vast store of the material was unearthed in 1883. The current theory is that around 1.8 billion years ago a colossal asteroid, thought to be similar in size to Mount Everest, slammed into the Earth depositing the nickel.

The Sudbury and Wanapitei impact craters in Ontario, Canada were created by asteroids crashing into the earth billions of years ago. The nickel-rich Sudbury Basin is the large, elliptical structure (60 x 30 km).

Nickel in humans

Nickel is also a mineral that humans need to consume. We only need around 150 micrograms a day to ensure good health. We get it from many sources, including dry tea leaves. Each kilo of dry tea leaves contains about 7.6 milligrams of nickel.

Nickel is not benign, and it can cause harm to humans if they are exposed to an excessive amount. Objects with a high content of the metal such as jewellery and watch cases, even coins, can cause irritation to the skin when combined with sweat.

Industrial uses of nickel

Nickel is a very durable, lustrous and ductile metal. It has many uses, but at least 50% of the world’s production of nickel is used to produce various grades of corrosion-resistant stainless steel. These stainless steels are then routinely utilised in a multitude of modern industries, including the automotive and aerospace sectors.

Nickel is also alloyed with other metals to give extremely hard-wearing metal alloys. The ability to withstand extreme environments means engineers can use these alloys in rocket engines and other extremely hostile environments. It is the ideal metal to form these so-called ‘superalloys’.

NASA space shuttle and launcher rockets heading into space after take-off. Nickel and other metals are used to create high strength metal alloys for construction.

The nickel alloy 276 has some truly remarkable characteristics. It is an amalgam of 57% nickel, 16% chromium, 16% molybdenum and smaller amounts of other metals. This alloy, unlike stainless steel, is corrosion resistant against hydrogen sulphide gas. This ability means items made from these alloys can be used deep underground, deep within the Earth’s crust where this gas often occurs.

World production of nickel

In 2018, global production was 2,300,000 tons. Indonesia and the Philippines accounted for 40% of that total and other large commercial operations can be found in Canada, Cuba, Australia, Russia and South Africa. The silvery, goldish tone of nickel is still very sought after with a substantial chunk of world production (9%) used to plate other objects.

Nickel is a very popular choice as a color alone – of the x number taps we produce for OEMs (Original Equipment Manufacturers) per annum x % are nickel-colored.

Metals added to stainless steel include Chromium (Cr).

Chromium is an element – atomic number 24 – and it has an atomic weight of 51.9961. Chromium sits in the periodic table between the metals vanadium and manganese and possesses a beautiful and appealing color, being a mainly lustrous silvery-white.

Shown here are high purity chromium crystals and a polished chromium cube with very different textures but both demonstrating the characteristic lustrous silvery-white colour.

The origins of chromium

Chromium is a beautiful and useful element – the name comes from the Greek word for color, chroma. It was discovered in 1797 by the French scientist, Professor Nicolas Louis Vauquelin. Professor Vauquelin is held to be the father of modern metallurgy. He was born in Saint Andre d’Hebertot in May 1763 and passed away on the 14th November 1829 after a remarkably distinguished career, which included the discovery of a second element, the metal beryllium. Beryllium made nuclear weapons possible, so a little bit of a double-edged sword there.

Prof Louis Nicolas Vauquelin (16 May 1763 – 14 November 1829) was a French pharmacist and chemist. He was the discoverer of both chromium in 1797 and beryllium in 1798.

Chromium in paint

Chromium ores were used extensively in the paint industry; for example, the pigment chrome yellow was very popular with artists and the paint industry. Chrome was an essential ingredient in the paint that was originally used to paint American school buses. These bright yellow buses are a part of American daily life.

The yellow school bus is an easily recognisable part of American culture and yellow paint derived from chromium ore was originally used to paint these buses.

However, paint manufacturers discovered that the yellow color they were applying was poisonous due to the heavy metals in it.

Chromite

It was recently estimated that there are 11 billion tonnes of minable chrome in the earth’s crust, making it the 21st most abundant element on the planet. That is not all the available chromium, that is the material we can reach using today’s technology.

The most commercially important ore containing chromium is chromite. Chromite ore deposits have been uncovered in South Africa, Zimbabwe and Finland. Smaller but still precious chromite deposits are located in the USA, Russia and Greenland.

The vast Bushveld Igneous Complex of South Africa is a large layered mafic to ultramafic igneous body with some layers consisting of 90% chromite making the rare rock type, chromitite.

Chromium in humans

Chromium like lots of other elements is vital for human health. It is thought that chromium influences how insulin functions and the organ with the most amount of chromium in it is the placenta. The recommended daily intake for an adult human is between 25 and 35 micrograms per day – a tiny amount!

It is also critical for animals who, if denied all chromium in their diet, develop diabetes.

Industrial uses

One of chrome’s most essential roles in industry is that is can be alloyed with iron, nickel and other metals to produce stainless steel. Some stainless steels can contain up to 25% chrome in their formula.

Another well-known use for chrome is in the plating industry. For years, every car produced all over the world had many chromed parts fitted. From bumpers to door handles, a thick layer of lustrous chrome was considered to add value and visual appeal.

The process of applying a layer of chromium to steel, known as chrome plating, was used extensively in the car industry to add aesthetic appeal and durability. Photo credit: GmanViz

Unfortunately, chrome plating is considered by many to be an incredibly damaging process for the environment. This view is gaining ground because chrome plating uses many dangerous acids and chemicals that are very harmful to both people and to the environment. As a result, chrome plating is falling quickly out of favour in many countries and is likely to become a thing of the past in the next few years.

Alternatives to chrome plating

Apart from chrome vinyl wrapping the only other alternative to chrome is PVD (Physical Vapour Deposition) colored stainless steel. With the production of vinyl being notoriously full of dangerous chemicals this really only leaves PVD as the environmentally friendly option. The PVD process does not require acids or other harmful chemical solutions to be used, which means cleaning a PVD plant is minimal compared to cleaning a chrome plating plant. PVD does not produce a harmful waste product, unlike chrome plating, and the process itself does not produce harmful vapours.

To learn more on the PVD process read:- The basics of Physical Vapour Deposition by architect, Federico de Paoli

Lever handle in PVD coloured stainless steel. PVD is a more environmentally friendly alternative to chrome plating as it does not produce a toxic waste product.

Titanium is a chemical element (Ti) – atomic number 22 – and it has an atomic weight of 47.867. On the periodic table, titanium sits between manganese and cobalt, possessing a beautiful pale silver color.

Titanium is a lustrous silver metal with the highest strength-to-density ratio of any metallic element. Photograph by Alchemist-hp

The discovery of titanium

Titanium was discovered in the year 1791 by the Reverend William Gregor in the county of Cornwall, south-west Britain.

On a walk one day, Reverend Gregor, while crossing a small stream, noticed a layer of black, magnetic sand. The sand resembled gunpowder in appearance. The name we use for this sand today is ilmenite – an ore consisting mainly of iron oxide and titanium.

Part of the sample he took was a reddish-brown color. He could see an oxide in the sample and knew it was a new metal but could not isolate it. He named the new metal – ‘manaccanite’ – in honour of the parish of Manaccan where he lived.

Titanium

A few years later in 1795, the German chemist Martin Klaproth discovered what he thought was a new metallic element. Klaproth called his new metal – ‘titanium’ – after the Titans from ancient Greek mythology.

Engraving of German chemist Martin Klaproth 1743 – 1817, the discoverer of titanium, by Ambroise Tardieu after an original portrait by Eberhard-Siegfried Henne.

