METALLIC SURFACES IN BATHWARE: “THE ELEGANCE OF ENAMELED METAL”
Metal bathtubs, rooted in a tradition of durability and elegance, are typically fashioned from either cast iron or steel bases. These sturdy metals are then coated with a layer of vitreous enamel, a unique material created by fusing powdered glass onto the metal through a high-temperature firing process. This process, ranging between 750 and 850 degrees Celsius, allows the powdered glass to melt, flow, and solidify into a smooth, resilient coating that amalgamates glass and metal into a single composite.
Vitreous enamel, also known as porcelain enamel in the U.S., has been a part of human craftsmanship for centuries, predominantly used in jewelry and decorative arts. However, its application has expanded significantly since the 19th century to include a variety of industrial and consumer uses..
Notably, vitreous enamel is adaptable to many metals, though it is most commonly applied to steel with controlled carbon content to prevent reactions at high firing temperatures. It can also be used on copper, aluminum, stainless steel, and hot rolled steel.
The properties of vitreous enamel are remarkable: it is smooth, hard, scratch-resistant (ranking 5-6 on the Mohs scale), and possesses excellent chemical resistance and color fastness. Moreover, it is durable, easy-to-clean, and impervious to fading under UV light, as enamel is glass, not paint. On the flip side, traditional enamel can be prone to cracking under stress, but modern variants have been enhanced to offer chip and impact resistance, thanks to improved thickness control and thermal expansion compatibility with the underlying metal.
Vitreous enamel’s resilience and aesthetic appeal have found it a place in various applications, including advertising signs, oven interiors, cooking pots, kitchen appliances, bathtubs, and even in commercial architecture. Recent innovations have seen the development of enamel/non-stick hybrid coatings, sol-gel functional top-coats, metallic appearance enamels, and new easy-to-clean technologies.
The core component of vitreous enamel is ‘frit,’ a fragile type of glass smelted at extremely high temperatures to create a liquid suitable for coating steel. Colors in enamel come from the addition of minerals, typically metal oxides, which offer a range of hues from delicate violets to warm greys. Unlike paint, these colors cannot be blended to form new shades but can create a visual blend through ultra-fine grinding.
In summary, the use of vitreous enamel in bathware, particularly in bathtubs, showcases a fusion of historical artisanship and modern technological advancements, offering products that are not just functional but also add an element of refined beauty to any bathroom.