Klaproth had discovered titanium in rutile minerals from a deposit in Boinik, Hungary. In 1797, Klaproth had the opportunity to read Gregor’s account of his discovery in 1791, and Klaproth then realised that the red oxide in which he had found his titanium and the red oxide in which Gregor had found manaccanite were identical. Titanium and manaccanite were the same elements, and Gregor was given the recognition as the element’s true discoverer.

However, the name titanium was thought to be more fitting, and that was the name adopted by science.

Purifying titanium

It was more than a century after titanium’s discovery, that scientists and engineers found a way to produce a 99.9% pure sample of the element.

It was eventually isolated in 1910 by the metallurgist Matthew Hunter in Schenectady, a small town on the east side of the United States. His process included heating titanium (IV) chloride with sodium to a red hot heat in a pressure cylinder.

It took another 30 years until the commercially viable process, the Kroll Process, was invented by William J. Kroll in Luxembourg. Kroll’s method worked by heating titanium (IV) chloride with magnesium and made the commercial production of titanium possible. At the time, only tiny amounts of the metal were produced, and even in 1948, the worldwide production of titanium was only 3 tons a year.

Demand for the metal continued to grow, and by 1956 global production of titanium reached 25,000 tons per annum. Today we produce well over 250,000 tons per year.

Commercial uses

Titanium is a strong, durable and lightweight metal that is in extremely high demand by many industries. For instance, a Boeing 777 has a maximum, empty, operating weight of approximately 304000 lbs or 137.8 metric tonnes. Of that enormous weight, 59 metric tonnes is constructed from titanium.

The Boeing 777 is constructed using 59 tonnes of titanium and about two thirds of all titanium metal produced is used in aircraft engines and frames.

Its superior strength and light weight relative to other metals (steel, stainless steel, and aluminium), means titanium is used in many sporting goods such as tennis rackets, golf clubs and bicycle frames. For the same reasons, it is also used in the body of high-end laptop computers like the Apple PowerBook.

The metal is soluble in concentrated acids but not water. If you were to submerge a sheet of titanium in seawater for 4000 years, it would only have corrosion to the depth of about the thickness of a piece of copier paper. This remarkable resistance against corrosion makes titanium the perfect metal to create the hulls of submarines.

Titanium is resistant to corrosion by seawater and is used in the housings and components of ocean-deployed surveillance and monitoring devices for science and the military.

Titanium also has a significant role as an alloying agent. It is commonly smelted with other metals including aluminium, manganese, iron and some grades of stainless steel to improve their ability to be welded.

For us at Double Stone Steel, titanium is a vital part of our PVD process. Without titanium, Double Stone Steel would not have a business!

Many of Double Stone Steel’s PVD colored stainless steel sheets and profiles are colored using a charged ion plasma gas, consisting of a mix of titanium and other metals.

A calm and uncovetous look at very expensive watches.

Stainless steel watches are now the worlds most popular watch type. Not only do these watches have a massive range of designs. But the price range is equally immense.

Whilst some of the cheapest wrist watches available on the market are made from stainless steel so are some of the worlds most expensive. Stainless steel is thought of by both manufacturers and consumers as a premium product in the watch world. Very high-quality stainless steel wristwatches cost just as much or even more than wristwatches made out of gold and platinum, for instance In 2007 a stainless steel Patek Philippe wristwatch manufactured in 1944 was bought at auction by a watch collector for $2.26 million. This makes it the second or third highest price ever paid for a wristwatch.

A Patek Philippe watch, 1944 model 1591 which is very rare. This one was auctioned in 1996 for $2.76 million making it the most expensive stainless steel case watch ever to have been sold. It originally belonged to the Maharajah of India.

Watch straps

Did you realise that there are three wristband categories for stainless steel watchbands? Whatever the wristwatch cost when bought new, there will be one of the three categories of wristband that apply to all stainless steel watchcase types.

Strap lugs

In the first category of bands, we have a wristwatch case with more traditional strap lugs. These lugs are also suitable for the consumer that prefers to choose leather or rubber watch bands. These stainless steel case types with traditional lugs allow the consumer to chose from a wide range of third-party watchstrap manufacturers.

Integrated wrist band

The second type of category is the integrated wristband which comes with integrated strap lugs, you can find examples of this stainless steel band in watches such as the Nautilus from Patek Philippe and on the Royal Oak wrist watch from Audemars Piguet. These models are incredibly comfortable to wear because they fit your wrist snugly and in a way that reminds the user of wearing a beautiful bracelet. However, watch collectors should always remember that the main disadvantages are that if your timepiece has an integrated stainless steel watch band, it will be unlikely that the watch can be fitted with any other type of watch strap, such a rubber or leather unless it is an offering from the original manufacturer.

Patek Philippe Nautilus 5990 Automatic Steel Case Steel Bracelet Men’s Watch/Unisex Black Dial Fold Clasp with integrated wrist band from The Hour Glass

The third category of stainless steel watch band is the classic hinged wristband with strap lugs. The group, in this case, is trying hard to complement the watch case. The world famous manufacturer Rolex has offered such wristbands ever since the late 1930s. Today Rolex sells around 4.8 billion USD of watches annually. It is also the 78th most valuable brand in the world.

Initially, such stainless steel wristbands were fabricated using riveted sheet metal, but today Rolex uses only very high-quality stainless steel.

The Rolex Oyster Bracelet, dating from the 1930s, is fitted to the Rolex Professional watch range and also on classic models such as Datejust, Day-Date and Sky-Dweller. It can come with the Oysterclasp, Oysterlock or Crownclasp.

The Rolex, Oyster wristband which in combination with the patented Oysterlock clasp is without doubt regarded as the Mercedes of wristbands. It is bettered only by Rolex’s Glidelock extension system used for the company’s diver’s watch range.

904L stainless steel

Like all watch cases produced by Rolex, the Glidelock system is made of 904L stainless steel. This type of stainless steel is much resistant to the corrosive effects of seawater than 316L surgical stainless steel, which is used by the majority of watchmakers today.

904L is a very high-quality stainless steel which has a little copper added to the mix during its manufacture to help give the stainless steel a higher resistance to strong acids, such as sulphuric acid. 904L stainless steel is also resistant to stress corrosion cracking, is non-magnetic and, like all stainless steel, hyper-allergenic.

Stainless steel watches and wristbands are frequently colored through the process of PVD to create finishes such as Gold, Champagne and – the current fashion favourite Rose Gold to enhance the aesthetic appeal of the product.

Left is the Lancaster Space Shuttle Rose Gold PVD Stainless Steel Chronograph Watch

Right is the DeNovo DN2020-42BGN Men’s Watch Rose Gold PVD Case Chrono Swiss Made

An explanation of engraving, etching and intaglios.

An Ancient Process

The process we refer to as acid etching is a well-known, ancient and reliable industrial process that uses various commonly available mordant acids and chemical compounds to impart a physical or an aesthetic improvement to the surface of stainless steel. Mordant is the French word for “bitting.” and refers to the actual liquids used to etch the metal when applied to the surface.

Acid etching was first used in the middle-ages by goldsmiths and gunmakers to decorate their products before finding a new home in the art world.

Part of a cuisse (thigh armour) dating from the 16th Century from Augsberg, Germany. Victoria and Albert Museum.

The artist’s technique

Acid etching was and is still used in the reproduction of high-quality works of art. The process was initially used as a method of getting the artist’s work into the hands of as many people as possible.

The engraver takes a plate of copper or mild steel. Then the artist will cover the entire surface of the plate with a waxy substance, referred to a ‘ground’. This substance is resistant to the acids chosen to be used.

The engraver will then, using a variety of tools, reproduce the original work of art by engraving the image into the waxy ground. The plate will then be submerged in a bath of the mordant, after a prescribed time the plate is removed, rinsed off and the ground removed. The image left will be an exact copy of the engraver’s work. This is a very skilled process, it takes time and money to produce works of art this way.

Johann Wilhelm Schirmer’s Aus dem Park Chigi, 19th century. Acid etched on copper.

Practical purposes

The process of acid etching works equally well on the surface of stainless steel plates, profiles and sheets and other metals such as aluminium and brass are also suitable for acid etching.

The surface left on the surface of the stainless steel is usually matt in nature and will be texturally different from the unetched part of the stainless steel. This means that the process is used to produce a non-slip grip to the surface of the stainless steel, making hand tools safer. It is also used to create decorative patterns, contrasting surfaces or text.

Acids

The original acid etched part of the surface is an intaglio surface, this means incised. There are various acids commonly available that can be used to etch steel and stainless steel including hydrochloric acid, nitric acid or sulfuric acid. Please be aware that all of these acids require careful handling. These acids can dissolve stainless steel and fingers.

Chemicals that form acid in water, such as ferric (iron) chloride or copper sulfate can also be used as etching chemicals. These chemical compound work faster than acids. The strength of the acid generally determines how quickly the steel will be etched, the stronger the acid, the faster the process. You can obtain etching acids and chemical compounds from online chemical supply stores. Do not make any dissolving bodies in the bath type jokes when ordering the materials!

Ferric chloride is mixed with water in an one to one ratio, and this will form hydrochloric acid in solution.
Hydrochloric acid is commonly used to etch copper, and it also works well on stainless steel. It must be handled carefully otherwise surface damage such as pitting can occur to the surface of the stainless steel.
Copper sulfate is used to etch mild steels rather than stainless steel. The Copper Sulfate is mixed in a one to one ration with sodium chloride (salt). The salt is added to stop the copper forming a layer of copper on the etched surface. Copper sulphate is a blue solution and will gradually fade to a transparent colorless liquid as the etching process takes place.
Nitric acid is best mixed in a ratio of 1 part nitric acid to 3 parts clean water.

Celtic design acid-etched on silver cufflinks by Eileen Moylan

A trip to see this haunting sculpture.

A journey to Iceland

If you decide that you want to take a trip or perhaps more appropriately a voyage to see the sculpture Sun Voyager in person, then you will need to wrap up warm. As a bonus, after travelling all that way to Iceland, there is a good chance you could also see and experience the breathtaking and ethereal northern lights.

Sun Voyager is situated in Reykjavík, Iceland. Reykjavik is the capital of Iceland and has a tiny population of 120,000 people. The population of Iceland is only around 342,000 people making it the most sparsely populated country in Europe.

In 1986, a competition was held by the authorities in the west district of the city. The committee in charge of the competition was looking for a way to mark the 200th anniversary of the founding of Reykjavik. Sun Voyager’s creator Jón Gunnar Árnason and his concept for Sun Voyager won.

The Sun Voyager sculpture in Reykjavik by Jón Gunnar Árnason. Photograph by Jo Dusepo.

After years of meticulous and highly skilled work the Sun Voyager, or Sólfar as the Icelanders call it in their language, was unveiled on the small headland of Sæbraut on the 204th anniversary of the city of Reykjavík. The date was August 18, 1990. Sæbraut is Icelandic for sea road.

Materials

Sun Voyager is constructed out of high-quality, polished stainless steel, The base is a circle of solid granite. It is a stainless steel masterpiece and shows just how stainless steel can withstand severe weather and freezing temperatures.

Sun Voyager was constructed in close accordance with Jón Gunnar’s enlarged full-scale drawing and fabrication was overseen by Jón Gunnar Árnason’s assistant, the artist Kristinn E. Hrafnsson. The stunning realization of Sun Voyager was carried out by Reynir Hjálmtýsson and his team.

During the time of the sculpture being created Jón Gunnar himself was seriously ill and a year before it was positioned on Sæbraut he died. This event gave rise to speculation as to the meaning of the sculpture and whether it represented the journey of souls to the world of death.

Interpretation

It is often also thought at Sun Voyager is an interpretation of a Viking warship or longboat. Both these theories are wrong, the Artist had in his thoughts a dreamboat, a magical vessel to free his mind to take him on epic journeys towards the sun. Sun Voyager is an ode to the Norse Goddess Sunna or Sol. Sunna is female, while her brother Mani, is the God of the moon.

Sun Voyager holds within its own dreamlike form the hope and the promise of undiscovered territory, an unreal world populated by shadows, gods and the eternal dreams of humanity, humanity that is full of freedom and the hope of never-ending journeys across the realms with the Gods beside us, guiding us.

Placement

The setting of the sculpture is indeed magical in itself with Mount Esja across the bay and looking towards the dramatic coastline curving from Grundarhverfi along to the entrance to the 30km long fjiord Hvalfjörður.

And yet the sculpture is close to passersby and motorists giving an easy view of this ethereal structure whilst walking or driving along Sæbraut to people busy in their everyday lives and perhaps adding a further dimension to their thoughts. Seen against the evening sky looking exquisitely elegant and scorpionesque with breathtaking grace and an integral dynamism it does indeed appear as if it were about to sail upwards into another world.

Sun Voyager sculpture by Jón Gunnar Árnason as seen adjacent to Sæbraut. Photograph by Benjamin Low, Polarsteps.

An introduction to hard-anodised aluminium coatings, their advantages and environmental implications for architectural cladding.

Grosvenor Waterside, Chelsea by MAKE architects with artist Clare Woods. This aluminium rainscreen cladding includes over 5300 anodised panels and a shotpeened design. Façade by UK Façades Ltd.

What is anodised aluminium?

Anodising is a common, stable and cost-efficient electrochemical process. It was first used in 1923, on an industrial scale. It’s an anodising process that thickens and toughens the naturally occurring protective oxide that forms on the surface of aluminium. This process creates a hard surface with clear benefits to the architecture sector for wide-ranging exterior and interior uses, including feature aluminium cladding.

What is a hard-anodised aluminium coating?

The specialist surface produced by anodising is referred to as a hard-anodised coating. This coating is part of the metal but also has a porous structure which allows coloring using organic and inorganic dyes. Hard-anodising converts the surface of aluminium from its original natural state to another one. A new surface formed in this way has markedly different properties to the surface found on aluminium in its natural state. It’s not a coating in the traditional sense as it’s produced from aluminium itself and is integral to it.

Benefits of hard-anodising aluminium

The Selfridges building, Bullring, Birmingham by architectural practice Future Systems. The cladding skin of this iconic curvaceous building, completed in 2003, includes 15,000 anodised aluminium discs.

Protection against corrosion

Depending on the exact method used, a finished hard- anodised coating can provide good protection against corrosion. Being the second hardest substance known to man, second to diamond, these surfaces are used in the space industry. Also as an anodised surface is an integral part of the surface of aluminium it has excellent adhesion. Due to their surface characteristics, hard-anodised coatings do not chip, flake or peel, which makes them ideal for you to use on architectural products such as aluminium cladding.

Color stability

Color stability is a second advantage of hard-anodising. As anodised aluminium is available in a variety of finish and color options, it is often used decoratively. Unlike Physical Vapor Deposition (PVD), a vacuum-coating process that utilises titanium nitride, with a hard-anodised coating you can specify either a gloss or a matt finish, disregarding the substrate. Also, unlike even simpler powder coated or painted finishes, hard-anodising allows the metallic appearance of the substrate to be kept. This can add aesthetic value to your architectural products, including aluminium cladding.

Ease of maintenance

Ease of maintenance is a third important benefit of hard-anodising. You do not require any special cleaning products to clean an hard-anodised surface, such as aluminium cladding. Using warm soap and water is often enough.

Meeting environmental regulations in anodising process waste disposal

Waste products produced during an anodising process include a degraded or weakened sulphuric acid (electrolyte) solution and an aluminium hydroxide compound. The waste aluminium hydroxide compound is produced by the aluminium released from a part being anodised and the hydroxide from electrolyte.

There are various environmental regulations and policies across the world that govern the allowable concentration level of aluminium in anodic process waste disposal. In this case, disposal usually means returning wastewater back to rivers. One such regulation is that degraded sulphuric acid has to be neutralised before disposal. It should also be noted that adding certain chemicals, to this waste to produce a pH number between 6 and 8 can render it less harmful.

Overcoming electrochemical wastewater treatment challenges in the specialist metal finish sector

Titanic Belfast Maritime Museum, Belfast: By architectural practices CivicArts and Todd Architects with interior designer Kay Elliott. The cladding of the 4 ‘pointed hulls’ of the façade of this 2012 signature project comprises 3,000 faceted silver anodised aluminium plates.

Treating electrochemical wastewater is expensive and technically challenging. The best possible way for any industry, including the construction industry, and the cladding sector of it, is to reduce wastewater disposal costs is to produce less of it. To help achieve this, electrochemical waste cleaning processes such as electrodialysis, acid scorpion and the use of flocculating agents are deployed.

Electrodialysis: Electrodialysis is a recognised process to extend the life of an anodising electrolyte solution by removing aluminium ions, in other words atoms, from the electrolyte bath. These atoms can be removed from such a electrolyte bath by passing them through filtration membranes to leave aluminium hydroxide. The collected aluminium hydroxide sludge, or slurry, is then sent for treatment and disposal.

Acid scorpion

Acid scorpion is the opposite to electrodialysis. It allows electrolyte to be recovered from aluminium, rather than aluminium from electrolyte.

Flocculating agent use

Flocculating agents can separate aluminium from electrolyte. These polymer additives combine with the aluminium hydroxide and congeal, creating a foam-like mass that is periodically removed.

In all the treatment methods discussed here the processes produce a heavy aluminium hydroxide sludge and the process for handling it is complex. Hydraulic presses squeeze out waste-water, the compacted sludge is then run through sludge dryers which further concentrate it to become 75 per cent solid. This solid can then be sent for disposal.

Combatting air pollution from electrolyte when anodising aluminium

Air pollution is a significant health and safety concern in anodising plants. Electrolyte gives off harmful fumes that are dangerous to breathe. Electrolyte on its own is dangerous if in contact with eyes or skin or ingested. These fumes can be removed from the process by passing the acid through various scrubbers during it. The electrolyte solution is usually between 10-20 per cent strong but if workers are exposed to the fumes on a long-term basis, it causes chronic health issues. There are two ways to combat air pollution from electrolyte: pre-treating and cleaning, and incineration.

Pre-treating and cleaning:

Gases from the electrolyte bath, cannot be released into the atmosphere without being pre-treated and cleaned. Industrial solvents and cleaners used in the pre-treating and cleaning of the anodising process are harmful and produce a collection of hazardous waste products that also need to be carefully disposed of once they are collected. If sludge contains high enough levels of aluminium, waste treatment companies will try to recover this valuable resource. If it can be removed from the sludge, it can be reused in many products including cosmetics, building products and various others. However, due to the composition of the waste, it’s rarely financially viable to process extracted waste aluminium.

Incineration

Another option for sludge disposal is incineration. This process will reduce the toxicity of the sludge and reduce its volume but it’s expensive and contributes to global warming.

Canaletto Building, Islington by architectural practice UN Studio. This landmark 2017 tower has metallic silver anodised aluminium feature cladding for its curved balconies

A comparison between Goldplating and Gold PVD for jewellery.

How to make Gold

If you are a manufacturer of jewellery, there are several different options available to enable you to achieve a gold look for your products.

If you are producing rings, chains or even watches the two of the most common ways to get that beautiful, iconic lustre that radiates from gold is to use the traditional gold plating method which comes with attendant environmental problems, or you can use the much more modern and environmentally friendly PVD coating process.

PVD does not use cyanide in any of its process, whereas most traditional gold plating does.

Watering can cufflinks in 22carat gold plate by Alex Monroe

Gold plating vs Gold PVD

We are often asked by customers to explain the difference between a gold color PVD coating and the more traditional gold plating methods.

PVD is a vacuum coating process that will produce a beautiful decorative and a very functional finish on the item being coated. PVD utilizes a titanium nitride that provides an extremely durable and a tough wearing coating. PVD coatings possess a far higher resistance to wear than traditional gold plating. It is a fact that the PVD coating will stay on the product longer than traditional gold plating.

Traditional gold plating is the process of laying a microscopically thin layer of real gold onto the base metal used to make the actual product. This base material can be silver, nickel, copper, brass or stainless steel. The use of silver as the base metal, when coated with gold, produces Gilt Silver. Gold plating bonds better with silver and titanium.

Antique Gold-plated watch sold via Sally Turner Antiques

Both plating methods give the finished product the look and feel of a solid gold product. Neither method adds any intrinsic value to the piece. Secondhand gold plated jewellery does not have a melt value. The melt value is the scrap value of the real gold gathered when a product is melted down. Traditional gold plating only deposits trace levels of gold onto the product. An ounce of 9 karat gold will plate tens of thousands of rings.

Silver daisy necklace with goldplated centre by Alex Monroe

Advantages and disadvantages

The main advantage of conventional gold-plating is that it gives the product the exact look of solid gold.
The main disadvantage of traditional gold plating is that it offers extremely low durability and is very easily scratched, it will also start to tarnish within 12 to 18 months.
Some of the main advantages offered by using gold colored PVD coating,

Very high levels of durability.
PVD provides better corrosion resistance against sweat, chlorine etc.
If the PVD jewellery gets dirty, you can stick it in the dishwasher without any issue.
Different shades of the gold color can be produced.
Gold PVD coatings can be up to ten times thicker than conventional gold plating.

Commercial drivers

Choosing between gold PVD coating and gold plating comes down mainly to the manufacturer’s production budget and the end user the product will be aimed at. Lower end including mass produced products will generally be gold-plated, higher-end products will use PVD.

Stainless steel Gold PVD bicycle chain bracelet from Istana

Because of its hygienic qualities and durability PVD is being favoured by the manufacturers of Body Jewellery ie the decorative items worn in body piercings. One seller has exploited the general reaction in its marketing by calling itself Ouch! Body Jewellery. The products range from ear studs, belly bars to nipple rings. As they say .. Ouch!

Describing the various processes of case-hardening.

Case-hardening is a metal surface process also referred to as surface hardening. It is an ancient technology that goes back to approximately 1400BC.

The origins of case-hardening

Around 1400 BC, hardening methods began to appear in armouries around the world. It was well known that the sharpness and hardness of a weapon’s edge could be enhanced by immediately plunging the newly formed weapon into cold water or oil after the item was heated up to the temperature required for forging. The temperate can also be judged by the color of the hot steel, you have to aim for a cherry red color.

It was known to make the edge harder and sharper, but it was not understood why the process made the edge better.

A tempered sword. Made of 5160 carbon steel the edge has been tempered slightly harder than a hammer.

Industrial processes

Case Hardening is a technique used to improve the durability and often the appearance of a metal surface in which the metal surface is reinforced by the adding of a thin layer at the top surface of another metal alloy. That thin layer of the alloy is generally much harder and durable than the original base metal.

2″ Case Hardened Steel Sheet Metal Screw with Pan Head Type and Zinc-Plated Finish, from Amazon.

Because the new hard surface completely surrounds the original item, literally encasing the object in a harder incasement it is known as Case Hardening.

Case Hardening steel is typically used to increase the lifespan of a particular product. This process is particularly beneficial to many types of product manufacturers from those that make gear cogs to those who manufacture firearms. Case Hardening is used on both carbon and alloy steels although usually mild steels are used.

The Case Hardened steel is formed by diffusing carbon, nitrogen or boron into the outer layer of the steel’s surface at high temperature. The newly Case Hardened item can then be heat treated to give the surface layer the desired hardness.

As Case Hardening allows the product to have an extra tough top layer with a more flexible inner core, it is an excellent process for use on padlocks, and chain links and other security produces. The Case Hardening allows the product to resist cutting and the more flexible and less brittle core of the product will be better able to withstand impacts. Case Hardening is typically carried out after the product has been fully formed.

Diagram to show the process of Carburising Case Hardened Steel. Image courtesy of Tec-Science.

Case Hardening is suitable for many uses particularly in items that are repeatably impacted with other surfaces. So rifle bolts, firing pins and other mechanical parts that would typically be exposed to a harsh, wearing environments such as a camshaft in an internal combustion engine.

Using Carbon for Case Hardening

One version of Case Hardening, using carbon has the following method. Firstly the steel is heated while it is in contact with a substance that has a high carbon content. In the middle ages, the ironworker would use bone meal, horse hoofs and various other rather icky organic compounds that are naturally high in carbon.

Then the steel will be held at a relatively high temperature between 850c to 950 c for a prescribed period.
The hot steel will then be quenched quickly in a cold liquid such as water or oil, the quenching will produce the hardened surface layer, or as we have discussed, the Case Hardening.

The Case Hardened steel can then be tempered in an oven or using a direct heat source to the desired hardness. Tempering is carried out at around 190c. Tempering is a slow process taking place over hours.

Creating art from a heavenly mix of metals.

Curtis Frieler and Jerry Fels

A charming pair of Curtis Jere Trefoil Chrome Cocktail tables that can also be used as coffee table bases in Chrome.

The name of the artist and furniture designer Curtis Jeré was, in fact, the shared pseudonym of two individual American artists, Curtis Freiler and Jerry Fels using the signature C.Jeré. Together the artists used many materials including exquisite and delicately colored enamels, thin sheets of hammered patinated brass, copper, polished stainless steel, glass and chrome. From these simple materials, the artists created beautiful and evocative wall sculptures, practical furniture and a range of other products.

Curtis Jere Bookends Male and Female. Iron with gilt paint

Curtis Jere did not only produce abstract art, they also created pop art using the forms of everyday household items, from a giant copper cheese grater to a pair of iron bookends painted in gilt paint.

Wall sculpture

Together the artists produced a collection of brass and chrome wall sculpture. These pieces are a series of beautiful abstract, metal cityscapes. These are my favourite pieces, some are made with chrome and polished brass and there is a much harsher set using patinated coppers and bronze.

Curtis Jere Wall Sculpture in Mirror Stainless Steel, Chrome and Copper

The artists Fels and Freiler were in fact, brothers-in-law. In 1963 they began collaborating on various artistic projects sharing a passion that would allow them to produce “gallery-quality art for the masses.” Their art/product was very reasonably priced but very well designed and constructed and many their table and wall sculptures can still be found on auction sites with nearly all in excellent condition.

Techniques

Curtis Jere used a variety of traditional techniques such as enamelling, pouring resin into moulds, and casting bronze and other metals to create their abstract metal works of various clustered and modular shapes.

Curtis Jere Raindrop Tree, 1969 in mirrored glass and enamel

One such beautiful example is their piece from 1969 called Raindrop Tree. They used fragile copper plates that they shaped into an organic floral arrangement that resembled the flowering of blossom on the branches of a tree.

Artisan House

To produce their sculptures on a more commercial basis, Curtis Jeré formed Artisan House and used this company to distribute their works to a worldwide audience. The company also produced their costume jewellery under the brand Renoir and Matisse. As well as their abstract pieces, the two artists also designed costume jewellery.

At its pinnacle, the brothers-in-law employed around 300 workers at Artisan House. They mass produced their gallery quality furniture, costume jewellery and their sculptures.

The workers were supervised by Freiler in his role a production chief and Fels as head of design. They shared metals, crimped wires, brazed, and welded brass, copper, and other metals before coating them with the artists’ typical luminous patinas. Freiler was famous for his meticulous attention and his exact instructions to the workers at the factory. Many of these workers were people from minority groups or disabled.

The Curtis Jere C Jeré signature, this one on a 1970s Tree branch made from Copper sold recently through 1st Dibs

Fels and Freiler decided to sell Artisan House in 1972. It has been sold and resold since. Curt Freiler passed away on July 22, 2013, at the incredible age of 103. in Los Angeles, California. Fels passed away in October of 2008.

Their work is still fashionable today thanks to the trend for Mid Century Modern and is sold for many hundreds of dollars, or pounds, around the world.

A look at the pros and cons of electroplating

Why do we electroplate?

Tragically there is no such thing as alchemy or magic when it comes to metals. If we could use alchemy, we would all be driving around in 24k gold cars. Whom amongst us would not want the ability to change common, low-value base metals into precious, rare metals? So magic is unfortunately out of the question but, the simple chemistry used in electroplating could be the next best thing.

Electroplating gives us the ability to use common or garden electricity, a sacrificial metal and a few cheap and readily available chemicals to transform an everyday metal, such as copper or steel, with a thin layer of another, much more desirable metal, such as chrome, gold or even platinum.

Electroplating gives us the ability to protect metals that readily oxidise (rust) as well as enhancing the metals appearance and is also used to cheaply transform inferior products into having the appearance of expensive products. For example, a solid gold watch can run from $10,000 upwards, whereas a gold plated watch can be yours for $70-80.

It is not a new process, electroplating was patented for the first time in 1840, the process is actually older than this date with the first experiments dating all the way back to 1805. That is 213 years ago.

Rotary Havana Two tone Rose Gold plated watch

The benefits of electroplating

Thanks to these abilities, electroplating has found its way into many other everyday areas. Some of the benefits of electroplating include the following,

Electroplating produces a beneficial protective barrier that can help protect the substrate against harsh environmental conditions. The substrate can be metal or plastic.
Electroplated parts that can come into contact with harsh environmental conditions can last longer therefore being cost-effective.
Electroplating is spectacular at enhancing the appearance of the surface of a metal and because of this jewellery is often electroplated with an extremely thin layer of precious metal to make it more appealing and attractive to potential customers.
Jewellers can sell their electroplated products that have the appearance and lustre of pure gold at a significantly lower price point than solid gold.
Electroplating will improve electrical conductivity. Electroplating electrical components with pure silver will help enhance electrical conductivity, making electroplating a precious and useful industrial process for the manufacturers of electronics and electrical components. The electrical device you are reading this article with is an excellent example of this process.
Electroplating is resistant to heat. The electroplating process using gold or zinc-nickel are capable of withstanding very high temperatures.
Electroplating with these metals will protect the plated engine parts and components from the high temperatures produced by the internal combustion engine. The protection offered given these electroplated parts will improve their lifespan.
Electroplating gives a smooth and uniform surface finish. It will fill pits and dings in a surface that has corroded. This means that a surface the has rust pitting on it or scratches can be sent back to the electroplating factory for refinishing. After the part has been re-plated, it will look as good as new.
Electroplating can also be used to prevent permanent tarnishing. Electroplated silver items are an excellent example of this. Silverware will keep its shiny appearance and are readily cleaned if they do tarnish. This helps silver plate retain its value over time.

Antique Victorian footed Gravy Boat/Pourer in electroplated silver. Sold via Treasure Valley.

Electroplating process

The process of electroplating involves passing an electric current through a solution called an electrolyte. An electrolyte is defined as ‘a liquid or gel which contains ions and can be decomposed by electrolysis, e.g. that present in a battery.’

The first step after cleaning and preparation of the item to be plated is to dip to electrodes into the electrolyte and to connect them into a circuit with a power supply. In our case, the power supply is electricity from the mains, but you can use a battery if you have to.

These electrodes are called terminals.

By passing electricity through the terminals, you complete the circuit, freeing the desired metal ions from one terminal and depositing it over the surface of the other terminal. So one terminal will be composed of the metal you wish to plate with, and the other terminal will be the part to be plated. As I said, almost magic.

The disadvantages of electroplating

Acids used in electroplating gold must be continuously adjusted so as not to cause the formation of hydrogen cyanide in the electrolyte, at ph values above eight, the fumes from the hydrogen cyanide will become lethal. Because of this wastewater and sludges produced in electroplating constitute a significant risk to people and the environment due to the cyanide contained in the slurry.

Cyanide is lethal to humans if taken orally. A single dose of cyanide may produce acute poisoning and rapid death. The extent of metal and cyanide pollution in the untreated wastewater of an electroplating factory without modern treatment systems, if discharged into sewers or watercourses has a high potential to harm human life as well as aquatic life including birds, fish and reptiles.

In a very modern factory with mandated treatment facilities, the quality of water is acceptable but never ideal.

Electroplating sludge. Image by Sludge Dewatering Press Lifeng Enviromental

Because of the waste products, it is difficult to open new electroplating factories. This means that most facilities in the USA are ‘grandfathered in’.

Electroplating has been superseded by other much cleaner and much more environmentally friendly technologies such as PVD which produce no wastewater or poison-laden sludge.

A discussion on space-travel, Mars, the Moon and Metal.

Commercial space travel

The year 2019 will see Earth’s first commercial, privately owned and funded spaceships blasting out of our fragile atmosphere.

Not quite the science fact that science fiction predicted for us, but we are marching towards it every day. I am owed a jetpack by someone, and I want to be zipping about in it at some point before I die.

These privately designed, commercially funded spaceships will be carrying human beings on board, both serving as crew and as paying passengers. People with a ton of cash to spare will be able to buy sightseeing trips into space.

These first, tentative steps in the commercialisation of space travel, will hopefully spur on the recolonisation of the moon and even get people to Mars. Visiting Mars will be a huge step forward for humankind, leaving Earth and being the first people to stand a completely uninhabited (or is it?) planet will be the most mind-blowing engineering milestone in the history of our small, blue world.

The Viking 1 lander’s sampling arm collecting soil samples on Mars in 1976. Image by Roel van der Hoorn.

Money as fuel

To get to humans to the planet Mars, or even past the Kármán line, the internationally recognised boundary of space you need many, many things including a load of highly intelligent engineers, talented fabricators but the most important item at the very top of the list is the universal lubricant, money! You need a lot of money. Rocket design burns through cash almost as quickly as the finished rocket burn through rocket fuel.

Elon Musk

Please step forward Mr Elon Musk and his money and his ability to raise even more money. SpaceX or Space Exploration Technologies Corporation, the rocket company, founded by Mr Musk is heading to Mars and at the moment is leading the field.

SpaceX Elon Musk’s Stainless Steel Starship

On Christmas Eve 2018, Elon Musk posted a photo of the bullet-shaped, stainless steel spaceship his company is working on. He calls it the ‘Stainless Steel Starship’.

SpaceX’s facility in south Texas is designing and building the spaceship. The beautiful ship is constructed out of glorious stainless steel!

Mr Musk has reportedly said that the stainless steel used for the construction of his spaceship is chemically different from the stainless steel used by NASA during the Atlas rocket program, SpaceX treats the stainless steel at cryogenic temperatures to create an exciting material that has a better strength-to-weight ratio than carbon fibre.
SpaceX plans to send their spaceship into space in a mirror finish. We at Double Stone Steel have the technology available now to add PVD copper color or PVD gold color to the rocketship! Someone call me!

Blue Origin

Jeff Bezos, the world’s richest person, and Elon Musk have decided that at some point in the future the planet earth will certainly become uninhabitable, this will either be caused by humans destroying the planet by pollution or warfare. It could be some terrible disease that will wipe us out. Or it could be by the planet being hit by a meteorite. Jeff Bezos, using his enormous private wealth of 150 billion dollars, founded Blue Origin a company with the enormously ambitious goal of making the human species a “multi-planet race” ie occupying more than one planet. This is the same goal as SpaceX. So if humans are wiped out on earth there will still be viable populations elsewhere.

Blue Origin’s first rocket system is called ‘New Shepard’. it was named after Alan Shepard, the first American to be blasted into space. This system will be used to take paying passengers into low earth orbit.

Using their rocket system New Shepard which was named after Alan Shepard, the first American to be blasted into space, Blue Origin will start sending paying passengers into space in 2019 or 2020. 2020 pushes the date back from the expected 2018. The tickets will cost around $250,000 to $300,000 per seat. Mr Bezos puts approximately one billion dollars of his own money into the company every year to keep it afloat.

Is it safe?

Let’s remember however that rocket launches are really quite dangerous. They enjoy only around 96-98 per cent success rate.

That rate sounds high but really? 2 to 4 failures out of every 100 rocket launches? Compare that to airline statistics, they have their safety pretty much buttoned up. One plane crash for every 1.2 million flights and millions of people are still very nervous about flying.

My favourite fact about airline travel is that statistically speaking you have more chance of being killed by a falling coconut than dying in an aeroplane crash. I will be getting on a rocketship when the odds are similar or better!

A round up of some interesting facts about this fascinating metal.

In the beginning there was Gold

Gold is such a remarkable material, firstly it was created in the resultant blast of energy due to the collision of two neutron stars. This monumental collision produces enormous amounts of heavy elements including gold. The gold is expelled at tremendous speeds from these collisions and heads out into space. At some point in the very distant past, the gold was attracted to the Earth’s gravitational field and headed our way. When it got to our planet, the planet’s surface was molten and most of the gold sunk down, deep into the core of the Earth.

An artist’s impression of two neutron stars colliding and how they would appear as they merge, ejecting matter and gamma rays.

Image by NSF, LIGO, Sonoma State University, A. Simonnet

The nature and use of Gold

Gold is a soft metal that is extremely malleable and is in fact the most malleable metal found on earth. To define the term – ‘Malleable’, in regards to metals, this means that the metal can be formed or thinned by hammering or pressure without cracking or splitting. The word malleable has its roots in the Latin word ‘malleus’, which means ‘a hammer’.

Gold’s aesthetic properties has great appeal to many people involved with artistic applications and its malleability makes it much more accessible for many uses than solid gold. Transforming gold nuggets into gold leaf allows us to use less gold for decorative uses.

As a chemical element it bears the symbol AU and has a density of 19.3 g/cm3 making it the 6th densest metal on the planet.

Gold leaf detail on Corinthian bracket, upper detail of the pilaster, simple leaf spandrel, and French crown. By Monumental Plaster Moulding based in Maryland, US

Gold leaf

The exact date we as humans started using gold leaf is lost in the mists of time. Surprisingly making gold leaf is one of the oldest continuously used industrial or artistic process in human history.

Gold leaf is usually defined as a sheet of gold that will ordinarily vary from four to five-millionths of an inch in thickness (0.1 to 0.125 millionths of a meter or micrometres. To give an idea of how thin this is an individual strand of human hair can range in thickness from 1/1500 to 1/500 of an inch. So a human hair is much thicker than a sheet of gold leaf.

Gold leaf

A single gold nugget of approximately 10 millimetres in diameter can be beaten into a single fragile gold foil of about one square metre.

If you take a single avoirdupois ounce, this can be hammered into a sheet of approximately 300 square feet. Avoirdupois is an unusual word, it is a 15th-century English word which means ‘as sold by weight’, That English word, in its turn came from an old French phrase, ‘aveir de peis’, which literally ‘goods of weight.’

Egyptian Gold

Around 5,000 years ago, gold works and gold mines started to appear along the banks of the river Nile in Eygpt which is rich in gold. The purpose of these mines was to extract the gold ore found in the river.

Broad gold collar made in the reign of Thutmose III ca 1479 – 1425 BC. Made from Gold, Carnelian, Obsidian and Glass. Displayed at the Metropolitan Museum, Fifth Avenue. The necklace was a gift from King Thutmose to one of his three wives as indicated by the inscription of his name on the back of one of the falcon heads.

Egyptian metal workers discovered the extraordinary durability and the astounding malleability that pure gold possesses and became the world’s first gold beaters and gilders as depicted in tombs from that time. Their tools were basic however as these early masters of metals hammered their gold using a heavy, almost perfectly flat round stone to create the thinnest leaf possible using this method.

The technique has not changed much at all in all those 5000 years. Instead of using stones we now use metal hammers to work the gold into beaten sheets.

The application of gold leaf over a surface is called gold leafing or gilding and water gilding is the most skilled and challenging way to use gold leaf.

Gold leaf in space

Gold leaf has even found its way into the space industry. Gold leaf when beaten thin enough becomes transparent. Nasa uses this transparent gold leaf to cover the astronaut’s visors because of its excellent ability to reflect infrared light whilst allowing in visible light. The thin layer of gold protects astronauts’ eyes from the unfiltered sunlight.

The location

Opened in 1996, the Museum of Contemporary Art in Niteroi is one of the smaller, but no less intriguing buildings designed by one of my favourite architects; the famous Brazilian architect Oscar Niemeyer. A building that reflects his skill of blending sculptural elements with Architecture, the museum designed by Niemeyer with the assistance of structural engineer, Bruno Contarini, is perhaps also one of the best examples of a building that takes intentional advantage of its location on a site imbued with natural beauty. Sitting on the Boa Viagem beach and overlooking the Guanabara bay and the city of Rio De Janeiro, the building is quite dramatic, yet fits in with the natural context and the adjoining residential neighbourhood. Depending on whom is telling the story, Niteroi is a suburb of Rio de Janeiro, municipality of Rio de Janeiro State or an independent city that seats across the Guanabara bay from Rio de Janeiro city.

Approaching the building

The full history of this building’s beginnings can be found elsewhere on the web. The focus of interest here is the experience of a visitor to the museum particularly as one walks up the approaching road towards the museum coming off the ferry ride across the Guanabara bay from the Rio de Janeiro side. As one walks up the Avenida Almirante Benjamin Sodre road which curves along the edge of the bay, the full effect of the building as ‘Sculpture’ gradually comes into focus at about 150m from the building’s entrance through a simple gate.

Approaching the Museu de Arte Contemporânea de Niterói, Brazil from the Avenida Almirante Benjamin Sodre.

Photography by Lola Adeokun.

The gateway to the Museu de Arte Contemporânea de Niterói, Brazil from the Avenida Almirante Benjamin Sodre.

Photography by Lola Adeokun.

The simple fencing around the Museu de Arte Contemporânea de Niterói, Brazil looking from the Avenida Almirante Benjamin Sodre.

Photography by Lola Adeokun.

The boundary fence and gate are simple and transparent, allowing the tranquillity of the hilly backdrop and the beauty of the building which has been described as a ‘flower’ by Niemeyer himself, or by others as a ‘goblet’, to be visible from the road. The narrow base or ‘stem’ which supports a wide-rimmed, concrete sculpted, goblet-like upper body seems to defy gravity, yet is rooted in the promontory, allowing views towards the ubiquitous residential blocks which make up much of downtown Rio across the Guanabara bay. Its geometrical dimensions- 16 meters height; accommodates three floors with its upper rim diameter of 50 meters- emphasises its structural daring as well; a tribute to the genius of Contarini too. Niemayer describes the ease with which the design flowed from the configuration of the site itself (translated from the museum website), stating:-

“How easy it is to explain this project! I remember when I went to see the place. The sea, the mountains of the river, a magnificent landscape that I should preserve. And I went up with the building, adopting the circular form which, in my view, the space would require. The study was ready, and a ramp leading the visitors to the museum completed my project”.

The base of the sculptural shape, reminiscent of a goblet. Oscar Niemeyer’s Museu de Arte Contemporânea de Niterói, Brazil.

Photography by Lola Adeokun.

Looking across Guanabara Bay from Oscar Niemeyer’s Museu de Arte Contemporânea de Niterói, Brazil.

Photography by Lola Adeokun

The glazed middle band on the exterior provides successful contrast between the upper wide rim of the building and the narrow stem of the flower or wine goblet and provides much needed views and connection with the exterior from the inside of the building. The building has curved display walls which take you in circular movements within the building and works quite well with the shape of the form, while the sweeping white walls which are shielded from direct sunlight protect the display objects and artefacts from damaging UV rays.

Going inside

The movement from the outside ramp into the interior circular corridor-galleries are like layers of an onion, which then terminate in a central display space which is lit from above. This cleverly takes the visitor from the sunlight into the muted view of the outer layer of the onion with its shaded and uninterrupted views of the bay. The view disappears as one moves round towards the centre in a concentric movement which by taking away the outside views, plunges the visitor into subdued light, focusing the visitor towards the display on the wall, yet the hold of the building form is only slightly relinquished when one arrives in the centre where the roof light brings in light and connection again with the exterior with paintings and graphic works mounted on the curved walls. However, despite the dramatic experiences felt over the years by many, attested to by the recent use of the external forecourt and red ramp for the Louis Vuitton’s Cruise 2017 show, the interior is perhaps less successful for the artworks. The artworks seem to struggle a bit in coming to the fore and are somewhat subservient to the ambience of the building form itself. The exhibition that I visited in this amazing building was quite contemporary, perhaps even risqué, and was certainly able to hold its own in the centre gallery, but I found my experience of the inner long curved galleries less memorable.

Sweeping curved white walls display artwork in Oscar Niemeyer’s Museu de Arte Contemporânea de Niterói, Brazil.

Photography by Lola Adeokun

The play of natural light within the curves and space. Oscar Niemeyer’s Museu de Arte Contemporânea de Niterói, Brazil.

Photography by Lola Adeokun

Perhaps it is a building which contributes significantly to one’s experience of the artistic world as much as the exhibits, but I would suggest that the onus is on the curators to help the artworks find expression alongside the moving expression of the building itself. So, as architecture, do I think the building ‘hits the mark’? Yes, but only if the art curated is equally assertive. The Museu de Arte Contemporânea may be one of Niemeyer’s smaller works- but only in size- it is a bonafide example of why the combination of sculpture meets architecture in my opinion, is worthy of a ferry ride from Rio across the Guanabara bay.

The works of art have to rise to the challenge of a striking building. Oscar Niemeyer’s Museu de Arte Contemporânea de Niterói, Brazil.

Photography by Lola Adeokun

Circular, sweeping interior rooflight. Oscar Niemeyer’s Museu de Arte Contemporânea de Niterói, Brazil.

Photography by Lola Adeokun

John Desmond Ltd have recently set up a dedicated factory in Wimbledon to create Double Stone Steel PVD colored stainless steel. This is the first production-unit to color large-format stainless steel in the UK and colors sizes up to 3 metres by 1.7 metres.

Capacity

The chamber size is 3.3 metres by 2.2 metres and will accommodate products and sheet material up to a size of 3 metres by 1.5 metres and certain items up to 1.7 metres. Depending on the final use and required durability PVD coatings will be created of varied thicknesses. The standard PVD coating is 0.35 microns.

What is Double Stone Steel PVD used for?

Architectural cladding for interiors and exteriors, decorative panels laser cut
Components, taps, architectural ironmongery
Furniture
Appliances and accessories
Structural components

With the use of V-cutting and folding, Double Stone Steel PVD colored stainless steel sheet can be fabricated to appear as solid material.

DB 1650 Monobloc mixer tap in Double Stone Steel PVD colored stainless steel in Copper brushed finish.

V-grooved and folded Double Stone Steel PVD stainless steel in Royal Gold for architrave, Shangri La Hotel, London.

With the capacity to produce Double Stone Steel PVD colored stainless steel in the UK this opens up opportunities for smaller orders to be processed ( previously orders had to be shipped overseas which greatly added to the lead time and costs). Now that lead times are based on despatch within the UK this means that smaller orders can be processed without the disproportionate overheads of transport costs. This opens up enhanced trade possibilities with other manufacturers, architectural metalwork providers and construction companies.

John Desmond Ltd, established in 1968, are architectural metalwork fabricators and specialists and work to the exceptionally high standards demanded by architects and designers.

See some of John Desmond Ltd’s case studies

To find out more about Double Stone Steel PVD or request samples visit.

Double Stone Steel PVD machine for creation of colored stainless steel, John Desmond Ltd, Wimbledon, London.

The PVD process – what is PVD?

PVD, which is an acronym for Physical Vapour Deposition, is the generic name given to a range of very hard, durable, wear-resistant, thin coatings. The key difference in the PVD process from traditional coating processes, such as electro-plating is that it uses a vaporised form of the coating material for adhesion to a given product surface, not a solution.

The first available and most common PVD coating is Titanium Nitride (chemical symbol TiN), which is a golden yellow color – this is most commonly seen on drills in a DIY store. The hardness of TiN is around 2300Hv which is over twice as hard as Hard Chrome plating and nearly three times harder than tool steel. PVD coatings are typically deposited to a thickness of only a few micrometers (approximately 1/50th the thickness of a human hair) and this very thin, hard surface layer is sufficient to greatly extend the life of cutting and forming tools, often by more than 5 times.

Double Stone Steel PVD machine for creation of colored stainless steel, John Desmond Ltd, Wimbledon, London.
PVD coatings (initially only the golden colored TiN) became commercially available in the 80’s and since then a very wide range of different coating compositions and associated techniques have been developed.

Historically PVD coatings were used solely on tooling such as drills, mills, taps, punches, dies and press tools. However other markets such as medical, motorsport and aerospace have found uses for PVD coatings on components, not made from tool steels.

Although generally more expensive than other more traditional coloring techniques, such as electroplating and lacquering, PVD coatings will not fade, scratch or tarnish so are chosen for situations where quality and longevity are desired. The color of any PVD film is a function of the composition of the coating, which means that PVD does not contain a coloring agent or pigment.

All PVD coatings are applied in a high vacuum coating machine at an elevated temperature. Therefore certain materials, such as plastics, zinc and brass are not able to be coated easily, if at all. All steels are absolutely ideal for PVD coating although it is also not possible to coat onto oxidised surfaces.

Double Stone Steel PVD stainless steel in Rose Gold for façades and tubular drops: John Desmond Ltd. The Arts and Cultural Centre, Shanghai Bund Financial Centre, China. – Architects: Foster & Partners; Heatherwick Studio

Just as with the electroplating of gold, the product is given a negative charge but it is placed inside a vacuum container, rather than a tank, in which the sub-atmospheric pressure can be accurately controlled. This vacuum-deposition process allows highly-charged ions to be deposited, molecule-by- molecule, on the product surface. The vacuum itself reduces particle density and provides a long path between particle collisions. Consequently, the vacuum-deposition process is highly accurate, allowing excellent control of the coating’s vapour composition.

As the PVD coating is essentially ‘sprayed’ onto parts inside the vacuum coating unit consideration must be given to the geometry of parts to be coated, for example, the coating does not penetrate very far inside a bore. During the PVD process parts are fixed to a jig therefore it is important to understand where parts can be held without compromising those surfaces requiring coating.

Different compositions of PVD coatings will have different properties such as oxidation resistance, corrosion resistance, hardness and friction characteristics. Whilst PVD coatings are essentially very inert and will not corrode, they cannot be considered barrier layers to prevent corrosion of the material to which they are applied to, for example mild steel will still rust (albeit more slowly) if PVD coated.

The accuracy in the creation of the finish and color makes the PVD process remarkably versatile in terms of the sectors and products where it can be used. Increasingly, it is being used as a replacement for the more traditional painted and electroplated decorative-metalwork finishes. The substrate, that is the stainless steel, finish is revealed through the PVD coating. So, a mirror-finish stainless steel will form a mirror-finish PVD material and a brushed finish stainless steel will form a brushed finish PVD.

Double Stone Steel PVD stainless steel in Black Hairline finish. - John Desmond Ltd

Double Stone Steel PVD stainless steel in Gun Metal Sandblasted finish. - John Desmond Ltd.

This makes the variety of PVD applications impressively broad – from automotive bodywork and engine components to medical instruments and surgical implants. It is even used for fashion accessories such as watches and jewellery, using specialist coatings such as carbon-based finishes for watches and titanium for earrings and piercings.

Double Stone Steel PVD: A summary of advantages

Provides coatings with properties superior to the surface they are applied to
Is more environment friendly than electroplating because it doesn’t have toxic chemical
solutions to be disposed of at the end of the process
Delivers accuracy to the finest tolerances, allowing its use in manufacturing both thin films (less than one micro-metre) and coatings
Has excellent hardness and scratch-resistance properties